Compression verses oil consumption.
 

Hi all. This forum looks awesome.

I have just purchased a 1972 Mercedes 250 W114.
My problem seems similar to the one below. My compressions range from 160psi to 175psi but the oil consumption is excessive. It doesn't really smoke too much unless it has been idling at lights etc. Bluish smoke.
If it needs a head job are there any other Mercedes heads that it could be replaced with.

Thanks for any input

Sounds like valve seals. To my knowledge the only head that works on your car is the one that came with the carbureted M130.

I have heard and read that seals can be replaced without pulling the head. This might make sense for you because your valves and rings seem to be in good shape.

Welcome to the forum. We a can't wait until you mess with your Zenith's or your heater blower.

Hopefully as cTaylor has mentioned you won't have to remove the head. A new head will cost $3K! Rebuild heads are difficult if not impossible to find . Having the head rebuilt is expensive $2K-3.5K. If you end up ever needing to have that done there are many many other things that you should get replaced at that time.

BTW I'm still fiddling with my Zenith carbs!! Yikes!!

Compression verses oil consumption.
 

Hi again,
Thanks for the speedy replies.
I thought that it could have been the seals. But how can I change them without removing the head? ie remove the springs without a lifter unless I could make up a lever with a slot or hole drilled into it? But there is still the problem of compressing the springs to remove the keepers from the valve stem.


And yes they are Zeniths but I wont even look at them yet.

I am not suggesting that you do this yourself, but it is possible.

There is a special tool that hooks under the cam or the rocker ball that compresses the valve spring so that you can get the keepers out and remove the retainer and spring. You can then get at the seals.

Believe it or not the keepers are called "collettes."

The trick to all this is to do it one cylinder at a time, bringing each to TDC and supporting the valves with compressed air blown in through the spark plug hole.

Compression verses oil consumption
 

After considerable thinking and the distance to the nearest M B service center I have decided to pull the head off and do it the conventional way. By the time I could find the compression tool or have one made up from a pattern the job would be probably done. Unless of course I open up a can of worms and one thing leads to another etc . At least I will be able to check it all out.
I will block my nose and jump in so to speak.
Thank you for the responses and I will probably come up for air next week sometime. lol.

You might want to get the Haynes manual for the '230 250 280 SOHC' since it has a good section on head removal. If it would help I can fax or mail you the relevant pages from the parts book which has good exploded diagrams. Send me a fax or address.

This is a fairly straightforward job. I would recommend removing the hood for more workspace. Unless you have a hoist, take the exhaust/intake assembly off first because it makes things damn heavy if you leave it on.