B2 Coupe GT Front Exhaust Pipe

IronJaw · 14-06-23, 05:34 AM

Hi Everyone,
I’m just wondering if anyone might be able to help shed some light on how the front section of exhaust comes off the car between the manifold and the front silencer.

Basically the front pipe has rusted through and snapped in two. I’ve bought a replacement one ready to fit, but a quick look underneath and it looks a bit hectic to get the front pipe off. From a glance it looks like the driveshaft has to come out to facilitate the removal of the pipe, but I’m not sure because I was on the floor with a Jack. The useless Haynes manual doesn’t tell me any useful information about it either.

Has anyone had experience with is on the B2 and if so I’d appreciate any help or advice.

Thanks

Colin Aitchison · 14-06-23, 07:58 AM

My B2 coupe Gt had a 2.2 KV engine, you can remove the front downpipe without removing the front drive shaft, my down pipe was a 2 into one style pipe, the 4 M10 nut you have to remove to remove the downpipe from the manifold are normally a lot of fun.

84CoupeGT · 14-06-23, 10:37 AM

I've just done this on mine (2.2, 5 cylinder), see latest post on my restoration thread. You don't need to remove anything to take the downpipe off (other than detach the rest of the exhaust from the downpipe). Obviously you need the front of the car raised up on stands or ramps. The 4 nuts which hold the downpipe to the manifold will likely be very rusty so spraying penetrating fluid on them for a few days before you tackle the job will likely help. The nuts are tricky to get to, I used a slim, long extension bar and needed a U-joint attachment at the far end for some of the nuts. When the nuts are off, you can withdraw the pipe but it does need to be "jiggled" in various directions on its way out. On mine, one of the studs broke off with the nut still rusted in position, so I had to buy a stud extractor socket to grip onto the stud and get it out. You can buy the studs new on eBay.

When reassembling, make sure you're not trying to get the downpipe back in the wrong route! I did this the first time (I was going up more vertically) - after a few minutes struggling I realised and felt very silly! Don't forget the washers and a new gasket. I used a silicone high temp sealant as well because the surfaces of the manifold and downpipe flanges were far from perfect even after lots of scraping/chiselling off the old gasket. I used traditional exhaust paste the first time which didn't work well and started blowing after a few months. I've not been able to start it since the latest installation but the silicon went on nicely and squeezed out a little around the joint (don't use too much though!), which has given me some confidence that the seal will be better this time.

Good luck, let us know how you get on!

IronJaw · 17-06-23, 05:53 AM

Thanks for the replies, it is appreciated. I’m glad the driveshaft doesn’t have to come out, I had visions of all sorts of associated components being disturbed and breaking.

I’m not tackling this job myself, unfortunately my back issues mean I’m limited at how much under car stuff I can do. If I had a full size ramp I’d be laughing but I can’t roll round on the floor anymore.

The NOS front pipe landed here yesterday so we’ll get that fitted by our tamed mechanic.

84CoupeGT · 17-06-23, 09:18 AM

Hope the work goes well. I know what you mean about the back, I've got to be more careful these days, can really feel it in my lower back for a week or two after crawling around under the car or leaning over the bonnet

IronJaw · 19-08-23, 05:50 PM

Thought I’d do a follow up on this, it’s been a while. Basically we’re no further on

The NOS (QH) front exhaust pipe I’d got allegedly didn’t fit the car and was a totally different shape to the one fitted, which annoyed me because according to the labels on the pipe it’s supposed to fit.

The garage tried to patch it up for us but it hasn’t taken and the car sounds like a tractor when you’re driving around. Unfortunately the pipe is mainly made of rust so there’s nothing to weld to either.

I can’t believe how difficult it is to get hold of parts for this car considering I can get any part for my Triumph or Trabant within 24-72hrs. The search continues for the correct part.

I’m thinking we’ll just have to get something fabricated using what’s left of the old one as a pattern.

84CoupeGT · 19-08-23, 10:26 PM

Quote:

Originally Posted by IronJaw

Thought I’d do a follow up on this, it’s been a while. Basically we’re no further on

The NOS (QH) front exhaust pipe I’d got allegedly didn’t fit the car and was a totally different shape to the one fitted, which annoyed me because according to the labels on the pipe it’s supposed to fit.

The garage tried to patch it up for us but it hasn’t taken and the car sounds like a tractor when you’re driving around. Unfortunately the pipe is mainly made of rust so there’s nothing to weld to either.

I can’t believe how difficult it is to get hold of parts for this car considering I can get any part for my Triumph or Trabant within 24-72hrs. The search continues for the correct part.

I’m thinking we’ll just have to get something fabricated using what’s left of the old one as a pattern.

What year and engine is your car?

IronJaw · 23-08-23, 06:19 AM

It’s a 1985 manual with a 2.0 5 cylinder engine. I’ve since sourced the correct pipe in two places, one being Audi Tradition and the other being Poland. I’m going to try the Polish one first as it comes with a fitting kit and it’s only £46.

The Audi one is £101 and that doesn’t include shipping and all that jazz.

The OEM part number is 855 253 101B should anyone need it for future reference.

84CoupeGT · 24-08-23, 10:39 AM

If the Polish one is Polmo (logo is a 'P' circled), that's the make of exhaust I got for my Coupe and it fits well, although my downpipe was ok, it's just the rest of the exhaust I bought. It's been on the car almost 3 years now and hasn't gone rusty at all, although has only done about 700 miles! I sprayed some high temp silver paint over the welded joints in the hope that may help preserve it.

One tip from my experience, when I first installed it I used exhaust paste which cracked and resulted in a blow. When I took off and refurbed the downpipe as well, I used RTV very high temp copper silicon, which was much easier to use and has sealed up the system perfectly - I've realised now the paste didn't properly seal even from the start, so definitely recommend using the silicon.

IronJaw · 28-08-23, 08:21 AM

I’ll have a look when it arrives, hopefully it won’t be too long coming here otherwise we’ll miss the MOT date. No way will it pass with the exhaust the way it is.

One other exhaust thing is like to change at some point is the back box, specifically the way the exhaust tip is. It really irritates me the way the hole in the bumper is for a dual tip but the coupe has this crap single pipe with an almost afterthought bend in it, which stops you from fitting any kind of exhaust trim to try and improve the look.

We’ll get there hopefully

14-06-23, 10:37 AM	#3
84CoupeGT Grown up member Join Date: Nov 2020 Posts: 309	I've just done this on mine (2.2, 5 cylinder), see latest post on my restoration thread. You don't need to remove anything to take the downpipe off (other than detach the rest of the exhaust from the downpipe). Obviously you need the front of the car raised up on stands or ramps. The 4 nuts which hold the downpipe to the manifold will likely be very rusty so spraying penetrating fluid on them for a few days before you tackle the job will likely help. The nuts are tricky to get to, I used a slim, long extension bar and needed a U-joint attachment at the far end for some of the nuts. When the nuts are off, you can withdraw the pipe but it does need to be "jiggled" in various directions on its way out. On mine, one of the studs broke off with the nut still rusted in position, so I had to buy a stud extractor socket to grip onto the stud and get it out. You can buy the studs new on eBay. When reassembling, make sure you're not trying to get the downpipe back in the wrong route! I did this the first time (I was going up more vertically) - after a few minutes struggling I realised and felt very silly! Don't forget the washers and a new gasket. I used a silicone high temp sealant as well because the surfaces of the manifold and downpipe flanges were far from perfect even after lots of scraping/chiselling off the old gasket. I used traditional exhaust paste the first time which didn't work well and started blowing after a few months. I've not been able to start it since the latest installation but the silicon went on nicely and squeezed out a little around the joint (don't use too much though!), which has given me some confidence that the seal will be better this time. Good luck, let us know how you get on! Last edited by 84CoupeGT; 14-06-23 at 10:43 AM.

14-06-23, 07:58 AM	#2
Colin Aitchison Senior Member Classic Audi Club Member Join Date: Dec 2013 Location: Back home in Tillicoultry Posts: 1,311	My B2 coupe Gt had a 2.2 KV engine, you can remove the front downpipe without removing the front drive shaft, my down pipe was a 2 into one style pipe, the 4 M10 nut you have to remove to remove the downpipe from the manifold are normally a lot of fun.

17-06-23, 05:53 AM	#4
IronJaw Grown up member Join Date: Nov 2016 Location: West Lancashire Posts: 157	Thanks for the replies, it is appreciated. I’m glad the driveshaft doesn’t have to come out, I had visions of all sorts of associated components being disturbed and breaking. I’m not tackling this job myself, unfortunately my back issues mean I’m limited at how much under car stuff I can do. If I had a full size ramp I’d be laughing but I can’t roll round on the floor anymore. The NOS front pipe landed here yesterday so we’ll get that fitted by our tamed mechanic.

17-06-23, 09:18 AM	#5
84CoupeGT Grown up member Join Date: Nov 2020 Posts: 309	Hope the work goes well. I know what you mean about the back, I've got to be more careful these days, can really feel it in my lower back for a week or two after crawling around under the car or leaning over the bonnet

19-08-23, 05:50 PM	#6
IronJaw Grown up member Join Date: Nov 2016 Location: West Lancashire Posts: 157	Thought I’d do a follow up on this, it’s been a while. Basically we’re no further on The NOS (QH) front exhaust pipe I’d got allegedly didn’t fit the car and was a totally different shape to the one fitted, which annoyed me because according to the labels on the pipe it’s supposed to fit. The garage tried to patch it up for us but it hasn’t taken and the car sounds like a tractor when you’re driving around. Unfortunately the pipe is mainly made of rust so there’s nothing to weld to either. I can’t believe how difficult it is to get hold of parts for this car considering I can get any part for my Triumph or Trabant within 24-72hrs. The search continues for the correct part. I’m thinking we’ll just have to get something fabricated using what’s left of the old one as a pattern.

23-08-23, 06:19 AM	#8
IronJaw Grown up member Join Date: Nov 2016 Location: West Lancashire Posts: 157	It’s a 1985 manual with a 2.0 5 cylinder engine. I’ve since sourced the correct pipe in two places, one being Audi Tradition and the other being Poland. I’m going to try the Polish one first as it comes with a fitting kit and it’s only £46. The Audi one is £101 and that doesn’t include shipping and all that jazz. The OEM part number is 855 253 101B should anyone need it for future reference.

24-08-23, 10:39 AM	#9
84CoupeGT Grown up member Join Date: Nov 2020 Posts: 309	If the Polish one is Polmo (logo is a 'P' circled), that's the make of exhaust I got for my Coupe and it fits well, although my downpipe was ok, it's just the rest of the exhaust I bought. It's been on the car almost 3 years now and hasn't gone rusty at all, although has only done about 700 miles! I sprayed some high temp silver paint over the welded joints in the hope that may help preserve it. One tip from my experience, when I first installed it I used exhaust paste which cracked and resulted in a blow. When I took off and refurbed the downpipe as well, I used RTV very high temp copper silicon, which was much easier to use and has sealed up the system perfectly - I've realised now the paste didn't properly seal even from the start, so definitely recommend using the silicon.

28-08-23, 08:21 AM	#10
IronJaw Grown up member Join Date: Nov 2016 Location: West Lancashire Posts: 157	I’ll have a look when it arrives, hopefully it won’t be too long coming here otherwise we’ll miss the MOT date. No way will it pass with the exhaust the way it is. One other exhaust thing is like to change at some point is the back box, specifically the way the exhaust tip is. It really irritates me the way the hole in the bumper is for a dual tip but the coupe has this crap single pipe with an almost afterthought bend in it, which stops you from fitting any kind of exhaust trim to try and improve the look. We’ll get there hopefully