Please help me diagnose this noise from the turbo

keplaffintech · 17/07/21 02:07 AM

Hi, I have an MkII XR6 Turbo with injectors, tune, and PWR intercooler.

All fine for the last month or so until today when my car has started making a loud noise from the intake / turbo. I'm pretty sure it happened after a WOT pull, but don't know if that's just co-incidence.

The noise is depicted in the video. It starts off pretty loud, but gets a little quieter when the car warms up. It is inaudible when off throttle, but can be heard at any point when accelerating, and is louder as you accelerate harder. I've noticed my car is notably down on power (timed a 6s 0-100 with this issue, used to be sub 5s prior).

The wet stuff is soap water, as I was trying to identify any boost leaks, but couldn't.

It sounds like it's coming from the turbo area, and as you see, when I move down to the cooler piping, or the right side of the car, the noise isn't nearly as prominent.

Thanks.

**El Andrew** · 17/07/21 05:49 AM

Pull the heat shielding off and check the bolts and nuts for engine to exhaust manifold and manifold to turbo. Sounds like a big exhaust leak. You may have even had a bolt back all the way out.

If so, all of you exhaust gases are escaping out rather than going through the turbine wheel and spinning up the turbo properly, which explains the loss of power

keplaffintech · 17/07/21 07:32 AM

The manifold looks ok:

However there seems to be a gap between the dump and cat here? Does this look normal to you? I did get the cat swapped out by a local exhaust shop.

I'll probably take it to an exhaust shop once this lockdown is over, unless it's a matter of tightening that bolt

**Puffwagon** · 17/07/21 07:46 AM

Mate that is definitely an exhaust leak. Remove the heat shield and check around all of the mating surfaces for a leak.

keplaffintech · 30/07/21 02:31 AM

Just wanted to bump this as I haven't been able to find any leaks on the exhaust manifold, all the bolts are present and tight as.

I have localised the leak sound coming from the back of the cold side(?) of the turbo. I did this using a microphone and headphones to track down the source.

I have noticed an area where black soot is building up in this area. Could this be the issue? I'm not familiar with the actual housing components here, and it doesn't make sense why this would be on the cold side if it sounds like an exhaust leak.

Pics here:

Please have a look and let me know if that looks suspect.

**Puffwagon** · 30/07/21 08:35 AM

See that bolt next to the oil feed and the other one next to the coolant line? The ones that are in the exhaust housing. They can back out and also the turbine housing can crack causing an exhaust leak. Have a look opposite the black stuff and see if the bolt is still in there.

keplaffintech · 30/07/21 10:12 AM

All of the bolts seem to be present, and are in pretty tight. I can't see any that are missing.

Para045 · 12/10/21 01:08 PM

Sounds a lot like my car a few years back, started off initially like an old lifter ticking and slowly got worse 🥺

I tried having a look around in the engine bay and under the car but couldn't find the exact issue and it looked like a major headache to remove everything to search for it 😵

Ended up taking it to a mechanic we know and he found that there was a slight bit of blowby on the exhaust manifold but most was because a bolt had come out of the turbo and it had blown out the gasket and was leaking pressure that way 😨

Thankfully it wasn't too hard or costly a fix and strangely I didn't really notice a massive performance drop when it was bad 😕

2012 XR6 Turbo Exhaust Leak 1

2012 XR6 Turbo Exhaust Leak 2