Need professional help! 190Ecooling System - PeachParts Mercedes-Benz Forum

#1 06-27-2004, 03:18 PM

Car: 1992 190E 2.6

Well I have done all I can so I come before you today to ask expert advice. I live in a small town in texas and I do not have a professional mechanic that works on MBs.
So I posted here with a thread and no one really answered my question.

here is the URL for the original thread.

190E woes. head/water pump?

A gentleman by the Name of Jim Anderson gave me a suggestion but it was already something I had known all along about the pulley.

So this weekend I began the task of tearing apart the damn front half of the engine. I pulled the radiator and cross member pulled off the water pump pulley water pump belt. then I decided I might as well replace the belt tensioner and the rod, nut and the sepentine belt.

Okay, I got all of that done and put it back together put in 6 quarts of 50/50 and the damn thing wouldnt take anymore? So I ran the engine for about 10 minutes till operating temp and then I checked the coolant level again. I went down a bit so I thought okay it must have just need to circulate a bit so I added a bit more 50/50 to the mix. Ran it again for a little shorter time period and It got up to operating temp, but then the fans kicked on, and I thought okay its been Idling for a while thats normal so I shut it off. Waited 10 minute s then backed it out of the garage and put it on the street. Well, the next morning I went to drive it to Wal Mart and when I turned the key the coolant level indicator came on immedeatly and I didnt panic at first, I just thought maybe its bogus. Well I opened the hood and low and behold not a single drop of anything in the expansion tank. It was as dry as the sahara desert. So I put more 50/50 coolant in it and Drove it to Walmart watching the coolant light carefully. It never came on and the car performed like a champ. I came out of wal mart turned on the car and the coolant light didnt come on which I was happy about. Well, I looked at my temp gauge, which is in accurate some of the time, actually im beging to think all of the time now. and it was already at 80 and I thought that was a little hot for sitting an hour. The outside temp was 70*, not hot at all. So I started it up and drove home well about half way through the 6 mile trek I pulled up to a stop light and could hear the aux fans just running as high as they could, and of course I was freaked out.

WEll, I decided to get it home not romping on it but keeping a slow and steady pace below 2000RPMS the whole time. I get home and park and shut off the engine immedeatly. I open the hood and yep its overheated not badly though it didnt reach the boiling point. or the 265* the coolant/antifreeze boils at it was just really hot. So I pulled out my stanley laser thermometer and took some temp readings.

325* at the exhauast manifold.
248* on the block.
225*on the valve cover
192* on the expansion tank cap.

Then when I looked at the expansion tank and it was filled to the top and the coolant was spiting out that overflow. and on to the ground. So I went inside mad, angry, hurt, sad, betrayed ect.
I came out about an hour later and the engine was still a bit warm but not abnormally so. I touched the expansion tank cap and it was a little warm but not hot. I opened it up expecting the worst, oil in the coolant because I was almost certian the head gasket blew. I shined my flashlight in the expansion tank and oh my god, I almost burst in to flames. There wasnt oil in the coolant as a matter of fact there was no coolant! Once again it was dry and there wasn't a trace of water in that expansion tank.
No puddle under the car.

I Screamed what in the he L L L L

So now im tuning to this site and its professionals. What could be causing this? I consider my self a deicent DIYer and have all the tools and service CDs for my car.

Has anyone seen this?

I have never seen a problem like this on any car let alone all the pre 1995 mercecedes I have owned (Including a 83 380SEC, 92 400E, 90 500SEL and 92 300E). This car is demon posesed!

Can anyone help me im a desperate fool at the end of my rope my daily driver has become my garage queen. The most common view of my engine since april is all torn apart.

Thank you for your Time.

Andrew Niiranen

#2 06-27-2004, 05:35 PM

Okay, If no one can help could you give me the number to a service advisor/expert who works on M103 engines and cooling sytems?

fj bertrand · #3 06-27-2004, 06:37 PM

does the heater work? That tells if the collant is circulating; also does this engine have bleed-off vents located at various points around the cooling system that have to be opened when filling the coolant? If these are not opened, air wil remain in the system and overheating is the result.

Concerning the loss of coolant, all your other fluid levels are ok, right? (trans, oil, etc.)

#4 06-27-2004, 06:57 PM

Does the heater work?

Yes, the heater works. It blows hot air all the time.

The coolant is deffenintly circulating.

Does this engine have bleed-off vents located at various points around the cooling system that have to be opened when filling the coolant?

I dont know. Is that a question or information you are giving me.
If it does can you point me to the locations?

If these are not opened, air wil remain in the system and overheating is the result.

Thats possible there were air bubbles in the coolant tank after the overheat, but I thought that might be normal for an overheat.

I just cant figure our whats going on with the level. It wont take coolant and then after it sits there is no coolant in the tank.

Very perplexed, looking forward to your response

thank you sir.

ANDY

stevebfl · #5 06-27-2004, 07:13 PM

You have two posibilities as I see it. One you didn't have all the air from the system and the t-stat didn't open so it got hot.

Two, you are consuming coolant and burning it, not a sustainable prospect.

Proving a small head gasket problem can be tough but bottom line is once you get the air out the only way you need more coolant is if it is on the ground or in the air (burned in combustion) or sitting in the tailpipe condensed.

Gilly · #6 06-27-2004, 07:14 PM

The line from what you call "the expansion tank" leads to.....well, an expansion tank. What you see under the hood is actually the "pressure tank", the line off of this leads to another rather large expansion tank (I usually refer to it as a "puke tank") which is inside the rear of the front fender.
The expansion tank will take up excess coolant when blown off or "puked" by the pressure tank, as required. Then, like most other cars of the modern era, when the engine cools off, a small valve will allow coolant to be drawn back into the system when the engine cools off.
So, depending on circumstances, you may have had a full expansion tank in the fender, which had some added to it through this experience and there is a small tube to allow the expansion tank to leak out onto the ground when it's full. So I'm guessing this is how it ended up on the ground.
As to why it isn't being sucked back in when cold, possibly a bad pressure cap (on the pressure tank). Is it an MB pressure cap?
The initial fill quantity seems a bit low, how much do you figure you've put in now total?
I recommend putting in as much as it'll take, wait 10 minutes or so and top it off again, then put on the cap and drive it with the heater turned on defrost position, so you can monitor if it's blowing hot yet or not. Then drive it to normal operating temp (NO MORE THAN THAT!), then shut it off (usually a mile or two is sufficient to achieve operating temp). Then shut it off, leave the cap on, wait another 10 minutes or until you see the coolant level drop (usually will do this suddenly), then carefuly remove the cap and top it off. Repeat the test drive, monitor the defrost temp. Once you have a hot defrost, usually you can just wait a few more minutes, check the coolant level again and you're done.

Gilly

neanderthal · #7 06-27-2004, 07:20 PM

was your heater switched to hot when you filled the cooling system? if not then air would have been trapped and you would not have been able to fill it completely. that would account for your first "empty reseviour."

i say always fill the reseviour with the heater set to hot and the front end of the car tilted up a little. that will cause bubbles to migrate towards the highest point; top of the radiator or overflow bottle. this will allow you get a better fill. and first run the car with the cap off to circulate the water.

Stan Pittman · #8 06-27-2004, 08:34 PM

Did anyone check the pressure cap?

#9 06-27-2004, 09:52 PM

Steve: My friend believes probability one is correct he is coming over to see.

He wants to know where are all of the bleed off points?

Gilly: Thanks I see the problems now. No it is not an MB cap it is however a 1.4 bar cap made by Germany? I got it off of european automotive.

There is no hose that goes to an expansion tank from the pressure tank.

It was cut and then the hose dangles down to about 8 inches short of the ground out of the port below the pressure tank cap It looks like it was spliced. Then I looked harder and noticed that the other half of the tube goes over by the firewall on the pass side by the strut tower and then dissapears. Why do you think some one would do that? something wrong with the expansion tank, or the most probable cause the last owner was even stupider (more stupid) than I am. What would you recomend to splice it back together properly.

Quantity: A gallon and a half of 50/50 coolant mix. But then I lost probally a quart or so of coolant as of now. I will have the whole system drained .

I just ordered a new hose from the pressure tank to the expansion tank.
I am assuming The wheel needs to come off and then there will be a panel in the wheel well. Or do I access it from the top?

Thank you so much gentleman.

ANDY

Gilly · #10 06-27-2004, 10:08 PM

Yes, remove the wheel and unscrew the panel on the back-side of the wheelwell. You may want to price out a new tank, they get really bad, especially if the headgasket blew and there was oil in it, an I think they're pretty cheap too.

No bleed-off points, I recommend doing the top-off as i previously described and don't sweat the bleeding off.

Get an MB cap.

Gallon and a half seems low. My books are buried right now to get the info, do you have the owners manual, capacities should be listed in there.

Gilly

Greg in Oz · #11 06-28-2004, 03:19 AM

To ensure the correct 50/50 coolant ratio, I always thoroughly flush the cooling system (including heater) with water which I then allow to drain. I then add the required amount of coolant concentrate (eg. for 9 litres total I add 4.5 litres of concentrate). I finally add water to bring it to the correct level. In this way you are sure to have the correct coolant ratio. It does not matter if the system was not completely empty when you started so long as what remains is clean water. For example, if you started with say 2 litres of water remaining in the system and added the necessary 4.5 litres of concentrate, you would then add another 2.5 litres of water to fill it and the correct ratio is achieved. If you use pre-mixed coolant, it is impossible to ensure the correct 50/50 ratio unless the system is absolutely empty before you fill it (which is highly unlikely).

As to bleeding the air from the M103 engine, if you want to be fussy, you can remove one of the blank plugs next to the temperature sensor on top of the cylinder head towards the front on the inlet manifold side. You can then fill it until coolant appears at this opening. This way you know the block and head water jackets have been filled. It does not guarantee that there won't be air trapped elsewhere though (eg. heater). As Gilly suggests, run it with the heater operating and regularly check and top up as required. This will ensure that all air has been bled from the whole system.

If after having done all this, coolant is still disappearing, then you have a problem such as suggested by Steve.

#12 07-01-2004, 03:39 AM

Thank you gentleman, especially steve and Gilly and Greg.

It was an air pocket in the system. I bled the entire system radiator, valve on the cyl. head, and the heater core. This time when I filled it it took the proper amount. I also installed a new pressure tank and hose from the Press. tank to the "Puke Tank".

The car stays cool and RUNS 10 fold different no shuttering at idle after getting past op. temperature. The cylinder head is fine from what I can see.

Now here is a new problem...

My Temp gauge is inaccurate!

this might be what caused this whole problem.

The temp was reading around 80C but.... now that the operating temperature is normal its hanging around the 60ish mark? So I thought hmmm. whats going on? I got the car to operating temperature and that was measuring the actual temperature of coolant system with my all to handy stanley laser temp gauge.

The gauge in the car was reading just above the second mark from the bottom. Yet my laser gun was reading 167* at the radiator and 178* at the presure tank.
So that has to be inaccurate.

I went into the car and the needle was slightly jumpy so my idiot reflex made me tap the face of the cluster. the tap made the needle shoot up to 120 so I flicked it harder and the stupid thing hung out around 80 then started flickering wildly before slowly going back down to 60ish.

I'm pretty sure its the gauge that is bad.

I have 3 questions.

1. Do I have to buy a entire cluster or can I just by the left hand gauges?

2. Is there an individual component that I can replace say a rheostat or potentiometer that controls the needle? All my other gauges work fine!

3. Is taking out/installing guages any different in a 190 than say a 380SEC?

Thanks for all your help

ANDY

3.

Gilly · #13 07-01-2004, 09:43 PM

You can buy just the gauge component of the cluster, yes. It would come out similar to a 126 chassis, yes.

On question #2, if I understand correctly, you would be talking about the engine coolant temperature sensor I believe, and yes, this certainly is an available part, but I agree wholeheartedly, sounds like the gauge to me, too. Tapping on cluster faces and seeing the gauge shoot up/down, sure sounds like a bad gauge to me.

Gilly

Chevota · #14 07-01-2004, 10:40 PM

Glad you figured it out. I've had trouble with air pockets before too. Now I always drill a small hole in the thermostat to allow air to escape, that is if I run a stat at all. I've had so many of them fail and come close to ruining engines that I usually just remove them if I can get away with it.
As far as the gauge goes, I never trust factory equipment. If it's important enough that I know the actual temp, I buy a quality unit like the Autometer Pro Comp series. Then I test it in boiling water to verify it reads 212 degrees (compensate for altitude if need be). I have a laser temp gauge too, it's best to read the thermostat housing because the the radiator and tank can be cooler. But if water isn't flowing due to an air pocket then the head will get real hot and the thermostat housing, radiator etc may remain much cooler.

Greg in Oz · #15 07-01-2004, 11:02 PM

Quote:

Originally posted by Chevota
Now I always drill a small hole in the thermostat to allow air to escape, that is if I run a stat at all. I've had so many of them fail and come close to ruining engines that I usually just remove them if I can get away with it.

MB thermostats usually have an air bleed hole as standard.

Running MB engines without a thermostat is definitely not recommended. They run a two-way thermostat which has two valves that operate in two coolant paths. When cold, coolant is allowed to circulate via the pump and water jacket. As the temperature rises some coolant is diverted via the radiator. At high temperatures all the flow is via the radiator. Removal of an MB thermostat will completely interfere with the intended flow of coolant and operation of the ccoling system. Some engines with a single valve may be OK without a thermostat (although the need to do this suggest some other problem) but do not remove the thermostat on a Mercedes-Benz engine.