P80 Idle Control slide or IAC 9454745 Cleaning

[CTHarris88]

So i swapped out my MAF with an extra my uncle had lying around. ( he has three volvo's including an 850 wagon same year as mine. Seemed a little better but not by much. He looked sort of behind the the power steering fluid pump and there was a little hose that seemed to go into the intake manifold on the passenger side. (im assuming this is the hose someone mentioned before maybe 3 inches long give or take. ) I honestly didnt see this when i was looking for it, that because there is barely anything left to it. The two ends were pretty much all that was left. He wasnt sure what the hose was called so I figured I'd ask here so i can find out what it is i need and go get one. Also someone mentioned that if its really bad I may ne a PCV job? I'm no rocket scientist but im pretty sure 75% of the hose qualifies as rotted or brittle.

[erikv11]

Yeah that is why I said drive it around - it doesn't sound like replacing the MAF will do you any good, more likely it is that vacuum hose we talked about. That hose is part of the PCV system, which almost certainly needs servicing. The hose in question runs from the end of the intake manifold back to the flame trap.

Matthew1 posted a good solution for when that hose rots out. Do some searching, you will find his thread, you can do that repair for now to get it back on the road for low cost. Then start reading up on PCV repair.

[atajalo]

great post - worked for me !

[panda30]

I have a question do u unplug Mass connetor while car is running or turn off first, to see if idle improves,thanks

[helohero]

Turn off the car first, then unplug the MAF. Then restart and see if the idling is any different.

[theador]

Can you use carb cleaner in the IAC?

[theador]

I hear a lot of talk of the vacuum hose on the inlet manifold near the power steering pump,but I still cannot find it on my 1994 850 T5 estate. Does this year definitely have it?

[polskamafia mjl]

Can someone explain what rotates on the IAC? JReed mentions twisting the IAC in your hand and making sure the plate rotates freely. I have a spare IAC and I don't see any possible way of twisting it and getting anything to spin.

[jreed]

Good question! If you twist the body of the IAC briskly in your hand, the internal baffle plate will rotate as well. When the passages are nice and clean, the plate will rotate easily without sticking or hanging up.

Internal baffle of IAC valve. Twist IAC in your hand and the baffle will rotate (if clean).

Volvo 855 IAC valve showing baffle.jpg (89.66 KiB) Viewed 2518 times

[polskamafia mjl]

Thanks! That makes perfect sense now.