0-psi Oil Pressure

[driversdomainuk 8]

Yeap you read right.....

 

Bascially when I start my Mi, which I use for hillclimbing, it has circa 60PSI oil pressure, then after 15 minutes it drops to around 20psi....however after a run of very hard high rev driving, at idle goes to 0psi...may be 1 or 2 but the needle hardly moves from 0...then i rev her and up to 50PSI, then back down off throttle....

 

I have no idea why this is happening, I have had then engine totally rebuilt, new bearings, oil pump, recon head, reground crank....I am even using a new mechanical oil pressure gauge with a seperate electronic warning light...

 

The engine sounds great, runs very well...it just does not make sense! Surely the engine would have blown up by now if indeed I was having such low oil pressure and the red oil pressure light keeps coming on when on track.....

 

Any ideas....Lots of engineers, mechanics who build competition engines have no idea.....what is the view on here...as I am not going to spend any more money on it, if its running so well...

 

cheers

Rob

[large 33]

What oil are you using and how hot is it getting?

[driversdomainuk 8]

What oil are you using and how hot is it getting?

 

I am using 10w-40 Mobile Super S - how hot? not too bad, no hotter than you would expect after a hillclimb run

[Miles 331 1 Cars]

Wrong oil for a start, Mobiel is one oil I;ve never had any luck with, 76 Racing oil's are a good one to look at.

The other thing, Was it a OE pump or a cheap pattern pump, again I;ve onl;y had problems with the latter

[driversdomainuk 8]

Wrong oil for a start, Mobiel is one oil I;ve never had any luck with, 76 Racing oil's are a good one to look at.

The other thing, Was it a OE pump or a cheap pattern pump, again I;ve onl;y had problems with the latter

 

Hi - what grade is the 76 Racing Oil..? Thing is I had this problem with the original oil pump.....besides if its the oil pump would this problem be killing my engine or not?

[driversdomainuk 8]

Hi - what grade is the 76 Racing Oil..? Thing is I had this problem with the original oil pump.....besides if its the oil pump would this problem be killing my engine or not?

 

 

The oil pump was from FAI - who are a top OE quality supplier...I know this as the UK Parts Alliance (who likes of Camberley Auto Factors are a member of) approved them as an OE supplier to all national accounts

Edited April 8, 2010 by driversdomainuk

[monkee87 2]

I have this problem too! It's on my standard GTi, i've just got a normal 1.9 8v engine. Got the stupid guessometer gauge too. When i start the car from cold it's half way up the gauge and then when hot it's resting on the bottom line just by the warning light... I don't know whether it's good or bad.. Warning light has never come on mind, so who knows!

[welshpug 1,621]

wouldn't really call FAI "o.e" quality myself having used their products quite a bit the last few years, not bad, but not o.e!

 

thats by the by though, if you have an accurate indication of zero pressure it wont last very long.

 

when it was "rebuilt" was the crank ground and matched to new bearings, or checked with a mic and the bearing toleracnes checked with plastigauge for std size bearings?

[rescue dude 0]

I have this problem too! It's on my standard GTi, i've just got a normal 1.9 8v engine. Got the stupid guessometer gauge too. When i start the car from cold it's half way up the gauge and then when hot it's resting on the bottom line just by the warning light... I don't know whether it's good or bad.. Warning light has never come on mind, so who knows!

 

 

The stop light come's on when pressure is below 12 psi.

 

When was the oil last changed? What oil are you using?

[James_R 3]

I'd put a std pump in there, 0psi at idle is not going to kill it like 0psi at 7krpm, but it will be doing harm.

Do you monintor oil temps at all?

[driversdomainuk 8]

I'd put a std pump in there, 0psi at idle is not going to kill it like 0psi at 7krpm, but it will be doing harm.

Do you monintor oil temps at all?

 

 

 

I have a standard oil temp gauge and does not appear to go to high to be honest...cant remember exactly - will look next time.

[driversdomainuk 8]

wouldn't really call FAI "o.e" quality myself having used their products quite a bit the last few years, not bad, but not o.e!

 

thats by the by though, if you have an accurate indication of zero pressure it wont last very long.

 

when it was "rebuilt" was the crank ground and matched to new bearings, or checked with a mic and the bearing toleracnes checked with plastigauge for std size bearings?

 

Yes - Plastigauge was used, all matched etc...

[driversdomainuk 8]

I have this problem too! It's on my standard GTi, i've just got a normal 1.9 8v engine. Got the stupid guessometer gauge too. When i start the car from cold it's half way up the gauge and then when hot it's resting on the bottom line just by the warning light... I don't know whether it's good or bad.. Warning light has never come on mind, so who knows!

 

mine is not the original one - it is a mechanical one. I got it replaced as it was showing low oil pressure....sadly so does the new one!

[ALEX 98 1 Cars]

Replace the wires to it (not just the connectors) mine was doing the same for years.

[driversdomainuk 8]

Replace the wires to it (not just the connectors) mine was doing the same for years.

 

thanks - I am running a new mechanical gauge not an electrical one..

[Anthony 1,000]

Replace the wires to it (not just the connectors) mine was doing the same for years.

If it's a mechanical gauge, there are no wires - just an oil capilary from the engine through into the cabin and into the back of the guage.

[driversdomainuk 8]

is it wise, when the car is a zero psi that I try and keep it at say 2000rpm, which means the pressure is around 30psi..?

[Pugnut 9 1 Cars]

its wise not to run the engine until you have nailed the pressure problem. it might be a healthy engine now, but you'll soon destroy it.

 

you've verified that the pressure readings are correct, so its time to take evasive action.

[driversdomainuk 8]

its wise not to run the engine until you have nailed the pressure problem. it might be a healthy engine now, but you'll soon destroy it.

 

you've verified that the pressure readings are correct, so its time to take evasive action.

 

 

but I took evasive action and spend £1000 getting it rebuilt and still the same problem.....

 

I will run it, and if it blows up I will put her into the garage until I can sort another engine.....

[rescue dude 0]

When was it rebuilt?

[monkee87 2]

The stop light come's on when pressure is below 12 psi.

 

When was the oil last changed? What oil are you using?

 

It was changed about 1500 miles ago, and a 1000 miles before that. Oil is still a golden color basically. Using 10/40 mineral oil as it's what was used back in 91 when the car was new.

I know the warning light works as it comes on before i start the engine like normal. It basically drops to zero when it's at idle when hot and when it's revving it's on the first line, regardless of RPM.

Don't know why it does it, my previous GTi's never did..

[sideways danny 0]

The oil pump was from FAI - who are a top OE quality supplier...I know this as the UK Parts Alliance (who likes of Camberley Auto Factors are a member of) approved them as an OE supplier to all national accounts

 

LOLOLOLOL

 

engine machininst/reconditioner I use will no longer use ANYTHING FAI make, due to very regular failure of their parts, and their appalling warranty handling

[PaulJLLD 0]

LOLOLOLOL

 

engine machininst/reconditioner I use will no longer use ANYTHING FAI make, due to very regular failure of their parts, and their appalling warranty handling

 

Il second that!

 

Also Do you run a oil cooler? my road rally car oil light use to come on when idling at controls after a good reving fitted a nice 16 row oil cooler and never happen since.

Edited April 13, 2010 by PaulJLLD

[welshpug 1,621]

60 psi cold really isn't enough, either you have large tolerances or the oil pump isn't any good. (that's 4.1 bar)

 

A good engine should see 72.5 psi (5 bar) whether hot or cold at circa 4k rpm from memory, at idle it will be lower when warm, all my engines give pretty much full pressure at cold idle.

 

(or 87 psi/6 bar if it has the XU10 / "upgrade" spring)

[macaroni 17 1 Cars]

I have a very similar problem with my recently rebuilt mi16 engine.

 

It has new shells/mains and an xu10 oil pump, but still the gauge sits at the bottom once the engine is warm.

Would I be better off with a standard mi16 oil pump?

 

Can anyone tell me roughly what psi/bar the markings on the gauge refer to?