[Clan]

Originally Posted by Zorbit

Our XC90 diesel has been playing up. It was intermittently losing power at lower revs, and when it did there was a nasty chemical smell from the front, and some exhaust smoke.

VIDA suggested MAF sensor reading low and DPF blocked.

No specific fault on dashboard, just the service engine message, no warning lights.

The fault was a split orange silicone type gasket between the outlet of the turbo and the plastic turbo resonator box. The gasket has separated and been pushed out of the joint.

To check the gasket all you need to do it remove the plastic tray under the engine, half a dozen 10mm bolts, and shine a torch up behind the engine. Access is difficult, the gasket faces are ribbed to help hold the joint together so you'll need to undo the jubilee clips - the top one is awkward, I used a very small Wera 1/4" drive ratchet, 4" extension, and a flat bladed screwdriver / 1/4" socket type driver ( like a socket but with a screwdriver bit). A fine toothed ratchet is useful as there isn't much room. There are two bolts holding the plastic under-engine pipe to the engine, remove those, loosen the jubilee clip on the bottom of the turbo resonator and pull the pipe out. Now you can remove the resonator, it touches an engine casting but there is room to remove it if you wiggle it.

The Volvo jubilee clip is very low profile so impossible to get a socket on the screw, replacing it with a standard stainless clip that can take a socket will make installation much easier.

I've reinstalled the gasket and tightened it up properly until the part I ordered arrives, car runs good as new again, but obviously only a temp fix, the split gasket will no doubt get pushed out again if left.

when you refit it , use brake cleaner as a lubricant to get the pipe on the turbo , it all evaporates and leaves no slippery residue to let the pipe blow off again ! you have about 3 seconds to get the pipe on as it will all have evaporated after that .