Hey Guys,
I have a 1998 Audi A6 quattro 2.8L I have kept up on my basic miantenace knowing that things can go bad and add up in cost. I got up saturday and went to go to work and when i tried to fire up my car i got crank and no fire. my roommate who is a Subaru mechanic head it and came outside to check it out. we first thought low/dead battery so we tried jumping the car and nothing. we know assume its not the starter since its cranking. he took me to work I got home and we went on the hunt for the problem. we tried the spark plugs and got arch from them and the fuel regulator and line both had fuel so we thought not enough pressure. Today my roomate brought home his his volt meeter and fuel pressure guage. the battery is good and the fuel guage says there is pressure. So here we are with no more ideas and no running car. this is where I need some outside the box audi ideas. hope someone has a suggestion.

Overview:

1) Cranking no fire, not starter.
2) Volt meeter shows good battery.
3) Fuel pressure guage shows good pressure and visual shows fuel where it needs to be.
4) Sparks shows good spark plugs.
5) checked teh fuses in the fuse box.

side note i have a ECu light for secondary air injection?

Thanks guys,
Dennis E.

 

If you have spark and fuel is present, then the only thing you are missing for combustion is AIR. These old 2.8L motors get a serious case of carbon build up on the intake valves (have no idea why) but you need to clean it out. The "old school" fix is:
Take off the main intake hose, after the MAF sensor.
Then have someone crank the motor while you spray some chemtool carb cleaner down the intake until it fires up. This may take a long damn time and it will probably back fire on you once or twice, but it sure beats taking it apart. Once it starts, keep spraying pluses of the carb cleaner in there (motor will bog down) until the can is empty. One can might not be enough. Let it idle for a while and let it burn off all the crap, stay away from the exhaust fumes while doing this too, it could really mess you up.

 

If you find it, let me know. My Intrepid (193000 miles) just did this, only it was running then died. Absolutely no codes. Good spark, good fuel. I towed it home and so far have replaced the crank, cam, and MAP (not MAF) sensors to no effect.

If I figure it out first, I'll let you know.

 

Since you said that your Audi is dead in the water I must inform you that boats and ducks belong in the water not Audi's!!

The air - gas and spark all have to get there at the correct time. Look for crank sensor problem or timing problem...

Since your getting no-fire at all, I'd try a little spray starting fluid to see if it burps a bit. If it does you can look toward a fuel problem -- if no burp it is probably electrical or mechanical --- like a Timing belt UGH

 

If it had a bad crank sensor it wouldn't have spark. This motor would have to be off timing 15+ degrees for it not to start. Although i would hope a subaru mechanic could tell what an engine sounds like with a snapped timing belt. Could happen though. I just realized that you didn't provide us the fault codes, so that should be done before doing anything else. If no codes pop up, do the procedure i told you about.

 

Thank the lord!! So a little update! Auditech79 thank you very much! my roommate brought home two cans of chemtool we got all set up he started spraying and I started cranking, one can down nothing we started the second can and I would say about half way into it (about of hour of time) we gave up and came to the conclusion that even though the battery had the volts it wasnt charged enough to crank the motor fast enough. So yesterday I got up and went to my girlfriends dads house and her dad was convinced from the beginning that it was the battery so he lent me his battery charger I hooked that up let it charge for about an hour. I started praying and kicked the tire for good luck, I cranked it and NOTHING!! I was pissed. So we were sitting outside and I was like forget it, Auditech said to keep cranking and since the car wasnt running I had nothing to lose. So I started cranking over and over about 10-15second each time. while cranking one time I stepped on the gas and the engine reacted, So after that i started cranking and giving it gas it was trying to go but didnt seem to get there and one time I thought it fired let go and it died so i was like crap. One last time I cranked gave it gas and it turned over but was running sluggish gave it a few revs and let it run for a little and clean itself out, shut it down and came back a few minutes later turned it over and fired up this time on its own without the charger. so long story short thanks for the old school tip Auditech79!!! now the hope is that she stays running for a little bit.
Dennis E.

 

Now that you know what the issue was, maybe add some SeaFoam to the gas or suck it up through a vacuum line. I've done both before, but let me tell you, if you do the vacuum line (about 1/3-1/2 can) and shut if off, let it sit for 15 minutes and then go back and restart - holy cow will it smoke!! It's best to do this at night and away from people - during the day someone is likely to call the fire department.

 

Definately seafoam the intake now, seafoam is much stronger (100% petroleum) and it will break almost all the carbon off the intake valves and intake runners. THIS will smoke like a bastard out the exhaust so do this in a well ventilated area. I would also highly recommend pouring a half can of seafoam in the oil and driving it for 50 miles, then change the oil and filter. This should clean the motor out completely.

 

Auditech would you do both the oil and gas or just the oil? would you also say suck it into the vaccum line or just pour it into the tank? thanks guys!
Dennis

 

Sucking it into the vacuum line will clear the intake which is whats needed most. The oil will help free lifters, and clean oil passages etc. Pouring it in the gas really won't help you out much, neither do those stupid injector cleaners in a can.