190 E Water Leak

[David Garrard]

My 1991 190E is losing coolant from the system but there are no obvious leaks. The radiator and reservoir will empty in about 3 weeks. The car is used every day but only for an average of 20 miles. What can it be? Any suggestions?

 

[Andy]

Hi David,

There is a posting some where on this forum on this very subject. But I couldn't find it. So here it goes.

The first thing I check. Assuming you have checked thoroughly for external water loss from the engine & pressure tested for any fine cracks anywhere?
Is check the head gasket. Check and see if excess steam is coming out of the exhaust. If not check for dampness on the side of the tunnel. The heater matrix pipes join the matrix in that area.

Check the head gasket first would be my bet, although checking the matrix for water loss is easy enough. Again assuming that there are no other external coolant leaks. The engine fitted to your vehicle do suffer from head gasket failure at times. You may have to take it into a garage to have a block test carried out.  If they have the right equipment the test will take minutes. Its a blue solution in a bottle. They then put it on top of the  radiator expansion bottle. If the solution turns from blue to greenish or yellow its bad news!


Regards
Andy @ www.mercedesservicing.com

 

[13022]

Yeah...I raised this also not long ago...

My 190e has been doing away with her coolant on the sly for the last 55,000 miles (in fact, since I bought her). Strangely it hasn't seemed to get any worse though...

Don't think the gasket is at fault and can't find any dampness from the heater matirx, but I suspect the problem IS worse when the heater is in use, over the colder months.

Have you noticed this too maybe?

I'm thinking that this must point to the matrix, but (successfully!) putting off a VoyageBeyondTheDashboard!...

 

[Andy]

Hi Mark,

Double check the heater valve on the drivers side below the windscreen panel. Check it for leaks.

Regards
Andy @ www.mercedesservicing.com

 

[13022]

Okay guys, the definitive answer in my case was a corroded radiator. Rather subtle in fact ... only when crawling through the worst of the traffic was the pressure high enough for the (near boiling) water to spurt out of the rad, onto the fan, then getting sprayed over the engine bay - hence no evidence until now. Fitted a new rad on Saturday and all seems well... except theres a smell of petrol on startup now! - It never ends does it !!!