ICV

Post Sun Sep 20, 2020 5:57 pm

I’m talking here about an S50 engine which runs great idles terrible, surges, smells rich although the rev counter is steady as a rock. No buzz from ICV, put a stethoscope on it, no sound. Been through looking for air leaks, smoke tested so have convinced myself the fault lies with the ICV. Now have a little book which says between pin 1 and 2 = 20 +/- 5 ohms. Pin 2 and 3 = 20 +/-5 ohms Pin 1 and 3 =40 +/- 5 ohms. I have the one fitted to the car and a spare and both read just over half those readings. The ICV which came of the car is clean, rattles when shaken. All the pipes leading to/from the ICV are clean
I get battery voltage on the red/white wire (pin 2) if I use the chassis for earth. If I use pin 1 or 3 I get 8volts.
The b3 at 170k idles like new and the ICV can be heard buzzing away. Can anyone offer any advice.

Post Fri Sep 25, 2020 10:18 am

ICV as in Idle Control Valve? if so give it a clean in petrol then try again.

Post Fri Sep 25, 2020 11:05 am

Been cleaned to death, all the intake in bits now and although the pipes look good I found a pipe from the intake to oil separator which is collapsed, soft as, picking up a new one this morning. Not confident that will solve the problem. We’ll see.

Post Wed Sep 30, 2020 12:52 pm

HenryM3 wrote: ↑
Fri Sep 25, 2020 11:05 am
Been cleaned to death, all the intake in bits now and although the pipes look good I found a pipe from the intake to oil separator which is collapsed, soft as, picking up a new one this morning. Not confident that will solve the problem. We’ll see.

Did it end up fixing your problem?

Post Thu Oct 01, 2020 7:32 am

HenryM3 wrote: ↑
Fri Sep 25, 2020 11:05 am
Been cleaned to death, all the intake in bits now and although the pipes look good I found a pipe from the intake to oil separator which is collapsed, soft as, picking up a new one this morning. Not confident that will solve the problem. We’ll see.

Be easy with the cleaning, i cleaned the ICV in my 325i with brake cleaner, ended up doing more harm than good, since everything was dried up and the valve was sticking mechanically. I picked up a used one, used WD40 instead and it is fine. I believe carb cleaner is also a good alternative, since it leaves behind a light film? unsure never tried it myself.

Post Thu Oct 01, 2020 11:18 am

I did use carb cleaner and on closer inspection found another pipe (icv to airbox) perished. Pipe is about 6" long but is costing over £30 at BMW and has a delivery time of the end of October. I am tempted during the wait to change the vanos solenoid "o" rings for the upgraded e39 m5 ones. On mine they have the orange sealer round the solenoid body which I believe indicates these are the original ones.
Still don’t know if the icv should buzz with just ignition on, I have read it’s controlled by the ECU as necessary. One of those things you wish you’d checked when everything was working fine.

Post Wed Oct 07, 2020 9:02 pm

Went ahead and decided to do the solenoid "o" rings, Ordered from local dealer who wanted £59 for o rings x8 and gaskets x2, after some haggling we settled on £48.[img]

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