My 1995 850 T5-R started rough idling very suddenly. While I have been troubleshooting I find that my IAC Valve is running continuously with the engine cold and in ignition switch position II. After a brief start to check for roughness and vibration the IAC also runs for a couple of minutes until the relay kicks it off. This is the lone relay at the center of the fan shroud and right in front of the turbo intercooler hose.
Is it normal for the IAC valve to be buzzing for an extended period? Tomorrow's job is to clean the throttle body and the IAC valve. The throttle body inside of the throttle plate is very filthy, the plate itself is varnished up. But looking into the EGR valve it appears to be a very clean EGR inlet and hose, I'm guessing PO did that fairly recently.
Any ideas or suggestions appreciated. New plugs and distributor / rotor today. Aftermarket spark plug wire set looked to be newer so not replaced yet.
How long should the IAC valve motor run for? And is mine stuck from the gunk in the lines?
1995 850 T5-R IAC Idle Air Control
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Volvo Manic
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- Location: Spencer, TN
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Ozark Lee
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The IAC valve will continue to run after the car is shut off but it normally isn't for minutes, maybe 30 seconds or so.
Cleaning the IAC valve is pretty easy and about any solvent will work. I've even used brake cleaner which is about as harsh as it gets.
...Lee
Cleaning the IAC valve is pretty easy and about any solvent will work. I've even used brake cleaner which is about as harsh as it gets.
...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
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Volvo Manic
- Posts: 11
- Joined: 10 June 2012
- Year and Model: V70,2000
- Location: Spencer, TN
Thanks Ozark Lee
I'm going to clean that up next and see.
The weird thing is the hose from the top of the IAC to the intake manifold is fairly new (definitely not original) but has the Oetiker clamps on it. Do dealers service departments install those OEM clamps when they are doing servicing?
The PO was constantly after the dealers service department for hard starts or no starts on wet days or after a rainstorm since the car was very new and under warranty. It's just always been a part of this cars heritage it seems. Looking at the long list of items they replaced it looks like they were just throwing parts at it.
I did new O2 sensors this summer at 100K miles for some bad mileage and then finally throwing a code. I found out that is at least the second set of O2 sensors replaced on this car.
Interesting, I just remembered my 1995 850 has an OBD-II reader on it, how did that happen?
It also has the flashing light system under the hood beside the windshield washer reservoir.
I'm going to clean that up next and see.
The weird thing is the hose from the top of the IAC to the intake manifold is fairly new (definitely not original) but has the Oetiker clamps on it. Do dealers service departments install those OEM clamps when they are doing servicing?
The PO was constantly after the dealers service department for hard starts or no starts on wet days or after a rainstorm since the car was very new and under warranty. It's just always been a part of this cars heritage it seems. Looking at the long list of items they replaced it looks like they were just throwing parts at it.
I did new O2 sensors this summer at 100K miles for some bad mileage and then finally throwing a code. I found out that is at least the second set of O2 sensors replaced on this car.
Interesting, I just remembered my 1995 850 has an OBD-II reader on it, how did that happen?
It also has the flashing light system under the hood beside the windshield washer reservoir.
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Volvo Manic
- Posts: 11
- Joined: 10 June 2012
- Year and Model: V70,2000
- Location: Spencer, TN
Updaye,
IAC valve not that bad at all, just a really thin layer of emissions deposit. The valve itself was very easy to open. Terrible throttle plate and surroundings though.
It looks like my IAC valve and motor may not be working though. The valve remained closed with the IAC motor running in a cold engine and outside air temperature 65 degrees. I don't know at what temperature it is commanded to open.
The resistance between adjacent terminals on the IAC motor is 12 Ohms, and it is 24 Ohms between the two terminals that are not next to each other.
IAC valve not that bad at all, just a really thin layer of emissions deposit. The valve itself was very easy to open. Terrible throttle plate and surroundings though.
It looks like my IAC valve and motor may not be working though. The valve remained closed with the IAC motor running in a cold engine and outside air temperature 65 degrees. I don't know at what temperature it is commanded to open.
The resistance between adjacent terminals on the IAC motor is 12 Ohms, and it is 24 Ohms between the two terminals that are not next to each other.
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