I washed the Prius Saturday. It was cold and I could not use EV mode to move it in and out of the garage without the ICE firing up. I shut off the car when the ICE was warming up with a high RPM. I just could not sit there and let it burn gas to finish a warm up. Today I drove the car. The ICE was running rough when first started, for about 10 seconds. I went on my way and did a 60 mile drive. All was well. No CEL. I am thinking since I shut it off during warm up (high RPM, running rich), gas fouled up one of the plugs, and took a while for it the clear up. What do you think?
I thought those were related to water condensation in the intake manifold. I have a 2012 which already has the revised manifold. Yesterday was also super dry, I doubt any water go to the intake manifold from the wash.
I think there was a TSB for new engine mounts too for roughness all around. Mine supposedly has the revised mounts too. I hope my theory is right. The 60 mile drive should have burned off any excessive fuel leaked down into the crackcase too...
Just started mine up this morning in garage and about messed myself when it was banging around until I shut it off, only have 10,000 on odo on my 2012. I restarted it and have had no repeat..yet... WILL be informing dealer at next o/c unless it happens again..
Yes, make sure the dealer takes a report on the issue. It is apparent the modified intake manifold didn't fix the issue. Perhaps they will try something else if enough owner's report the issue.
Johnny, The pair of times this has happened to me was when I powered the car up, and shut it down when the engine hadn't run more than 3 - 5 seconds. It had nothing to do with cold temperatures nor water, just me trying to minimize useless engine warmup.
The key workaround here is to not shut off the ICE during its warmup cycle. Evidently the TSB's have not solved the root cause. Also some dealers will require the vehicle to throw a DTC code before they will perform the TSB's. Spiderman has the right idea to have your dealer take a report on this to keep them informed that the manifold fix did not solve the problem.
I'd invite you to go out to your car after it has sat for awhile (a few hours, overnight works), press the power button, let the engine come to life and then power down the car after 2 - 3 seconds. Then restart and see if you have the engine knocking. Honestly, I wouldn't recommend you doing it, because I don't know if the engine knocking is damaging, but if I do that to my car, I'm pretty sure to get the engine knock event.
If I start the car cold, move it around the driveway and the ICE starts, I keep it running for 5 minutes or until it turns off, whichever comes first. That prevents a noisy startup next time. If I accidentally turn the engine off after only a few seconds, the next startup will almost always be noisy and require a turnoff and restart to cure the noise.
Yep. I think I learned this. Must be some kind of gas fouling the plugs or IM from the super rich warm up cycle. Thanks for everyone for confirming the experience.
I don't think you need to run it for 5 minutes (but that will certainly work). 10 - 15 seconds should be plenty.
I just had my 10k service done on Monday. Started the car this morning after it was cold soaked to about 32F. I was surprised by how much engine noise i heard after I initially started it. Took about 6-8 seconds to quiet down. Concerned me enough that I checked my oil level. That was okay. I'm adding oil pressure to my ScanGauge II tonight, to see if that has any bearing on this concern of mine. (Never mind, just found out there is no oil pressure reading available) Now what? Never had it happen in previous 10k miles or 98k miles on my 2008 Prius.
Not much you can do other than report it and have the dealer document it, even if it didn't throw the CEL.
Jonny Zero, Where can I find this TSB about upgraded engine mounts to smooth things out? I never experienced the 'roughness' but I have a little buzz in the right most area of the dash that is only there at a certain engine RPM. Maybe new engine mounts would make that go away, you think? BTW, Quagmire is a real creep, you think?