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Audi 90 quattro 20V Video Summary

4K views 9 replies 4 participants last post by  troysherk 
#1 ·
Hey guys, I made a video going over the details of my car and its problems. There are a few questions in there, and several things I could use advice on. Please take a look, it's only a few minutes long. Thank you!



Troy
 
#2 ·
Lol Those little exhaust pipes look soooo cute Troy...J/K. Umm ya it sounds like the hydraulic accumulator is on it's way out. But before you get into that...are you sure that when they replaced the high pressure hose that they got all the air out of the system?? That will cuz the pressure problem and flow problem thus...(NO ppower steering). The coolant leak....Hmmm I doubt it's a frost plug but these 20v engines do have a mind of their own. I'm suspecting a connection problem or even the overflow tank itself. 20 year old plastic has a tendency to crack over those 20 years from heating up and cooling down so try that first. Where is the coolant noticable on the ground?? front or back of the engine...right side/left side?? Let me know how you make out. Car looks beautiful bro. Oh and ya the exhaust leak is probably the connection from the header pipe to the main pipe. Just might need new hardware and tighten her up. Cheers!

Greg!
 
#3 ·
I sort of misspoke in the video. I said "had it replaced" when I was talking about the hose, but I really meant that I took it off, took it to a hose shop where they spliced it and replaced the bad section (leaving the original fittings), and then I reinstalled it. I did not fill the hose with Pentosin before attaching it, which might have been bad, but I did bleed the system afterward and make sure all the air was out. We were pretty thorough in that regard. Maybe the air in the hose pushed its way into the pump and broke a seal? Not sure if that sounds plausible. The steering had intermittent issues before, but now doesn't work at all.

As far as the coolant leak goes, I'm not sure. I haven't parked it on pavement in a while (it sits with two wheels on grass and two on the driveway usually), so if it is leaking, I'm not sure where. When we found a leak before, it appeared to be coming from the middle toward the back (so right around the back of the block) but this is sort of in the same area as the leaking hydraulic hose, so maybe it was Pentosin that we mistook for coolant. More investigating needed there. I'm just hoping it's not burning coolant.

Thanks for the compliments and advice, as usual!

Troy
 
#4 ·
Troy,

You asked for it. I would suggest copying this into a word document and printing it out as i'm braking this down in order of your questions... lol

As far as your brake light being on I would first pull out the center console and check the wiring and clean it up. After 20 years of coffee and beer being spilt it can look nasty down there. This could also be one of the reasons for the ABS light because the rear diff lock switch is there as well which can trigger the light. I would check that first because it's the easiest. If it stills stays on check your wheel speed sensors.

Did the ABS light come at the same time as you lost your power steering? If the answer is yes then your ABS issue should fix itself once you fix the P/S as the brake hydraulics are run off the power steering pump. That's the 3rd line coming off the pump.

Remove the Hydaulic fluid reservoir and hang it with a bungy cord so it's above the rest of the components with the lid off and start the quattro up. Go bank to bank with the steering wheel 10-15 times then let it idle with the wheels straight for a few minutes then continue to go bank to bank 3-4 times every 5 minutes for a half hour to an hour. If there's any air in the lines this will get rid of it.

Was the car running when you cracked the line? If yes and If you have a pressure gauge T it into the high pressure line start the car and it should read around 1500 PSI if the pump is functioning properly. If it doesn't replace the pump and do the above. If the issues are still there I would suggest buying the factory manual and a multimeter.

I was lucky. I got my 90 quattro 20V for $620 from the guy I work for and he had spent thousands on it until his wife said enough is enough. He had replaced the 20V engine with the 2.2L turbo MC engine out of an Audi 5000 along with several other upgrades and he had the factory manuals for both the 5000 quattro and the 80/90/coupe quattro's which came with the car as well.

Check out the link below and buy it!!! This is the best advice I can give you. Don't mess around with the Haynes or Chilton or aftermarket CD Roms. If you plan to keep your Audi this is as good as gold as absolutely everything is covered with pictures and step by step diagnostic procedures. For less then $200 you can buy almost all the diagnostic tools you need for this car. the book weighs 6.5 pounds and has close to 1900 pages.

It is currently unavailable through Amazon but do read the review at the bottom. I do not agree with him at all. The manual is written from an engineers perspective and has all the numbers and information needed to tear the quattro down to the last nut and bolt and put it back together and to perform any electrical tests needed. I've used several Chilton and Haynes manuals and they are great for brakes, suspension, powertrain swaps and basic electrical but that's about it.

Anyways, that's my opinion. Click the link below and read his and make your own decision. If you understand what you're reading how each system works then this is the book you want. I'll take a 1900 page manual with full photo breakdowns of components, parts list, test procedures and all the specs and electrical numbers over a 250 page manual with a handful of photos and tips on where to put the jack and how to get a rusty bolt off!!

Audi 80, 90, Coupe Quattro Official Factory Repair Manual: 1988-1992: Including 80 Quattro, 90 Quattro and 20-Valve Models: Amazon.ca: Audi of America: Books

As for your A/C check out "duracool.com". You can probably get this from Napa or any parts store. they make a 3 piece kit with adapters to "T" into the lines. One of the cans is a dye so you can see where it's leaking so I would start there.

As for the Quattro not starting there is a ryme and reason to it happening. I am 99% sure the cause is in the wiring on the driver's door. Over the years water has gotten in there and slowly corroded the wiring. The anti theft system is part of a circuit that includes the 4 way flashers, back up lights and the door locks. If you are able to solve the problem by locking and unlocking the driver's door then the issue is with the wiring from the door lock to the rest of the system. I am guessing the relay or a bad contact as it works after a few tries.

Anyways, Hope this helps..
 
#5 ·
First off, thank you very much for that detailed response! I'll do my best to respond to everything.

I haven't taken the center console apart yet, so I don't know if there's a bunch of crap down there, but I wouldn't be surprised. When I bought the car, the "ABS Off" light was on as soon as you started it. I took it to the Audi dealership and they replaced a fuse or relay and that shut it off... until you start it up and drive several hundred feet or up to around 20 mph usually.

The power steering issue is separate from the ABS issue as far as I can tell. I had a leak in the high pressure line, so I took it to a hose shop and had it fixed (as detailed above) and reinstalled it. After that, there was no power steering assist. Before I replaced the line, it was intermittent. Going around a corner, like say a left turn at a light, I would maybe have assist at the beginning, then lose it halfway through, and regain it at the end of the same turn. It was mostly random, but may have been related to braking or something.

When we cracked the line after installing the hose, the car was running and only a trickle came out. No spewing or anything. I'm pretty sure the pump needs replaced. Sounds to me like it was going out before and the air we left in that hose line when we reattached it finished it off.

Thanks for the insight on the electrical problem. In the video when I was outside the car and the lights were off, I probably could have gotten in it and started it, but I was messing with the door locks because sometimes it would be fine unlocked and then the lights would be on again as soon as you locked it. When I turn the ignition at the beginning of that segment and the lights come on, they soon turn off. As soon as they turned off, I would have probably been able to start the car. I just wanted it to turn the lights on by locking and unlocking so there was some video of what was going on. It didn't really cooperate. Haha

Also, thanks for the heads up on that manual. I have checked it out on Amazon a couple of times, but it's been out of stock each time. If I can find one, I'd like to buy it, but money is also somewhat tight (college student) and if I can fix my problem by looking at a Chilton manual for free, then I'd rather do that. When I can though, I'll get the bentley manual.

And yeah, it does sound like you lucked out on your Audi! You should put some pictures up. You can also register your Audi on this site: 1991 Audi 90 Quattro 20V at http://registry.audi20v.net (that's my Audi that it links you to). I'm not sure it does much, but it's nice to see other people's Audis.

Thanks for the reply again! Hope to see you on the forums in the future.
 
#6 ·
I know I lucked out. I'm just finishing doing a big tune up and some upgrades and putting it back together now. The head is currently at the machine shop getting tuned up along with the camshaft and my new turbo just arrived at the shop. Have you ever heard of "intended acceleration"? Google this site. The ECU in my 90 is from the 5000 and was sent to him in Washington and he re-programmed it like 10 years ago when my boss built this car. The front brakes are off a G60 and the tires are 205/45R16 Z with a 1 inch lowering kit.

Man I am not kidding when I say this Audi handles as good at 220KM/H as it does at 100KM/H. I live in Whistler and work in Pemberton so there are open mountain roads to rip around all around...
 
#8 ·
I could use some advice on the ABS issue on my car. I was thinking it was a bad brake accumulator, but after reading a little on 20v.org it seems like it might just be because my power steering pump isn't working (due to these two systems being tied into the same hydraulic system). The ABS issue has persisted for longer than the power steering has had no assist, but the steering had some assist issues even before that, so it could still apply.

Anyway, the "ABS Off" light on the dash comes on after driving like 100 feet. According to 20v.org, "If a sensor is bad, the light will stay off when the car is started, and then come on after driving the car from 10 feet to 2 miles. If the problem is elsewhere, it may turn the light on before moving the car." The Audi dealership told me the sensors were fine. The seller told me they needed cleaned. I'm not sure what's going on as my previous car didn't have ABS and I've never worked on the sensors for one with it.

I've heard there could also be an issue connected with the diff lock switch. Pressing the switch has never done anything (the ABS issue has also been there since I bought the car).

Basically, I don't want to waste time and money by installing things I don't need to (pump and brake accumulator are $350 each) but I want to fix the problems. If you can help but need more info, please don't hesitate to post back and I will reply promptly. A friend of mine offered to help me and has an awesome place to work on stuff, so I might take him up. I'd like to get this car roadworthy before summer ends!

As usual, thanks for all the help.

Troy
 
#9 ·
Troy, I would have ur power steering issues taken care of first then deal with the ABS. There r no other issues with ur brakes other then no ABS right? Once the power steering is working fine then I've eliminated that from possibly being related to the ABS issue. If ur brakes work fine and u r not losing any hydraulic fluid then I would assume he hydraulic system is fine and would then move onto testing the electrical side of the ABS system. After the PS is fixed inspect and clean the diff lock switch and inspect the ABS wires and connectors for corrosion, front and rear. If they all appear fine let me know and we'll go on from there.
 
#10 ·
Will do. The brakes seem to work fine other than the ABS. In the winter, the pedal would occasionally be stiff at first and then become soft again after a stop or two (it would kind of vibrate while doing so). This hasn't happened in a while, at least since the power steering quit working altogether.
 
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