NEW!!! Service Bulletin for Engine Knocking at Startup T-SB 0012-10

Thanks for the suggestion but I think replacing pistons and rings would definitely cost a lot more than just replacing the gasket.

 

If I needed to replace pistons/rings, might just spring for a new short block; they're around $2K USD.

 

Pistons and rings cost a LOT less than a short block.
Quicker with a short block though.

 

Yeah, I figured that. But for me, the tipping point was reading through the nuts-and-bolts of a block rebuild, ring orientation, pressing out/in the piston pins, checking the tolerance of same,, orientation of piston rings, checking crankshaft bearing races and their tolerances, checking condition of cylinders (and maybe honing), and so on. Pretty much totally overwhelming, for me at least; $2K for brand-new would help me sleep at night.

 

You always must hone with new rings...piston rings are easy to adjust.
Not sure about the wrist pins. I'd read and watched a video of them heating them and pressing them out.
Then I've seem them just use the same tool I have for removing the wrist pin, for a Prius of course, so
I don't know.
You could put in new rod bearings, but I'd bet the original ones would be fine. And since you aren't removing
the crankshaft, no need to check those bearings.
This is in the case of replacing the head gasket, and pistons/rings. If you bent a rod, or over heated the engine,
that's a different matter.
This would be the least expensive way for the "average" person to do.
Getting a Gen4 used low mileage engine and just using the block, would be a less expensive option then a new or refurbished
3rd or 4th block. Then you'd only have to worry about that rubber Toyota put in the block....
Labor is the most expensive part, for the most part.

Getting a Gen3 remanufactured full engine, with the new intake manifold and just swopping them out would be the quickest.

 

It's been a few months since I had the recall service done on my inverter. Mostly summer, but some early spring freezing temps.

Never once had the startup shake. It happened pretty regularly over the two winters season I've had it.

I don't wonder if there isn't some ECM changes that can help?

 

An engine machine shop does rebuilds like this several times a day. Its engine out so a lift is required but its the way pro mechanics and dealers do it. They outsource the technical block and head work to those with the experience and tools. Perhaps $500 in labor in an immigrant state like Texas.

 

What is the start up shake like?

My 2010 once in a while at startup made a noise that reminded me of the cooling fan hitting the shroud. Yes, I know the Prius has electric fans.

All of the sudden usually at start up the engine has this violent shake! I thought at first since it’s nearing 300k that it’s about to blow a rod, but once the shake goes away the engine runs smooth. Then I thought I gotta have broken a motor mount…

If I do have this shake issue I’m kinda surprised that it’s so violent now, though I did recently swap in a used manifold,

 

What was the reason for swapping in the used manifold, was it intake or exhaust, how recently, and if it was intake, did you check the condition of its EGR passages?

 

That's pretty amazing.

Second that. More info in my signature.

 

Damn it's almost like that's my car lol! Exact same noise. I've read a zillion fixes for this, spark plugs, intake, coolant issues. The car does sort of smell like it has a gas leak and I noticed some coolant loss. The overheating light came on the dash, I added some fluid and it went away...for now. Sounds like it's time to send her to the scrap heap

It was the intake manifold. I replaced that, the pipe going to the EGR valve, the EGR valve (was throwing an error code) and the EGR cooling circuit. All were plugged solid.

Kinda weird after that I also replaced the tires with Continental low rolling at the same time and am now getting 10 MPG less than usual (down from 44)/

 

Did I read correctly that you put in a used intake manifold?

What was the condition of the small EGR passages in that one?

 

lol yes used. It was sparkling clean, no blockage, came off a lower mileage wreck. Just to clarify I didn't see any blockage on my intake manifold (original one), but I bought another used one because from reading on here in cleaning the EGR circuit sometimes the manifolds crack. I had a mechanic change all the parts and give me the old ones back.

If the head gasket is leaking would you typically see fluid on the ground?

 

I don't think that's common. Maybe on the ground beneath the tailpipe in very advanced cases (after you've been driving with barn-sized white clouds behind you for a while).

 

I haven't seen any smoke at all yet. I just read the bulletin and it mostly occurs at or below 40 degrees. It's know where near that cold here yet. I'll have to find someone to do a leak test.

 

You won't see smoke until the head gasket is really bad. Even then the engine will smooth out after the initial rattling but the rattling is likely to occur after traffic light engine shutdowns rather than just cold starts. The coolant is burned through the cylinder and not leaked into the sump or on the ground.

Some get a rebuilt engine, some have a head gasket replaced. Any good mechanic can do either. Some report rebuilt engines installed around $3,500, or head gaskets alone for $2,000 with a rebuilt head. Other engine damage is a concern if overheated or excessive periods of rattling occurred. With a rebuild these concerns are mitigated and most can expect another 100k-200k out of the engine.

Brake booster failures are often more expensive than a head gasket repair or a new hv battery, at least when the booster is replaced outside of the special extended warranty.

 

Thanks for the info! Sadly around here trying to find anyone to rebuild an engine is like finding a pot of gold. I think at almost 300k it may be time to buy another Prius.

It’s now making that knock after warm up. It just started doing it after leaving a store a few mins after driving.

 

Welp now I'm prepping for her 10 to start anytime I guess . Thank goodness we've a few Corollas round here. Sienna van to 01 the good un

SM-A715F ?