MINI Cooper Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
63 Posts
Yes!! I thought I was the only one to experience this. It was an extremely heavy stumble/shudder when driving in heavy rain... only seen at part-to-half throttle and at specific RPMs (about 2500RPM if I recall correctly).

This was one of the many problems with my 2002S that led me to sell it.
 

·
Registered
Joined
·
63 Posts
ELECMININERD said:
Glad to know that I wasn't the only one out there.
Did you take it to the dealership? I know that it is a hard problem to duplicate...

-Jan
Hi Jan,

No, I never visited the dealer for this particular problem. Like you said, it's just too difficult to reproduce and I only experienced it only three times in a calendar year but the symptoms were so severe that each time it occured I wondered if I would be walking home that day. Unless the dealer kept the car for months, they would likely never see similar conditions, and even then not for long enough to diagnose this truly bizarre problem.


I'm going to go way out on a limb here and speculate on possible causes . Clearly, water is the mitigating factor, but I'm uncertain about the mechanism of action -- dunno whether the engine is ingesting water spray or we're facing a symptom of poor fuel mapping. Maybe the two ideas are related (e.g. the airmass sensor can't cope with water vapor, returns some bizarre value and the fuel control computer pulls the wrong values for the injector spray?). Maybe it's some other misc. electrical fault?

I've heard of some blown engines due to hydrolocking when driving through approx six inches of standing water due to the low-placed air pickup tube. Maybe this is related?? Is there such a thing as partial hydrolock (just enough water spray in the cylinder to make it difficult to compress, but not impossible)? Water vapor hitting an extremely hot surface (such as the inside of an engine) would cause the water to flash to steam, releasing a tremendous amount of energy. If it flashed to steam on the compression stroke, this would act a bit like a mild backfire on each stroke which might be perceived by the driver as a stumble.
 
1 - 4 of 4 Posts
About this Discussion
3 Replies
2 Participants
jonturner
MINI Cooper Forum
Join our Mini Cooper Forums to talk about your new Mini. From reviews, mods, accessories, reliability concerns and more, this Mini Owners Club is full of info!
Full Forum Listing
Top