Engine: B5244: Revs dip, engine occasionally stalls after selecting 'P'

[blueblock]

Hi all,

I've recently got hold of a really nice 2001 V70 2.4 170 (one owner, FSH, yada yada) to go with my 240 - I've done a few things to it thus far but one thing has me rather stumped. From time to time when I take the gearbox (AW55) out of any of the forward or reverse positions into N or P, the revs drop and the engine stumbles a little before (usually) recovering to normal idle. Occasionally when put into Park at the end of a longer drive the engine stalls (it has never stalled when going into neutral). I always come to a complete stop and apply the handbrake before engaging Park with the gearstick. For the record, it idles absolutely fine the rest of the time, no other weird behaviour noted from the gearbox. Spark plugs are new and correct.

Has anybody else experienced this? Is it a weird artefact of the load coming off the engine when the gear is deselected and the pressure in the torque converter reduces and the ECU consequently backing things off a little too much? Any input appreciated.

[280E]

Sounds like an ETM problem - just do a search :-)

[oragex]

See above. Also worth cleaning the throttle body a little on these n/a, it is very easy to do https://www.youtube.com/watch?v=BGxVoGbDK1I

[davebb]

Hi also look for any air leaks, split pipes,
Dave

[ThomasG]

Been there, got tee shirt..

Clean the insides of throttle, may be worthy checking the air filter, too.

But main one is the throttle. Crud on the edges of the plate restricts air flow to levels below of what's needed for idling. This happens only with throttle "almost closed"- that is- dropping the revs to idle.
Some spray throttle cleaner, lint free cloth, screwdriver (star ir flat- depends on what hose clips you have fitted there) and about 10 minutes of time.
Don't be afraid to push the throttle plate to get behind it, just be sure not to leave anything that might be sucked into engine behind.

[blueblock]

Thanks guys. I'll keep an eye out for any of the other ETM symptoms, although none yet thankfully. I don't know if it's been replaced before. Unlike my 240, which has a wad of paperwork the size of a house, I have no documentation to tell me whether any work apart from regular servicing and a timing belt was done on this car.

I will definitely whip out the throttle body and clean it though. I did the same on my 240 a while back and it definitely improved the out of gear idle so fingers crossed it'll help here too.

Otherwise I have to say I'm really enjoying 5 cylinder life (turning circle aside, of course).

[ThomasG]

In the very unlikely event you need a replacement ETM, just give me a shout ..

I bought one (was told to by garage) when old one needed just cleaning.. Still have it..