Low compresion on one cylinder

[Arjun]

Hello,

I am about to buy a 280sl.  The body is excellent  (no rust).

Being a low mileage car that runs great it has one low cylinder (125) vs 180.

I am told the engine would last another 10K, before a rebuild is in order.

Being everything else is fine, (actually great), can somebody be a devils advocate.

[knirk]

Arjun,
Do you have the readings on the other 5 cylinders?
And what about the oil pressure at idle and the exhaust color?

Per G. Birkeland
69 280 sl aut 834
Norway

[A Dalton]

Adjust the valves on that cylinder and re-check the compression..
 If it still is low, do a leak down test....

[Arjun]

The leak down test has been done. The other 5 cylinders are between 170 and  180.  There is no blue smoke.  The car runs great.
I am told by an experienced mechanic most likely it is the rings and that he would not to an engine rebuild now.

[A Dalton]

....then it probably is the rings.. but I would adjusts the valves  [ all] anyway...

[Shvegel]

It should be relatively easy to determine if it is rings or valves etc. When doing a leakdown test you can listen to the exhaust, intake and oil filler to determine where the air is leaking out. Also a compression test can be repeated then oil is poured into the cylinder if the compression goes up it is the rings. Regardless you could probably go  awhile before rebuild depending upon miles driven per year. The tough part is that by the time you do it all(and you might as well since it is apart) you can spend up around 10k.

[ja17]

Hello Arjun,
95% of the time it is the cylinder head if the car has less than 200,000 miles.

Joe Alexander
Blacklick, Ohio

[Arjun]

There is a consensus as to not to do the rebuild now. The car has 75K original miles to it and I plan to use it 2k every year.
When I'm told the car can be drive 'awhile', would you be able to put a 'number of summers' to it. I understand I am trying to get an accurate 'elusive' number. Its just that the car is perfect in terms of rust and the rest of the mechanics have checked out fine.  Top $$$ is what I am paying. (going to pay)

[ja17]

Hello Arjun,


See if the 75,000 mileage is documented through service records. It seems that when sevice records mysteriously are missing or cannot be found then the car may  actually have more miles possibly 175,000 or more!

Even if the previous owner's service records are missing, the dealer will have copies of the sevice records. these will verify actual mileage.

If this car actually has 75,000 miles then the engine should not have serious problems. Most likely  a head reconditioning will make it 100%.

Joe Alexander
Blacklick, Ohio

[rwmastel]

quote:Originally posted by Shvegel

The tough part is that by the time you do it all (and you might as well since it is apart) you can spend up around 10k.

Patrick,
Can you elaborate on this?  Is this $10,000 to send it to Metric Motors, or have a local MB dealer do it, or have a local experienced independant do it, or do it yourself?

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420