coolant sludge

[shanksy]

Hi,
My coolant warning lamp came on yesterday and upon checking this morning I find the coolant is right down and filled with nothing but oily sludge.

Would this definately be the head gasket or could it be something slightly less sinister.

Car is a '94 W124 Coupe 2.2 138k

Thanks in advance

 

[NW_Merc]

Has it been serviced? Leaky radiator?

 

[shanksy]

Just due a service, got a quote yesterday funnily enough. Was fine around Christmas when checked and not been losing any for the last year since bought.

 

[grober]

Several possibilities- head gasket being one of them. Top up the coolant when the engine is cold and then start looking for leaks first. Your water pump might have gone- or radiator leaking etc. etc. does your engine misfire slightly on first starting? is there white smoke [steam] coming out of the exhaust? is the radiator top hose very hard once the thermostat has opened? any bubbles of gas coming up thro the coolant?

 

[shanksy]

OK, topped up whilst cold and could not find any leaks. No misfiring on first start, no steam coming from exhaust and no gas coming up through the coolant. Not sure about the top hose becoming very hard once thermostat opened as i'm not sure where the thermostat is (beginner at mechanics)

After leaving the engine running for quarter of hour, coolant has possibly dropped slightly but not 100% sure.

 

[grober]

OK best to get a sniff test of the coolant headspace gases. Garages use an exhaust gas analyser to check for combustion gases above the coolant. Easy to do and very sensitive. If its positive you can then get a compression test done on each cylinder to locate the leak.

 

[shanksy]

OK will do.
Just one more thing, would I be wise to keep off the road until sorted or is it likely to be OK while coolant is topped up? I use the car to commute in the week.
Appreciate the help grober.

 

[grober]

Really depends on-how bad the CHG is gone (if indeed this is the problem) how far your commute distance is, how badly the oil is contaminated etc etc Difficult to say really. Since you have probably been driving it in this state for some time provided you check the coolant daily and keep a close eye on the temp gauge a few more miles is probably not going to hurt. However if your commute is 100mile round trips down the motorway then be prepared to be stranded on the hard shoulder with a lot of steam coming from under the bonnet from an overheated engine. Its your car I'm afraid you have to assess the risk yourself knowing your own personal circumstances.

 

[BlackC55]

I would not drive it very far with a CHG gone which it sounds like your engine has. The head needs to come off to see what has happened.

It is quite a common problem on that engine. I have done loads of them.

If you need any help as you are local (Hants) give me a shout.

 

[shanksy]

Ok thanks guys, appreciate all the help.
I will drive to work tomorrow and see how it goes. BlackC55 I will be in touch tomorrow, cheers

 

[shanksy]

Thanks for the advice the other day BlackC55.

Can anyone advise if this manual is the best to cover replacing head gasket on M111 engine, or recommend any better ones.

Mercedes-Benz E-Class - Petrol W124 & W210 Workshop Manual 1993-2000: Easy-to-follow Instructions Covering Service and Repair of 111 and 104 Petrol Engine: Amazon.co.uk: Clarke R M: Books

Thanks