Hello,

I'm new to the forum. I have a 2008 NAH with 95k miles. It's recently gotten very cold where I live, and I notice when I first drive the car in the morning, the engine makes a lound sputter/cluniking sound as I come to a stop. It seems like the car is trying to switch to EV mode, but the engine won't completely shut off. It also seems like it's worse when the blower is on, possibly due to the electrical load on the car. It goes away after driving for about 10-15 min, and hte car functions normally.

I had the oil changed at a mechanic a few months back (Sept), I'm wondering if he used something like 10w30, and if that would have an effect when it gets really cold out (say 20 degrees). I typically use 0w20.

Any other thoughts would be greatly appreciated.

 

I wonder if it's similar to the well-known rough shutdowns exhibited by the Gen 2 Prius (04-09 model year) when the ICE is cold (doesn't need to be cold out). Google for site:priuschat.com rough shutdown "gen ii"/

As for blower and electrical load, that's doubtful. As with Toyota hybrids, I highly doubt the NAH has any alternator. 12 volt DC power should come from a DC to DC converter and that gets powered by the HV bus. Doesn't matter if the ICE is running or not.

 

Thanks for the link, it seems to be the same problem. I'm wondering if new plugs, etc would fix it? I've owned the car for 4 years and this is the first year this has happened.

 

FWIW, Gen 2 Priuses exhibit the rough shutdown from the very beginning, when new. I've personally experienced it when it was brand new and I think it gets to be not as bad over time, or one gets used to it. It's just a quirk of the car and there's no fix nor any reason to.

My 06 Prius mostly sits now as I'm now leasing a '13 Leaf.

 

I think I may have gotten to the bottom of it. My 12v battery died and I replaced it, seems to have fixed the problem.

It seemed like the voltage was low, which affected the switch to EV mode when there was a power draw from the electric heater.

Thanks for the help.