When I take my foot off of the gas the car dies brutally with a clanking sound - literally sounds like the starter has re-engaged or it ran out of oil or some other catastrophe. But then it starts right back up nice and smooth.

I've been revving it to 3500 - 4000 in park, sport mode on, trying to purge air from a recent coolant top-up extravaganza. That procedure is working fine - I can see the temp rise and fall as the air works it's way through the system. However, as soon as I take my foot off the pedal I get the death clank.

Has anyone had this happen or have any bright idea as to why it's happening?? I'm pretty worried about it. Definitely seems abnormal.

Thanks - Sesan

 

Turbo? Could be a loose intercooler connection/air leak.

 

What are the details of your car? Does it do this when under load or only in idle? Without knowing more, it's hard to tell, initially sounds like it could be a massive vacuum leak, ignition/flooding issue, electrical issue to cut out so suddenly. Have you had codes read?

 

No - it only happened the one time under the specific circumstances that I laid out above. I've had no other issues. It has a rough idle but that smooths out once the oil comes up to temp and I think that is relate to the AOS. I haven't been able to reproduce this problem - granted I haven't wanted to either so I didn't try very hard! But I did have it revved the next day to about 3500 for a few mins - there was a slight stumble when I took my foot off the gas but I also took my foot off more gradually.

You know - it is almost as if it had a bad dashpot - except it doesn't have one of those.

What bothered me the most was the horrible noise it made - not so much that it died.

Anyway - I'll keep an eye on it.

Thanks for weighing in!

 

Looks to be AOS assuming yoour coils are ok.... Pop off the cap and check diagrham for tears.. but most likely, it is.... It makes the car run like ****.... Get a new one and the car will be good to go... If not, may be looking at the low pressure fuel pump in the tank

 

I did check the diaphragm and it looked OK. However, I had the intake off and I noticed a bunch of oil on that AOS side of the plenum and the valves on that side are a lot dirtier. There is another diaphragm inside which I suspect has failed. I also ordered a new cross-over pipe as mine is broken where it connects to the cam cover - it seems to be sealed OK but it could be small vacuum leak.