Club 80-90 Forums

Worn turbo seals can cause low oil pressure!!
Did you check the intermediate shaft?

Are these things covered in the bentley manual?

I didn't look as didn't know where to!

Personally I can't see turbo bearings having much influence on the matter.
Should have at least checked the main bearing shells while the sump was off, as these have more influence on oil pressure than anything else bar the pump.

The "Bentley" covers the intermediate shaft end float but not the bearings,the "jx" engine isn't covered!
Windy, the seals on my old turbo did affect the oil pressure ; oil light on at tickover,1.5 bar at 3000 rpm( with new turbo 1 bar at tickover 3 bar at 3000 rpm)
But I think he should have checked the big ends ( give them a wiggle) and taken the main bearing caps off and had a look.

I did try and give things a 'wiggle' and there was no movement. And given the they all use stretch bolts I was not keen on putting new ones in. It's not too hard to drop the sump and look again.

I'll check the more affordable options first, such as the turbo.

Take the hose that fits on to the turbo ( the kinked bottom one) and wiggle the compressor shaft up and down .

Check the turbo and check the mains and big ends.

If any of the bearings have spun then it could be those causing your lack of pressure. I'm more inclined to suggest that the turbo wouldn't cause this symptom because the tolerances are that close that it won't cause such a big drop in pressure over normal operating temperature.

I think that your pump is worn and that you possibly have a spun bearing.

Your options are many and varied, from replacing the JX like for like, to an AAZ 1.9 (plug and play), to an MTDi (also plug and play) and on to a real TDi (AFN, very much not plug and play but worth it).

Dave.

Hi I had BOD problems with my westy jx oil lamp on when hot and so on
fitted new oil pump and main bearing shells old ones with some wear (no stretch bolts!) and replaced the pressure switches
5 years later still ok

I'm getting the main bearings done & balanced; fingers crossed that will be enough.

Thanks for the help. Will update post when I know it's fixed.

This is an update for those trawling the net for answers. It's in at the garage and a possible likely cause is big end bearings. The motor has been run up from being sat for over a decade and potentially 'spun' a big end by pumping congealed / dirty / moisture laden oil through the galleries. Clearly causing major problems, temporarily fixed by a new con-rod cap on number 2 (as pic above shows).

The whole unit is coming out for a full lower section re-build and balance. I'll update in detail when I know this fixed it for sure.

OK, so it turns out the main bearings and big ends are fine. The low oil pressure is due to the collapse of bearings on the balance shaft / intermediate shaft / jack shaft (no wonder it confuses me this engineering lark!), which I believe runs the vacuum pump and oil pump.

The issue here is that it appears some incorrect bearings had been fitted and subsequently collapsed!

The mechanic suggested that I need to get a old block, or find out what the spec on the bearings are as VW does not sell them or even have a specification!

Can anybody help as I'm kind of stuck! (you are not allowed to use 'AAZ' in any replies!)

Brickwerks have the intermediate* shaft bearings ( I got mine from them ) you might need to reamer the new bearings ( to fit )
*balance shaft.

So they do. Many thanks.

And to update (Dec 2016), this resolved the low oil pressure issue.

So low oil pressure & buzzer of doom was due to failure of intermediate shaft bearings. This is a very involved job, highly experienced mechanic territory.