2001 V70XC - 200,000 Miles Makeover Topic is solved

[vtl]

Exhaust leak?

[BlackBart]

That is a bit of a scary noise.
But intermittent you say?

A leak in an air pump or something?
A belt or timing belt impact somewhere?
Doesn’t seem like a deep main bearing knock.
Doesn’t seem like a higher pitched rattlly rod knock.

[vtl]

This is almost assured an exhaust leak. Check the exhaust manifold gaskets and the flex section of downpipe.

[xHeart]

That is a bit of a scary noise.
But intermittent you say?

A leak in an air pump or something?
A belt or timing belt impact somewhere?
Doesn’t seem like a deep main bearing knock.
Doesn’t seem like a higher pitched rattlly rod knock.

This is almost assured an exhaust leak. Check the exhaust manifold gaskets and the flex section of downpipe.

Thanks!

The tapping is mixed up with engine noise, this is a video of same tapping noise from the engine bay:

IMG_0752.MOV

(11.73 MiB) Downloaded 114 times

[BlackBart]

I like the exhaust leak theory - that makes a lot more sense. Like vtl said, up by the head or manifold.

My '04XC makes the similar diesel-like clatter at idle and I've not known if that was normal. Normal valve train clatter I assume.

[vtl]

Exhaust manifold warps and gets the leaks at 1st and 5th cylinders. Also 4 cylinder gasket typically cracks for some reason.

[vtl]

Straight edge, visible gaps:



Exhaust leak:



Soot:



Cracked gasket:



Cracks in downpipe:





I see about same picture in every I-5 engine that gets exhaust manifold off.

[vtl]

Turbo can crack, too. I replaced my old turbo with a new stock Volvo, got one for $599.

Downpipe was rusty and cracked, replaced with Snabb 3" DP. Very pleased with it.



New Jetex catback had holes, I didn't have a welder back then, so sold it to a Volvo fellow for cheap. Also it was way too loud for my taste, decided to pull a trigger and buy a new Volvo catback.

New exhaust manifold gaskets, studs, bolts - all Volvo. Decided not to resurface the manifold this time, the gaps were OK.

The car is quiet now, has extra oomph with the new turbo and a bigger DP.

[xHeart]

Turbo can crack, too. I replaced my old turbo with a new stock Volvo, got one for $599.

Downpipe was rusty and cracked, replaced with Snabb 3" DP. Very pleased with it.

New exhaust manifold gaskets, studs, bolts - all Volvo. Decided not to resurface the manifold this time, the gaps were OK.

The car is quiet now, has extra oomph with the new turbo and a bigger DP.

I like the exhaust leak theory - that makes a lot more sense. Like vtl said, up by the head or manifold.

My '04XC makes the similar diesel-like clatter at idle and I've not known if that was normal. Normal valve train clatter I assume.

Helpful!

Replacing gaskets and fasteners at exhaust manifold - turbo - catalytic are my maintenance step.

[vtl]

Plan for the following maintenance step: body plastic cladding removal and corrosion inspection



This is my (donor) chassis, MY05, 265k miles. I've got it less than 3 years ago. A lot of rust in the rear wheel archs, on the inside. Had to trim the worst spot.

Because inner rust is hard to reach and remove, I did what I could and then soaked everything in Noxudol 700. Noxudol is sort of hard to get in US, but still possible. This is what Volvo uses at factory. I plan to finish grinding off the rust bugs hidden under the plastic, oxidize the metal w/ acid, spray 95% zinc primer, spray Noxudol 700 to every place I was not able to clean thoroughly and lay down Noxudol 1600. That should slow down the corrosion and also add noise proofing.

Door sills are in a good shape. I removed the plastic, didn't see anything bad. But sprayed it all inside through the holes with a good charge of Noxudol 700.

Removed the front wings as well. Now corrosion, but I'll cover chassis with 1600 as well, for my own comfort.

Next summer is rear subframe drop, for $700+ bushings replacement and rust proofing the connection spots where subframe gets bolted to the chassis. They are/were rusted on all P2s I had/have.

Sigh... Rust proofing starts with the first owner of the car. My Tundra will not rust, I'd guess Still has to clean my garage floor from the sticky 1600 drops.