Oil buzzer and low pressure! Help!

[christhemann]

Hi all,

Its just that way with cars, no sooner youhave one thing fixed something else breaks...And its bloody freezing outside!
(MK2 Scala 1.8 Carb, 95k miles).
Recently changed the rocker cover and gasket as I couldn't stop it leaking...

And now the oil buzzer and warning light came on today, it's never happened before!
-I followed the faq guide on here to test both oil sensors, they behave the way they are supposed to.
It looks like its the high pressure sensor triggers the buzzer and light, and low pressure one triggers just the warning light.
So from this I was getting the idea its too high pressure?
-I bought an oil pressure gauge from halfrauds today, and fitted that to the hole where the low pressure sensor goes.
It showed around 15-20 psi? at idle, but when revs are raised it went all the way up and up to around 80 - 100psi!
-I've seen people suggest on here the oil pump / pressure relief valve which I understand are combined together in the sump. Is it possible to replace just the one, if so wheres best to get one? How difficult is it to do this, bearing in mind I actually need to replace the sump anyways as its rusted?

Anything else worth trying? Appreciate any advice.

Cheers,
Chris

[ianaudia4]

I helped Tony (Mazallan) with his GTi before he sold it. We found that the cable was goosed that went to the sensor, replaced with new (soldered) and the problem went away!

[ghost123uk]

80 to 100 PSI is fine , in fact means you have a good motor :)
Mind you, was that with a hot motor or a cold one ?

The buzzer does not go off when the pressure is too high, only when it drops below 1.8 bar (whatever that is in psi !!)
If the pressure is too high the first sign you usually get is the oil filter explodes !! (or the seal pops).

btw, I take it you are using an OE or MANN brand filter ?

Your fault is most likely electrical in view of the oil pressure readings (breaths a sigh of relief).

Poss the high pressure one (or the other) misbehaving, or just a simple wiring "issue" (hopefully not in the binnacle to do with the delicate cellophane type printed circuit board - I hate getting all that apart !)

[christhemann]

Thanks for that. So the buzzer is definetly driven by the yellow wire sensor?
I actually replaced that one due to a leak about 6 months ago...

Pressure was on a coldish engine, I had let it stand for about an hour after a 15minute drive and then started again.
1.8 bar seems to be 26psi (I assume only at 2000rpms?).

I always use Mann filters, (as thats my surname, lol). But this time I got it serviced in March by the Phirm, not sure what filter they used!

[christhemann]

Have ordered 2 new pressure sensors from VW, so will try that next.

I've also got a spare set of clocks which I could canabalise to borrow the oil pressure sensor buzzer/circuit which I understand is the L shaped thing clipped inside the speedo gauge.

For now i'm gonna try and fit the Oil pressure gauge into the car (with creative duct tape bodging), and see what happens when the buzzer sounds!

[ghost123uk]

For now i'm gonna try and fit the Oil pressure gauge into the car (with creative duct tape bodging), and see what happens when the buzzer sounds!

That is a good idea, at least it will put your mind at rest re any more serious problems :)

Have ordered 2 new pressure sensors from VW, so will try that next.

Also a good plan :)

Take care when stripping binnacles as that flexible plastic circuit board is all too easily damaged ! = very annoying when it happens, ask me how I know

[christhemann]

Bit of an update...

Kind of confirmed my fears.
I fitted the pressure gauge properly, and drove the car till it heated up to temperature. Pressure was fine until this point, once it reached temperature the pressure dropped below around 15PSI at 2000rpm!
Apparently minimum is 2bar (29psi) at 2000rpm before the buzzer and light come on.

So there certainly seems to be a problem.
I've got a new oil filter, engine flush and oil to do an oil change in the hope that maybe theres some crap stuck somewhere?

Other than that, really hoping its not the bearings or something serious.
Any other ideas?

[ghost123uk]

Not looking too good there I am afraid Chris
The loss of pressure when hot is normally a sign of bearings and/or pump not right.
Try a new filter cetainly, but (and this is only my opinion, others may wish to chime in with a comment), flushing and new oil is not likely to fix it and may be just a waste of good new oil.

Have you had an experienced mechanic have a look, well more of a listen really, as worn bearings (rare on these engines by the way) can normally be heard, rumbling most of the time if mains, and a sharp knocking sound if big ends.

And I know what you mean re these things happening at the worst time, in this case the freezing weather
(I have just been under ours (sorned for a while) getting it ready for an MOT, then back on the road).

If the worst comes to the worst, at least there are plenty of good 1.8 carb engines around and it is only a weekends work to swap them over. There is a complete car with a (presumably) good engine on here for £100 Also they are common and cheap enough in the breakers. Ones out of Passats seem to go cheaper at the breakers :) Or you could use it as an opportunity to upgrade power for little money as the 2.0 ltr Skoda engines (from a breakers) fit in with little fuss. A mate of mine did this and when he told the insurance company, they put his insurance DOWN by £60

[christhemann]

Cheers, wow no not looking too good.

Has anybody replaced their big end bearings in situ, along with oil pump for this reason?
Would really appreciate a list of steps they took, parts needed etc...

Gtxtra mentioned he had his replaced this year without removing the crankshaft.
Would you need to measure them first with a plastigage thingy, and how would you know how much damage has been sustained?

Really not sure I can afford a garage at this point.

[ghost123uk]

Cheers, wow no not looking too good.

Has anybody replaced their big end bearings in situ, along with oil pump for this reason?
Would really appreciate a list of steps they took, parts needed etc...

Gtxtra mentioned he had his replaced this year without removing the crankshaft.
Would you need to measure them first with a plastigage thingy, and how would you know how much damage has been sustained?

I cannot recommend that course of action as the crank is very likely to be worn or damaged (if as we suspect the worse has happened) - You would need to measure the crank journals and if, after going to all that trouble you find they are not 100% you will need to do loads more work = money

Really not sure I can afford a garage at this point.

Garage

No way !!

A replacement motor fitted yourself is way cheaper and not hard to do.

Edit = P.S. - Does anyone on here think it might just be a weak oil pump ?

Edit 2 = Check out ebay item 270662453915 and check out where it is :D

[christhemann]

Thanks again for that and all the advice.
I actually have spoken to that guy before (the seller on ebay), so will bear him in mind.
Not sure what the difference between an EX engine and a GU is though.

If at all possible i'd prefer to keep my engine, but obviously got to look at the economics of it like you say.

The odd coincidence of this problem is it happened the next day after having fitted a new rocker cover + gasket...
Any link?
I'm wondering if the sealant I scraped off the old gasket might have ended up in the oil, although I tried to be careful.

[GTXTRA]

as per PM - hi chris - yep confirming that tim at the phirm replaced the oil pump on the 16v last spring and whilst the car was up on the ramp with the sump off he changed the big end bearing 'shells' - all very accessible at that point.

[MikeH]

You can replace big end shells, but it really depends on the state of the crank journals. If they're damaged it can wreck the new bearings, or cause them to catch and spin in the caps (bad news).

Before you consider that, I'd drop the sump off, check the gauze filter on the bottom of the pickup pipe (they can get blocked up). If that's clear, take the pump off and measure the clearance in it with feeler gauges (as per Haynes manual).

You may find it's something simple, before you start thinking about bearings, or new engines.

Is the buzzer still going off with the new sensors?

[christhemann]

Right an update finally!

Thanks ghost123uk for the suggestion of that engine. I actually contacted the seller who is someone I have spoken to before,a very local VW expert with a garage. (i'd highly recommend him).
He mentioned he had a lot of experience with blocked oil strainers on Sciroccos/MK1 Golfs, and was worth looking at that first.
I ordered a new oil pump (08448) and sump kit (02004) from Febi in advance.

So at the weekend, I took that car up there very carefully. About 10minutes down the road, oil pressure dropped to around 15psi and did not rise with the RPMS! Buzzer came on.
Got there and Chris (the mechanic) checked it over, we decided to get sump off.
-Drained oil,took off sump, and oil strainer was blocked with a gunge and film!
-Also he noted the oil was very thin, and seemed a poor quality (i'm suprised as the Phirm serviced it in March).
-Took oil pump off, and it was totally knackered. Barely would turn by hand.
Inside the oil pump was badly scored and a feeler gauge revealed gears were worn.
-Whilst sump was off, he checked crankshaft end float and inspected bearings. Said these were fine, and there was no "sludge" from bearing wear.
-Changed the oil pump after priming with oil, fitted new sump and gasket.
-Fitted a new oil filter and filled with oil, also checked my oil pressure gauge as the fitting was leaking.

-Started up, and immediately better pressure. When warmed to to temperature it reads about 15-20 at idle, and rises to about 40-45psi at 3000 rpm.
Sometimes it still seems to get close to the "limit" where the buzzer used to kick in at 26psi 2000rpm. I wonder though if the gauge is not accurate as the buzzer is no longer sounding and no oil light showing.
So even after a 30minute drive, no buzzer as yet.

Any idea if electrical Halfords "Autogauge" Oil pressure gauges read under what they are supposed to?
Seems funny that when I put on headlights or any electrical devices, the oil pressure gauge drops!
Not got a mechanical one to try.
Oh well, hopefully saved the engine for a bit longer.

Cheers,
Chris

[christhemann]

Just realised, I fitted the oil pressure sender to the head (with adapter to allow warning light sensor to be fitted also).
I read that people say it should be fitted to the oil filter housing, I imagine pressure would be a bit higher here?