Bmw E36 3 Series Hunting Problem

[Dominic]

Hi guys,

I was just wondering if any of you have come across this before. I have a 320i 92 model and every now and then (especially when the a/c is on) the rev counter begins to hunt... ie from 1000rpm to 2000 and back to 1000. it keeps happening quite frequently. I thought the issue would be the airflow sensor and I replaced it. The car peforms much better but the problem hasnt stopped.

Does anyone have an idea as to what this could be? Right now Im thinking a hose leak/loose hose from one of the hoses going into the engine letting in extra air???

Any help would be appreciated...

[VWvortex]

  Dominic said:

Hi guys,

I was just wondering if any of you have come across this before. I have a 320i 92 model and every now and then (especially when the a/c is on) the rev counter begins to hunt... ie from 1000rpm to 2000 and back to 1000. it keeps happening quite frequently. I thought the issue would be the airflow sensor and I replaced it. The car peforms much better but the problem hasnt stopped.

Does anyone have an idea as to what this could be? Right now Im thinking a hose leak/loose hose from one of the hoses going into the engine letting in extra air???

Any help would be appreciated...

I belive this is a common problem on Peugeot's as well.. something to do with the speed sensor.

Edited April 6, 2008 by VWvortex

[madmax]

I've had this problem caused by the TPS- Throttle Position Sensor.

[Devinda_Z]

  madmax said:

I've had this problem caused by the TPS- Throttle Position Sensor.

not too sure if this is an inherent issue with BMW's ,but in general i too concur with madmax that its possibly symptomatic of a faulty TPS..

[The Don]

In cars using Mitsubishi made idle speed controllers (Hyundai, Proton) this problem is caused by that controller failing, but I do not think BMW uses Mitsubishi parts, but it could be the equivalent

If its not the TPS or the above you should check your ECU out.

[pathola 1]

  Dominic said:

Hi guys,

I was just wondering if any of you have come across this before. I have a 320i 92 model and every now and then (especially when the a/c is on) the rev counter begins to hunt... ie from 1000rpm to 2000 and back to 1000. it keeps happening quite frequently. I thought the issue would be the airflow sensor and I replaced it. The car peforms much better but the problem hasnt stopped.

Does anyone have an idea as to what this could be? Right now Im thinking a hose leak/loose hose from one of the hoses going into the engine letting in extra air???

Any help would be appreciate

Hi

I use a 92 318i and Felt my tacho also climbing up for no reason when A/C is on. 1000-1500 range but not all the time. showed to M*****'s and said the symtoms are commonn some UK imports as the A/C's not factory fitted. For some UK imports iddle is way too slow and it's a bit hard to pull the AC...... This is what M's No1 guy had to say......

[maithri]

Check the throttle body for contamination, clean if oily, then drive normally for a few miles to allow the self learning parameters to re set. The later models have a vaccum valve controlling the breather system that fails and allows extra air to foul the mixture. I have seen this only in the late 90's early 2000 onwards models. It goes without saying that any air leak from the hoses and pipes in the intake system can cause trouble.

Maithri

[lowrider]

Hi

From the info you have given, i take it that you have the straight 6, single cam motor with timing belt. If so, under the inlet manifold, there is a pair of valves which are connected to vacum hoses to compensate inlet man vacum when you switch on the ac.It basically picks up the iidleing and keeps it stable with the ac load.Check them n make sure they are connected without any leaks.Thats a bit of an old motor with minimal electronics so doesnt like vacum leaks! The airflolw meter can also do the same but if you pry open the top cavr on the airflow, its quite easily adjustable.