Watch your Temprature guages - PeachParts Mercedes-Benz Forum

boneheaddoctor · #1 12-15-2005, 07:51 AM

Watch your Temprature guages, I noticed over the last 2 days my temp guage was only going up to 60 degrees C on the highway....this was a very recent happening so I stopped and got a new thermostat and put it in last night......so this morning it is running at 85-90 C like it should be on the highway..... and it gets there far quicker than it used to get to 60 C. Point being running too cold is bad for the engine as well as running too hot....and a bad thermostat can fail in either direction.

#2 12-15-2005, 08:47 AM

My gauge reads under 80 by maybe 5-10 degrees and the heat doesn't get HOT just warm enough that I am not a popcicle by the time I get to work. (even better reason for block heater,eh) Btw, to do the block heater from the top like you said you did, will I have to replace anything besides the in. and ex. manifolds? also does a thermostat R and R need anything else(paper gasket or goop) or just the oring that came in the set? zachariah

t walgamuth · #3 12-15-2005, 08:55 AM

your stat may be just fine. a diesel needs work to generate heat.

removing the block plug from above is about impossible wo removing a lot of other stuff. from below is prob best. with a lift. and a 3/4" drive breaker bar with a six foot pipe.

the t stat has a rubber gasket that should be included in the box. be sure ti install the stat with the flat disc toward the engine.

are you close to lafayette?

tom w

boneheaddoctor · #4 12-15-2005, 09:01 AM

Quote:

Originally Posted by zach

My gauge reads under 80 by maybe 5-10 degrees and the heat doesn't get HOT just warm enough that I am not a popcicle by the time I get to work. (even better reason for block heater,eh) Btw, to do the block heater from the top like you said you did, will I have to replace anything besides the in. and ex. manifolds? also does a thermostat R and R need anything else(paper gasket or goop) or just the oring that came in the set? zachariah

I would get a second O ring..there is a short tube that holds the O ring between the intake and tubo...it has two O rings not just one....but likely the old one will be fine. the manifold gasket kit only contains ONE Oring...

thermostate needs nothing but the rubber seal that usually comes with the thermostat....you don't take the housing off the block...you take off the three bolts that face the front of the car...the part the radiator hose attaches to.

My temp guage will hit 80 in town within 5 minutes slow driving 25 mph (I did have the block heater on last night).....and stay at 90 on the highway...

TO be honest doing it from above on a W116 is easy.....the bay is wider....but is a bit of a PITA with a W123 as there is less space to work unless you have smallish hands....I don't.

#5 12-15-2005, 09:49 AM

Don't feel bad, my wife just volunteered me to replace the stat in her friends Ford Escort this weekend.

boneheaddoctor · #6 12-15-2005, 09:58 AM

Quote:

Originally Posted by Craig

Don't feel bad, my wife just volunteered me to replace the stat in her friends Ford Escort this weekend.

nothing like having your sevices volunteered....at least its not to do a timing belt...

#7 12-15-2005, 10:20 AM

Quote:

Originally Posted by boneheaddoctor

nothing like having your sevices volunteered....at least its not to do a timing belt...

I shouldn't be a big deal, hopefully it won't be a complete rust bucket. I don't need to deal with any broken bolts, etc.

Hit Man X · #8 12-15-2005, 12:21 PM

I agree too cold is bad as oil doesn't heat up properly... like my SDL. I think the stat is stuck open.

joel price · #9 12-15-2005, 12:32 PM

Has anyone else found relacing a thermostat on a w124 to be a royal pain. I had a lot of dificulty getting the bolts in the housing and keeping the thermostat inside the housing
joel

Zerohour3k · #10 12-15-2005, 01:02 PM

Just so I'm getting this right..

To replace a stat on my W123 (84 Euro 300D), it's a simple procedure of just unscrewing the housing, and popping a new one in.. or..?

Sorry.. call me a newbie, but I just am unsure of the proper procedure to do this. From where it's located (behind the fan, and towards the left, when you're facing the car).. it looks to be a bit of a PITA to get to. Any tips / tricks / how-to's?

boneheaddoctor · #11 12-15-2005, 01:03 PM

Quote:

Originally Posted by Zerohour3k

Just so I'm getting this right..

To replace a stat on my W123 (84 Euro 300D), it's a simple procedure of just unscrewing the housing, and popping a new one in.. or..?

Sorry.. call me a newbie, but I just am unsure of the proper procedure to do this. From where it's located (behind the fan, and towards the left, when you're facing the car).. it looks to be a bit of a PITA to get to. Any tips / tricks / how-to's?

yes three 10mm bolts and pop the old one out and the new one with new rubber seal back in....arrow facing up....make sure to not put it in backwards.

you lose about 3/4 gallon of coolant.....with a 3/8 ratchet and a 10 mm deepwell socket its a breeze....you won't be doing it with a open or box end wrench.

Zerohour3k · #12 12-15-2005, 01:43 PM

Thanks for the quickie how-to! I'll be sure to get on this later. Sounds like a job easily done in the dark, even.. which is probably what I'll end up doing anyway. Just need to see if I have a 10mm deepwell laying around.

boneheaddoctor · #13 12-15-2005, 01:47 PM

Quote:

Originally Posted by Zerohour3k

Thanks for the quickie how-to! I'll be sure to get on this later. Sounds like a job easily done in the dark, even.. which is probably what I'll end up doing anyway. Just need to see if I have a 10mm deepwell laying around.

I did it 8pm last night with a flashlight in 10 minutes.

ConnClark · #14 12-15-2005, 01:50 PM

Around town in stop and go traffic my temp gauge seems to dip to around 60 when the heater is on. I'm not certain if I should get concerened or not in this case because my trips are usually so short. I'll be taking MY 300SD on a 150 mile trip today so I'll keep tabs on it on the highway.

I think the defrost setting on the heater circulates coolant through the heater core regardless of engine temp. This may be why my temp gauge is low. On other settings it doesn't come on initially when the engine is cold.

boneheaddoctor · #15 12-15-2005, 01:52 PM

mine is holding close to 80c around town at 25 mph stop and go...with heat running at a little above 20 degrees F outside