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Discussion Starter #1
Hey everyone,
I had a water pump bearing seize and timing belt slipped while I was driving about 50 mph. You can guess the rest...6 broken valves, 2 bent valves, nicks in 2 of the piston heads and one bad one on the edge of #8 (I think it's #8 at least). All of this damage is on the driver side of the engine. I'm looking at one new piston and a new/used head.
Question is how hard is it/what is involved to remove a piston from the underside of the engine with the oil pan and head removed? Can't replace the engine altogether due to budget. These 2UZ-FE engines are expensive even if purchased used with high miles! Plus I have to do this outdoors and I don't have a cherry picker.
Thoughts?
 

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Discussion Starter #3
I should mention that this is a 2005 SR5 Sequoia with rear wheel drive, not a 4x4. 4.7L V8 2UZ-FE engine. No rust on vehicle. Gotta fix this so i can sell it. Please help.
 

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I am a bit surprised at the lack of responses. Over one hundred views on this post and no comments at all? I thought for sure someone would put in their two cents. Maybe nobody has ever attempted to take out a piston by loosening the bolts from the bottom of the engine through the oil pan area? There's gotta be somebody out there!
 

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I doubt that a lot of folks here have done this type of work. I've never seen any other discussions about tearing into the engine like this. Most people would scrap the vehicle or buy a used engine at this point. I know that's not in your budget.

Are you removing the crank? I'm no expert but I can't see how the piston would get past the crank. You may want to hit up harbor freight and pick up a cherry picker and engine stand if you are serious about rebuilding this engine. What's your budget for this project?
 

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Discussion Starter #6
Actually I have about $2k to put into it. The theory is that you can loosen the bolts holding the piston to the crankshaft from below the engine and then push the piston up through the top of the block. No need to remove the crankshaft, in theory. But I'm only interested in replacing one piston. Is that gonna cause wear problems on the other 7 pistons while this new one breaks in? Will there be some other consequences as a result of only replacing one piston? I'm fishing in the dark here.
 

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Way beyond my pay grade but I am pretty sure I have seen guys on here pick up used motors for less than a grand. Maybe your better off to spend half of what you were thinking on a used motor. If you can get one locally you can probably get it tested before buying.
 

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I'd say you need to be careful not to throw good hard earned money after bad. How many miles does the engine have on it? Do you have the head off already? How do the cylinder walls look?

I have done exactly what you are talking about and it certainly can be done.

If it was my truck I would find a place to work under cover and pull the motor. Once its out you can do a thorough inspection and be sure you've identified all the problems. Then you can sort out the wisdom of repair v. replace. I would worry about spending a lot of money on a rebuild unless I was sure I did it 100% right so it will last. I've done it the down and dirty cheap way in my life and you have about a 50% chance of success.

Good luck with it. Hope it works out.
 

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Hey everyone,
I had a water pump bearing seize and timing belt slipped while I was driving about 50 mph. You can guess the rest...6 broken valves, 2 bent valves, nicks in 2 of the piston heads and one bad one on the edge of #8 (I think it's #8 at least). All of this damage is on the driver side of the engine. I'm looking at one new piston and a new/used head.
Question is how hard is it/what is involved to remove a piston from the underside of the engine with the oil pan and head removed? Can't replace the engine altogether due to budget. These 2UZ-FE engines are expensive even if purchased used with high miles! Plus I have to do this outdoors and I don't have a cherry picker.
Thoughts?
I'm not a Tundra expert though I did own one and I have worked on my share of engines. Here's my take.

Yes, you can get the piston out if you have the head and pan off while the engine is in the truck. You cannot get the piston out the bottom. You will have to get the connecting rod unbolted and then push the piston out the top. That's the only way the piston will come out if it is still in one piece. If it weren't in one piece, you'd be in need of a bore job or a sleeve, which doesn't happen in the truck.
 

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Pull an engine from junk yard or one that will pull for you? don't know how much it would cost but feel results more predictable than what you may be facing otherwise.
 

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Man, this is a ton of work.

With those broken valves in there hammering on the pistons, we have no idea what the connecting rod bearing(s) look like either. You may have broken the lower piston skirts as well. Typically one would find these pieces in the oil pan.

Knucklebusted is correct, the piston and the associated connecting rod have to come out through the top, but you may need to have a piston ridge reamer to cut the very lip on the top of the block before the piston will slide out.

I also agree with rpg51. Pay careful attention to deep scores on the cylinder walls.

I really can't tell by your photo. How damaged is that piston. It looks like a blob of metal just sitting there... Is the piston cracked?

Listen - down and dirty, this may be worth a gamble. Slap a used head in - button it up - and see what happens...
 

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Discussion Starter #13
All helpful suggestions, thanks! To answer questions...car has 165,000 miles on it. Cheapest 2UZ-FE vvii (2005-2007 model) engine used was $1900 and that was Ebay with free shipping...junk yards around here don't have any right now. But all the local shops won't install used engines because they have been burned on them.
 

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Discussion Starter #14
No visible cracks in the pistons. My current mechanic thinks most of the damage was done by the former mechanic who "performed" a compression test on the engine after the belt slipped. I was ignorant at the time and took him at his word when he told me that was a textbook diagnostic test in this situation. Problem is he didn't adjust the timing belt, first.
 

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Was the timing belt change at the recommended 90k........asking because my engine has close to 90k on it and I would like to stretch it out.
 

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I have done a number of engine rebuilds through the years, and IMO, you are wasting your time trying to replace that piston. I am assuming you would install new rings along with the piston, and in order for those rings to seat, you would have to hone the cylinder to get the correct crosshatch finish. If this was done in the truck, you would end up with a lot of dirt and metal shavings getting all over the crank. Yeah, I guess you could clean everything off with brake cleaner, but I would be worried about that stuff getting sucked into the bearings and scoring them. Even without that, it is kind of a crap shoot that the new rings would ever seat properly - bores typically wear slightly egg shaped, and they need to be perfectly round for proper ring seating.

As someone else mentioned, short of installing another engine, your best bet might be to either get your head reworked of find a good used head, install it along with a new head gasket, and roll the dice. That piston might still seal and hang in there even with that nick taken out of it. I had a Chevy 454 in my boat that developed detonation and blew a chunk off the ringland like that. I would have not known anything was wrong except that the chunk got sucked into an intake valve and put a nick in the valve. This caused the engine to backfire through the carb under load. Other than this, it ran fine. I later pulled the other head and found a second piston with the same thing. I had run a compression check and this particular cylinder was holding just as much PSI as all the other ones.

Good luck, and let us know how it works out for you. There are enough of these trucks out there that you shoul be able to find another engine.
 

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Discussion Starter #17
Was the timing belt change at the recommended 90k........asking because my engine has close to 90k on it and I would like to stretch it out.
Hi Billy bob,
My belt and pump were replaced at 111k miles according to the sticker under the hood plus the carfax I have for the vehicle. I bought it at 130k miles. The suspicion is a very cheap water pump or the pump was never actually replaced. Don't know for sure yet...haven't removed it from the engine yet to see what brand pump was the culprit.
 

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Discussion Starter #18
I have done a number of engine rebuilds through the years, and IMO, you are wasting your time trying to replace that piston. I am assuming you would install new rings along with the piston, and in order for those rings to seat, you would have to hone the cylinder to get the correct crosshatch finish. If this was done in the truck, you would end up with a lot of dirt and metal shavings getting all over the crank. Yeah, I guess you could clean everything off with brake cleaner, but I would be worried about that stuff getting sucked into the bearings and scoring them. Even without that, it is kind of a crap shoot that the new rings would ever seat properly - bores typically wear slightly egg shaped, and they need to be perfectly round for proper ring seating.

As someone else mentioned, short of installing another engine, your best bet might be to either get your head reworked of find a good used head, install it along with a new head gasket, and roll the dice. That piston might still seal and hang in there even with that nick taken out of it. I had a Chevy 454 in my boat that developed detonation and blew a chunk off the ringland like that. I would have not known anything was wrong except that the chunk got sucked into an intake valve and put a nick in the valve. This caused the engine to backfire through the carb under load. Other than this, it ran fine. I later pulled the other head and found a second piston with the same thing. I had run a compression check and this particular cylinder was holding just as much PSI as all the other ones.

Good luck, and let us know how it works out for you. There are enough of these trucks out there that you shoul be able to find another engine.
Hi Tom,
Thanks for the advice. I'll keep my eyes peeled for an engine. It would be the easiest way to go, I agree. Never considered the mess that goes with replacing the piston and rings like this. Thanks again!
 

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Most likely was a Gates timing belt kit installed if replaced. Gates belts are outstanding but their pumps are absolutely junk. Why I only go with OEM on mine especially on interference engines.
I personally have save seen 3 or 4 Gates pumps fail within a year or so after installed in different yrs/models of cars so its not just one design failing. They really are about the lowest quality out there!

No idea on 4.7 lower end design but the 2.2 Toy in my wife's old Camry had a counterweight assembly attached to the crank so getting to the rod bolts wasnt near as easy as most cars. If it has that setup or you ever see it just understand its all gear driven and must be synchronized with everything again when going back in.

Personally I'd just replace the head & just roll with the piston it has.
It will be fine the way the 4.7 is built, I know theres been chips in other engine makes without problems.
It wont make any difference in its operation or longevity either one if a compression test shows it's holding once together again.
Slap her together & rock on I say!
 

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I have done a number of engine rebuilds through the years, and IMO, you are wasting your time trying to replace that piston. I am assuming you would install new rings along with the piston, and in order for those rings to seat, you would have to hone the cylinder to get the correct crosshatch finish. If this was done in the truck, you would end up with a lot of dirt and metal shavings getting all over the crank. Yeah, I guess you could clean everything off with brake cleaner, but I would be worried about that stuff getting sucked into the bearings and scoring them. Even without that, it is kind of a crap shoot that the new rings would ever seat properly - bores typically wear slightly egg shaped, and they need to be perfectly round for proper ring seating.

As someone else mentioned, short of installing another engine, your best bet might be to either get your head reworked of find a good used head, install it along with a new head gasket, and roll the dice. That piston might still seal and hang in there even with that nick taken out of it. I had a Chevy 454 in my boat that developed detonation and blew a chunk off the ringland like that. I would have not known anything was wrong except that the chunk got sucked into an intake valve and put a nick in the valve. This caused the engine to backfire through the carb under load. Other than this, it ran fine. I later pulled the other head and found a second piston with the same thing. I had run a compression check and this particular cylinder was holding just as much PSI as all the other ones.

Good luck, and let us know how it works out for you. There are enough of these trucks out there that you shoul be able to find another engine.
Yep-
I knew a guy who found a chipped piston in an old 351 Ford engine. No idea what caused it maybe bolt in carb from previous owner he said? May been him?..lol
He never knew if it was tore down & removed or blew out exhaust so who knows what happened? He installed his new aluminum heads he bought for it and drove it super hard for years though. I never saw how big the chip was but he said it was a big one.
I remember us doing 360's one after another at intersections at 3am in that old 70 Mach1 Rustang..too funny...
Actually it was a beautiful, red/orange with black stripes.
 
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