toyota prius gen 3 engine knocking solved

lots of threads here. search google is easier, look for priuschat hits, ot put it in your search terms.

how many miles on your car? you need to clean the egr circuit.

search egr, intake manifold, oil catch can, head gasket, oil burning, coolant, knocking, shaking, cold soak and etc.

 

l’ve been using google search, 99% are for the cold start knock. Unless it’s the same issue?

280k, already replaced the whole EGR circuit.

 

sorry, i misread your post. i can only imagine engine wear, but i'm not sure.

 

Leak-down test.

 

No worries info it all the time

I suspect the same, it’s just odd how smooth it runs after the knock goes away.

Thanks, trying to find a shop to do that. I thought I read a post though that said due to the way they leak into the cylinder heads the test might not show anything.

 

do you get it on every cold start?

 

While not directly stated, I believe his knock is after warming up and under engine load.

LSPI maybe? Or is the car moving at high speed? (I'd initially try a higher octane fuel).

 

It doesn't do the cold knock currently, but it happened in the past a few times. Now it knocks while driving and after the engine is already warmed. So like 10-30MPH. Not sure if I've heard it do it at speeds above that. I initially thought the same thing, bad gas and then went with 93 octane and fuel cleaner. It didn't clear the issue. I might try it again, but currently I decided not to drive it as I'm afraid I'm going to throw a rod.

 

Knocking not at idle, not at full load, but under moderate load?

Checked the four small EGR passages in intake manifold?

 

I mean it’ll knock at idle upon startup, but not cold. If it doesn’t knock at start up while warm then it’ll do it while driving.

The EGR circuit, cooler and manifold were replaced a couple of months ago. I can’t believe it’s clogged again, but it does burn oil.

 

Just checking. There are, of course, other things that can contribute to driveability issues.

 

Yeah, I was going to do the injectors and plugs. I went with 93 octane and fuel cleaner which initially seemed to clear up the issue and then it started again. I have lost some coolant and for about 5 seconds the overheating light came on the dash. I think I may just throw some money at a leak down test to see if that's the issue or not.

 

@nicholas.bray
If you had knocking come back or use techron every 5k miles

Im having this issue and replacing spark plugs didn't help
Will try techron