Oil Light / Rev Counter Problem

[spike240]

Hi - first post on here, and yes it is help I am after.
I have owned my Audi 80 2.0 E for about 6 years.
It has just developed an intermittent fault which I will try to describe.
On two fairly long distance trips (400miles+) the oil light comes on (doesn't flicker) it comes on with authority and at the same time the rev couner needle goes to zero. The needle then may go to 3k revs and back to zero a couple of times, then the oil light goes out. This may be repeated a couple of times then it won't happen again on the same trip. Trouble is there is no pattern to this prob.
Last trip (520miles) the oil light came on 2 miles down the road, then never came on in the next 250 miles. It then came on twice on the way home.
Since this problem started I have changed the oil light switch and have recently changed the oil and filter. Incidentally the oil and filter are changed every 3 to 4K anyway.
If anyone can point me in the right direction I would really appreciate it.
It goes without saying that the oil level has been correct all along.
Thanks in advance for any replies.
Regards
Brian

[W.Murphy]

Possible cause for the oil light coming on could be the wire from the oil switch is touching the engine or body work. Which would cause the light to illuminate.

Hope this may help

[scotty33]

I have had a problem with an oil level alarm which was caused by a bad engine earth.

I also suggest you check out the ECU relay, I assume your car is 1992>? I know 2 people that had the revcounter issue but this was in 2.0 passats, they never got to the bottom of it, but the passat has the same relay as the Audi 2.0.
More info here, pasted from the ABK juddering thread:

Words courtesy of Steve in Da Bury

I think my car might be cured!! touch wood.

It's something so simple, it took about 30mins total to do.
I've only been for a fairly small run so far - tomorrow I'll be doing my commute so I'll know almost for sure then - will let you all know. (confidence grows with time, don't want to get too carried away yet)

Under the steering wheel is a facia panel which can be removed it's about 4 8mm bolts, (this facia covers the entire area under the steering wheel between the center console and the edge of the dash.)

Remove the fascia panel and there is an area in which relays may be present. (Relays are small usually black or grey cube shaped.)

On my audi 80 2.0E 93 ABK I could spot two relays, one really long one and a smaller squarer one tucked slightly higher up. I think the long one had a 3 digit number like 203 written on it and the smaller on has 30 written on it.

I removed both, I couldn't get the long one apart easily and didn't want to force anything, but the smaller one came apart fairly easy once removed from the car. Inside the relay casing there is a small pcb. (circuit board). On this board in the top corner I spotted a dry joint!!

I got out the soldering iron and resoldered the joint. the other joints looked ok so I pretty much left them as they were and clipped the case back onto the relay.

Having refitted the relays I've been for a test drive and I hope it's not placebo effect of my excitement of maybe curing the car after being frustrated with it for so long, but it 'seemed' to run much better than before and no hesitation/ juddering over the few miles I did.

I think anyone who has problems with their ABK audi should check this relay. It can easily be checked in about 15 minutes.

Before I did this I have spent money on 2 manuals, a diagnostic lead (which did not show any faults) distributor, fuel filter, ht leads, coil and coil pack!

I think the theory is that the dry joint causes a drop in voltage which causes problems with the computer (ECU) Interesting though my diagnostic lead showed no faults.

I found a site with some images of relays with dry joints. Should give you a clue as to what to look for.
http://www.marklamond.co.uk/tech-hon...main-relay.htm

this is the one you are looking for:




__________________
1998 Passat estate S tdi 90hp

1990 Audi coupe 20v

[spike240]

Thanks for replies everyone.
Scotty what was the position of the "bad earth" you spoke of?
A VW/Audi garage near me suggested a bad earth somewhere, but I don't know where to start looking. If it was the main earth surely the starter would be the first thing to fail?
Anymore input very welcome.

Thanks again

Regards

Brian

[scotty33]

My 20v has different injection and wiring but the earth wire was one of three that are crimped to 'eye' type connectors and mounted to a stud on the inlet manifold. The wire broke off at the crimp,

I post the relay info, these are known to suffer from bad soldering, I don't really know that this particular relay could be your problem, but as I said above, The passat has the exact same relay and I know of two of those that had similar issues.
It is not hard to remove the panel under the dash and pop the cover off relay 30 to check the soldering?

[spike240]

Thanks for the info Scotty. I'll have a look at both those things and let you know how I go on.

regards

[Chris J]

Spike,

Thank goodness I looked at the forum tonight.

I own a 1994 M reg Audi 80 Avant which I bought in July last year.

Ive had exactly the same problem on and off for the last 12 months (ie) the oil warning light comes on and the rev counter drops to nil: vice versa when the red oil warning light goes off, then the RPM counter starts functioning again!!

Just as with you there is no set pattern to when this happens; sometimes I may have been on a long trip and it has occurred after a couple of hundred miles , yet at other times its happened almost as soon as Ive set off and has kept on recurring.

Ive had a new relay 30 fitted last Saturday in an attempt to rectify another problem which Ive been suffering from ie intermittent engine judder which is the subject of a separate thread on the forum and Erinch et al suggested a new relay 30.

So far Ive had a new circuit board fitted behind the 2 main clocks on the dash board,new oil sensors, new oil filter ( to try and cure the oil warning light/ rev counter problem ) new fuel pump, new rotar arm , new coil ( to try and rectify the engine judder)[all before joining the forum] and recently the new relay 30 for the last few days.

Am waiting to see if the relay 30 does the trick .

Would appreciate it if you would let me know how you get on with the oil warning light/rev counter problem

Regards and thanks to everyone who has made suggestions so far

[spike240]

Hi Chris - thanks for posting. I have had a quick look for any dodgy looking earth connections but found nothing. Haven't checked the relays yet - just haven't had time.
One thing I would like to ask you though - have you had the oil pressure checked. I was going to fit a mechanical oil pressure gauge, to make sure the oil warning light is lying, but alas have not had the time. To my way of thinking if the oil pressure is good then the fault must be electrical, and rather than waste time and money trying to solve or find it- I can live with it. Bloody annoying though.
We only use the Audi occasionally so it's not at the top of my priorities.
Anyhow thanks again for getting in touch, and I would really appreciate any feedback or improvements you find, after having the relay replaced. You never know that might have just done the trick.

Regards

[Chris J]

Hi Spike,

Thanks for coming back to me so quickly.

I have the Avant SE model, and fortunately with it comes an oil temperature guage and an oil pressure guage.

My oil pressure has never been a problem which has been reassuring. On this basis therefore Ive now come to the same conclusion as you that it must be an electrical problem.

I will let you know if the relay 30 improves things. I find it irritating more than anything else to have this interaction between the red oil warning light and the RPM counter.

I dont want to tempt fate but Ive had no problem since the relay 30 was fitted last Saturday but this in itself is not conclusive, at least at this stage, that the problem is fixed because, like you, Ive found it to be an intermittent problem with no real pattern to when it is more or less likely to happen

Regards

Chris J

[milescook]

We have to make this a sticky at the top of the board! I've lost count how many times this topic has come up!

Admin?