M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: Gray S. on February 28, 2008, 04:09:50 PM

Title: Need some help on asessing motor health
Post by: Gray S. on February 28, 2008, 04:09:50 PM

Hey everyone,

Its my first post here, but I've been reading up quite a bit in preparation of a 318is purchase.  I've got a couple questions for you guys with a good bit of m42 knowledge.  A car I am looking at has had the head gasket replaced and head milled to be flat, as well as the entire cooling system essentially replaced.  The car is located in Alabama so I am guessing that this amount of work was done because the car probably overheated.  The owner right now isn't sure because all the work was done by the owner before him.  I just got an email from him saying that he had a leakdown test done on the car and obtained Cylinders 1,3 and 4 were 95% and 2 was 90%.  

The car has about 148,000 miles on it and a little seepage from the front main seal and power steering unit, but no major leaking whatsoever.  Can someone give me an indication of the health of hte motor from this.  Is the leak down ok for an m42 of this age?

The car has maintenance records dating back to 1992, and it appears to have been very well taken care of, I'm just curious about the leakdown test.  

If someone could help me out I would really appreciate it as I look forward to becoming an m42 owner soon!

Thanks,


Gray

Title: Need some help on asessing motor health
Post by: D. Clay on February 28, 2008, 04:37:27 PM

Head gaskets blow on iron block and aluminum head engines. They have different coefficients of expansion when heated. Aluminum more than steel. This stresses the head bolts as the engine heats up. After a sufficient number of heat cycles, the bolts are stretched to the point where the gasket blows. Some never do and some do that have less miles.
You could have your own leakdown test done to be sure. !0% is normal. 20% is getting along toward the end of the continuum.