Hi,</P>


Further to my recent post regarding my 190E burning oil for the first 15 mins after startup, I recently attempted to drive on the motorway last weekend.</P>


In 5th gear at 60mph I realised that I was not getting enough power, and could not get near to 70. I then noticed a rather large smoke plume behind me. After slowing down to around 40mph in 4th the smoke went away again. Further tests reveal that this doesn't happen at 55mph in 5th.</P>


Sounds prettty serious to me! Does anyone have any ideas beyond a shagged engine?</P>


Thanks in advance,</P>

 

I would say that the valve guide seals for a start are knackered! this is what is causing the smoke from the exhausht system. The oil in the sump which is being pumped around the engine is being sucked into the cylinders past the deffective valve seals. i assume that the car is using oil. The are two options available to cure this problem.

But firstly do a "wet" compression test by pouring about 50ml of oil into each bore with the spark plugs removed, then use a compression tester. This test will show if it is a lower cylinder problem if the readings increase from before the oil was added. i.e bore wear. In this case it is more feasabil to simply buy a complete mercedes 190 engine and fit it from a breakers yard. cost= £400- £600. (compression tollerences 140 to 160psi)

OR

Get the cylinder head overhauled. This involves what i have done to my w124 200 which by the way wasnt anywhere near as severe as you car but was simply using about a litre of oil every say 600mile. The cyinder head is removed and an engine machining shop will re-grind the valve seats and more importantly repalce the valve guides and seals. In my case this has completely stopped the oil consumption and the car has brutal power as it is running about an amazing 160psi! my car had a good block therefore it was sensible to put the £200- £300 into overhauling the head.

Do the compression test ASAP as the car could be dangerous as buring oil can infact ignite in the exhaust system!

I have Explianed this in detial as it is obviously quite a problem and i have first hand experiance of it, if you have any questions reply, but more importantly get the car seen to as it sounds like a major problem.

P.s does the car by any change hesitate when cold starting off at lights, this would suggest cylinder head problems.