[jakenney]

Daughter's 1.8Turbo started sounding like a monster truck - you know no exhaust! Took it to Meineke, for $250+ they would 'try' to find what was wrong by replacing the exhaust manifold. Skipped that and took it home. Turns out there were some loose bolts on the back of the engine where the downpipe connects to the exhaust manifold. Tightened them up. I also found a turbo pressure hose that was ruptured, replaced it and the noise went away.

Today she started the bug up and the noise had returned. 15 minutes later it was gone as I quickly removed the cowling, and reached around back of the engine and tightened up those three bolts.

My question is: How do I keep those three bolts tight? I can't get a torque wrench back there, so they are muscled up as tight as I could go. Should I order new bolts?

Suggestions?

 

[jfoj]

So lets be a bit more clear, I think on the 1.8T there are 4 nuts that hold the down/flex pipe to the exhaust manifold. These usually do not come loose. There is a flat metal gasket between the down/flex pipe and the exhaust manifold.

Also the flex pipe can also tear and break as well.

If the flex pipe is bad, do not cheap out and try to just replace the flex pipe, you can get a complete, new converter from ebay delivery to your doorstep for about $250.

2002 2003 2004 2005 VW Beetle 1 8 1 8T Down Pipe Catalytic Converter New | eBay

I put this on my 2003 because I had a piece of the converter broken off and rattling around in between the 2 converters.

I thought this was a decent quality unit with a good flex pipe. Would not suggest a Walker or other muffler supplier as the flex coupler was not very decent quality.

 

[jakenney]

Not the flex pipe, the entire exhaust is relatively new. The noise was abated this time by simply tightening the bolts. They were not just loose they had almost worked their way out.

 

[jfoj]

The OE exhaust flange nuts are not round, they are kind of oval shape so they are kind if like self locking nuts?

Also I thing they are a special material that will not rust so bad as well?

The flange gasket has a metal bead that is flattened once it it tightened down, so it is a "one time use" gasket as well.

 

[esse10]

bolts

this is a long shot but worth a try,

I believe they do have a loc-tite for use in high temperature applications you might want to do a google search on that. I'm not sure how high of a temperature rating that would hold. I have never seen this problem in any of my cars in 30+ years of driving and doing my own repairs. looks like jfoj has done this kind of work before..........

 

[jfoj]

Short term solution is just double nut/jam nut the 4 exhaust studs, they should be long enough. Try to get stainless steel nuts to make removal easier.

But the best solution is a new gasket and nuts from the dealer or an online VW supplier.

 

[jakenney]

I may have not described the issue correctly. It is not the flange with the gasket where the downpipe connects. The three bolts can only be reach from above and are on the top of what I believe is the exhaust manifold (perhaps they hold the turbo on?). I will take the cowling off and snap a picture later today. Thanks for all the suggestions in the meantime.

 

[jfoj]

Could also be a loose and/or cracked exhaust manifold?

Not sure exactly how the turbo interfaces, probably another flat 4 bolt flange?

 

[jakenney]

The attached photo (borrowed from a UK site), indicates that the bolts in question actually hold the Turbo on! I tightened them as tight as I could get them so hopefully they won't loosen up again.

 

[PRM502STREET]

Did it quiet down?

Sent from AutoGuide.com App

 

[jakenney]

Yes, noise went away immediately. I also replace a hose on top that goes from the charge pipe to the diverter. Replacing the hose initially fixed the problem, then the noise returned - that's when I dug deeper and found the turbo was loose.