engine idle speed

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jackwatch
Posts: 7
Joined: Thu Sep 24, 2009 5:38 pm
Year and Model: 1999 V770
Location: New York City

engine idle speed

Postby jackwatch » Tue Sep 29, 2009 5:55 pm

Hey
I have a '99 V70 automatic in NYC with 73K mi. It gets around 20mpg mixed driving and almost 30mpg on a 2,000mi trip last summer. The engine idle speed drops as the car decelerates, almost like a manual transmission without depressing the clutch until the last second. It hasnt stalled yet but appears to be getting worse. Can this be a transmission problem, timming belt?


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jblackburn
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Posts: 13957
Joined: Sun Jun 08, 2008 9:54 pm
Year and Model: 1998 S70 T5
Location: Alexandria, VA
Flag: United States of America

Re: engine idle speed

Postby jblackburn » Tue Sep 29, 2009 6:48 pm

I'd start with vacuum lines...check to see if you have any obvious cracks or leaks in any of them.
'98 S70 T5
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

jackwatch
Posts: 7
Joined: Thu Sep 24, 2009 5:38 pm
Year and Model: 1999 V770
Location: New York City

Re: engine idle speed

Postby jackwatch » Wed Sep 30, 2009 5:20 pm

checked the vacumn line first, added injector cleaner to gas too.
found that Hi test gas helped alot, but im not doing that to a 10year old car. Also read that it may be related to a temp sensor , that tells the computer to increase gas/air mixture until too rich.
they said it was a simple fix, but i got bumped off line and couldn't reestablish that thread again.
No chance its related to the timing belt? I have 73K and its not due till 105K, but i understand these belts have a shelf life of around 10 years, irespective of milage.

jackwatch
Posts: 7
Joined: Thu Sep 24, 2009 5:38 pm
Year and Model: 1999 V770
Location: New York City

Re: engine idle speed

Postby jackwatch » Wed Sep 30, 2009 5:25 pm

engine generally idles at 800 or so,
when this happens, after warming up, rpm may drop to 500-600
noticed in last few days AM temps 65-70 this was not so noticable.
the temperature sensor is starting to look better. whish i knew where it was.
ill get back if i get anything on it.
later

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jblackburn
MVS Moderator
Posts: 13957
Joined: Sun Jun 08, 2008 9:54 pm
Year and Model: 1998 S70 T5
Location: Alexandria, VA
Flag: United States of America

Re: engine idle speed

Postby jblackburn » Wed Sep 30, 2009 5:34 pm

I seriously doubt it's got anything to do with the timing belt, BUT you might want to change that. I changed mine at 140K a few months after I got this car, because although it had been replaced before, I wasn't sure how long ago.

On a quick search for the coolant temp sensor:
http://www.matthewsvolvosite.com/forums/viewtopic.php?f=9&t=18176
This is for an S60, but essentially the EXACT same engine.
And:
http://www.matthewsvolvosite.com/forums/viewtopic.php?p=31221

This may be going on my car too; I thought it was something to do with the transmission, but it has stalled on me completely once going down a big hill, and attempted to once more, but I managed to get my foot back into it before it cut off; it hasn't done it in 2 months since.

Good luck! If this doesn't solve it, I'd go back to the vacuum lines and spray around the lines with some carb cleaner, and see if you have any engine surges.
'98 S70 T5
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

User avatar
jblackburn
MVS Moderator
Posts: 13957
Joined: Sun Jun 08, 2008 9:54 pm
Year and Model: 1998 S70 T5
Location: Alexandria, VA
Flag: United States of America

Re: engine idle speed

Postby jblackburn » Thu Oct 01, 2009 7:54 pm

Just noticed you have a '99; have you had the ETM recall done on this car? This could also be early signs of a failing ETM.
'98 S70 T5
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

jackwatch
Posts: 7
Joined: Thu Sep 24, 2009 5:38 pm
Year and Model: 1999 V770
Location: New York City

Re: engine idle speed

Postby jackwatch » Tue Oct 06, 2009 5:17 pm

will double check the vacumn lines ,
tail smell realy rich Ill check around some more for the link on the location/replacement of this sensor ( remember it was like $125 CAD)
Recalls?
I had recalls for headlights, taillights, throttle software upgrade, and should have had recalls ( in my opinion) on loose dashboards, cheap switches throughout the car, am radio buzzing in tunnels like a 1965 chevy nova. Dont get me started, ford ruined this car. but the basic drive train seems sound. 1999 they cheapened up the interior and the body.
gone through 7 tires , 4 in the front alone. poor deisgn, light struts, heavy engine / trans axel.
I used to keep a running "story" on what happened to this car, but no one believes me any more. Had many , many small electrical issues, Some one even suggested reavy spring rains in sweden flooded the storage area for this model. couldnt find anything on that.
I quit the $1,000/per visit club at the dealer and am constantly looking for a mechanic that has a clue. Dealer waited out the 4 years till the warrantee was gone. I need to keep this car for another 10 years to make the overall cost reasonable.

Any way thanks for the info, if i find anything more on the idle variation I'll pass it along.

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jblackburn
MVS Moderator
Posts: 13957
Joined: Sun Jun 08, 2008 9:54 pm
Year and Model: 1998 S70 T5
Location: Alexandria, VA
Flag: United States of America

Re: engine idle speed

Postby jblackburn » Tue Oct 06, 2009 6:04 pm

You said the exhaust smells really rich...do you have any codes stored (they will save codes even if the check engine light isn't on)? From that, it could also be an oxygen sensor or the like.

Also, on a completely unrelated note, I'm sorry to hear that; mine has been great...for the time that I've owned it (coming up on 3 years). Maybe all the kinks were worked out before I owned it, but as far as I can tell most of the things that normally fail on these cars are still original on mine. The previous owner owned it 7 years since it was new, and said it was one of the best cars she ever had as well. The only thing I've had to fix (well, immediately anyway), other than body damage and tires has been the mass airflow sensor. I've got a running list of things that need to be fixed, but I've never broken down...more than I can say for my old '88 Accord that was in and out of the shop for several hundred dollars worth of repairs every month. My Volvo has been one of the best cars I or my family has ever owned, honestly. It seems to be built more solidly than my mom's 2007 Accord, and is much more reliable than my dad's Jeep Liberty, not to mention a total blast to drive compared to cars like my girlfriend's Taurus. You'll have issues with any older car you own...but at least you'll be safe =)

The best thing you can do is try to find a small independent mechanic that works specifically on Volvos/Saabs...ask around to people you may know that own similar cars, as that's often the way you hear about these kinds of mechanics. Dealers are a total rip-off for anything. Or learn to work on it yourself!
'98 S70 T5
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!


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