V70 T5 Problems - idle, turbo boost

dkoltz1 · Post by **dkoltz1** » 29 Aug 2010, 12:43

I've had some discussions with jablackburn this morning about some problems I've encountered with my 1998 V70 T5 - namely, stuttering when you step on the gas from a stopped position & I have no turbo boost, whatsoever. The following e-mails contain some of the background leading up to my current problems. Any advice would be GREATLY appreciated!

Sent: 50 minutes ago
by jablackburn

I'm not sure what else would cause a fuel-injected car to bog at a start-off. The computer should learn and correct for that.

The wastegate, attached, should be a little difficult to move by hand, which is understandable if yours is rusted as much as mine. It still does a fine job of opening when it should.

One other thing - try unplugging the MAF sensor and driving it. Any improvement? Could your intake pipe perhaps be loose or cracked?

Aside from that, I would suggest starting a new topic in the forum, and just cut and paste what you have told me, and what you've tried. Maybe someone there will have some ideas of things to try, or know exactly what the problem could be.Quote dkoltz1Re: '98 V70 T5 Problems
Sent: Today, 10:28
by dkoltz1

Tried the battery disconnect and carb cleaner - nothing new to report.Quote dkoltz1Re: '98 V70 T5 Problems
Sent: Today, 08:32
by dkoltz1

Great - thanks again! I read a post by MIJ where he indicated that he could acuate the wastegate valve quite easily. I disconnected the spring clip and manually operated it back and forth to make sure it wasn't stuck in the open position. However, with the actuator arm reattached, it's not "easy" to move the wastegate valve to an open position.Quote jablackburnRe: '98 V70 T5 Problems
Sent: Today, 08:11
by jablackburn

Just covering all the bases. They probably did it right.

You may want to look around for another vacuum leak somewhere - a can of carb cleaner sprayed around vacuum lines will clue you into a leak if you hear the engine rev.

Wait til tomorrow to reset it then so you aren't driving without a radio. A quick call to the service dept of a Volvo dealer will get you a radio code. If they ask you to bring the car in, look up Volvo of the Triad (Winston-Salem, NC) and give them a call. They will just ask for your VIN number, but double check the top of the radio (2 tabs push in and it pulls right out) and write down the serial number you see there in case the radio was replaced at some point in the car's life.

Disconnect the negative cable, push on the brake pedal a few times to drain the charge, and connect it right back up.

The rear O2 sensor has nothing to do with the way that the car runs - it simply monitors the cat. converter efficiency - so you don't need to worry about that one.Quote dkoltz1Re: '98 V70 T5 Problems
Sent: Today, 08:00
by dkoltz1

I had a local Volvo repair shop replace the intake manifold gasket earlier this week (once they found the problem that was the source of my huge vacuum leak). So, I'm trusting the work they did (fingers crossed as a type that).

If I pull the cable, I don't have the radio codes - any way to obtain those from a Volvo dealer? Not sure why, but they weren't included with the car when I bought it used (no key fobs either) - very frustrating. How long do you need to leave the cable disconnected?

Regarding the TCV, I replaced all hoses with new silicone, as recommended by IPD. I'm going to buy new hose clamps and replace a few of the stock ones that I reinstalled and may be suspect. Thanks for the recommendation on the heat shrink tape - I'll see what they have at HD. I should mention that I replaced the rear O2 sensor, which the shop mentioned was faulty.Quote jablackburnRe: '98 V70 T5 Problems
Sent: Today, 07:43
by jablackburn

Hey dkoltz,

I just saw your reply to the other post as well - sorry, it's Sunday and I'm being lazy this morning I'll leave that there for someone else to reply to if they've got thoughts, but here are mine:

It sounds to me like there is some kind of air leak somewhere in the system still. If you are 100% sure the seal on the intake manifold is good now, it might be worth a try to reset the adaptives (yank the battery cable & step on the brake pedal a few times, then reconnect it) again.

I had to replace 2/3 of the turbo vacuum hoses on my car because they were cracked and falling apart as I replaced my TCV with the IPD one. The compressor side (red) hose is particularly prone to cracking - thankfully, mine hasn't - but if you're still having faded boost problems, that might be one you'd want to check out.

In addition, make sure the idle control valve ends and throttle body hoses are clamped down good and tight. They both worked their way loose after I messed with them.

The SAS seal may need a bit of work - if exhaust is leaking out, it will give the O2 sensor a false reading, which could result in the stumbling on acceleration. I think a bit of high-temp heat shrink tape may work - head to Home Depot and see what they've got.Quote dkoltz1'98 V70 T5 Problems
Sent: Yesterday, 22:02
by dkoltz1

I recently replaced my PCV system with the help of your post. Unfortunately, I managed to clamp the hose clip between the block and intake manifold, resulting in a leak that caused all kinds of problems (sputtering, erratic idle, etc.). After trying to self-diagnose the problem myself, I was resigned to taking it to a shop ( who ultimately found the root of the problem). However, after getting the car back from repair, the idle is still a bit irregular and the car almost dies out when I give it gas from a stopped position.

Prior to the PCV system replacement, I noticed that I'd lost my turbo boost. To this day, it's still not kicking in when I stomp it down. I've checked hoses and the wastegate valve is not stuck in the open position. I should tell you that I replaced the stock TCV with the IPD unit. Turbo was working fine for some time after installation - so, I'm not sure whether or not that factors into this. I also replaced the stock exhaust with the IPD turbo-back exhaust. How critical is the seal on the secondary exhaust air port? I noticed that the threaded insert is not exactly as tight as it should be...

I'd appreciate any input you can offer - thanks!
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Post by **matthew1** » 29 Aug 2010, 13:09

Sounds a lot like a vacuum line. I hate to throw an encyclopedia at you, but you might want to poke around these MVS search results for vacuum line.

dkoltz1 · Post by **dkoltz1** » 29 Aug 2010, 13:13

I'm with you - but, nothing reveals itself with carb cleaner sprayed around the suspect connections.

dkoltz1 · Post by **dkoltz1** » 29 Aug 2010, 19:59

Problem solved! The line on the bottom of the idle control valve was knocked off by the shop where I had work performed earlier this week. Reattached - idle problem eliminated and turbo boost has returned to normal. However, CE light came on during the last outing... to be determined.

Post by **jblackburn** » 29 Aug 2010, 20:33

I kinda figured it had to be one of those hoses. Mine did similar things after the replacement when it blew the hoses off - you could hear a definite woosh of air from the turbo. Make sure your clamps are all down good and tight before you start romping on the turbo away from home

The light is probably it being annoyed at something now that it sees as "different" now that it's running right. I'd yank the battery cable again and let it re-learn its adaptives properly. I do this after I change any sensor or other component that may change the fuel-air mixture.

dkoltz1 · Post by **dkoltz1** » 29 Aug 2010, 23:29

Thanks again for everything today - couldn't have done it without your help!