98 V70 AWD turbo charger bypass valve

Post by **kahl** » 31 Mar 2016, 13:21

On my daughter 98 V70 AWD I noticed that there was little of no noticeable kick in the turbo charger. Was not throwing any codes, TCV ops checked good and the three turbo lines were only a year old. After some research I came across IPD vidieo on the bypass Valve or the diaphragm being torn. This car was showing all the symptoms of a torn diaphragm. After removing the intake turbo pipe and some hoses there were three 10mm bolts holding on the compressor bypass valve cover. After removing the cover the diaphragm and spring easily came out. Upon inspection of the diaphragm found no tears but chaffing causing holes letting air thru thereby providing little or no pounds of boost.

The IPD kit contained three springs, stock, slight upgrade then aggressive. I choose the middle spring. Install was straightforward. The step by step pictures and narrative included in the kit were outstanding.

The car has regained it's performance. It was a noticeable difference.

Post by **erikv11** » 31 Mar 2016, 13:37

Great post, this problem is more common than people may realize. Almost all of the original CBV diaphragms have holes in them, every one I've checked so far.

Post by **MadeInJapan** » 31 Mar 2016, 16:51

I have a Volvo one that is in perfect shape if anyone needs one. I can take a picture and send it to you via email or txt too.

101 · Post by **101** » 31 Mar 2016, 17:34

Mine had a small hole at 211K miles. This should probably should be added to a "Stage 0" workscope. It's inexpensive enough and easy to replace.

Post by **abscate** » 01 Apr 2016, 04:41

On my 1999 T5, this was one of the worst replacements I've ever done on a car. I think it took me 4 hours to do those three M6 bolts with all sorts of convolution of 1/4 ratchets and wobbles. Access was very tight compounded by the metal coolant hose.

Performance afterwards put the local BMW challenger into rear mirror retreat. I used the blue spring

Bluevanacd2005 · Post by **Bluevanacd2005** » 01 Apr 2016, 07:48

Not trying to highjack the thread, but I see IPD also sells a block off plate. Has anyone installed it? Bad idea?

Spenser

101 · Post by **101** » 01 Apr 2016, 07:59

101 wrote:Mine had a small hole at 211K miles. This should probably be added to a "Stage 0" workscope. It's inexpensive enough and easy to replace.

abscate may be right. I need to qualify my response about this part being "easy to replace". It's easy to replace when the cylinder head is off the car.

I didn't try to access it with the engine fully assembled.

Post by **abscate** » 01 Apr 2016, 08:17

101 wrote:
101 wrote:Mine had a small hole at 211K miles. This should probably be added to a "Stage 0" workscope. It's inexpensive enough and easy to replace.

abscate may be right. I need to qualify my response about this part being "easy to replace". It's easy to replace when the cylinder head is off the car.

I didn't try to access it with the engine fully assembled.

Ha! Multiple lashes for witholding information!!!

The worst part of this job was getting it back on in two hours, then seeing that the nice new turbo valve had popped out and fallen under the car while I had not noticed, so I had to remove it and do it again. The fact that it took another two hours the second time tells you how nasty it was.

Link to thread on 1999-on Compressor Blowoff Valve

https://www.matthewsvolvosite.com/forums ... =1&t=70733

Post by **rguzz** » 01 Apr 2016, 10:45

There is also this for the Mitsubishi OEM crowd. This will be the direction I'll be heading. At this point my 850 will never be a racer. http://www.xsboostturbochargers.com/pro ... dge-srt-4/

Post by **erikv11** » 01 Apr 2016, 11:01

On a 98 and earlier, the job is a pain but not nearly as bad as it was for abscate; I think there are different metal cooling lines back there? Anyway it takes an hour if you go carefully but it is not a killer.