My 1991 Audi 90 20v - Back on the Road!

[Obli]

Hi all,

I've been updating a thread at Classic Audi for the past 6 months. With the site being down and my excitement being uncontainable, I had to post!

I started work on my old 1991 Audi 90 20v 6 months ago.

The car was last on the road 10 years ago. I kept it at my old house and then at my parents house for 6 years - thank you Mum and Dad for putting up with it! While there, it wasn't moved for 6 years and stayed outside, eventually under a cover. It hadn't been started for a few years. When I was last using it, she was running rough, the ABS light was on constantly, it was losing coolant and the gauge was intermittent, losing a bit of oil and hydraulic fluid. Basically the issues got on top of me and the car was laid up. I got a newer Golf V5 cheap as a substitute. Nice car but it was never the same. I almost couldn't bring myself to look at the Audi for a few years. Guilt and fear, I suppose. The car was saved from being crushed by my Dad. I had to move the car for a house move. I called a local guy asking what he'd give me for it. £50.

"What will happen to the car?" (thinking it might get broken for spares)

"It would be crushed mate."

I felt sick at that thought, as did my Dad... So it ended up at my parents, sitting there a sorry state.

When we looked inside the car in February (2022), the doors were stuck, everything was mouldy and nothing much seemed to work. The car wouldn't start initially. I wondered if it was too far gone and beyond my capabilities.

On August 22nd 2022, after about 6 months of hard work a few days a week (and a bit of a learning curve!), she passed the MOT first time! I was speechless!! The car felt really good on it's drive over to the test, but I expected it to fail on sill corrosion plus a new hitlist of jobs.

I've had a great deal of (invaluable) help and advice from the lovely Classic Audi community. Without their input, I'd be nowhere with the car. Thanks Kit, Dave, John et al. and of course Haynes, Bentley, Autodoc, 7Zap etc.!

Special thanks go to Michael Dewar (Mikes2), who sadly passed away unexpectedly in May 2022. Mike loved his Audi 90s. Iirc, he had three, selling one recently. He was using his 90 20v as a daily runner and had clocked up about 360,000 miles on it. Mike was an incredible help to the community over the years, including on Audifans.net. He kindly offered his time, advice and spares! One of the last things he did was to send me a new headlight lens and reflector, immaculately packed. He never saw it fitted - but it's now proudly in use on the car.

So this one is for you, Mike ??


I recorded a rather sedate (boring?!) drive home earlier. Slow traffic... Will find better roads sometime and mount the camera better (it's picking up a lot of bumps, bashing the window and I stupidly had my window open for a while).

Still, the car is driving lovely and I'm loving being back on the road with it, in a world of oversized, vulgar 2 tonne generic SUVs I'm amazed by the refinement, smoothness and effortless pace the car makes, and the handling still feels quite good - supple but planted. I'm still going steady in it. New tyres, brakes... lots has changed, been disturbed, removed, cleaned etc. and I'm redeveloping my confidence with the car. Plus, the age of the cambelt is playing on my mind. Dave, I know this was a while ago but if the offer of cambelt assistance / advice is still there, I'd love to make that trip over to you sometime, if convenient. I've got all the cambelt bits! Thought it might be an idea to pick Kit up enroute (although this will be news to Kit...!). Just a thought

Here's the riveting video... https://youtu.be/u_9jeUVpU0g

[Tractor Dave]

Well done. The engine sounds very smooth.
I'm happy to assist you but I have a project on the ramp at the moment. It might be a while as it needs lots of work.

[John.]

Good for you !!

It's a great feeling getting a new MOT the year after you got the last one........ you must be ecstatic ?!

[K Simmonds]

Dave does indeed have his hands full at the moment, I would offer to do the belt for you however my elbow would be an issue when it comes to the bottom pulley and even dealing with simple little fixings can catch it out, though it is getting better slowly. I'm not doing any mechanical work currently which is most frustrating given how many project's I've got and my fantastic workshop which is now not far off sorted apart from the attic. Though it does currently have two immobile car's in it both of which require work that's very heavy.

Have you got a new toothed bottom pulley? I always like to at least have one on hand having dealt with a couple of cars with sheared off keyways, really you want one of Chefs billet versions if you planning on keeping the car long term as they're bomb proof and unlike the originals will last forever and countless belt changes.

I'm sure you've told me but how old is the current cambelt and what sort of mileage has it covered?

It's really not a difficult job at all once the front ends off as the access is great, you just need a locking tool and a 3/4 drive breaker bar.

Again, congratulations on getting the MOT pass!

[Obli]

Thanks gents.

Yes John, ecstatic to be driving the car again. The engine feels very smooth and is breathing well I'm enjoying simply driving again

No worries Dave, thank you. I see you've got your hands full with classic Audi goodness.

I'm tempted to take the job on myself. Would be a good thing to learn and equip myself to do. It won't be the last cambelt (unless I catastrophically balls it up!).

The current belt has only done 20 - 30,000 miles, but is 12 years old!

I have the belt, idler pulley, water pump and a crank pulley bolt. I don't have the pulley, locking tool or 3/4 inch drive breaker bar. I'll check out the Chef jobber. Where can I find him?

Kit, I hope your bits are feeling better soon. I can understand your frustration but look after yourself - you'll be back amongst the action soon

All the best,

James

[K Simmonds]

Thanks for the good wishes, I feel okay generally, it's just my left arm that's problematic, got to give it more time.

Chef is Terry Bullwon on here, he's about most days and has pulleys in stock.

[Obli]

Good evening all,

I'm rather taken with driving the old girl at the moment. Got a video of a morning drive to share. Will upload more. Not sure if people enjoy watching these but there's a shortage of them on YouTube, which I hope to correct!

https://youtu.be/TIbKRV6HWu8

I've got a couple of hydraulic hose leaks to address. I get a hydraulic pressure autocheck warning temporarily if the brake pedal is pressed hard or when pumped a couple of times at idle. Probably need a new bomb too!

I'm hoping to source a return hose (from steering rack to reservoir). This one is 7A and RHD (90 20v or Coupe 20v) specific. Part no 894 422 891 H. Does anyone have one for sale, pretty please?

The other hose that is weeping is the 'pigs tail' hose (from cooler/reservoir to pump) - should have a second hand hose sorted out. I think ultimately I will try to get new ones made up as I intend to keep the car for life

Reservoir level is still good, close to max so I'm not losing a lot of fluid atm. Hopefully fixing the weeping hoses will help alleviate the warnings too. It unsettles passengers more than it does me

My brake pedal feel is not sharp, though. I've fitted my refurbed calipers (Big Red), new Bosch pads and discs and renewed/bled brake fluid with ATE SL dot 4. Pedal seems to have too much of a dead zone / a fair bit of travel, but when the pedal is pressed firmly the brakes work well. I'm wondering whether I bled them properly... I did master cylinder, back right, back left, front left and front right in that order. I didn't do the clutch. It doesn't feel like air in the system. Pedal isn't spongy. I used the Sealey pressurised brake bleeder kit and put through nearly 5L of new ATE fluid - ridiculous, I know, but there always seemed to be more air bubbles, despite them reducing in count. I do recall having to nip up one of the bleed nipples on the master cylinder after as I noticed a bead or two of fluid after using the brakes. It was tight but perhaps not enough. Part of me doubts whether I correctly held open the brake compensator lever correctly during rear caliper bleeding. Manuals I read say hold compensator arm back (towards rear axle?). However, with the rear of the car up on axle stands, the compensator lever was already fully 'back' so holding / wedging it seemed pointless.

I've not bled brakes before so there's every chance I've made a silly mistake. Any advice would be greatly appreciated.

[Tractor Dave]

Older standard Audi brakes are just like that. I can't believe there would be any air bubbles left after passing 5 litres through the lines . I normally get it done with just over a ltr. Do get your leaks fixed mind. The pas pump powers the brake booster (via the bomb) and any loss of pressure will effect performance. The bomb just stores pressure for when the engine isn't running and shouldn't effect on the go performance. If you get new pas lines made up, make sure you include the little reducer in the pressure pipe or they will vibrate.

[Tractor Dave]

Forgot to mention that new discs and pads need to be run in. Gentle braking only for first 100 miles otherwise pads can get glazed. And you did clean the new discs well with brake cleaner to get the protective oil off?

[steve briance]

Have a look in the facebook s2 forum for a thread by me regarding brake bleeding... Mine were so bad i struggled to activate ABS in the wet and no chance on a dry road.

The issue was identified to be bubbles stuck in the ABS pump.

Running the pump and activating the solenoids moved the bubbles on through the pump and out at the wheel eventually. I was surprised there were any in there as had also run many litres through and taken it to a garage for them to try.

Pedal now has more feel and immediate bite and with no other parts changed at the time, this can only be due to the bleeding.

For info - later s2 cars have a feature in vagcom to run exactly the same abs pump/solenoid activation as part of brake bleeding so, for me that suggests it was a known issue if a fix was devised.

[steve briance]

Here you go.

https://m.facebook.com/groups/AudiS2...8400738742039/

[Obli]

Thank you gents.

I followed a general brake bedding procedure (gentle 35-5mph braking, allowing cooling between slowdowns) and didn't use the brakes firmly for 300 miles. Up to then I was braking lightly, moderately if required. Also used brake cleaner liberally after fitting new brakes, just before the first run out.

Cheers Steve. Interesting to hear about your experience with the ABS unit. I'll have a look for your thread on here. Thanks for the Facebook link but sadly it's broken (content not found?).

I happened to check my ABS yesterday for the first time since the car's been recommissioned. Originally, the car's ABS light wasn't going out after engine started. I replaced the ABS controller and that resolved the issue. Yesterday, I did a couple of firm stops on a gravel lane from 10mph. ABS is making the usual groaning noise with the brake pedal pulsing. All seems good. Tried it with ABS disengaged via the kill switch and the wheels locked up as expected. Don't think my 1990 manufactured car will have the ABS purge function so perhaps I need to revisit that gravel lane...

As Dave suggested, the first thing for me to do is fix the leaks and re-establish correct operating pressure. I'll do that

As a side note, does your 7A engine radiate a lot of heat? When I open the bonnet there's quite a bit of heat. After a steady 20 minute drive today at a constant 40-60mph (21°C outside), the inlet manifold is too hot to touch for more than half a second! Engine seems to take ages to cool down. Everything very hot. Coolant temp seems ok (90 - 100, maybe 103 in traffic, when the gauge works!) and after-run fan coming on after engine off for a minute or two. Coolant is new G11. Expansion tank cap hisses when released so is holding some pressure although the coolant level has dropped a little in the first 300 miles of use. I'm seeing a small wet patch under the car after use so will stick a dish down to collect and identify the fluid. Methinks I have a coolant leak too!

Poor old girl. Had quite the wake-up call recently!

[steve briance]

My cq20v is a 1990 model and definitely doesn't have the ABS purge feature! The thread in the s2 facebook forum is how to do it by using wires and certain earthing cables in the abs controller. It isnt on this forum but on the facebook forum as i find it easier to upload photos.

One thing i noticed with my pedal which got me thinking was that press it once and there was a lot of travel, press it second time straight away and it improved. I suspect this was the bubbles being compressed and staying compressed until you came off the brake again. Only a guess of course but as it only costs a bit more time and brake fluid, its got to be worth a go.

As for underbonnet heat - yep. All engines get hot - it is bound to when its got oil and water in it thats 90-100deg c.

Gauges reading good, fan operating properly and enough coolant in the tank - doesn't sound like a problem to me.

[John.]

I'm thinking driving the car on loose ground and working the brakes so the ABS operates would be the same as doing the "electrical purge"?
After doing the above, blead the brakes.

[steve briance]

I'm thinking driving the car on loose ground and working the brakes so the ABS operates would be the same as doing the "electrical purge"?
After doing the above, blead the brakes.

To a point but, as there isnt any real flow of fluid through the ABS solenoids there isnt much chance of any bubbles passing through and being free to leave when you get home and hook up the bleeding kit.

The benefit of doing an DIY abs purge is that you can actually have your choice of bleeding kit hooked up while the motor and solenoids are operating. Flow = bubbles move.