Compression loss

1996 MERCEDES BENZ SLK230
160,000 MILES • 2.3L • 4 CYL • TURBO • 2WD • AUTOMATIC
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EDD DANGER BENNETT
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When driving on the motorway with course control the car lost power suddenly, using the accelerator made no change and the car began appearing to fire on only Two cylinders.
Pulling over steam was visible from the bonnet but did not pour out, the engine temperature remained in a safe range.
After turning the car off I was unable to start it again. The starter motor can be heard working but the engine does not appear to ignite.
Oil and water have not mixed and it feels like a loss of compression or fuel in the engine itself, but I do not know what could have caused this or where to start trouble shooting the issues.

Any help and advice would be very appreciated.
May 14, 2018 at 2:55 AM
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STEVE W.
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From the description it sounds like head gasket failure or a warped head. That would explain the feeling of running on two cylinders and the steam. Depending on how it failed (sounds like to the outside of the cylinders) you will not see oil/water mixing as the coolant is not going that way, plus the coolant would settle to the bottom of the pan and usually you would not see it on the dipstick unless there is a lot in the oil pan. The "milkshake" look to coolant is a sign that the engine has been running a while with a leak. In your case it failed, you pulled over and it has not started again.

The first step would be to do a leak down and compression test as well as a good visual inspection. Those will give you a better indication of the state of the actual engine.

https://www.2carpros.com/articles/how-to-test-engine-compression

This shows a few other things to look for as well. Do not bother with the chemical test as the engine needs to run for that test. However the pressure tests would be valid.
https://www.2carpros.com/articles/head-gasket-blown-test

It is also possible that the failure is deeper in the engine like a broken crankshaft but that is not as likely.
May 16, 2018 at 1:15 PM