Flashing Oil Light...............Part Two!

[illumin]

My oil light has decided to start flashing again today along with the car running a bit rougher than usual (not sure if the two things are connected).

For those that didn't read my last post about this, basically my oil light started flashing after an oil change - turned out that the car has been running for a long time with 3 litres of oil in it rather than 4. This was due to a previous owner not spending £1.68 at the dealership for a dipstick guide and instead using a bit of hosepipe........

Had a few days with no light, oil temp around the 96 degrees mark but car running gradually worse. Keeps trying to stall on the downrevs - oil light seems to coincide with that........

Is the engine just dying a slow death due to prolonged lack of oil and being thrashed about a bit?(Btw it now has the correct amount of oil in it!)

Could it be electrical? My dash clocks (Motometer) did go haywire for a while a couple of months ago, changing the earth straps seemed to sort out the problem, but can't help thinking they are still not right. The MFA mpg meter is also screwy at the moment - says I'm doing about 9mpg! Could the two things be connected?

Tbh, getting fed up with the car - it's one thing after another, thought VWs were supposed to reliable???

Any ideas gladly received.....................

[Mk2Kezza]

Had my vdub repaired this summer after a lengthy layoff and the MFA said she was doing 12 mpg? Didn't have a clue why, but she was running sh!te, stalling and sometimes smelt of petrol - This turned out the be the fuel presure regulator not working correctly and fuel was being dumped into the engine. When my mate dropped the oil it was thin as! Your's maybe a different problem but its worth investigating
I finally got one off a Mk3 golf as it has the same pressure rating - 3 p.s.i I think.

[rubjonny]

VWs are reliable, as long as they haven't had some complete muppet owner who would use a piece of hose as a dipstick guide tube, or in my case twist the starter motor live wires together & wrap bodge tape round it

You're going to have to start diagnosing the problem logically, it may just be a coincidence.  BTW, if the engine revs drop too low then the oil pump will also be spinning more slowly so I'd imagine you would loose oil pressure. First thing I'd do is check the 2 oil sensor boots for oil seepage, and the wiring for damage.

You also want replace all the vacuum tubing, not forgetting the one behind the throttle body which you can't get to without removing the inlet boot   For the price of it you might as well replace the lot to save messing about! Next check the blanking plugs on the brake servo pipe for damage, and the inlet boot for cracks, particularly in the folds.  Also replace the rubber bung that the black 'flying saucer' plugs into on top of the rocker cover, even if it 'looks' ok it may still have cracks around the lip on the base and give you a nice air leak.
Last of all make sure the oil filler cap is screwed on properly, sounds silly but its easy to do (whoopsy!  :embarassed:)

Oh and check your oil level again, you might have a leak!  I had a nice pinhole on the front of my sump which would only leak when the engine was up to temperature as the oil thinned down it could squeeze out the hole!

[illumin]

Thanks for the replies - it is unbelievable how some people bodge repairs, especially in this case - he must have been a right cheap git!

Been to a couple of garages this morning, still none the wiser as they came up with completely different theories from changing the oil pump to it being a dash problem. 

Will have a check around for air leaks at the weekend see what I can find......Btw someone mentioned previously that the vacuum pipe that goes into the back of the dash clocks can affect the MFA mpg reading (my car is actually doing about 34mpg rather than the 9 that the MFA says). Apparently it goes through the bulkhead into the throttle body, but haven't been able to find it. There are a couple of pipes at the back of the throttle body that have been blocked off, not sure what they are. Does anybody have a diagram/picture of which pipe I should be looking for?

[rubjonny]

Why yes:
http://www.clubgti.com/forum/forum_posts.asp?TID=94620

See the braided hose below the blue arrow?  Thats the one that goes off to the dash clocks.  If this is disconnected you'll get a nice vacuum leak

[SI_GTI]

iam havin exactly the same problem the horrible buzzin noise is gettin on
my nerves as well,i have changed the oil temp sensor,took the sump off and cleaned the strainer out and still no good.however my mfa is also giving funny readings out as well such as 99mpg!!
i think iam gunna try a diff set of clocks

[illumin]

My clocks have always been a bit dodgy, thought I had fixed them by changing the earthstraps before.........

The oil light hasn't been on again for a couple of days so fingers crossed that's the end of the matter. If it does come on again, I'm gonna try flushing it before changing the oil and filter again. A local "VW specialist"(there are loads of em here in Northampton!) suggested changing the oil pump as it's "only" about 100 quid, but not rushing into that just yet......

Getting a different problem sorted out today - outer CV joint, wish my car would stop falling to bits!!! 

[illumin]

Spoke too soon!!!!!!!!!!  Oil came on a couple times while out and about this morning bloody car!

Haven't checked for air leaks yet, but the oil light coming on seems to be definitely connected to the revs dropping too low. Basically, when depressing the clutch the revs drop right down, oil light flashes (although not every time), then the engine corrects itself and the revs come back up, oil light goes out............very strange 

[Judderi]

If you sort your idle problem out then you may not get the oil light problem anymore.

[illumin]

If you sort your idle problem out then you may not get the oil light problem anymore.

That's kinda what I have been thinking..........Would an air leak be the culprit, or specific parts like the ISV/temp sensor?