300tdi oil pressure mystery after rebuild

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topdeadcentre

New Member
Posts
7
Location
Melbourne
Hi all,

We recently did a rebuild of sorts on a 300tdi which was really just a freshen up with new rings and bearings in the end.

Anyhow, upon starting there was no oil pressure. This was confirmed with a mechanical gauge, where we got absolutely no pressure at all.

Cranking with the oil pressure switch off shows that there is oil flow

So it seems as if there is something wrong elsewhere which is causing no resistance and preventing pressure build up. We are confident all the bearings were the correct size.

We then overfilled the engine with oil to see if we could get it up and flowing but no luck.

After that, we rigged up a pump with a gauge to the oil switch oil to try to check if the relief spring setup operated correctly at the 55 psi it is supposed to but we couldn't get it to hold any pressure at all.

So the sump came off and the plunger and relief spring were confirmed as put in correctly.

Basically there seems to be a leak in the system somewhere preventing resistance necessary to build up pressure as the pump appears to be providing adequate flow (or at least enough to provide some level of pressure..)

We are at our wits' end so any assistance would be greatly appreciated!

Cheers,

Jim.
 
Why did you feel the need to change the rings and bearing? What were the engine's symptoms that you weren't happy with?
Did you just change the big end bearings or the main crank bearings too?
 
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