Me W124 is idleing a bit mad Ted!

[Slaphead]

Ok, I've had my manual W124 2.0 for a few years now and it's been great but it always idled a bit on the low side..... if I wasn't careful I'd stall if moving off at lights etc. Anyway, I had the oxygen controller (is that right? - could be air sensor?) changed and while it ran a little better my exaust (which was a little rough) became very rough! I changed the front section of the exhast - no real difference. I've now changed the back section and the revs are now up to 1,500rpm while idleing! No mad increase in fuel consumption though.... but,... the exhaust (a Europarts one) isn't sounding much better than it was at first

Any ideas?

 

[mike65]

Dougal, I dont think its anything to do with the exhaust, the fact you have a high idle suddenly might have something to do with a sticky throttle (its a "102 engine" issue) or possibly the Air Idle Valve. It might be failing, or you could have dodgy electrics or connecting air pipes.

Mike.

 

[Slaphead]

Thanks Fr Mike,
I'll try the trottle first - no harm giving it a clean anyway, it's a problem I've had before and it's easy to sort out. I don't think it's electrics... purely because this has coincided exactlywith the exhaust change, but the air pipes is an obvious one really and I'll check those tomorrow too once I get the suit off!

(Sorry if you now have an image of me standing in shirt and boxers leaning over the wing of a w124!)

 

[tom7035]

Hi slaphead, you could try the following, which would only take a few minutes and no cost. If it doesn't help then you haven't done any harm anyway, and in the meantime others with more expertise than I will undoubtedly come in to help you.

There's a black plastic-like cover about 5" x 3" on the side of the throttle body which uses 4 'security' torx screws to prevent 'unauthorised' access. (These screws have a pin in the centre so you will need the torx bits with the hole in the nose to undo them). Inside is a very lightly sprung (or weighted) electronically controlled lever 'gizmo' which on mine was sticking and affecting the tickover in all sorts of ways. A squirt in the innards with magic WD40 did the trick! This was around 6 months ago and no problem since.

Good luck.

 

[Slaphead]

thanks Tom, I'll try that.

 

[Slaphead]

I forgot to mention that the idleing speed is often erratic and sometimes the engine starts "hunting" - revving all by itself but as if I was pumping the acclerator.

 

[tom7035]

Exactly as mine was.
Good luck.

 

[stwat]

Hi slaphead, you could try the following, which would only take a few minutes and no cost. If it doesn't help then you haven't done any harm anyway, and in the meantime others with more expertise than I will undoubtedly come in to help you.

There's a black plastic-like cover about 5" x 3" on the side of the throttle body which uses 4 'security' torx screws to prevent 'unauthorised' access. (These screws have a pin in the centre so you will need the torx bits with the hole in the nose to undo them). Inside is a very lightly sprung (or weighted) electronically controlled lever 'gizmo' which on mine was sticking and affecting the tickover in all sorts of ways. A squirt in the innards with magic WD40 did the trick! This was around 6 months ago and no problem since.

Good luck.

That would be the air flow sensor. I think i need to have a look at mine reading some of the probs.

Stu

 

[flyingtech55]

Hi Guys

Did you not read the post I made regarding the same problem I had on the M102 (E) engine with the same unstable idle, hunting, stalling, revving up all by itself etc..

It was the idle switch. I supplied the part no. price etc. It definately fixed mine and was much, much cheaper than the idle air valve.

Gliderman

 

[Slaphead]

Hi Guys

Did you not read the post I made regarding the same problem I had on the M102 (E) engine with the same unstable idle, hunting, stalling, revving up all by itself etc..

It was the idle switch. I supplied the part no. price etc. It definately fixed mine and was much, much cheaper than the idle air valve.

Gliderman

Sorry GMan, missed that one!

 

[mike65]

Hi Guys

Did you not read the post I made regarding the same problem I had on the M102 (E) engine with the same unstable idle, hunting, stalling, revving up all by itself etc..

It was the idle switch. I supplied the part no. price etc. It definately fixed mine and was much, much cheaper than the idle air valve.

Gliderman

I should have thought of that when I mentioned sticky throttle, that unassuming item can cause much grief.

Mike.