A few niggly niggles!

[Johnnyz4coupe]

Hi all

My coupe might have a cold and i was hoping someone could try and point me in the right direction.

1. The ABS light come on and off intermittently which is annoying. I got the other half to take it into work last week (She works at Audi) and one of the techs read the codes and it said it was the ABS pump. So i've found somewhere that recons these for about £200 so that's sorted!

2. Lumpy idle!!
This is only after the car has warmed up and started back up. So if i go for a drive and start it back up again anytime within 3-4 hrs, it searches for about 10 seconds before settling.
It also happens after its warm and i turn it off and then back on again almost straight away.
Ive changed the spark plugs. Two of the plugs in the car were different makes to the rest. Not sure if that is something sinister but all six are now NGK Iridiums.
Also replaced the solenoid things at the front of the engine.
New oil and filter.
Cleaned the IACV and MAF sensor.

3. Flat spots
This happens under gentle acceleration and is worse under load.
Its hard to explain the acceleration thing. Its almost lie it hits a power band which happens at different revs.
The other day, the ECL came on and a day or so later, it went off. When the woman that controls my life took the car into work for this and the above issues, the only code that did come up was for the ABS pump!!
When i did some hard acceleration onto the dual carriageway after a day later, it was horrible. A massive flat spot that caused the engine tone to change, the growl noise. It spooked me a little so i came off the power straight away. The CEL wasn't on prior to this and hasn't come on since.
The car is always run on V-power and has the eco-boost additive run with it too.
I've checked the plugs and all are tight and not loose (with a torque wrench).
I've take all the coils off and cleaned them. When i put the back on, i rotated them.
I then ran the car up to temp and then unplugged each coil in turn. Unlocking each one resulted in the cylinder shutting down as predicted.

So now i'm stumped guys. No codes are thrown up. The CEL light comes on and off.

Please help me!!

[ph001]

Model might help!

[Smartbear]

Hi, I know the eccentric shaft sensor can give a lumpy idle & a loss of power-try disconnecting at idle to see if the idle smooths out?
It’s expensive but can be got cheaper via German eBay I think
Rob

[buzyg]

Model might help!

I'm guessing it's an E86 3ltr, but yes it would help OP.

[buzyg]

Here you go tis this one.

[Johnnyz4coupe]

Model might help!

I thought all coupes were the same? I have posted it up on the E85/E86 problem page.

[Johnnyz4coupe]

Hi, I know the eccentric shaft sensor can give a lumpy idle & a loss of power-try disconnecting at idle to see if the idle smooths out?
It’s expensive but can be got cheaper via German eBay I think
Rob

Thanks rob.
Where is the sensor?

JJ

[Johnnyz4coupe]

Found the sensor!

So i got the car up to temp, removed the sensor and it almost stalled but settled back down almost straight away.
It looked all clean and dry in there. I sprayed some contact cleaner in there and on the plug and put it back on and there didnt seem to be any difference.

[Smartbear]

Found the sensor!

So i got the car up to temp, removed the sensor and it almost stalled but settled back down almost straight away.
It looked all clean and dry in there. I sprayed some contact cleaner in there and on the plug and put it back on and there didnt seem to be any difference.

I’d rule that sensor out then
Rob

[Smartbear]

Model might help!

I thought all coupes were the same? I have posted it up on the E85/E86 problem page.

There is also an e86m with a 3.2l s54 engine
Rob

[AveZ4coop]

I had something similar when a coil pack started to die. I did get an occasional misfire, but no engine warning light/fault code, only happened under load. Was intermittent for about a month and then engine warning light and five cylinders......six new coil packs and plugs, and problem solved.

I don't know enough to say this is definitely your problem, but just thought I would share my experience as it could be the same. I got a full set of coil packs (genuine Bosch) for about £125.

[Johnnyz4coupe]

Thanks mate

I’m thinking that’s the next thing to try as it’s throwing up no codes to point me in the right direction.

Would that also account for the crap idle?

[ph001]

Changing coils won't harm but lumpy idle and flat spot would get me thinking about VANOS. You say you have changed the vanos solenoids but there could be something internal leaking oil presure. Ducklakeview on here has a lot of experience on VANOS so could certainly give you some advice.

Other possible thing is a blocked crankcase ventilation valve which is reasonable common on the silver topped 3.0Si - they changed the design in 2007 to integrate the CCV into the cam cover. On yours it is separate so more serviceable. There is also a pipe that runs from it down to the sump that can collapse. I'm not convinced this would only cause your problem when stopping and re-starting straight away / within a few hours though.

Given the very noticeable flat spot and growly sound, vanos is more likely.

There are 2 off DISA valves on the 3.0Si. They don't fail that commonly like on the M54 cars but one is relatively easy to get to and it would be worthwhile removing it to see if there is a lot of oil in your intake. If there is then the CCV is defo stuffed. The 2nd DISA valve requires the removal of the inlet manifold to inspect. If they fail, it can give issues similar to vanos (i.e. poor idling and flat spots).

[Mister T]

Worth checking for splits in the hose between the MAF sensor and the inlet

[Smartbear]

Worth checking for splits in the hose between the MAF sensor and the inlet

The si engine doesn’t have the bifurcated section that commonly splits on the m54 engines, of course the hose can still split though
Rob