S124 300te head gasket

[twothirty]

Hello,

We have a lovely 1991 S124 300te 12v which we use as our daily runner. It has only 85k miles clocked up but has developed an issue which i suspect is failure of the head gasket. It is losing oil and i see fresh oil from the top front of the engine which smells when the engine has warmed up

The coolant warning light came on a couple of days ago and i topped it up tonight (50/50 MB coolant and de-ionised water). It took a litre and brought to the surface a thick layer of caramel sludge which i guess is oil contamination. The last time i looked at the oil filler cap it seemed clean but the assumption is that the head gasket has failed. A local garage said it could be contamination via the radiator?

I am willing to pay to have the HG replaced as i love the car but can anyone recommend whether this should be done by an MB specialist, a head gasket replacement specialist or could it be done by a local general garage? What would be a reasonable price (i.e. how many hours labour is likely)? Should replacement gasket(s) and new bolts be sourced only from MB? Just trying to get an idea how much this work is likely to cost. We are based in S London.

Any suggestions/tips/experience would be great.

Thanks all.

 

[bolide]

I'd have it diagnosed & quoted for by an MB specialist while it's still a runner. Labour charges in London are liable to be a bit frightening - it might be worth taking it to an out-of-town specialist with lower overheads

I'd only use MB parts

If the rad has failed you'll have water in the transmission fluid - the indy will check that

The M103 engine is a lot easier for CHG replacement than the M104 as it has 12 valves rather than 24. But labour will be the largest expense

I would think it's going to be a >£1000 job with VAT. Ask the indy if a secondhand engine would be a cheaper alternative

Nick Froome

 

[Will]

On an otherwise sound 85k miler 300TE I'd personally stick with the original engine unless something terminal came to light, but second all the other advice above.

If you're keeping the car, maybe combine the job with the other associated service items and the bill might seem less frightening - eg, coolant flush and replace, oil and filter change, new spark plugs, air filter etc. Look at replacing the valve stem seals whilst it's apart too.

Labour costs will be the bulk of this job so I wouldn't skimp on the parts. A genuine MB head gasket, cam cover gasket and bolts if needed won't be much more than £200/300 at a guess. Worth asking for some discount too

 

[WG M-B]

If it is the hg its a very straight forward job.

 

[carat 3.6]

Make sure to take it to someone familiar with these engines when you do have the gasket changed, alot of people don't set the timing chain tensioner properly causing bigger problems.

 

[WDB124066]

Just make sure they use a reinforced gasket, there are still a few non reinforced ones floating around that MB will try and sell you!
Frankly I'd get someone on here to do it for you, all the experience in the world and if it goes wrong, like they can do, you have a far better chance of it being put right without having to bring out the axe and watch the little feckers run for their lives while reaching for the cell to call the police....

 

[twothirty]

Thanks for the pointers. I dont want to replace the engine as it starts well and runs/changes very smoothly. My concern is that the work seems quite complex in terms of having to prise the engine in half and then putting it all back to exact tolerances, etc. so would be good to find someone who has experience of doing this type of work. Has anyone had theirs done and can recommend a garage to do this?

In the meantime, is it ok to use the car provided all fluids are topped up? I have been monitoring the sludge-in-coolant situation and is worse of late. The car is used for a daily 5 mile commute.

Thanks.

 

[d w124]

I would not drive it any longer.I just had the HG on mine done in SE23 London and can highly recommend the Garage or even better see if Carat 3.6 ^ can spare some time

 

[jaymanek]

Just done mine... straight forward job but some of the simple things like sealing the front casing etc can catch the non MB experienced mechanic out.

A specialist would be best.

Wont be cheap though... To do a proper job you will be looking at best part of £1K.