Not sure if I should continue a thread or start a new one. Recently bought a 2010 Prius from an auction 190,000 miles on it. I have another 2010 Prius that is running great at 160,000 miles. After winning auction at $3, 000.00, I started engine with the dreaded death rattle, drove it home and began removing engine components for a head gasket replacement. I found the service bulletins and decided to replace the pistons and rings as well with Toyota parts (one of the piston rods was bent). Had the cylinder head machined with a complete valve job. Lightly honed the cylinders for for a few seconds just to clean them up a bit. Reinstalled everything while paying close attention to all timing marks. Upon starting the engine I heard rattling and the engine shut down on its own. Alright, I must have missed something and begun disassembling everything again. Timing marks remain in perfect position. I put a borescope down thru the spark plug holes and there is debris and carbon on top of the piston (the valve hit the piston possibly). I am continuing with dis-assembly and will be removing the head tonight after work. Could the machine shop have missed something? After reassembly the first time, the only thing not connected was the ground strap to engine block. Any thoughts about my issue. Any help would be appreciated. For what it is worth, I have watched all the Youtube videos and have the Toyota Service Manual.
Many people do hear the knock after first rebuilding their engine. You should have ran it around the block and then see if anything changes afterwards. Did you clean out the intake and EGR circuit?
There was a couple of Pine Hollow Auto Diagnostics video posted here recently: customer DIY'd a head gasket replacement, engine had bad shake thereafter, and what shook out (excuse the pun) was at least one of the rockers atop the valve stems and hydraulic adjusters had fallen off. He found it after exhaustive electronic diagnostics, eliminating everything else first. Commendable approach, but if it's not too much hassle might be worthwhile to just the pull the valve cover off again and check. (If you haven't already gone beyond that, on your recheck.)
I appreciate the responses. I couldn't drive the car as the engine shut itself down and freaked me out a bit. I have done jobs like this years ago, so I am not completely clueless... just a little. My code reader stated an all cylinder misfire? I forgot to add in the original post, that I also installed new coils, plugs, EGR valve, water pump, timing chains and gears. I did clean out the EGR cooler (wasn't clogged) and the intake manifold (wasn't very dirty). I just pulled off the EGR and remaining coolant hoses last night and I am ready to pull the head again. I can only work a hour or two at night due to my job. I keep going back to timing. If I remove and re-install the the cam shafts with the 2 timing marks on the cams and the (1) on the crank located where they are supposed to be, pistons 1 and 4 both completely up, everything should be spot on correct? I don't know the correct firing order off the top of my head, I just go from left to right for visual purposes. This time, I am going to measure the cylinders in the hopes they are still within tolerances. Thank You
"IF" they timing marks are correct for both cams and crank, there is no reason to remove the head. It's sound more like a disconnected vacuum hose, or electrical connection. How long did it run? Did it actually RUN, or just turn over? The hybrid battery will turn the engine over for about 10 seconds waiting for the engine to start. Check the rocker arms and lifters, there are little caps that sit on the valves. They can fall off very easily. Since you have NEW pistons, there should be NO carbon on top of them. Did you clean the intake manifold? There might of been debrief in the ports? You should look for the simple things first.
See post #5. You only have to remove the rocker arm cover then you can see where the cam sprockets are. If you put the engine at tdc on the crank, look at the valves for #1 cylinder, closest to the sprockets. "IF" the intake and exhaust valves are closed, and the positions line up in the correct positions, your timing is correct. If either valve is open, rotate the engine another 360 degrees and check again. Do not worry about the special plates on the chain used to intially set the timing. But, if you rotate the engine enough, up to 30 times. ALL 3 special links WILL line up correctly. "IF" the timing is correct. Removing the spark plugs makes it easy to rotate the crank. You SHOULD really check the easy stuff first. Something is NOT pluged in all the way or at all. Or a vacuum hose is loose or disconnected. Check the PCV valve hoses, it is very easy to miss connecting those. Remove the air filter housing so you can see if the hose is connected to the intake manifold.
Thanks, I am beyond the easy stuff now as I pulled the head again last night. All the lifters had the caps on. The car ran smoothly for a few seconds than rattle rattle clank and shut down. Prior to this I did rotate the crank close to 30 times and the timing marks all lined up perfectly. The crank keyway was up as well. The PCV hose was connected. I bought a new PCV as well. Maybe I hooked a vaccume hose to the wrong spot. All those hoses.. damn. I am thinking about removing the crankcase again and pulling the pistons. I put in new pistons and rings and I was sure I got them right as I did the rings under magnification ( I am old and my eyes are not what they used to be). Maybe I got those 3 lower rings wrong on one of the pistons. Could the new coils, plugs or EGR have something to do with it? I am uploading a picture as I had a nut left over from the first rebuild and found this spring after I began 2nd removal. Anyone know where these could go? I kept all the parts labeled and segregated. These escaped me.
