Hello all,
I have a situation with my tailpipe that I cannot figure out. Doing a quick check of the car before a road trip last month I found the rear tail pipe hangers had broken off the pipe. Since we were leaving the next morning I welded them back on myself. I checked for clearances by moving the pipe around by hand and everything looked excellent.

On the trip we encountered rutted highway filled with water (raining hard) and we encountered slush at the higher elevations. As best as I can tell each time the front wheels directed a heavy stream of water or slush at the tailpipe the tailpipe would hit the rear driveline and make an incredible loud squealing noise that would only stop if I stopped the car. Once the car stopped rolling I could proceed again and the noise would be gone. Once back home I found were the tailpipe contacted the driveline however despite how hard I shoved the tailpipe forward, backward, and sideways I could not get the tailpipe closer than 1" from the driveline.

I heated the tailpipe hangers and bent them upward to lower the pipe. However this did not solve the problem. It seems that the tailpipe must be changing shape or length in order for it to hit the driveline. It also seems that when it hits the driveline the spinning action of the driveline holds the tailpipe up and against it which would explain why the noise will only stop when the car stops rolling.

Has anybody ever encountered something like this and if so how did you resolve the issue?

TIA,
BWSwede

 

On some xc70s when the exhaust gets cooled suddenly by slush/water - the exhaust constricts/bends and touches the driveshaft - making a very disturbing noise. It has happened to me and I have seen a video of the exhaust actually touching the driveshaft. There is a modified bracket/mount to hold the center of the exhaust system away from the driveshaft if needed. To verify you should look for the paint ground off of the driveshaft where the edge of the circled resonator is . Believe it or not the 2 or 3 inches of clearance you see now - becomes 0 when suddenly cooled down. The exhaust warps up and touches the driveshaft. Sorry I am not sure of the part number for the additional bracket needed to prevent this noise.

 

Hoonk,

I continue to get blown away by the knowledge shared with members of this forum. Thank you very much for your reply. What you describe and what you have circled on the diagram is exactly what is happening to our car. Now that I know it is a known issue and there is a part (or once was a part) to brace the mid section of the tailpipe I can start looking for the part. If I can't find the part perhaps I can find a picture of it and fab one up myself.

Thanks again for your reply. I'll be sharing it with my wife who thinks I "broke" her car.

BWswede

 

Hello all,

I am having difficulty finding the part the Hoonk describes in his post. Has anyone else dealt with this issue and either have the part number, a photo of the part, or a photo of what they did to remedy the situation?

TIA,
BWSwede