Max engine temp under load
 

This weekend I had my '87 300TD fully loaded with books luggage, picture frame on the roof and family. While traveling over the Cumberland gap on I68 west of Cumberland, as I usually do on that streach of hilly highway, I preformed an Italian tune-up.

For the first time ever (since I fixed the plugged ALDA line) I reached full load on this engine for an extended period of time. By this I mean that with the accelerator pressed to the floor the car stopped accelerating in third gear before reaching MAX RPMs.

I know, the exact required conditions for an Italian tune-up. We'll the good part was that my new (Jan 02) head was still clean as a wistle -- not a single burp of black soot.

The bad part was that the engine temperature never reached an equalibrium. It continued to rise slowly until, when it reached 120 deg C. (The temp line just below the red line on my guage.), I cried uncle and eased off. Temp stopped climbing and returned to 84 deg C shortly after cresting the hill and removing the load.

This hill is 4 mi or less in length so all this happend in a matter of minutes. I realize that engine load is the main factor in engine temperature, but I would have expected to reach an equalibrium temperature somewhere below the red-line. It didn't seem to be happening that way. With a recent head replacement in mind I wasn't going to see where the temp stoped rising!

In the list's experience what would I expect to be the fully loaded operating temperature of the '87 603 turbo engine?

Thanks,

I've climbed some very steep hills with my SDL, and I know that some of them, I had the car at full-throttle to get up the mountain at 40mph, and the temp guage was rapidly rising. This mountain trek was only about 1/2 mile, but at the top I was at just under 100c.

When you have the car at full load for 4 miles, I would expect you to get an overheat condition like you said.

I just cruised up the largest hill on I-75 near here with the a/c on full and the temp got to right under 100 dC (in the black 300D). There was always some space between the needle and the 100 dC mark.
It was 100 dF outside and with the a/c on inside the car was probably 75-80 dF. At least the sweat evaporated pretty fast :)

I have also noticed that my temperature goes up on hills. I guess this is normal for these cars. Has anyone ever taken one of these up a mountain road like Angeles Crest Highway, or route 70 through the rockies? Los Angeles gets pretty hot in the summer so I have my eye on the guage at all times.

120C sounds me a litlle bit too hot !
With my 240D, I have never go over 90C.
The normal temperature when I drive calmly is about 82C (the needle is just above the 80C mark). When I 'm running on a hill, with the car loaded (with the foot on the floor, of course...), the temperature increase slowly, but so far it never go over 90C.

I should precise that on the 240D the radiator fan turn continuously contrary to the 300D which have a fan clutch. Maybe it can have an influence on the cooling.

I have taken my 87 300TD up a prolonged 18% grade with AC on and car under full throttle in second gear. The temp went to 110 deg C. This is after a recent valve job, new radiator, tpsta, fan clutch, oil-cooler and hoses. It did level off at about 110 but then I backed down. If you search for a thread I started a while ago, and read through it, you will get a good understanding of the operating temp on these engines. I did the search try this.
http://www.peachparts.com/shopforum/diesel-discussion/33994-1987-300td-confusing-running-hot-problem.html

I’m not sure about other models, but the thermostat on my 83 240D is on the return water back to the engine. If you think about it, by placing the thermostat on the return to the engine and not on the water leaving the engine, you are always cooling your engine with a minimum of 80 degC water (176 degF), which certainly isn’t very cold. Even if the radiator could cool the engine more, the thermostat placement won’t let it. In engines where the thermostat is in the water leaving the engine (before the radiator), the radiator is allowed to cool the water farther than the 80 degC, maybe down to 70 degC?, since the Tstat has no idea and doesn’t care how cold of water it sends to the engine at the discharge of the radiator. We don’t have that ability on these engines, however.

Another consequence to the MB placement of the thermostat is that when it closes, the water in the radiator may cool to a point lower than 80 degC. Later, when the Tstat “sees” this cold water it shuts itself, which isn’t always what the engine needs. Also having the cooled water flowing over the Tstat (including the bypass water) makes it think the engine is cooler than it is. Basically, these engines have to heat up quite a bit to the point where the water going into the radiator is 100+ degC to raise the water temp at the Tstat to the 94? DegC fully open point. (depending on your actual outside temp, speed, etc. of course)

I’m sure being good diesel engine engineers MB wanted to always make sure they had a hot engine for good combustion, but it does make for a roller coaster of a ride for the temperature on these engines. There is something to be said for a Tstat on the engine discharge with hot water directly off of the engine pumped up against the Tstat. It knows exactly how hot your engine is.

JohnM 83 240D 4 sp 151K

The 602 engine is the same way, with the t-stat in the lower hose. I never understood why, as serviceability is much better when the t-stat is in the upper hose.

-Joe

The thermostat on all MB's is like this, I believe, for some very specific reasons. First, nearly all cars have some provision for at least low flow during warm up, so the cold coolant is not forced to go through the radiator, and you get the engine as well as yourself warm sooner. The main drawback of such systems is that when the thermostat first opens after the engine and head especially, are somewhat warm is that in very cold climates coolant at ambient (sub zero) temperatures is suddenly admitted and thermally exercises the head and block materials. Second, the water pump flow rate is controlled by the thermostat, meaning in part load conditions the water pump is likely throttled on either the input or the output side, depending on the arrangement of components. This can lead to cavitation damage in the pump housing and impeller.

MB's system involves a thermostat with two moving parts. One is used to close the radiator bypass line, while the other is used to control the flow through the radiator. MB does this to ensure the water entering the engine is within a temperature range they determine is healthy for the engine. The placement of the whole affair in front of the pump is intended to ensure the cold water from the radiator is mixed with the warm water from the engine as thoroughly as possible. Additionally, the flow rate through the water pump at a given rpm is near constant since the thermostat never throttles down on a flow path without simultaneously diverting that flow volume to another.

Overall the system is very technically elegant and robust, with the intent to protect the engine while maximizing the passenger comfort on a cold day by minimizing the warm up period. The weak link is the thermostat though, as both flow control plates need to move according to design to maintain the intended flow conditions. As a result the system is sensitive to the selection and installation of the thermostat. Any binding due to shipping or handling damage, or deposits from coolant chemicals on the alignment sensitive parts and the thermostat will fail. In my 190E 2.3-16 the failure mode I have seen twice is the engine gets warm, reaching normal operating temperature, the thermostat opens and begins to regulate temperature, then gets stuck in the "send the water to the radiator" position, and the engine would run cold. Not good for mileage or the cat. The car would run so cool the mileage would drop 4 or 5 mpg.

Hope this helps, Jim

HGV,

Thanks for the pointer to your thread. I had read it prior to posting and was hoping that you would weigh in on this thread as well.

I'm still curious as to whether or not this engine (603) has an equalibrium under full load. My independant mechanic claims that the cooling system is only as big as it needs to be and these engines under full load will continue to increase until the engine over heats.

Keep in mind that full load is what you have under full acceleration. Like when your testing the max boost preasure. Most of the time this is only for a few secs at a time. But in a case where you have a long climb with a fully loaded vehicle you can get max boost going for an extended period.

The other question is whether or not the viscios (SP) clutch on the fan makes a difference at highway speeds? If my clutch isn't ingaging at 105 deg C as expected would that restrict the air flow enough to make a difference at highway speeds?

Thanks,

I have always felt that the fan clutch has minimial effect at highway speeds. It would just propeller itself with the blast of highway speed air being rammed through the radiator. I once had the unfortunate experience to have the crank shaft pulley shear off my old 63 190D. No place to hook the fan belt. I ran the car and it actually ran cooler at freeway speeds without the belt on. ALways thought that was interesting. Of course it would overheat at low speeds. The fan clutch is affected by radiator temp via latent heat from the radiator. Exit temperatures from the engine are indicated on your temp gauge, so I assume the fan clutch should be engaged at high temp but low speed and not at high speed. For the clutch to engage at high speed, the air temp would have to be in excess of 105 deg C. Unlikely when you have air approach speeds in excess of 100mph. To test this theory, attach a basic thermometer between the fan and radiator, run the car at speed, come to a rapid stop, run out of the car and check the temp. Might work. I am almost to the point to do a detailed engineering evalaution of the cooling system on the 603 engines. If it was not for the variable speed aspect of the pump, it would be easy. One day in my free time. One thing I will check on my car is exhaust back pressure. This has not been mentioned as a source of an engine running hot, but it deffinantly is a source of additonal; heat being be added to the cooling system. Also engine timing. Anyway, watch out fopr those speeding tickets. Also, does your temp run constant or does it move around in normal driving.

henry


Henry

HGV,

My wagon runs steady between 80-90 which is to say somewhere less than half way between the 80 mark and 100 deg mark. It only fluctuates when explainable things happen, like sitting in traffice with the AC on or running hard uphill.

Marshall Booth had this to say on the diesel mailing list:

"As I have been told and proven many times, loss of temperature stability at high speeds is USUALLY a sign of restricted coolant low (could be radiator OR thermostat OR water pump - but that's rare) while loss of control at low speeds is USUALLY an air flow problem (but remember the fan(s) doesn't/don't come on before 95+ degrees C or higher)."

So I think there may be a flow issue. Of course before chasing down a ghost I'd like to know if the temp should reach a stead state under load or if it can be expected to overheat when run full out long enough.

Thanks,

When struggling to figure out why something is not working as it once did, and for all my Diesels the normal operating temperature, regardless of how hard it was working or not, was always withing a needle width of the 80 degree C or 175 degree F thick mark on the gage, it is best to have a good idea of how it was designed to work.

The thermostat does see hot water from the engine, and that is what initiates its movement. However, as the engine warms up and the thermostat moves around, it responds to water flowing at engine temperature and whatever the temperature of the water is coming out of the radiator. Its intended design is outlined in the manual I have for my 240D (as well as the 300D) from 1975, which applies to the W123 versions as well since the update to the manual identifies no changes for those models.

I scanned the flow diagram, some illustrations of the thermostat operations and some text. I will try to attach these here, in a sequence of posts unless the quality (black and white text and illustrations do not do well at the 60k size limits) is too poor.

I hope this helps get a solution for what is ailing these cars. Jim

Well, that was pretty poor but it still seems legible. I will rescan and see if there is a way to make the figures come through better. Jim

Actually, Jim, it looks pretty good. Thanks, -Mike

Mike, be sure you separate the responses from people with a different engine than yours. Anecdotal sub-105C temp numbers from an OM617 are 100% useless to you (and me, and HGV). The OM60x are totally different animals and will run hotter than the old iron-head beasts. But I'm sure you already know this. :)

I'm surprised your car went up to 120C, that is quite high, for only a 4-mile stretch. What was the ambient temperature? Have you cleaned out your radiator AND condensor so they are bug- and debris-free? Otherwise, as I mentioned on the diesel list, use a bottle of WaterWetter (if you're not already), and if your fan clutch is original (metal blade) I'd seriously think about replacing it as a preventive/predictave maintenance item.

The rest of my previous email still stands, i.e. if the car never goes above 105C under ANY other conditions, I wouldn't worry too much. But I'd still check out the fan clutch. I'd love to hear your resuts if you do replace it. Maybe try "forcing" it on, like someone else did (wiring it to the pulley somehow)??


Good luck,

Dave,

I have noted the different behavoirs of the two engines and filtered accordingly. I will definatly be testing the visco fan clutch and clogged air flow in the rad. Probably not until this weekend, though.

Yes, it definately went to 120 deg indicated. It was warm and humid. The external temp was showing 90degF, but it behaved likewise (though less extreme) on the way home and the temp was in the 70s.

It was Jim Cathey that wired his fan. He seemed to have the most promising anecdote if he was crossing the Rockies at highway speed.

I'll post the outcome as soon as I have more to share. Thanks,

OK, I'll weigh in on this thread. Since the temps have summered in Tennessee, I have seen my new to me 1987 300D get pretty warm.

Driving down the interstate with the ambient temp at 95F, when hot soaked, my indicated temp is about 95-98C. With a steep grade, it will range to about 105C and return to 95-98C on the flat pretty quickly.

If I get off of the interstate and shut the car off. When re-started it will indicate about 115C for a very short time and immediately begin to moderate as the car moves, even at low speeds.

I have replaced the thermostat with no change in behavior. I have determined (at least to my own satisfaction) that my Visco fan clutch is a non-performing asset. It does not change speed with the engine, regardless of indicated temp and has absolutely no drag on it at idle, again, regardless of the temp.

I have purchased a used Visco fan clutch from PGAuto and will install it sometime this week. I will report my experience here.

One thing that I do find interesting, is that the car does manage to keep itself below about 115C. I can only surmise that the auxillary fan is responsible for this. If I let the car idle from a cold state in the driveway, the aux fan will begin to come on well below 100C. I guess, as the demand for AC lessens due to the interior of the car getting near the required temp set by the climate control, the "coincidental" aux fan help goes away. This is how I explain the fact that the car will go to 115C when coming to a stop after a long hot soak. The aux fan must be coming on because of temp at some point, which is keeping the temp from running away.

Ambient temp seems to make a huge difference. At 80F ambient, the car rarely goes over 90C, and then for very short times.

If I see the temp going up (which I watch closer than the speedometer these days) I can bring it down quicky by punching the defrost button and spinning the wheel to max. This can be uncomfortable for a time.

As I said, the fan clutch is next and I'll let you know. Comments and suggestions are welcome...

BR,

Steve (8C>

Steve,

What you describe is eerily similar to what I saw when I bought my first 1987 300D a few years ago. It should not get to 115C at idle - period. If that 115C is only after shutdown, hot soak, and restart, that might be OK, but never 115C without a shutdown involved! If it does get to 115C at idle, it's not the fan clutch, it's the radiator. Swap the clutch first since you already have a "spare", albeit an unknown good one. :eek: FYI, the electric fan runs on low speed when the R12 pressure exceed ~22 bar (?) and kicks on high when coolant temp exceeds 105C.

I'm assuming you have already flushed the cooling system, used fresh MB coolant, and hopefully a bottle of RedLine Water Wetter? On a different note, the plastic reservoir tank was updated twice. The latest part number includes a silica pack inside to help control corrision with the iron block & aluminum head. The new tank from online vendors is ~$40.

These radiators are known to have a tendency to plug or corrode internally in a short time, possibly in 2-4 years (mine did)! The flow is fine, as viewed with a hose stuck in one end and watching the outflow, it just doesn't transfer heat well. This makes it a real PITA to troubleshoot. BT, DT. A new one is $225-$325 (Nissens vs. Behr), or you can have yours rebuilt by Reseda Radiator for ~$125 plus S&H both ways. Any of the above are fine IMO, but be warned the Nissins doesn't have the metal reinforced necks, and your original won't either (unless it's been replaced in the past).

Both of my '87's, and my sisters, have recently rebuilt/replaced radiators. All 3 now refuse to get over 100-105C under any operation conditions (but we don't have any REALLY long, steep grades to test on like Mike does.) Climbing to Reno from Sacramento up the Sierra Nevada mountains still won't get it over 100-105C tops, and that's at 70-80mph up the grades with the AC on.

We had temps to 104F here today. I drove the car with the AC on max, and even standing on the throttle a lot to accelerate it wouldn't get over 100C. Mostly ran between 90-100C (90C steady on the freeway, 95C at idle, up to 100C under load).


HTH,

Well, here is another try at the scanned images from the manual. I will try the schematic of the system, then two sketches of the thermostat, and some text. Jim

Here is the thermostat under initial conditions, before it starts to open. Jim

Here is the thermostat in the normal or part load condition. It is possible for a thermostat to get stuck in this position and let too much flow short circuit the radiator path, leading to over heating. Sorry about flipping the figures sideways, but it was the best compromise to get decent resolution. Jim

Under full load the path under the thermostat from the engine ("d") gets fully blocked off and forces all the flow to the radiator. In a properly functioning Diesel I have never seen this condition not keep up with the heat load. Especially at idle as a Diesel at idle will hardly reject enough heat to the coolant in the winter to keep the engine warm, or the heater functioning effectively for the cabin. Here is some additional text from the manual, which suggests the operator should not get too antsy about excursions to the higher temperatures in certain conditions. Jim

Thanks Dave,

I have read most of your posts from the archives. The pics of the cracked head a really scarry, which is, in part, why I am so diligently seeking lower temps.

I certainly would not want to take issue with your statement about the radiator. It will probably have to be replaced. But, as you said, it is a PITA to diagnose and the fan was a no brainer. This coupled with the fact that I could try the fan for $60 with a 100 day warranty made this my first step.

BTW, I have checked the top hose for pressure overnight, none, thank God. And I have checked for signs of coolant/oil co-mingling, also negative. I could almost see this going through your mind as you composed you post, and rightly so.

I will get to the bottom of this and solve it. I have driven Mercedes in my business since 1993. I average about 5000 miles per month. I have always bought gas cars (recently V8s) with 100,000 miles and clocked them out. This 300D is a experiment for me. I have been buying cards for $16m to 20m, driving them for 200,000 miles and selling them for $6m to $8m 3-1/2 to 4 years later.

I have fallen for the 124 diesel in a big way and hope to bring this '87 to top shape and then continue to repair it, indefinately. Even to the point of replacing the engine, whenever it becomes necessary. It all boils down to dollars/mile for me. If I can be successful at getting into a reliable car with necessary repairs for $5m to $6m (I'm currently still under $4m in this car) and then spend another $5m per annum to keep it up, I have achieved a lower cost per mile than is possible when depreciation has to be factored into the equation.

This car may have higher maintenence costs than my typical ride but the depreiciation dollars have already been paid by the PO.

I appreciate your comments and I will keep you informed of progress.

BR,

Steve (8C>

Jim,

Thanks for posting the pictures. I haven't broken down and bought the manuals yet so this is a big help.

John

Hey Steve,

If you've never replaced the fan clutch on a W124.133 (or .193), it's NOT easy. If you don't have the two special tools I **highly** recommend pulling the radiator. This will also allow you to clean the radiator fins, and condensor fins, thoroughly while it's out. Also a good time to inspect the serp drive belt and tensioner (tends to fail every 50-100kmi - must be perfectly parallel, if angled at all, replace ASAP). Clean up the face of the clutch & flat bimetal spring before installing. DO NOT remove, bend, deform, or otherwise mess with the flat diamond-shaped spring, you will ruin the clutch!!!

With the special tools you can R&R the clutch in 5 minutes with the rad installed, without the tools plan on 30-60 minutes, lots of French, and skinned knuckles. They tools needed are:

Short, stubby 8mm hex socket tool (3/8 drive) - cheap, ~$5-10 from dealer??
Spinner tool to spin the bolt out (hard to describe - I should take a picture of the one I made for ~$5, instead of spending $50-75 for the MB tool)
Serp belt holding tool so you can torque the bolt on & off (NOT cheap - $50-$90)


If you're interested I might be able to take photos, and/or get part numbers.


Have fun! :D

The 603 series engine has a different cooling system than the 5 and 4 cylinder ones. It has a by-pass function on the t-stat that recircs hot coolant through the block until it completely closes at 100 deg C. Then it runs 100% coolant from the radiator. I take this as the design intent is to have the engine run somewhere between the beginning opening temp of the t-stat of 80deg. C to the fully open position of 100 dec. C. (no bypass). Does anyone have an idea what the temp rise through the engine should be? Also if you are interested I have a brand new in the box radiator for a 87 300TD. I ran it for two hours and realized that my old radiator was fine. It is a Behr and in new condition with all the protective caps installed.

Henry

Hi Henry,
I would definately be interested. Please contact me off line at sschweg@concentric.net. If you will give me your phone number, I will be happy to call you.

BR,

Steve (8C>

Fan Clutch Testing
 

Saturday I drove to CT and the engin temps under way were perfect. The air was cool, (60s) and the eng. temp was 85 deg. Couldn't make it budge 'til I got back to traffic in NYC.

When I returned I did the roar test. There was some roaring above 3000 rmps, but I was not impressed. I did not hear the roaring subside at the upper RPM limit. In addition the fan freely spun when the engine shut of. I read and it seems logical that if it is tightly engaged it will stop more abruptly. All this happend at 100 deg and slightly above. It is also the original metal blade type.

Does anyone think I'm wasting my time and money to replace this clutch?

Steve, did you replace your fan yet? I plan on getting mine done next Sat. I'm eager to hear if it makes a difference.

OK... I replaced my fan clutch and now my temperature guage is broke...

:D

In truth, I'd rather be lucky than good :D :D .

Seriously, I had a buddy help me and we replaced the fan clutch. You're right Dave, PITA:eek: . Anyway, this morning I headed for the Saturn plant in SpringHill, about 1 hour form the house. The ambient temp was about 85F. The car never got over 90C despite some.. uh... spirited driving.

When I got to SpingHill, it was lunchtime, so I locked the car with my spare key and let it idle while I went in and got a sandwich. I came back out and let it idle with the AC on COOL while I ate my lunch.

It never got over 100C. In fact, when moving at, say 30mph, it wanted to run at about 85C.


I left there about 4:00pm with the ambient temp about 92F. I drove it hard back to town and stopped for fuel when I got back. I shut off the car and fueled, restarted and entered stop and go local traffic for about 20 minutes. Never got over 100C :D .

I think I am going to declare that the fan was the problem.

Thanks for all of the feedback. I will take the long grades next week, but I'm pretty confident. It's like a different car altogether!

BR,

Steve (8C>

Hi Steve,

Glad you fixed it! Something I didn't think of before was that a failed fan clutch could replicate symptoms of a bad radiator. Here's how: If the clutch is OK but just never engages (to spin faster than ~1500), it would cool OK at idle but not under load and/or when really hot. BUT, if the clutch was totally shot, and wasn't even matching RPM's up to 1500 then it would barely pull any air at all, even at idle. It would be kind of freewheeling all the time. That would cause hotter operation at idle. I wasn't sure if the clutch could or would fail like that, but I suppose it's possible, and your experience somewhat confirms it. But anyway, if it won't exceed 100C under most conditions with warm ambients, I'd say you are all set! Congrats! :cool:


Best regards,

My temp gauge starts at 100f and has intervals for 175 and up to 250 were the red line is...i hear some of you talking about 80 - 90 degress. When im driving it usually reads between 100 to 110.
Its a '79 240D...is this a normal operating range, im in the south(NC) Hot days so far this summer and the AC is not working.

Hi PSetzer,

Your guage appears to be in Farenhiet while ours is in Celsius.

(F-32)/1.8=C

so...

(212F-32)/1.8=100C water boils
(175F-32)/1.8=79.4C

(100F-32)/1.8=37C (accuracy unlikely?)

BR,

Steve (8C>

Hi Dave,
I think this was exactly the case. The fan was just there, had little or no resistance.

I guess it's all about flow. Air flow AND coolant flow. I would say that the right combination of either could mimic the behavior of the inverse amounts. I mean to say that poor air flow and ok coolant flow can offer the same symptoms as poor coolant flow and OK air flow, under some conditions.

At any rate, I am very pleased so far and have the fingers crossed. Thanks again for your suggestions...

BR,

Steve (8C>

Good to hear
 

Steve,

Excellent! This is the same result I'm hoping for. I think that my clutch is doing just that kind of intermediate behavior. It wouldn't freely spin at idle (I tried to stop it with a bald up paper bag), but it would free spin for 10s of secs after engine shut down.

At 3000 rpms it would finally sound like it was roaring a bit, but would never stop when it reached the upper limit.

Hmm, my wife put a lot of miles on this car without me last summer. She was also the one who first experianced the coolant loss that was the first symptom of the head being cracked. I even got it close to the red-line once my self the summer before.

Well, that's a shame. I wish I had tested and replaced this fan when I first got it. :(

I'll be really good at owning one of these when I'm finished with this one. :)

Running hot
 

Gentlemen,

It's been awhile since I read all this thread so bear with me if someone else has already made this suggestion. My son has been literally sweating this problem out on his favorite 300TD and after going through everything, he comes to me and informs me that he's found a sight crack in the plastic pressure tank. Then I realize that he's been fighting an unwinnable battle.

So if any of you are having a similar problem, do a pressure test on your system first. If it fails holding pressure, look around the filler neck on the plastic tank. Bet you'll find a crack. New tank, new pressure test, pass, problem solved.

Ben

Hot under load no more!
 

Folks,

We'll it's completely confirmed. My overheating problem was directly caused by a failure in the viscous fan clutch. Today was hot in NYC (100 deg. indicated on the dash temp gage). The engine temp never passed 100 deg. C. even while sitting in traffic and running around at low speed.

The next real problem is weak cold air from the AC. Last week I had it recharged to no avail. Nick, my independent, looked at it again today and claims that the problem is the expansion valve. He came to this conclusion by watching the pressure gage he connected and taping on the expansion valve with a large screw driver and seeing the pressure drop momentarily.

He was measuring from the Schrader valve on the cold side (driver side by fender) and it was between 60 & 80lbs. He said he expected 40.

He says this is a four hour job, ouch. Does anyone have an option of about this problem. Any one have some way to confirm his diagnoses? Or better yet, a trick to try and coax one more summer out of this valve?

Thanks,