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Old 05-09-2015, 11:23 AM   #6
Ski in NC
Technical Guru
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City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 5,455
Originally Posted by FF View Post
The "old single weight oil" was probably what the engine was used to.

By using a more modern mullti-weight , your engine probably now has modern detergents eating at all the crud.

A leaking pan and other gaskets is normal when this change is made.

If its NOT the gauge the spring and ball in the oil pump pressure regulator will need to be cleaned..

Maybe the new oil will do it for you?

Old oil was rated CD (Compression ignition ) D grade additive package.

The new oil will be CF , the F being higher detergent
Don't send this guy down the wrong path.

Commercially available single vis oils have detergents just like multivis.

A stuck regulator will not control oil pressure at a constant 60psi. A stuck regulator will cause oil pressure to either go super high or super low. His symptom is a step change in indicated pressure, but it is still controlling well at the new higher pressure.

This is a symptom of classic gauge trouble. The next step is to put a mechanical test gauge on and read true pressure.

Could be 60psi was/is normal and previously the electric gauge read low, who knows, but nothing wrong with 60psi.

As far as I know, but could be wrong, the pressurized oil on the 275 is not ducted anywhere near the oil pan rail, so his leak is likely unrelated.

Snug up pan rail bolts. As gaskets age, they shrink and bolts get loose. Don't overtighten, just snug.

Check blowby vent for restriction. A good way to do this is to run engine with oil cap off and block fill hole off by hand and feel for pressure building up, there should be none.
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