I have a 155k prius I got very cheap long story short. Had a predicted bad head gasket. Coils, plugs, egr, and few other things got replaced. Drained the oil, no shavings. Took the plugs out to check, cylinder 1 is clean/wet, and meaured the pistons at tdc and compared to check for a bent rod due to hydrolock. The cylinder 1 rod was 2 (maybe 3)mm shorter. Does that make sense for the rod to be so slightly bent or might the head or valve cover I used to assist measurement cause that small difference? The engine burnt coolant for sure, milky oil, heard a noise when i started it at certain times but it stopped. Is the engine trash and go jdm? Should I try digging into it and rip off the head to check? Any suggestions appreciated. Thanks all
A simple compression test will be the proof in the pudding. Don’t bother going any further...put a good used engine in it. Cheaper in the long run.
Could have done away with the first 1.5 minutes... and he didn't follow up with the compression.... You would get a lower compression reading if the rod was bent because it wouldn't be coming all the way up, thus lower compression.
I said nothing about a head gasket leak. Just a lower compression because the rod is bent. What caused the bent rod??? Measuring it would show it does not come as high as the other non bent rods. Coolant level going down means there is a leak, somewhere. And if the head gasket is leaking, like may Prius engines, usually between cylinders 1 and 2. "most likely" water in that cylinder. "probably" from a leaking head gasket?
With the engine positively burning coolant and milky oil, the head gasket is most likely the culprit. However, if the engine was spun over with a combustion chamber full of coolant, it most likely bent a rod. That adds up to two very good reasons to just get a used engine. Pretty much can’t go wrong with a JDM. That’s what I would do and I’m stickin with it.
leaking head gasket, accumulation of coolant in cylinder, compression stroke with something that doesn't compress, hydrolock, rod gives. Cylinder 1 was a few mm short at tdc and clean upon inspection/no carbon build up(igniting with liquid?), wet, and I smelled sweet coolant being burned a at one point white smoke also some resulting rough milkshake oil.
With all the evidence you've presented, it seems that every is pointing to a leaking head gasket, and that water was in the cylinder, resulting in a slightly bent rod. Options would be: Remove head, have it checked to see if it's warped, replace the connecting rod, new head gasket, new valve guide seals, reinstall everything. Used motor that hopefully doesn't have a bent rod or leaking head gasket. New/remanufactured motor with head installed. New/remanufactured short block, head from original engine. (if it is not warped, or you have it resurfaced). Whatever you decide, you can't use this motor any longer as it is.
Never done this, just from what I've read, and depending on your budget/expectations: Buy a new shortblock (everything below the head gasket, have the head thoroughly looked over and cleaned by a machine shop, and reassemble with the complete Toyota gasket kit. I guess that's the a Rolls Royce route though, and a salvage engine is cheaper (maybe), and more straightforward.
The problem with getting a used engine is that you can't depend on the history of it. I've put in many used parts in various cars with about a 75% success rate. Engines have been 50-50. "My" personal opinion is to get a remanufactured short block and "have the head thoroughly looked over and cleaned by a machine shop, and reassemble with the complete Toyota gasket kit."
Appreciate your time. To replace the rod wouldn't I have to basically disassemble the engine almost entirely? Unfortunately I have had a sudden reduction in budget due to something unrelated, so time/labor over price.
Yea unfortunately I have just had something happen that really eats into my budget, so I need to figure out an affordable route or park it for a year.
If you have the time, expertise, and a substantial bank account, go ahead and do it the hard way...rebuild the or get a reman. shortblock. Just remember that the logistics of this kind of endeavor are going to test your resolve. Or, you can opt to get a good used engine and be done with it in a fraction of the time. Now the question pops up, “How do I know I’m getting a good used engine?”. Well, you should do you homework to find a salvage company that is trusted in the industry. Many of the ones with a good reputation will offer you a limited warranty and a mileage report. Expect that the lower the miles on the engine, the more the price.
You have to pull the oil pan to get to the bolt to remove the rod. Money always plays in on what you do. As bzzap said, finding a "good" used engine might be the easiest/fastest way. Purchasing 1 connecting rod won't be too expensive. You can check the head with a straight edge. Maybe a machine show will check it for little or no cost if you just bring it in. The head gasket set includes valve guide seals which you can replace yourself. Removing and installing the head you can do yourself, removing the oil pan and removing and replacing the bent rod you can do yourself and NOT spend all the money on labor. If you have some mechanical skills. This s the LEAST expensive way to do. You could also check junk yards or repair shops that might have a bad engine you could get cheap. and salvage a connecting rod from it, and use the original piston. Hopefully, the head is not warped. It seems that this is rare, from what I've read here. It always seems to look like a massive job when you begin. But if you take your time and look at one section at a time, it's not so bad.
I don’t have anything really to offer other than some visuals. I was told our engine had a bent rod on cylinder 1. Here’s what it looks like without the head: iPhone ?
