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Discussion Starter #1
Yet again my oil pressure wanring is coming on intermitently.

It comes on for a split second and goes away.

This has been going on for around 2 months now and I just decided what the hell - if the engine is damaged IM going to have to rebuild it anyway so lets see what happens.

No odd noises, I rev the car under full load all the way to the limiter and nothing goes wrong.

Ive removed the oil filler cap to see if any oil is reacihng the top and there is loads, I rev it and oil flies out.

Surely after 2 months of hard driving if the engine oil pressure was too low alot of damage should have occured and it wouldnt perform.

I raced a TVR 4.2 Cerbera this morning from 50mph onwards and there was nothing in it. The engine feels more powerful after the 305 bhp dyno I had done a while back (it does have a chip now).

Could it be the oil pressure sensor thats faulty?

If I Do get engine failure then Im going to look at a stroker rebuild. A freind of mine has just rebuilt an S14 engine and says its not as hard as everyone makes it out to be. but it is time consuming....so what.
 

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Discussion Starter #2
Just spoke to Bexleys and they say to change the oil pressure switch as this is most likely to be faulty.

If then it still shows oil pressure to be low then there is a problem.

My sump gasket is leaking quite badly.....could this be enough to reduce oil pressure to a level which the swtich would pick up?
 

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Cyrus said:
My sump gasket is leaking quite badly.....could this be enough to reduce oil pressure to a level which the swtich would pick up?
Pressure, no, it would have to be like a firehose to do that!


I agree you probably just have a failing sensor/switch.




My gasket leaks too, maybe 5 to 30 drops overnight depending on temp and weather.

I keep a twice-weekly eye on the oil level, just in case it starts to fail rapidly!


Since I keep an eye on it, it's not an issue. Remember engine needs lifting to redo it, so it's not really a home fix. Someone knowledgeable also pointed out that the gasket crumbles rather than stretches, so tightening the sump will not really cure it and could do worse.

Best bet would be to save some pennies then get the gasket done at the same time as replacing the engine mounts, as the engine has to lift to clear the sump pan from the front steering mechanism. You might as well get the garage to do the gearbox mounts too; in for a penny, in for a pound! Not a killer bill though.


Many have also had the timing chain tensioner replaced at the same time and I think there's a gasket or "thingy" (technical term) there that can leak too.


When the sump is off for the gasket, you should be able to see the oil pump IIRC. Depending on your cars vintage and your wallets shock absorbing capability, you might want to have this replaced if it's looking tired. How long are you planning on keeping the car?


Clean the sumps contents out, checking for nasties or metal debris that may be symptomatic of other problems. Unlike the poor 540i and other V8 owners, you shouldn't find any bolts floating about!! ouich

Above all, don't panic!

Ivan.
 

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Cyrus said:
Yet again my oil pressure wanring is coming on intermitently.

I rev the car under full load all the way to the limiter and nothing goes wrong.
Presumably you were hoping for an enormous *bang* followed by a short trip in an ambulance and a nice surgeon removing all the shrapnel from your body, in order to prove you really did have low oil pressure and not a faulty sensor switch after all?


Remind me never to let you use this method of problem diagnosis on my car!! LOL hmmm


Ivan.
 

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Cyrus said:
Just spoke to Bexleys and they say to change the oil pressure switch as this is most likely to be faulty.

If then it still shows oil pressure to be low then there is a problem.

My sump gasket is leaking quite badly.....could this be enough to reduce oil pressure to a level which the swtich would pick up?

I would go along with Ivan here.
The chain tensioner as std is a Hydraulic oil presurrised unit. Dump it for the E36 mechanically tensioned unit & change The O ring seals etc.

The oil pumps themselves are reliable. How they are retained is not however.
The fasteners have a nasty habit of backing themselves out & can then be dropped into the oil pick up area of the sunp from the movement of the pump whilst under load.
From memory, I think that 3 bolts hold the pump in position.
It takes a many yrs for them to work loose & not all do it.
But it is a potential failure mode & IF all the bolts let go, then you really are in trouble.

If the sump gasket is leaking, its a good indicator that its time to bite the bullet & inspect / change some bottom end parts & look at the chains & sprockets whislt you are at it.

Cheers
Farrell
 

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Have you washed down your engine bay since you got your car? I ask as this is when I managed to mess up my oil pressure switch. A little too much water got on it and messed it up so that it would illuminate from time to time.
 

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Discussion Starter #7
Got under the car and the sump leak isnt as bad as Bexleys made it out to be.

Its very minor.

The oil pressure warning has totally gone asway and performance is as normal.

I have bought a new oil filter and pressure switch from BMW so will be fitting that tonight.

Never washed my engine bay, I just hand clean it.
 
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