Fuses to check when the car won't start

Engine does not start, low compression, according to ADAC oil pump !?


when I wanted to start my darling today (A4 B5 Avant 1.8l, BJ. 1998) it started normally, then went out and didn't start again. The starter is still turning, the toothed belt is also ok and when the ADAC was there it removed the spark plugs, everything ok, but no compression on any cylinder (0.4 or 4 bar instead of 1.2 or 12, no longer knows exactly !?). No water or oil consumption that would be somehow suspicious. Then the ADAC man looked in the smart computer and then said it would be the oil pump or a switch on the pump that is hanging and therefore the oil pressure in the engine is too high as the switch on the oil pump no longer closes and therefore pumps oil unthrottled . But that wouldn't be low compression, would it !? I am now totally confused as a layman, do you have any other ideas or ideas? Unfortunately, the workshop I trust is about 60KM away, so too far to be towed and I would have to leave some money on Monday for a friendly and probably some money, so I wanted to collect a few ideas.

Thanks in advance for a few answers!



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15 answers

you mean 4 bar.

strange that it is on every cylinder. the fact that it has no compression definitely has nothing to do with the oil pump.

if it really doesn't have any compression on any of the cylinders from now on, it is only the timing belt that can actually be skipped. although that doesn't actually match the 4 bar.

strange damage picture!

Yes, the ADAC man measured every cylinder !? I also thought of the timing belt at first, but he looked at it and said it would be ok (whatever that means !?) So definitely not torn, but could he also have seen whether it was skipped?

hardly believe that the ADAC can see the tax times with the naked eye.

have you ever checked the voltage from the zr?

explain again exactly how it ended and how it sounds or what happens when you try to start it.

Voltage is ok according to ADAC. Well, got in, turned on, but went out again immediately after starting it, but without any jerks, clacking, noise, etc. Then I thought it just went out again and tried to start it again, then went up to the starter no longer, no move made to start again, no sound from the engine. When the ADAC was there and I restarted every time I measured the compression, I had the feeling that it wanted to, turned the starter well, but the engine did not start. Doesn't that sound strange now, just like when an engine doesn't start after a cold night !?

ok, let's ignore your "bad" compression values ​​...

what does the car do when you turn on the ignition?

do you hear how the gasoline pump works. that is a buzz from the area of ​​the right rear wheel, you may have to ask someone to turn on the ignition and you go to listen.

fuses times all checked.

just like I said your comp. values ​​are somehow not to be interpreted correctly for me.

maybe he also measured himself, judging by the statement about the oil pressure, he hasn't done his job long anyway.

First of all, thank you very much for your help! Yes, the ignition is on, everything is as usual, all the control lights go on, then go off again, the ventilation starts, everything is actually as usual. Tomorrow I'll be listening to the fuel pump and checking all the fuses again! I'll go again tomorrow! Have a nice evening!



Sooo, fuel pump "buzzes", fuses all ok, tried again to start, starter turns, only the engine just doesn't start. Well, tomorrow morning off to the friendly one, then we'll see!

Unscrew a candle and put it in the plug and hold it to the engine block (grab the rubber on the plug !!!) and ask someone to start it from the inside.

And now you either see a spark or not, if not something is defective in the ignition system ... distributor or whatever ...


Also looked at the immobilizer?

Maybe look for a closed exhaust ...

Does gasoline arrive at the front?

Edit: Fault memory, assumption: speed sensor, camshaft sensor, or krubel shaft sensor or similar Defect

Toothed belt jumped over, ignition misaligned and bang, the engine no longer starts, but still turns. If you let the starter turn, you will probably hear slight misfiring, but please listen carefully :), but it is better not to start the goat again. Off to the trailer and off to the ":)".

If so, then you are lucky. New toothed belt, new pulleys, set ignition, key in and "hum".

You can check the timing belt yourself. Take off the cover and put your hand in there when the engine is off, of course. You will feel whether the strap is too slack or not.

It's a good thing that happened to you at the start.


Kind regards.


N'Abend together :) So, the car was at Audi, the service man got in, tried 3 times to start and then the car started: rolleyes: Lt. Error memory, the temperature sensor was defective (only stored error), it probably reported too low a temperature, received too much petrol and then flooded. By the way, compression was flawless, so much for the ADAC specialist: mad: So the sensor has been changed, runs flawlessly again, BUT: The temperature is still not displayed correctly, so it moves at a maximum of 70 degrees. Is the thermostat defective? It's going to be a never-ending story


Originally written by buddhabauch

Yes, the ADAC man measured every cylinder !? I also thought of the timing belt at first, but he looked at it and said it would be ok (whatever that means !?) So definitely not torn, but could he also have seen whether it was skipped?

ha ok yes maybe at first glance, look at the underside of the belt to see if there are any teeth on it, recently had one in my hand, the teeth were missing on about 20cm ....!