1987 300sdl overheats in traffic - Page 2 - PeachParts Mercedes-Benz Forum

amosfella · #16 10-10-2008, 05:42 AM

if the tstat was removed, the car would probably not get much above 50 degrees. I had a tstat that was stuck open, and on a 80f degree day, the engine water temp sensor didn't get above 55c.
Check the antifreeze/ water ratio, possibly a change is due.
Take the tstat, and put it in a pot of water. Put it on a stove, and heat it. Have an infrared thermometer ready. When it opens, or pops, measure the temp. Should be about 80 degrees even. When putting antifreeze and water back in the system, take the top hose off at the rad, put a funnel into it, and fill the engine till it's full. You'll know when it's full as it will burp out the hose. Pour it slowly though. Tehn reattach the hose to the rad. after that, fill the overflow tank. Too much of a chance of overheating the engine if you just fill the overflow, and they try to run the engine. My head gasket went about a week after I changed the antifreeze the first time. I have doine it this other was several times since, and have not had a problem since.
if you have all that apart, undo the radiator, and pull it out. clean out between the AC evap and the rad. it's probably clogged with dirt, leaves, and other crap by now. get something like a nail brush to help you clean it out. Don't use a wire brush, bad things will happen. If you have never had the rad out and cleaned that ares, now's probably a great time to do it, the previous owner probably didn't. Perhaps even replacing the whole rad wouldn't hurt.
Check the fan clutch. Get a fan clutch from a 99 E300DT, and the 11 blade fan that goes with it.
About the heating, check the monovalve, and the aux water pump behind the firewall.
All of the above will make a huge difference.
my $.02

a2t · #17 10-10-2008, 08:50 PM

Quote:

Originally Posted by compu_85

My fan would turn on when my fan clutch was bad

I wish I had done more reading before I bought my new fan and clutch... the cheaper one from the newer cars is a nice alternative to the pricey OEM replacement.

-Jason

Whats dif in price between new style clutch + plastic fan vs just regular clutch? Last I checked it was a wash, and Id rather keep metal fan and just repl clutch...am I missing something? Is there any reason to use new style clutch vs old style? Old style lasted me 279k miles ...

compu_85 · #18 10-10-2008, 09:11 PM

The original style clutches aren't available anymore as I understand it.

a2t · #19 10-11-2008, 01:01 PM

Quote:

Originally Posted by compu_85

The original style clutches aren't available anymore as I understand it.

http://catalog.peachparts.com/RenderScriptTemplate.epc?_cmd=epccat_VehicleAAA&cookieID=2HH0RV1HJ2HH0RVSYM&yearid=1987@@1987&makeid=MB@@MB@@X&modelid=300%2DDT%2D002@@300D++Turbo&catid=G@@Cooling+System&subcatid=G5010@@Fan+Clutch&mode=PA&subcatid=G5010@@Fan%20Clutch&applicationid=000240864&source=www.peachparts.com&clientid=catalog.mercedesshop

cnev300d · #20 10-13-2008, 07:35 PM

Quote:

Originally Posted by sixto

The aux fan has 2 modes - it runs at full speed as triggered by a coolant temp sensor, it runs at reduced speed as triggered by the AC refrigerant high pressure switch.

What does the heater have to do with anything?

Sixto
87 300D

I've been told that if your car overheats, turn on the heater to distribute the heat to cool the engine down.

Thanks for all the input. I had some time to work on it over the weekend. I flushed out all the old coolant (green) with a water hose and ran it for awhile and it didn't overheat. So I'm thinking there must be something clogging up the lines. I pretty much just pipe the water hose into the hose at the engine block and into the heating unit at the firewall and flushed. I have a gallon of zerex g-05 which I will use. Anyone know how much is needed for the refill?

I did check the monovalve too and it appears the rubber part has holes in it, so I replaced that. There's heat now in the cabin.

Unfortunately I broke the radiator drain plug so the car is still out of commission until that can get replaced. I tried to pull out the radiator but wasn't able to since I didn't want to mess around disconnecting the transmission cooler lines.

I wanted to check on the tstat too, but it looks like it's buried pretty deep, unlike on the 85 300d where it's in the front.

As for the fan clutch, I couldn't pull out the radiator so wasn't able to pull that out either. So not sure if that's working. But it doesn't seem to over heat now!

amosfella · #21 10-14-2008, 02:47 AM

Go at the Tstat from the bottom. Don't worry about the trans lines. Just tape plastic bags over them. Take the rad out.

lvfast1 · #22 10-14-2008, 08:28 AM

Quote:

Originally Posted by a2t

Whats dif in price between new style clutch + plastic fan vs just regular clutch? Last I checked it was a wash, and Id rather keep metal fan and just repl clutch...am I missing something? Is there any reason to use new style clutch vs old style? Old style lasted me 279k miles ...

In case you missed my post (#8) you can use the 606 fan clutch with old metal fan with no additional hardware...on om603, poss? om602 not sure about other engines....part# 606 200 01 22 look it up on fastlane or supplier of your choice it is signifigantly cheaper and same or better quality..i have done this mod and am pleased i also live in las vegas and have tested it in 105+ temps with a/c up grades...The old one was original also with very high mileage..but was shot

ARLO

LUVMBDiesels · #23 10-14-2008, 12:45 PM

Did you make sure the collant was at the proper level? I would also burp the system. Having no heat and having the temp go down rapidly when he gives it fuel makes me think it could be the coolant level...

He can also get a infrared thermometer and check the radiator for cold spots.
I do not trust 20+ year old radiators. The ine in my SDL was replaced about three years ago.

a2t · #24 10-18-2008, 12:11 PM

Quote:

Originally Posted by lvfast1

In case you missed my post (#8) you can use the 606 fan clutch with old metal fan with no additional hardware...on om603, poss? om602 not sure about other engines....part# 606 200 01 22 look it up on fastlane or supplier of your choice it is signifigantly cheaper and same or better quality..i have done this mod and am pleased i also live in las vegas and have tested it in 105+ temps with a/c up grades...The old one was original also with very high mileage..but was shot

ARLO

Ahh I see. Thanks for that!! Probably what I'll do.

Last question tho - would the plastic newer fan pull more air than than the older metal one? If it does, plastic 1 might be better for cooling. Not really a need to have it metal, although I do prefer the "melted down Tiger tank" philosophy that MB had in the 80's. Seems 11 blades would be able to draw more air at same rpm. And I need all the cooling I can get!

lvfast1 · #25 10-18-2008, 01:25 PM

Quote:

Originally Posted by a2t

Ahh I see. Thanks for that!! Probably what I'll do.

Last question tho - would the plastic newer fan pull more air than than the older metal one? If it does, plastic 1 might be better for cooling. Not really a need to have it metal, although I do prefer the "melted down Tiger tank" philosophy that MB had in the 80's. Seems 11 blades would be able to draw more air at same rpm. And I need all the cooling I can get!

I dont know if the plastic fan will pull more air there is more blades but thinner also, there is probably a weight and spinning mass difference tho as far as drag on the engine goes...i have the one i ordered but i did not install it because it came a day late..so my car keeps the metal fan..If you or anyone are interested in the plastic fan i have it, new unopened box for 1/2 the price plus shipping.. i suspect we cannot talk about this in the thread but you can pm me for info pictures of the package, packing slip, etc..and the price... I received it september 16 2008 brand new OES part from online MB wholesaler...
P.S I read to install plastic fan it needs the three 606 fan clutch bolts from dealer, if you search om606 fan clutch upgrade the thread i got my key info from explains the bolt issue it just did not clarify the not necessarily needing plastic fan..no one confirmed it on that thread...

(Fan blade sold to a forum member 10/23/08)

a2t · #26 10-18-2008, 06:23 PM

Thanks, if I decide to go with the plastic fan I will get in touch with you. Unless it offers more airflow, Im sticking with metal.

a2t · #27 03-22-2009, 07:50 PM

winters come and gone ... and this car is still running well at 285k so ... need to fix cooling issue.

starting to see h20 temps to 100c and climbing so i guess its time to pony up.

maybe just the fan clutch for now, then rad if that doesnt do it. 98-99 E300 clutch is $155 on worldpac. A Nissen rad is $243, ouch. Dont know if Nissen is even preferred brand, I thought it was Behr. I would certainly want one with the metal sleeve in the upper rad outlet.

gsxr · #28 05-04-2009, 10:11 PM

Cnev300D, any update on your cooling woes? Another point to ponder, which I don't think was mentioned in this thread, is that the fan clutch engages based on air temp. If the airflow is blocked directly in front of the clutch, even a NEW clutch won't engage. You need to make sure the radiator & condenser fins are clean, and also that there's not a cold spot on the radiator in front of the clutch. It's easy to tell when it's engaging... with temps at 100°C or higher, pop the hood, and kill the engine with the "stop" lever on the IP. The fan should come to a stop within 1-2 revolutions. If it freewheels, the clutch is not engaged - but again, this does NOT automatically mean the clutch is bad!

BTW - Nissen is not a preferred radiator brand, if you can get a Behr for a few bucks more. The Nissen does not have the metal reinforced plastic necks, and for the W124 fitment, the Nissen does NOT drop into place - you have to hack up the plastic tank to make it fit.

Fan blade - rumor is the 98-99 fan has additional blades, and may move more air than the earlier style with fewer blades. But that's mostly speculation, AFAIK...

gsxr · #29 05-04-2009, 10:16 PM

Quote:

Originally Posted by cnev300d

I wanted to check on the tstat too, but it looks like it's buried pretty deep, unlike on the 85 300d where it's in the front.

The t-stat isn't buried that deep... remove the air intake snorkel from the front of the turbo to allow more access, and also remove the round electrical switch (single wire attached) that is directly in front of the t-stat housing. This makes access a breeze. Stick with Wahler or Behr for a new t-stat.

Quote:

Originally Posted by cnev300d

As for the fan clutch, I couldn't pull out the radiator so wasn't able to pull that out either. So not sure if that's working. But it doesn't seem to over heat now!

The radiator doesn't need to come out to remove the fan clutch, but you do need some special tools (shown below). With the proper tools, you can have the fan & clutch off the car in 3 minutes. Worth every penny! The prices have gone up since that photo was taken, tack on another 20% or so...

a2t · #30 05-04-2009, 10:24 PM

As for fan clutch - check out this thread i just started.

OM603 to OM606 Fan Clutch Mod ????

if it works, it will save you $266.

Basically using OM606 fan clutch with metal fan from OM603. Im still trying to determine if it will work, some say yes, others no.

I will find out!

** EDIT - Yes it works well