Seven days idle/loud clatter on startup

[Wots]

I went on vacation for seven days. When I came back and started my 08 Prius it sounded like a diesel engine. It ran real rough for 10 seconds. I assume it was the valves clattering for lack of lubrication? Other wise it seems to be running fine.
I have 34000 miles on it and use Pennzoil 5/30. Anything to be concerned about?

Thanks

[cnschult]

5w30 is correct

is it Pennzoil platinum synthetic with adaptive molecules?? (synthetics work better in cold weather and last much longer than conventional oil) hint: synthetic oil + a toyota filter will only last 11K miles, but synthetic oil + a fram extended guard filter will last 15K miles and that filter is only a dollar more.

even running an engine for 10 seconds w/o sufficient oil is dangerous, it can seize the engine. When the car is at rest oil goes back into the pan, when the car starts the oil pump circulates the oil, if you have a faulty oil pump you don't have much time to get it fixed free under warranty. I would contact your dealer.

[qbee42]

The Prius doesn't start its engine (ICE) like an ordinary car. Since the Prius has a large and powerful electric motor to do the starting, and another even larger and more powerful electric motor to move the car without the engine, the Prius plays it safe and spins up the ICE before starting. The ICE is spun up, oil pressure is verified, and only then is spark and fuel applied.

Tom

[acacia987]

i sort of have a similar question. ever so often on the first start of the the day i will get a similar clatter when the IC engine turns off. Its sporadic, and i asked the dealer but was unable to get it to duplicate the sound. any thoughts?

[qbee42]

Originally Posted by acacia987

i sort of have a similar question. ever so often on the first start of the the day i will get a similar clatter when the IC engine turns off. Its sporadic, and i asked the dealer but was unable to get it to duplicate the sound. any thoughts?

The Prius spins the ICE to a preset stopping position. This facilitates a clean restart. Sometimes the spin to the stopping position is rougher than others, especially when the engine is new or cold.

Tom

[jayman]

The only time I've had an issue with valve clatter on startup with other cars, is if I used a cheap aftermarket oil filter. Depending on application, the anti drainback valve may be poorly made, or missing, allowing a very dry start

[richard schumacher]

Don't overlook the obvious: go check the oil level.

[priusguam]

I came back from a long vacation and exactly the same thing happened to me. Scared the crap out of me. In my case I also received a bunch of warning lights about 5 minutes later and ended up replacing the main battery under warranty. Although I'm pretty sure the two issues are unrelated. From now on when I'm away for more that a week I will have a friend start my car regularly.

BTW, it runs fine now and hasn't done that since then. Im glad because Ive owned a lot of second hand cars and am pretty savvy mechanically and I've never heard anything as rough as that start up on my Prius.

[uclabruins]

Uh oh. I'm worried about starting my Prius. I've been away for about 10 days, so I'll see if I hear a similar noise when I start it tomorrow.