advice needed re. failed oil pump!!!!

[Toby_Unna]

i need some help regarding what to do with my engine! as i'm obviously not as good at building cars as i thought i was

the car's been running a bit badly for a couple of days - surging and hesitating on a steady throttle and also with flat spots during full bore acceleration.

i assumed a fueling or electrical problem and was trying to diagnose it.

however the oil pressure lamp came on yesterday, which i took as a bad sign!

i've never had an oil pressure problem on a car before so i don't really know what to do now. when cranking with the cam cover and spark leads off there is no oil visible coming from the spray bar. and similarly no oil leaking out when cranking for a few seconds with the oil pressure switch removed (the light always went out immediately).

what i want to know is can i take these two pointers as a definate sign that the oil pump's dead?

and secondly is there any way to find out (without complete dissassembly) if or how badly the engine is damaged? my thinking is that the engine has been tightening for a fair few miles before the light came on, giving the poor running symptons, and therefore that's it's scrap.

however it still turns over easily by hand and still idles flat and sounds quiet, not tappety. which surprises me and makes me wonder if the oil light and pressure problem is a coincidence, in addition to an electrical glitch?? i didn't drive it once the light came on. surely if the pressure had got low enough to give running problems 2 days ago then the light should have come on earlier?

HEEEELLLLPPPPP!

[Borderbmw]

Not good,normally oil pressure lights only light at very low pressures,which by that time the damage has already been done,the only real way to tell without total stripdown is to change the oil pump,and oil etc and see what happens mate.

Hope you might be lucky

[glenn]

is there no way to connect a clock type oil pressure gauge, into where the oil switch goes? that way you would know exactly what the pressure was

[Toby_Unna]

i started it today with the pressure switch removed and no oil even leaks out of the hole when it's idling or reved gently.

fooked!

The only thing is, the oil light used to come on occasionally in my old m30 528i, when the oil was thin and hot and the car was idling low, and the handbook said this is normal operation.
so i need to find out whether it really has been running at very low pressure for 2 days and has screwed the engine, or whether the pump failed suddenly when the light came on and the running issues were a coincidence - meaning there's unlikely to be any damage.

i won't even bother putting a new pump on if i decide it's been running with minimal oil pressure for two days...

[Andy335Touring]

What a bugger mate !

Wonder if the oil pick up pipe has come lose or has got blocked ?

[Toby_Unna]

yeah you've got to wonder, i have the pump from the old m30 on the bench and it's pretty heavy duty stuff, don't really know how it could break unless the chain broke, and you'd think the cam chain would be under more stress, it's the same spec of chain.

only problem is it still idles fine and sounds quiet so i don't know whether to put a new pump on (Ԛ£50) or just drop a different lump in, there's plenty around...

[Andy335Touring]

only problem is it still idles fine and sounds quiet so i don't know whether to put a new pump on (Ԛ£50) or just drop a different lump in, there's plenty around...

Either way your looking at quite a big job but the pumps cheaper than a new lump !

[Toby_Unna]

that's the problem, it isn't.

so many people looking around to do 335 conversions, there's a fair demand for the later sump and pickup to put an m535i/635i lump in, they go for Ԛ£50 ish, which is Ԛ£50 off a new m30 if i scrap this one...

[johnl320]

bad news that Toby i have been watching your car progress over the last few months and can't believe how quickly its come on . Just my opinion but if it was mine i would change the pump and pray. i hope you get it sorted , good luck
john

[bullitt]

Drop the sump and check the big end journals & shells for any draw marks or heat discolouration caused by lack of oil & do a compression check.. If they are ok prime & change the pump!!

Good Luck!!!

[ian332isport]

It may also be worth draining the oil and see if there's any metal filings floating around in it.

Sorry to hear you are having problems though.

Cheers,

Ian.

[cabrio327i]

Hi Toby, I would check the oil pressure first before stripping the engine appart, try and get hold of a pressure gauge and pipe that will screw into where the sensor fits in the block, at least try another pressure sensor just to make sure the old one is not faulty if you still get no signs of oil pressure then you will have to delve deeper mate, cheers dave.

[cabrio327i]

Hi Toby, Forget what i said, did not read your write up properly, as you say you have allready checked spraybar etc, sorry dave.