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General Information => Troubleshooting => Topic started by: Smokey Eddy on September 24, 2011, 07:04:51 pm

Title: low oil pressure
Post by: Smokey Eddy on September 24, 2011, 07:04:51 pm

I just changed main and rod bearings <500km ago as well as lifters about 20,000km ago.
All the bearings were done when I built the engine about 40-50k ago. So the I'M shaft bearings are a little old but from what could see they looked ok.

I know the oil pump would be the next logical spot to go.
Opinions?

Cold.       Idle 2000 3000+
                 50    75     100+
 Warm      25  30/40  50 
HOT       5-10    12    <20

Those numbers seem really low to me for having fresh bearings.
I'm running lubro moly fully synthetic 5w35 ( or 5w40)
It's a 1.9 aaz with a really old garret t3 from a previous 1990 1.6td.
I'm wondering if the turbo is spilling the pressure.
I changed the cold side seals and bearings but the hot side was fused shut.

Title: Re: low oil pressure
Post by: Wayland on September 24, 2011, 07:38:22 pm

Did you replace the oil pump when you built the engine, or at least measure the gear backlash?

Title: Re: low oil pressure
Post by: Smokey Eddy on September 24, 2011, 07:47:38 pm

I did not! :D
I'm asking if you all reckon an old turbo bleeds more oil or a worn pump causes lower pressure.

Title: Re: low oil pressure
Post by: Wayland on September 24, 2011, 07:50:18 pm

I would strongly suspect the pump.

Title: Re: low oil pressure
Post by: Smokey Eddy on September 24, 2011, 08:08:07 pm

Even if the turbo is really old? It still boosts great though...
I'll replace the pump.

Title: Re: low oil pressure
Post by: fatmobile on September 24, 2011, 10:10:40 pm

You can prime the pump with a drill and watch to see how much flows past the cam journals.
 I've had those bleed off oil pressure.

Title: Re: low oil pressure
Post by: Smokey Eddy on September 24, 2011, 11:06:27 pm

Hmm that's interesting although I wouldn't know what is too much?

Title: Re: low oil pressure
Post by: fatmobile on September 26, 2011, 10:22:36 pm

I hadn't done this before,.. but knew when it was flowing too much oil from journal 5.
 I did check it with plastigauge after seeing it.

Title: Re: low oil pressure
Post by: Smokey Eddy on September 26, 2011, 10:26:50 pm

The head isn't very old but the turbo and pump are very old. Especially in comparison. were yours pretty aged by this point?

Title: Re: low oil pressure
Post by: rallydiesel on September 27, 2011, 09:15:24 am

Where are you reading from? Those numbers don't seem that terrible. I had an oil pressure gauge that read about 10 psi too low (VDO). Is your oil warning light blinking?

Title: Re: low oil pressure
Post by: Smokey Eddy on September 27, 2011, 11:20:17 am

No blinking lights. Read from the cylinder head.

Title: Re: low oil pressure
Post by: BigVWman on September 27, 2011, 02:17:57 pm

numbers aren't super bad. Doesn't head oil sender trigger a light at about 4.5psi and filter flange somewhere around 18-23 at 2000rpm?

Title: Re: low oil pressure
Post by: Smokey Eddy on September 27, 2011, 02:36:29 pm

I re-routed the one at the head to the filter flange

Title: Re: low oil pressure
Post by: burn_your_money on September 27, 2011, 04:00:29 pm

Quote from: Smokey Eddy on September 27, 2011, 02:36:29 pm

I re-routed the one at the head to the filter flange

That sounds like a bad idea to me.

Measure the oil pressure at the flange. If it is within specs then the oil pump is ok.

Title: Re: low oil pressure
Post by: Smokey Eddy on September 27, 2011, 04:06:14 pm

Thanks fellers