Is the S3 pump and S4 pump the same? I have reason to believe that my omp is crapping out on me and was wondering if an S4 pump would fit an SE engine.

Also, As I was searching around for answers, I noticed that the omp was always refered to as "lubricating the seals" But never was said it had anything to do with aiding in compression. Is this true?

 

The oil does aid in compression. Can't say on the difference between the S3 and S4 MOPs. If you have a 12A, the mops are different.

 

That's what I was figuring, I mean logic suggest that this is what's going on but I wasn't sure.

 

Just order the rebuild kit from lowe's and do yours. The phone number is around here somewhere... just search for Lowe's.

Until the kit reaches you in the mail, premix.

The -SE OMP is unique to the -SE. The S4 and 12a versions are different.

The amount of oil the OMP injects is so small that it wouldn't have an appreciable effect on compression.

Jon

 

I think I read somewhere that the oil helps seal the edges of the apex seals thereby increasing compression.

 

So which is it then?