Engine knock @ 119,820 miles on a 2013

You might want to edit the title. I was wondering how you already had 119,820 miles on a 2023 Prius.

 

Use the report button, ask moderator to fix.

 

The knock is very likely due to leaking head gasket, and the only thing that fixes that…

Was there an earlier cleaning, and at what miles?

 

Dam a 2023 that’s already knockin.

 

The best thing is to diagnose quickly and fix hg if necessary, using a quality borescope inspection in the hands of an experienced mechanic. It is about the only reliable test early on in these cars.

Not much you can do otherwise that is not a waste of money or does not cause other problems down the road. Assuming a head gasket is failing and you don’t want to get rid of the car quick.

These engines don’t have classical hg symptoms like combustion gas in the coolant or coolant in the oil. Early stage hg leaks are rarely detectable with compression or leak down tests.

First the waste of money options:

Egr cooler cleaning (do it with the hg job); new plugs especially if already changed by the maintenance schedule (although this sometimes clears it for a week or two); new coils or injectors (waste of money unless they fail). If they fail they don’t clear up quick and run good for the rest of the day.

Want to clear it for a month or two and end up changing the hg and radiator and heater and thermostat? Pour some block leak sealer in the coolant. Sometimes an extra bonus down the line is a bent rod, broken piston or hole in the block.

If it’s an oil burner as well get a rebuilt engine.

 

After 3 days of rain, I don't think jumping into a head gasket replacement is the first thing I would do. I've seen several cars that have a significant misfire for the first minute after starting after a decent rain. Would be crazy to jump into a multi-thousand dollar job that fast.

 

Look at the rest of the car really carefully Is this something that you want to try and keep another 3 years armrest door panels happy with everything about the car except the engine problem All righty then We were not so we did not. Funny story my wife thought she was and did and is turned out to be one of the most expensive cars we've ever owned and doesn't go anywhere The proverbial driveway queen so it just sits getting ready to get parted out although my other half sits there and tells me it's going to get fixed and it's going to ride again and I'm like yep well you'll need to get a better job to make that happen as you see what this is costing so it'll sit out here for 3 years and nothing will happen with it finally I'll get it to salvage after everything is falling down out of the car all around it some people just don't know when to say when and that's a very tough thing to have to learn.

 

How about checking the coolant level? Simple, fast, cheap. If it's down that's a good clue for a bad headgasket. Mileage seems too low to be the head gasket, but you need to get it sorted fast and I wouldn't drive it that way.

 

DANGER DANGER WILL ROBINSON DANGER!!!!
The more you let it knock, the more damage you are asking for.
It can/does cause a rod to bend/break and possibly go through the block.
And possible damage to the head.
You should not drive it.
You could try to put a vacuum on the coolant tank. Maybe the won't drip
into the cylinders.

 

Sitting in drivers seat, cylinder one is on right end. Standing at front, cylinder one is to your left, next to engine coolant reservoir, timing belt cover.

swap the coils/plugs and see if misfire code changes would be my first test.

 

Cylinder #1 is the one closest to the timing chain/harmonic balancer. The cylinder closest to the transmission is #4. Since the event lasted only 25 seconds; I doubt you have an ignition coil or spark plug issue. This may be just a one-off, too much moisture in your oil catch can mod. Just monitor it and start saving for a head gasket replacement job. If this starts becoming more frequent, you should get the HG replaced as soon as possible - to avoid engine damage. Ditto, if the coolant levels begins to drop - it probably isn't noticeable now, since you caught it early.

Good luck......

 

^ Would be good to know. Also, was intake manifold cleaned?

 

Not oil catch cans are equally effective. And even the best won't stop it all. It's a fine mist, really flying through there; you waylay some, but not all. I've got a couple of Moroso 85474's, in series, and still there's a sheen at the intake manifold nadir.

 

The others are cleaner then?