overheating after coolant change please help! - PeachParts Mercedes-Benz Forum

TurboSDL · #1 04-24-2009, 03:23 AM

i changed my coolant today and after i filled up my car with new coolant it has been running right between 100 and 125 and thats with the heat on full blast. if i turn the heat off the temp will go higher i changed the thermostat thinking that might help but it did nothing at all, is there any way to bleed the air out of thesystem via bleeder screw or anything? im at a loss it was ok before but the coolant was dirty so i decided to change it. please lmk asap, i need this fixed fast. thanks- j

compress ignite · #2 04-24-2009, 04:46 AM

Elevate the front End (You Need to "BurP" it!)
Air Pockets(I do not know the procedure for a W123 , SomeBody will chime in !)

I'd not run it at those Temps.
Until After you've "Burped" It.

RAYMOND485 · #3 04-24-2009, 05:04 AM

1984 300D TURBO 149K
ON A FRONT NOSE UP HILL, REMOVE THE UPPER RADIATOR HOSE AND FILL
HOSE, YOU HAVE AIR IN SYSTEM

Brian Carlton · #4 04-24-2009, 09:17 AM

Quote:

Originally Posted by RAYMOND485

1984 300D TURBO 149K
ON A FRONT NOSE UP HILL, REMOVE THE UPPER RADIATOR HOSE AND FILL
HOSE, YOU HAVE AIR IN SYSTEM

Agreed. The head is full of air........filling the upper hose allows coolant to go directly into the head.

TurboSDL · #5 04-24-2009, 12:04 PM

ok, im gona try it now and let you guys know what happens... thanks for the feedback.

Shawn T. W. · #6 04-24-2009, 12:21 PM

Also sometimes with the cap open, you can squeeze the lower hose, it will push air out . . .

TurboSDL · #7 04-24-2009, 01:23 PM

this doesnt seem to be working, i have the car as high as it will go on jackstands and as i fill the upper hose going into the head the radiator starts pouring coolant out, so i ran it a little while with the upper hose bungied to where its facing the sky but after a while of filling it alot the radiator begins to pour coolant out of the neck where the hose is detached. then when i put it back on and let it run the same thing happens, the temp gets up there real high and its really starting to piss me off!!! sombody please tell me what to do! my other car has too dead of a battery to be driving it around once i shut it off it wont start again without a jump so i kinda need this car working right now, im too cheap to buy a battery!

lietuviai · #8 04-24-2009, 01:33 PM

I've always added coolant after the engine has warmed up enough to open the thermostat. I had a similar problem after replacing the radiator a few months ago. It got hot and then it burped by itself. I then added hot water straight from a water heater to prevent any cold water shock.

Skippy · #9 04-24-2009, 01:46 PM

When I did the coolant in my 300D, I just filled it normally, then drove it about a mile, let it cool for a while, added more coolant to replace the air that came out of the engine, and repeated a few times.

You did dilute your coolant 50/50 with water, right?

TurboSDL · #10 04-24-2009, 02:05 PM

yes 50/50 drove it, did everything u guys said to do so far and still hot.. its gotta have air in the system im sure, iv worked on cars for the last ten years and im a student at UTI and im about to graduate so im firmiler with auto/ diesel but this just has me puzzled... im kiinda just waiting for the resivor to burp crazy style then the coolant to drop but it hasnt happend yet.

Brian Carlton · #11 04-24-2009, 03:31 PM

Quote:

Originally Posted by TurboSDL

this doesnt seem to be working, i have the car as high as it will go on jackstands and as i fill the upper hose going into the head the radiator starts pouring coolant out, so i ran it a little while with the upper hose bungied to where its facing the sky but after a while of filling it alot the radiator begins to pour coolant out of the neck where the hose is detached.

The only way this occurs is if the thermostat is defective. Coolant cannot get past the closed thermostat to fill the radiator via the lower hose. If the thermostat is partially open, it might be stuck in that position, thereby slowing the warmup and also failing to fully open.

Does it take more than 5 minutes to get to 80°C?

curtludwig · #12 04-24-2009, 05:08 PM

Is the thermostat in backwards?

Please don't ask how I know to check this...

TurboSDL · #13 04-24-2009, 05:31 PM

Quote:

Originally Posted by curtludwig

Is the thermostat in backwards?

Please don't ask how I know to check this...

you kno what i think it might have been, i switched it around so well see if that helpps, what side goes toward the head the side with the spring on it or the side without the spring? the thermostat fell right out when i pulled it out the first time so i couldnt really tell what way it went in there but if sombody can tell me what way it goes in that would be great... im takn a little break right now to sit by the ac for a lil bit.

Basstrip · #14 04-24-2009, 09:04 PM

The spirngs goes towards the head. That will allow the hot water pressure to push the little around flat plate and open tmst to allow water to the radiator and process the cooling system.

TurboSDL · #15 04-25-2009, 06:50 AM

thanks for all your feedback guys, the cooling system finally burped like bigtime and the temp went down and now it stays between 80 and the mark right after 80 so it seems to be doing good so far so hopfuly theres no more air in the head.