Hesitation In 2nd On Hard Acceleration @ Upper End...

[guyeye]

I've had this problem since day one (January 1 of this year). It hasn't really bugged me much since I'm kind of a hyper-miler, but I just wanted to get some input and find out if it could be telling of something bad in my future.

Normally, the XC runs smooth as silk. But occasionally, when I have to pass someone and push it to where it kicks down into 2nd gear and it starts winding up, just before shifting to 3rd, there is a hesitation. It's not flare, and doesn't seem to be tranny related. The engine itself just seems to miss at the upper end of the RPMs. Any ideas? I've got brand new NGK Platinum plugs. The coils "Look" OK. I just got an ETM gasket from FCP Groton and hope that when I get a little time, a good ETM cleaning may help, but I cant help feeling like this could be a sign of something more serious.

BTW, I just recieved my chinese Dice unit and got the latest Vida software all loaded up through VMWare on my MacBook Pro. Just haven't had a chance to hook it up yet. Thought I'd take the little online tutorial first, since I have a history of jumping into these things head-first and screwing things up.:p

[JRL]

Get rid of the NGKs and install Volvo plugs, That's the first place to start.
Volvos seem to run the best with stock plugs

[guyeye]

Get rid of the NGKs and install Volvo plugs, That's the first place to start.
Volvos seem to run the best with stock plugs
Good to know.
Same issue though, before plug replacement.
I'll try it though- love starting easy.

[JRL]

It could be anything
A dirty throttle body, slightly clogged breather system, boost control valve.

You would be surprised how much better these cars drive with a clean ETM
Or...slightly worn out coils, etc

[guyeye]

Thanks JRL. The ETM's getting a good cleaning when my new Volvo plugs arrive from FCP Groton. I'll check the PCV system (see if there's suction at the oil filler) when I get home. Any way to check the boost control valve short of swapping it out?

[JRL]

Oil fill AND dipstick

[Captkent]

I had the same hesitation during excelleration when I bought my XC 70 a year ago. Took it to the local Volvo dealership with no results and the claim that it seemed "normal".

I just got my car back from my favorite Indy shop and they changed the spark plugs and cleaned the throttle body. Its like a new car. Smooth as can be. A rather amazing turnaround.

[guyeye]

So, I replace my new NGK Iridium plugs with Volvo plugs and cleaned my ETM. New car! Hesitation is gone. I don't yet know how much to attribute to disconnecting the battery. Time will tell.
Many thanks to all who gave their 2 cents- it was worth way more!

[PierreC]

Had something similar a while ago ... turned out to be the turbo control valve which I then replaced with the heavy duty (and quicker acting) one from IPD. Did all the pipes with the silicon hose at the same time ...

[guyeye]

Had something similar a while ago ... turned out to be the turbo control valve which I then replaced with the heavy duty (and quicker acting) one from IPD. Did all the pipes with the silicone hose at the same time ...

You know, I was going to do that. I got all the silicone. I even "sprung" for an IPD CBV, but I couldn't find the IPD HD TCV. Looks like they've stopped making it, because it's not even listed as out of stock. It's just not there.

If I'm going to go to all the trouble to do all the silicone and the CBV, would an OEM TCV just drag the whole effort down? Seems like it'd be better than the old tired one, right?

Also, am I missing something or searching the IPD site wrong? Is the IPD HD TCV history?

[howardc64]

There is a theory the HD TCVs makes no difference.

Many people (me included) experienced replacing HD TCV with no difference and replace the top 2 of the 3 hoses with silicon and got performance.

You might just try to replace the 2 hoses to silicon with the stock TCV and see what happens :) Here is a discussion

http://www.volvoxc.com/forums/showthread.php?t=20331

[guyeye]

Hey Howard,
Thanks for the input. I saw that thread when I got JRL's response in this thread earlier, suggesting the TCV might be worth investigating.

Since my hesitation woes seem to be put to rest for now, my plan is to replace the Intercooler hose & coupler with silicone (they're pretty oil degraded) and do to TCV lines with silicone (I'm kinda looking forward to all that spiffy blue stuff under the hood :rolleyes:) and see if I notice anything. I'll wait on a new TCV as I really hate to be a frivolous parts replacer.

I'm hoping to redo the turbo drain line seal (I'm getting a fairly good coating of oil on my Haldex and belly pan) and that CBV while I'm at it. Might be a bit too ambitious to do it all at once as my assistant is 3 years old and doesn't have much of an attention span :o.