Is it considered normal for the ICE to shake lightly here and there (not constantly though) during cold idle? Its not misfiring hard or maybe not at all from what I can tell, no check engine light illuminated either. Car has 59,000 miles on it. About 3 weeks ago I cleaned the throttle body and removed the MAF for a cleaning. It seemed to smooth it out a little bit. Normal?
Sometimes my cold idle is not all that smooth either, it's never real bad though. A couple of times a year I'll add a bottle of injector cleaner to a tank of petrol, and I think that does help a bit.
I would say that is reasonably normal but if you are bugged by that, you might remove and inspect the four iridium spark plugs. Also look at the spark igniters while you are at it for rust stains (due to water getting through the igniter O-ring seal) or cracking in the plastic body, and replace if any issues are seen.
I'd say it's probably normal. For me, it's not so smooth either and the engine RPM varies in cold idle... could be a few seconds at one speed, then it changes and so on.
This is comforting information guys. I did recently notice the engine seemed to shutter just a bit when shutting off at a light. I was wondering about it. My son suggested running some injector cleaner through it and it does seem to have helped some. But who knows. Just hearing that it's reasonably normal helps the most. Thanks.
Thanks for the replies! I get the cold shut off shudder too once in a while and I understand the reasons for that, but this thread isnt that. Im talking about when you are stopped and the ICE is idling or when I first start the Prius and am backing out my driveway; the idle is rough. Not so bad, as say a cylinder misfire, and to be honest most people probably wouldnt even notice it, but as a gearhead I notice it. Patrick - I thought about that as Ive read on here about water getting into the spark plug wells. Right before I bought the Prius this past fall, the previous owners had a full detail done, including the engine bay. If the detailer used water with any force to wash/rinse the engine, I can definitely imagine some water in the spark plug wells.
Yes, there can be intermittently rough shutdown. It can either have a VERY noticeable shake at shutdown or sometimes (w/o the shake) sound like dieseling (similar to old cars overheating cars that made noises after you shut them off). There should be plenty of old threads on the intermittent rough shutdown.
