Coolant leak M103.
 

Hi all!
We have a slow coolant leak on my sons 1988 300TE.
I think it is loosing about a quart a month... we get the warning lamp and I topped it of and then a month later the same.
I looked all around for where it was going, and kinda felt it might be the heater matrix. I kept getting a wiff of antifreeze in the engine bay and sometimes the interior... but could not see anything until yesterday.

I was under the car looking for the scource of the oil drip we have, and I noticed antifreeze on the crossmember.
I looked up and there was a trace of it on the side of the engine block, exhaust side. I looked up further and the highest spot I could see was right next to the firewall,on the lower exhaust manifold stud/nut on #6... just a drip hanging off the bolt head.

Now, could it be the headgasket weeping or is the another coolant line or vessel there?
If it is, would retorqueing the head work... it does on my Alfa Romeo's!
Could this also be the reason we get an intermittant misfire when the engine is really hot... coolant weeping into a cylinder when under pressure?

How bigger job is the headgasket and at 65,000miles, what else might need doing IF it needs it?

On an 88 I'd replace the valve seals and have the valve guides checked.

There are hoses around the intake manifold are difficult to reach with the engine intact. Maybe some of those could be replaced as a precaution.

Sixto
93 300SD

Thanks Sixto.
We already did the idle hoses and discovered a trick to help everyone replace them with the engine intact.. we hope!
Here is the link...
http://www.peachparts.com/shopforum/showthread.php?t=159346

Mine has had a weeping headgasket leak for 130,000 miles. No symptons other than loss of coolant. No cross contamination of oil and water. Plugs look fine. Runs fine.

Headgasket is not a big deal. Under $1,000 dollars at an indy. Do the seals. Valves won't need it yet.

Steve
'92 300E 245,000 miles

I will take some pics later today and post... he is driving it so I should have some more leakage.
I will also pull the pugs and see if #6 looks ok.
I am still thinking that we could pull the valve cover and retorque the head.

Bad idea. Do a search and you will find a couple of threads on this re-torquing idea.

Steve

Put a pressure tester on it when the engine is completely cool or as cool as it can get in this weather and then pump it up and check it in an hour or so and see if you can find the leak. If the leak is real bad it may show up right away.

If you end up doing head gasket do water pump too and maybe tensioner if it's original.

Update!
 

Did a pressure test...
First thing we found was that the radiator was leaking from the drivers side plastic tank header!
Done that now, so I will test it again.