98 W202 C230 Coolant Leak - Pics
 

Hey everyone,

I have a slow leak that I have not been able to locate for a few weeks. I've had to add coolant about once a week, depending upon the amount of driving.

Tonight, because of the cold and damp weather, I was able to find the leak.

I'm attaching pictures, but I can't imagine where the leak is coming from. The coolant appears to be near the transmission. This is the first time I've been able to see any leak, every other time I looked, I have not been able to find any fluid.

I hope someone is able to make recommendations.

One picture shows the general area of the close up shot. It appears that there is coolant in a hole on the transmission bell housing.

Thanks everyone,

Kevin

You will need to wash off the area then pressurize the cooling system to find the leak. The AC condensation drains are above the trans, if the heater core leaks I'd expect coolant to come out of these drains as well to prevent flooding the interior.

I don't know if there is a spot on the engine that will leak here, I only have inline 6 cars. ( the SL and a 97 C280 )

Hi,

First of all you should not have green coolant in there! Zerex G-05 only!!

Second, the main block drain is just forward of that location. It is impossible to see without using an inspection mirror (or being under the car). It is 17mm if I remember correctly. Doesn't need to be super tight but yours might be loose.

To be fair the green will make the leak easier to see, but once you find the leak flush it out and put the right stuff in!

I have never heard of anyone having a leak in that area so I am guessing it is the block drain. Go buy an inspection mirror if you don't already have one. Very handy to have.

Its the head gasket at back of head

Nulu, I believe you are correct. From my searches, it appears that the rear portion of the head gasket is prone to failing.

Thankfully it's only draining out, not into the engine.

I have a shop that will replace it for $1200......not what I wanted to spend around the holidays, but I need the car to be running.

I'll share the info on how the fix goes, as I've never used this mechanic before, but I'm encouraged based upon our discussions.

As to the coolant, I've used the Prestone "Any Vehicle, Any Make" because I cannot find Zerex G05 anywhere around here. Although just recently I found a website that sells it for 12.59 per gallon (zoro.com), so going forward....

Green antifreeze works fine, however it needs changed every 2 years vs the 5 or so for extended life.