Folks,

I've got a C32 which is loosing a small amount of coolant per day. We're talking about 0.5" of coolant over my drive to work say 50 miles per day.

The car has been to Mercedes and pressure tested and no coolant was lost from the pressure test. There are no signs of any external coolant loss.

If it was the air / intercooler issue would this show up under pressure test ?

Anyone any ideas on the best way of diagnosis ?

Thanks

BS.

What is the milage on your car?

Do you notice S/C not working some times when you accellerate?

Does the transmission shift rough sometimes?

Any other symptoms?

I had small coolant loss along with the S/C working sometimes only. They changed the intercooler pump (the most certain part to fail in a C32) and I have not noticed coolant loss so far, two weeks later (should check again tonight). Seems the faulty pump was leaking a bit...

Its a 2002 w. 41k.
Couple of months ago the S/C started to fail, and I had the IC pump shortly after, this resolved the issue. Transmission feels fine and when the SC IC pump was replaced the dealer checked that the transmission has no coolant in it..... that was all before the coolant loss though !

No signs of any external leakage sadly, however I will put the car on a lift this weekend and check the pump througly.

The only way to confirm coolant leak is to remove one of the intake manifolds (it is the one with AMG cast on). If your intercooler is leaking you will see green residue.

If it is green, than the only fix is to replace it.

Good Luck!

On with monitoring the loss...

If it is the air/water intercooler, does it loose the water whilst engine running, or when the engine is shut off ? Surely the air pressure from the compressed air that it is trying to cool would keep the water in the intercooler ????

10mm (3/4") of coolant loss during past 24h which involved 38miles of driving. You can see 2 really faint lines lower one has a line and a T(uesday), the upper has an M(onday), but it's real faint.

BTW, this seems to be a generic coolant, judging by the color. I read on this forum that we should use a special (MB brand?) coolant that has anti corrosive component. It is more yelowish (no green tint) in color. That may help prolong the intercooler core life, if it is not the culprit in your case.

Never touched it. All MB's doing.

You will need the following parts;

112-141-2080 qty 2 $5 ea
112-098-0080 qty 2 $5 ea
112-141-1180 qyt 1 $5
112-500-0000 qty 1 $924

I just did one.

What be those parts Jon ?
I guess the $924 one is an IC unit

Gaskets

Cool, thanks.

Just found all the parts on a local MB parts search engine.
I won't go into details as I'm trying to get MB to fix it.... lets just say that MB cannot find the cause for the loss, although admitted to the fact it is loosing coolant.

Car is under warranty, but it physically isn't broken... aAAggggrrrrrr

Having a nightmare with it. 2 visits down the line with MB and still not resolved.
One of these days I hope it hydrolics through water ingress....

Jon, was your C32 at over 140k miles when you sold it? Seems you got some good mileage out of it...

I sold my car two weeks ago. The car has seen many track miles.

Coolant leaking into the engin is a big problem for your plugs and cats. Plus the car is not as fast as it should be.

The dealer gave me a new SC, intercooler, plugs, and cats at 60K mile when my car was under warranty. The problem happened again at 140K.

Exactly my issue, it does not "feel" as quick as it should at time, but not as bad the IC pump failure issue. Because there are no signs of any leakage it would appear that the issue cannot be taken any further which is disgraceful.

I'll PM you. Wont go into public details. I know they read this forum... well I told 'em to !

Spoke with the Warrenty people this morning. Under their Terms and Conditions they will not pay for an investigation into the coolant loss as the car has not failed. Upon failure they will pay for labor and parts.

As I pointed out, this is a stupid situation. Potentially the engine may, in the worst case hydrolic.

Fine bring on a major engine catastrophie...bring it on !

Guys with C32's ~ Have any of you had the Intercoolor failure, if so how long did it take before something substancial failed ?

Apparently coolant loss is not deemed as failure

I would not follow their foolish suggestion. I recall someone explaining how to access and open the cover to see the intakes yourself and check them for residue.

just take a look at it yourself, it will only take about 20min...then you can stop playing the guessing game with the stealership...