W124 Engine Coolant
 

After I was turning the engine on and it warmed up it I was
giving a smell of engine coolant.

I replaced all rubber hoses one of which was broken.
Now I do not see any leaks, however after the enigne warms up I still get the smell of hot engine coolant . Where could this be leaking from additionally? IS the heater assembly pretty much leak proof? I assume that the radiator is not leaking.

Engine coolant
 

mlrolin, Did you clean all the fluid that leaked out in the engine area, antifreeze smell can hang around, unless its washed off. And vapors can enter into the HVAC system.

TimReid

Reply
 

Yes I did with a power wash.
I am just wondering if the Germans designed the heater in such a way that it wont leak.
Maybe I should search for leaks in the engine itself?

I would defiently check for spills, and wait it out. See if the smell goes away or gets worse. How is your coolant level?

Reply
 

Does anyone have a pic of the heater assembly of a W124?
Are there any rubber hoses or gaskets there?

The coolant level is pretty much constant in the excess reservoir
at least.

Get a pressure tester
 

For tracking down hard-to-find coolant leaks, the best bet is to get a pressure tester. The down side is they are about $75. You can get them at Sears or some auto parts stores. Often if you have a slow leak somewhere (like a clamp) you won't see any visible leaks or white residue, but once you pressurize the system while it is cold, the leak is usually obvious.

Reply
 

This sounds as a good option with the pressure tester,

also if the coolant level is too low~~ I would assume that due to

its

lower mass/ammount it would tend to boil or get closer to a

boiling point, thus it would work above its nominal

operating range and would evaporate easier through

any tiny holes in the hoses(if any are left). I guess I should have

added sufficient coolant after I replaced the hoses since my

coolant level now is actually below min but stable.

I kept smelling collant and stuff on my brothers car. I presurized it. On the back of a 560 you can see that there is a hose and it had a pin hole in it. and it was burning on the exhaust manafolds. Just presure test it. I have a napa pressure tester for coolant, maybe you can rent one from checker or autozone

90 300E COOLANT LEAK
 

Yesterday, when I parked my car after driving, I noticed cooant dripping on the ground. It was coming from somehere from top of the engine oil reservoir. I removed the air filter, but did not find any wet spot. The expansion tank has sufficient water level. The water pump & thermostat feels dry.

Any help to solve this mystery leak will be appreciated. Thanks

Try a new reservoir cap from mercedes benz.

Benzidude, Your leak is probably coming from the fitting on the left rear of the cylinder head where the heater hose attaches. There is an o-ring that seals the fitting to the head.

Re: Get a pressure tester
 

Or you can rent the $75 gadget at Auto Zone or other mass-marketer for $75 and get it all back when you return it.

The pressure test will let you know where/if you have an external leak.

90 300E COOLANT LEAK
 

RPM55,

Thanks for your advice. Iwill check this evening. By the way, in my car, the hose going to heater is located at rear of cylinder head near firewall on right side ( back of air filter) . I assume this is the same hose you mentioned in your reply.

Thanks