Check your "Y pipe" or "intermediate pipe" if you're low on power
Thread Starter
Member
Joined: Apr 2020
Posts: 97
Likes: 34
Exige S | V70R | CTS-V wagon | JKUR | 13 S65 (Mocha/Armagnac)
Check your "Y pipe" or "intermediate pipe" if you're low on power
Good evening.
I recently bought an S65 which I thought might be down on power. After doing some inspection, I found the culprit - the "y pipe" between the intercoolers was cracked, something I could barely see, but was likely leaking a significant amount of boost. As I removed parts to access it, I figured out that the lower portion was cracked in a number of places which had allowed the seal to leak as well. This seems like a part which will fail due to heat over time and something everyone should inspect if they're around that area.
Cheers!
Pics below:
https://imgur.com/a/cKeV0Vp
I recently bought an S65 which I thought might be down on power. After doing some inspection, I found the culprit - the "y pipe" between the intercoolers was cracked, something I could barely see, but was likely leaking a significant amount of boost. As I removed parts to access it, I figured out that the lower portion was cracked in a number of places which had allowed the seal to leak as well. This seems like a part which will fail due to heat over time and something everyone should inspect if they're around that area.
Cheers!
Pics below:
https://imgur.com/a/cKeV0Vp
Super Member
Joined: May 2019
Posts: 671
Likes: 288
From: Omaha, NE
2007 S600
I just replaced mine as well. It had blown off the throttle body once... I probably didn’t have the hose clamp right enough. This was during the summer of 2019. When I removed it recently to get at the left coil pack, I found it had split half way around the underside where it attached to the TB. No way to really repair it so I ordered a new one. I also replaced the turbo to intercooler coupler hoses with some new reinforced silicone parts and used T-bolt hose clamps. There’s a noticeable difference in power now that I’m getting full boost all the time.
Thread Starter
Member
Joined: Apr 2020
Posts: 97
Likes: 34
Exige S | V70R | CTS-V wagon | JKUR | 13 S65 (Mocha/Armagnac)
I just replaced mine as well. It had blown off the throttle body once... I probably didn’t have the hose clamp right enough. This was during the summer of 2019. When I removed it recently to get at the left coil pack, I found it had split half way around the underside where it attached to the TB. No way to really repair it so I ordered a new one. I also replaced the turbo to intercooler coupler hoses with some new reinforced silicone parts and used T-bolt hose clamps. There’s a noticeable difference in power now that I’m getting full boost all the time.
Super Member
Joined: May 2019
Posts: 671
Likes: 288
From: Omaha, NE
2007 S600
Amazon, where else? 
Summit Racing and eBay are also viable sources. They're 60mm or 2-3/8" hoses.
Like I said, I ordered 2 and cut them down to 2-1/4" long. You could probably do it with one hose cut in half, the factory hoses are 2" long.
Summit Racing and eBay are also viable sources. They're 60mm or 2-3/8" hoses. Like I said, I ordered 2 and cut them down to 2-1/4" long. You could probably do it with one hose cut in half, the factory hoses are 2" long.
Super Member
Joined: May 2019
Posts: 671
Likes: 288
From: Omaha, NE
2007 S600
Word of advice -- check the hose clamps again after driving it. I test drove mine a couple of times and everything was fine. During the second drive, I made a couple of full throttle runs getting onto highways. On the second one I heard a distinct (though muted) whistle at high RPM. I checked the Y-pipe, and sure enough the large hose clamp on the TB was loose. Now, I know for sure I tightened it. My theory is that it was out of its groove on the rear side, out of sight, and I tightened it on one of the ridges on the top or bottom of the groove where it's supposed to be. Then under load it shifted into its normal position, leaving it un-clamped. I tightened it again and it's stayed tight since them.
