[Dommyem]

I fitted some de-cat Down pipes at the weekend, all went well except for when I drove away and accelerate hard. I can hear some kind of blowing / rasping leak coming from the front of the car. Can I just add that fitting down pipes is no simple 4 out of 10 difficulty task - it's a bag of dicks of a job, took us 8 hours - we are not mechanics.... Anyways - I took my car to my local mechanic and he said I need new clamps that connect the down pipes to the turbos as they're worn and not tightening up correctly. At this point I wondered if it was a gasket problem and checked online (even though I do not recall even seeing one when we did the DP swap). I asked him if it was the gasket and he said it is a dry seal (no gasket). So I did some searching and it seems some people think there is one, and some people think there isn't. Can someone please clarify?

[ajbecerra]

No gasket only thing I can think of is dp wasn't seated correctly on turbo or vband isn't tight.

Dichtung Turbolader/Katalysator

[mojobmw_e90]

Yea there is a gasket. It's a round ring thats somewhat made out of clay. Sits on the lip

[E92 420]

Yes there is a gasket it sits inside a recess in turbo exhaust housing https://www.turnermotorsport.com/p-2...-s63n-engines/

[brewnami]

I've done two sets of downpipes and I don't recall a gasket on the v band side, only on the exhaust side...

[335inDe]

In my opinion I'd find a new mechanic. I've had my downpipes on and off 20+ times on my old 07 the clamps never wore. In my opinion only thing that can happen is they break from trying to open them too wide. The way you can tell if your downpipe is positioned correctly is when you slide your clamp over the downpipe flange grab the two tabs where the bolt goes in and squeeze them. If positioned correctly you can almost squeeze the two tabs together. If not positioned correctly the clamp will be very hard to meneuver and won't be able to squeeze it with your fingers very much at all. In this case you can have small exhaust leaks, if you put car on ramps and slide under while running you can hear it or feel the air puffing sometimes. Hope this helps, good luck!

[PourBoi-Jay]

This thread came at a perfect time, as I've just bought a set of DP's.
Should I pass on buying these turbo-to-DP gaskets?
https://www.ecstuning.com/BMW-E90-33...E/2/ES2800268/

I've read all the tutorials and watched some DIY videos, and none of them mention replacing any gaskets at that location.

[vladi627]

Originally Posted by PourBoi-Jay

This thread came at a perfect time, as I've just bought a set of DP's.
Should I pass on buying these turbo-to-DP gaskets?
https://www.ecstuning.com/BMW-E90-33...E/2/ES2800268/

I've read all the tutorials and watched some DIY videos, and none of them mention replacing any gaskets at that location.

Don't need to replace them unless you damage them at some point during the install process. Most of the time they just stay in the little groove it goes in on the turbo.

[PourBoi-Jay]

Fair enough. I just bought a set just to have, in case I do damage them.
Better to be safe than sorry, especially at only $20 for the pair

Thanks!

[Dommyem]

FOUND IT! It hides in the turbo. Its barely visible when fitted.
Gasket:

View post on imgur.com

Gasket fitted:

View post on imgur.com

removed:

View post on imgur.com

Can see it here: http://www.realoem.com/bmw/enUS/show...diagId=18_0681

Samsonite....I was way off!

[SackOHammers]

I've done DP a few times on 335i. Just to reiterate and confirm what others have said. The DPs have gaskets at both ends. You probably will not need to replace the gaskets at the turbo end (as long as you're careful and don't damage them). The gaskets that connect to your midpipes will need to be replaced.
Ok, so your VBand. You need to make sure you can close the tabs the bolt goes through. If you find that you're tightening the VBand really hard, you feel like you're about to break it or strip it, yet the two tabs have a 1/2 inch gap and aren't going to close, then you have a problem. Or if you feel like the stock screws are not long enough. You have a problem. The problem is the vband is not correctly seated, and it's probably in the back of the connection and you can't see it. It's not correctly around the flange. For me, if I just can't jostle the VBand clamp to get it to seat, I remove the vband, pull the downpipe away from the turbo. Take a deep breath, then try again. Fit it all up there together, but this time keep in mind to really make sure the back of the VBand clamp is correctly seated over both flanges. Then you should be able to tighten the VBand and get the two tabs close together or touching without feeling like you're going to snap something.

[amrazM]

Originally Posted by 335inDe

In my opinion I'd find a new mechanic. I've had my downpipes on and off 20+ times on my old 07 the clamps never wore. In my opinion only thing that can happen is they break from trying to open them too wide. The way you can tell if your downpipe is positioned correctly is when you slide your clamp over the downpipe flange grab the two tabs where the bolt goes in and squeeze them. If positioned correctly you can almost squeeze the two tabs together. If not positioned correctly the clamp will be very hard to meneuver and won't be able to squeeze it with your fingers very much at all. In this case you can have small exhaust leaks, if you put car on ramps and slide under while running you can hear it or feel the air puffing sometimes. Hope this helps, good luck!

This is exactly right, a lot of times the clamp may look seated on one side but not all the way around.