850: High revs during winter !

Guest (Daniel) · Post by **Guest (Daniel)** » 10 Jan 2004, 07:58

My car : 850 GLE 1996 manual ... I'm the orginal owner and I'm happy with my 850 with ONE exception !
During winter, at very low temperature (CANADA), below -20C (-15F approximately), I have experienced this situation, sometimes frigthening! : after 15 min of driving, when I change the speed or when I put the transmission on N, the motor speeds up to 5 to 6 thousands RPM. This situation occurs for 2 or 3 very LONG minutes... I feel that the accelerator pedal seems to be stucked. What is your diagnosis?
A problem with the oxygen sensor? or the throttle body ? Should I change the idle valve? Thank you in advance.

Guest · Post by **Guest** » 08 Jul 2004, 18:36

try cleaning throttle body

Post by **matthew1** » 08 Jul 2004, 19:10

Check vacuum hoses too

potroast · Post by **potroast** » 08 Jul 2004, 20:14

sounds like the cold is causing the butterfly valve in the throttle body to stick open slightly.

ozzimark · Post by **ozzimark** » 10 Jul 2004, 19:08

slightly would be a lot less than 6k rpm

athough the throttle body sticking open seems to be the problem in this case.
vacuum leaks generally don't have enough airflow to get the rpm's that high, but you should probably have a look at em anyhow.
if neither of those solve the problem, have a look at the idler motor, despite the fact that it is very improbable that it is causing the problem.

potroast · Post by **potroast** » 10 Jul 2004, 21:35

ozzimark wrote:slightly would be a lot less than 6k rpm athough the throttle body sticking open seems to be the problem in this case.

Not really. It takes very little to get the engine to rev to 6000rpm when in neutral.

Guest (Daniel) · Post by **Guest (Daniel)** » 29 Sep 2004, 20:03

Thank you all.

I found on the WEB a safety recall from Volvo ... related to this situation.
I'll contact Volvo Canada in order to fix this problem ...

This problem has been described previously at the following address:
http://www.vmrintl.com/Usedcars/Car%20% ... 093-97.htm

Number: 94V173000: Potential # of Units Affected: 14000
Model Year: 1994
Summary: Under very cold weather conditions, ice crystals can form at the throttle in the engine intake system, and prevent the throttle from returning to idle. The condition can cause loss of speed control and can result in unwanted acceleration and a possible accident. Dealers will replace the throttle body, throttle cable, charge air cooler piping and crankcase ventilation hoses.