1998 V70 T5 2,3l Very high idle at start

pjcat · Post by **pjcat** » 06 Nov 2015, 22:05

My T5 recently started to do this: when I start it and the engine is cold, it revs up to 2500rpm for more than a minute and then it falls back to normal, somewhere around 1000. Then if I press the accl. just slightly it does stutter a little, like the revs. go down for a split second and then up again. Otherwise driving feels very normal.
Fixed recently the PCV system successfully and don't have any error codes.
Found this thread here to: https://www.matthewsvolvosite.com/forums ... =1&t=54785
I am just not sure where to start? Any clues?
Thanks
Pat

Post by **RussB** » 07 Nov 2015, 03:08

Clean out the IAC (idle air control) valve with some carburetor cleaner. Do the throttle body as well while you're at it

pjcat · Post by **pjcat** » 09 Nov 2015, 09:43

RussB wrote:Clean out the IAC (idle air control) valve with some carburetor cleaner. Do the throttle body as well while you're at it

Did clean out the IAC yesterday but it is still reving up when cold.

Post by **benpineapple** » 11 Nov 2015, 13:40

Remove the throttle body and clean it very thoroughly. Could be sticky in some spots, which would be most noticeable when cold. You'll need a new throttle body gasket for reinstallation, they're super cheap.

Either way sounds like an air related issue, too much of it.

pjcat · Post by **pjcat** » 17 Nov 2015, 11:02

benpineapple wrote:Remove the throttle body and clean it very thoroughly. Could be sticky in some spots, which would be most noticeable when cold. You'll need a new throttle body gasket for reinstallation, they're super cheap.

Either way sounds like an air related issue, too much of it.

Did clean the throttle body very good at the same time I also cleaned the MAF. But no success yet, still revs up. I recorded again the noise the IAC makes when I turn on the ignition. Can you guys confirm that it is normal to make so much noise? Maybe it is time to get a new one?
Thanks

crismit125 · Post by **crismit125** » 19 Nov 2015, 09:04

Is there a check engine light on? I had the same thing happen to me after a PCV job (rev 2500-3000 at idle), it turned out to be the throttle position sensor (TPS) that went bad. Most likely due to using carb cleaner when i cleaned the throttle body. Another place i would check it the throttle cable, it may be too tight. There is a plastic hex at the end near the TB that you can twist to adjust the tightness. Adjust so that the throttle plate is just fully closing. As for your IAC valve, it sounds a little different. Mine is a little more high pitched and smooth sounding.
Hope this helps!

Post by **cn90** » 19 Nov 2015, 10:02

Could this be from a bad ECT?

ferocity02 · Post by **ferocity02** » 19 Nov 2015, 10:18

My IAC makes a similar noise. Doesn't sound good but it works.

I'm thinking a vacuum leak. Since you just did the PCV job maybe a vacuum line came off.

pjcat · Post by **pjcat** » 20 Nov 2015, 11:01

crismit125 wrote:Is there a check engine light on? I had the same thing happen to me after a PCV job (rev 2500-3000 at idle), it turned out to be the throttle position sensor (TPS) that went bad. Most likely due to using carb cleaner when i cleaned the throttle body. Another place i would check it the throttle cable, it may be too tight. There is a plastic hex at the end near the TB that you can twist to adjust the tightness. Adjust so that the throttle plate is just fully closing. As for your IAC valve, it sounds a little different. Mine is a little more high pitched and smooth sounding.
Hope this helps!

Yes since when I did the PCV job first I got an error the lead me to change the TPS sensor, so there is a new one installed already. I could clear that error code but soon later I got a P0442 (small evap leak) which I was not able to solve yet.
The throttle cable I will inspect more thoroughly; it is kind of old as it has lost a lot of the insulation outside already. Thanks for the tips.

pjcat · Post by **pjcat** » 20 Nov 2015, 11:06

cn90 wrote:Could this be from a bad ECT?

How would I test the ECT?