Boost problems, TCV maybe? - Volvo Forums

imhereftw · #1 11-02-2009, 05:34 PM

2004 s80 2.5t

I recently upgraded my muffler, well virtually got rid of a muffler all together, and replaced it with a glass pack.
I notice it picks up a lot better but around 2-3k rpms my car gets jumpy and hesitates as if I'm tapping on the gas petal. I hooked up a boost gauge to see if it might be boost related and as I floor it and my car starts to studder the needle on the gauge bounces up and down from 9 to 13 psi. (tuned btw) I went to check for codes, even though I had no check engine light on, and got nothing.

I called IPD for a little help and they suggested it could be my TCV. Could this be the problem or something else? Note, I never had this problem before taking the muffler off, but ipd and my local mechanic doubt it would be the problem.

Thanks!

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imhereftw · #2 11-03-2009, 09:27 AM

I would really like to figure this out before I go and spend money on something I may or may not need

Bender · #3 11-03-2009, 09:47 AM

Miles?

could be the TCV or the MAP.

I would (personally) replace BOTH.

imhereftw · #4 11-03-2009, 02:06 PM

It's at 85k miles, I'm going to go through and clean the current TCv with a little carb cleaner see if that makes any difference.

Bender · #5 11-03-2009, 03:41 PM

honestly - not really worth it - the factory ones are not intended to be cleaned. I would strongly recommend replacing it.

imhereftw · #6 11-03-2009, 06:26 PM

well I did clean it just to try it and, nothing =/. I would really like to try and figure something out that doesn't involve spending the money to buy a new one. My brother suggested that I check for leaks. it could be perfectly possible that I tore an old line since I upped the boost output. I'm not exactly sure how to check for leaks though seeing as it's a little different from car to car.

are there any common points of failure I should check as well?

Bender · #7 11-04-2009, 08:05 AM

not a boost leak - if it was you would be experiencing the issue the whole way through the band.

get a new TCV from IPD and replace all your vac lines while you are at it just to be safe.

That said, it could be EITHER TCV or MAP sensor. this one WILL take money to fix

imhereftw · #8 11-05-2009, 09:18 AM

Alright, I'll try replacing the TCV first because I thought if I were having a problem with the MAP it would give a trouble code.

Thanks for the help so far btw!

Bender · #9 11-05-2009, 09:43 PM

MAP may or may not throw a code - TYPICALLY it does and TYPICALLY they fail in hot weather.

imhereftw · #10 11-05-2009, 10:32 PM

Quote:

Originally Posted by Bender

MAP may or may not throw a code - TYPICALLY it does and TYPICALLY they fail in hot weather.

Well the weather here in Maryland is generally pretty mild especially lately and this occurred while the outdoor temps were in 60's and there is no check engine light or idle codes so I'll try replacing the TCV first, even if that isn't the problem sounds like a good upgrade anyways!