WR engine Ur quattro odd noise

Colin Aitchison · 05-06-23, 09:58 AM

Hi guys, I have an odd bearing whine noise, but I know it is not bearing, please read on, when the engine is hot this odd whining noise comes and go's, I can get the noise to vanish when I open the oil filler cap slightly, now as this engine is a vacuumed sealed engine anything you do to let normal air pressure into the crankcase will have an adverse affect on the air flow metering flap and close it a little, even taking the dipstick out will make the engine run poorly, so back to the noise, it is coming from the rear of the engine below the distributor area, fitted new seal to distributor, in my mind this is a vacuum sealing problem and could this be the rear oil crankshaft seal or the alloy housing seal to the block on the rear of the engine, I do not have any oil leaks at the rear of the engine, as you are aware the box has to come off to get to this seal and is a 2 day job, do you guys have any thoughts.
Thanks in advance.

urquattr085 · 05-06-23, 09:01 PM

Hi Colin

I've heard the rear crank seals can make a noise if leaking vacuum/pressure but I would have expected an associated leak.

Following with interest as I have something similar but mine seems to be from the top of the engine. I dk have an oil leak at the rear though

Isimmo · 05-06-23, 09:50 PM

For us, the only “odd” bearing noise we had in our WR was indeed a shagged bearing… At 140k miles and at circa 30-years. Fortunately we diagnosed it before we pushed bearing material scour through the engine, which mitigated a fair degree of the damage internally, but it was a full rebuild with 30throu rebore, new pistons, and all reciprocating consumables.

Honestly, if it’s an un-rebuilt original engine (and many are, amazing), I’d utterly preserve what you’ve got. Get it assessed properly, because you really don’t want a chewed up crank or block because that potentially buggers up matching numbers etc.

Colin Aitchison · 06-06-23, 08:52 AM

Thanks guys, looks like a gearbox removal to have a look.

urquattr085 · 06-06-23, 10:16 PM

Good luck with it Colin, I did my 80q clutch when I was much younger so I understand what lies ahead.

I ran mine out this evening for the hell of it.
My noise is road speed related & not engine speed related so it looks like I have a different issue, I sincerely hope it's not diff or gearbox.

Hanuman · 07-06-23, 10:40 AM

I had the high pitched, but fairly low volume screech, and it was the rear crank seal.
As the clutch was the original at the time, I managed to get a fixed price (audi dealership, Pete Chimes was instrumental in getting this) deal, doing the clutch, release bearing, rear crank seal, and the gearbox input seal all at the same time.

The leak can actually be quite benign initially, resulting in slight, nearly negligible tweaking of the mixture to compensate. Over time, people (self, for one) often don’t realise that the engine is running way off ideal, yet it can still meet the emissions at MOT with ease, until you eventually realise that there is something off.

But few people also go to the lengths of isolating the entire breather system in diagnosis, so living with it is often the way.

Colin Aitchison · 08-06-23, 05:37 PM

Thanks guys for all your help, will up date as things happen.

05-06-23, 09:01 PM	#2
urquattr085 Senior Member Classic Audi Club Member Join Date: May 2016 Location: Displaced Northerner in Essex Posts: 1,528	Hi Colin I've heard the rear crank seals can make a noise if leaking vacuum/pressure but I would have expected an associated leak. Following with interest as I have something similar but mine seems to be from the top of the engine. I dk have an oil leak at the rear though __________________ 1985 WR quattro 2010 A6 3.0Tdi Allroad 2010 A3 1.4 tfsi Sport - Sold but still in the family 1984 80 Quattro - Sold many moons ago 1981 Coupe GT - Sold to buy above

05-06-23, 09:50 PM	#3
Isimmo Super Moderator Classic Audi Club Member Join Date: Jul 2007 Location: Sissix-by-the-sea Posts: 15,218	For us, the only “odd” bearing noise we had in our WR was indeed a shagged bearing… At 140k miles and at circa 30-years. Fortunately we diagnosed it before we pushed bearing material scour through the engine, which mitigated a fair degree of the damage internally, but it was a full rebuild with 30throu rebore, new pistons, and all reciprocating consumables. Honestly, if it’s an un-rebuilt original engine (and many are, amazing), I’d utterly preserve what you’ve got. Get it assessed properly, because you really don’t want a chewed up crank or block because that potentially buggers up matching numbers etc. __________________ 1985 WR quattro, 1985 20vT RallyRep, 1993 MTM ABY S2 Avant. 2010 S3 Sportback.

06-06-23, 10:16 PM	#5
urquattr085 Senior Member Classic Audi Club Member Join Date: May 2016 Location: Displaced Northerner in Essex Posts: 1,528	Good luck with it Colin, I did my 80q clutch when I was much younger so I understand what lies ahead. I ran mine out this evening for the hell of it. My noise is road speed related & not engine speed related so it looks like I have a different issue, I sincerely hope it's not diff or gearbox. __________________ 1985 WR quattro 2010 A6 3.0Tdi Allroad 2010 A3 1.4 tfsi Sport - Sold but still in the family 1984 80 Quattro - Sold many moons ago 1981 Coupe GT - Sold to buy above

07-06-23, 10:40 AM	#6
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,010	I had the high pitched, but fairly low volume screech, and it was the rear crank seal. As the clutch was the original at the time, I managed to get a fixed price (audi dealership, Pete Chimes was instrumental in getting this) deal, doing the clutch, release bearing, rear crank seal, and the gearbox input seal all at the same time. The leak can actually be quite benign initially, resulting in slight, nearly negligible tweaking of the mixture to compensate. Over time, people (self, for one) often don’t realise that the engine is running way off ideal, yet it can still meet the emissions at MOT with ease, until you eventually realise that there is something off. But few people also go to the lengths of isolating the entire breather system in diagnosis, so living with it is often the way. __________________ I wish they would keep the damned Chinese away now that I can go home, so that I can enjoy Fish amok and a draught Angkor

06-06-23, 08:52 AM	#4
Colin Aitchison Senior Member Classic Audi Club Member Join Date: Dec 2013 Location: Back home in Tillicoultry Posts: 1,311	Thanks guys, looks like a gearbox removal to have a look.

08-06-23, 05:37 PM	#7
Colin Aitchison Senior Member Classic Audi Club Member Join Date: Dec 2013 Location: Back home in Tillicoultry Posts: 1,311	Thanks guys for all your help, will up date as things happen.