Oil Pressure issues

[Billman]

also the holes on the top thingy seem a bit bigger in the RS2

I am going to pull them out ans see if theres a difference and maybe axchange them.

[mcandmar]

My ABY motor also had the washer in it when i tore it apart. It would make sense for the diesel engine to have a different bypass valve as it dosent rev as high and wont need to bleed off as much pressure.

[Billman]

my concern is the oil pressure on idle.....i am missing approx 0.8 bar of pressure :-D

if the spring is weak wouldnt that mean that the valve would open alittle easier (even at idle).....that could maybe explain some drop even there.....maybe i am trying too much to explain this.

AndyP had also the same issue but dont know if he got a solution. Both engines are strokers.

[mcandmar]

AFAIK it shouldn't open until max pressure is reached at 5bar or whatever it is. I would expect it to be fully closed at idle. If its stuck partially open then it will reduce idle pressure.

If AndyP had the same issue issue with a diesel block i would suspect its to do with the different one way valve behind the pressure sensor that feeds oil to the cyl head. If its less restrictive you may have more oil/pressure being fed to the cyl head.

[Billman]

There is a spring that is fairly tight, much more than the one way valve in the 2.2 engine. The question is is there another tried solution?

[AndyP]

AFAIK it shouldn't open until max pressure is reached at 5bar or whatever it is. I would expect it to be fully closed at idle. If its stuck partially open then it will reduce idle pressure.

If AndyP had the same issue issue with a diesel block i would suspect its to do with the different one way valve behind the pressure sensor that feeds oil to the cyl head. If its less restrictive you may have more oil/pressure being fed to the cyl head.

I've tried swapping back to the one way valve that came out of the TDi block and it made no difference, also tried shimming the relief valve spring, no difference.

My engine gets 5bar cold, but drops quite quickly i.e. after 2-3mins ticking over it down to 3 bar. When hot I'm getting 1bar at idle and it maxes out at 4bar at around 4000rpm. I'm not overly concerned by this as my old 3B engine did the same, but I'd like to know why a new engine has no more pressure than one that has done 200k?

There also seems to be a difference of opinion between here and Motorgeek as they think that 1-4bar hot is OK, whereas on here 2-5bar is seen as normal.

[A80Avant]

if it makes any difference my engine which is the same since rebuilt (but normal 2.2), i have been using a new AAN oil pump and i have 5bar on cold, 5bar on anything above 2500-3000rpm and on idle here is what i have:

on 75C coolant: 2.2-2.5bar
on 80C coolant: 2bar
on 85C coolant: 1.8bar

i use 10W50 titan fuchs and about 100K after the rebuilt, i still get the same oil pressure figures.

[terrybullwon]

I've tried swapping back to the one way valve that came out of the TDi block and it made no difference, also tried shimming the relief valve spring, no difference.

Andy have you tried a calibrated mechanical oil pressure gauge or something like this?

http://cgi.ebay.co.uk/MECHANICS-MAST...#ht_2351wt_905

I would not trust the electrics too much they are near on 20 years old

[AndyP]

Yes, I had this made at the local hydraulics place



It only confirmed what the gauge in car was reading.

[terrybullwon]

looks the ticket.

And shimming the spring on the relief valve to create more oil pressure does nothing?

I will be selling my diamond coated pump when i make my new sump but that wont be for a good few months, this would help your issue i am sure

[Thuppu]

Andy, what turbo and oil-linings are u using? Was there a thread about the oil pressure drop if the turbo oil-linings flow too great..? A restrictor in the linings before the turbo will rise the pressure.

[quattro84]

What about the oil squirters? Same on a diesel? Do they have a (working) one way valve? Otherwise they use a lot of oil.

[AndyP]

looks the ticket.

And shimming the spring on the relief valve to create more oil pressure does nothing?

I will be selling my diamond coated pump when i make my new sump but that wont be for a good few months, this would help your issue i am sure

Oil pump is brand new anyway. I tried shimming the spring and yes, it made no difference. The stock spring is not supposed to open until 6-7bar so unless these is a real problem it should never move anyway, right?

Turbo is a GT3071 and oil lines from 034, with the restrictor in place.

Oil squirters are from the TDi AAT block. I've checked the part numbers and they are different from derv to petrol, anybody know what the difference is?
If anything I would have thought the TDi ones would be smaller, combustion chamber temps on a TDi are not as high as a petrol.

[JP]

Different oil squirters have different flow and pressure ratings, depending on internal spring and spout diameters. If they are different part numbers it could very likely be a starting point to look at. I'be also come across faulty ones that are stuck open which would cause a drop in pressure too. I've got both AAT squirters and AAN ones on the shelf. I'll see if there is a way of rigging something up to test them tomorrow.

[AndyP]

Nice one