(Duh duh DUH!) Burnt my valves

solsnowbarger

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Whelp, after much fruitless effort on attempting to fix the "small" causes of a misfire I finally took it into a trusted shop in town. They called back with the diagnosis of burnt valves, and a quote on fixing it that doesn't bear repeating ($3800 parts and labor.)
Now, I believe that they'd go all the way and do everything possible to fix it up nice for that price, but I'm just not about to drop that on a truck I paid $6000 for. I just recently bought it from the original owner, the proverbial old lady from Texas who only took it antiquing. It's an 2002 2wd SR5 and has 101,000 miles on it, inside and outside are absolutely perfect, and there has never been a cleaner underside with not one spot of rust to be seen.
I don't know too much about engines, but I'm all for trying to do this myself. Am I correct in thinking that a couple new heads might be in order? What all else should I look into fixing at the same time, and what should I be concerned about? (didn't overheat as far as the temp gauge said)
Thanks brothers, I know this is asking for a lot of info. I'll eagerly await your replies.
Solomon
 
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Whelp, after much fruitless effort on attempting to fix the "small" causes of a misfire I finally took it into a trusted shop in town. They called back with the diagnosis of burnt valves, and a quote on fixing it that doesn't bear repeating ($3800 parts and labor.)
Now, I believe that they'd go all the way and do everything possible to fix it up nice for that price, but I'm just not about to drop that on a truck I paid $6000 for. I just recently bought it from the original owner, the proverbial old lady from Texas who only took it antiquing. It's an 2002 2wd SR5 and has 101,000 miles on it, inside and outside are absolutely perfect, and there has never been a cleaner underside with not one spot of rust to be seen.
I don't know too much about engines, but I'm all for trying to do this myself. Am I correct in thinking that a couple new heads might be in order? What all else should I look into fixing at the same time, and what should I be concerned about? (didn't overheat as far as the temp gauge said)
Thanks brothers, I know this is asking for a lot of info. I'll eagerly await your replies.
Solomon

Good old misfire caused by leaking valves. They most likely found it leaking from a leak down test. Yes head rebuild would be the next step. I wonder how a valve ate its self without boost or a lean condition, there maybe another issue that caused the valve to fail. Maybe a bad injector.
 
Yeah, I had originally thought an injector was causing the misfire, but replacing the injector on the misfiring cylinder #2 didn't change anything. Albeit, I used an aftermarket one off eBay, which wasn't wise.
(Any good threads I should've found by now on the subject of a head rebuild?)
 
Am I correct in thinking that a couple new heads might be in order?

Well, new or fix the ones you have, which will likely be a lot cheaper. Once you get them off, take them to a machine shop to get checked out for cracks or other damage. If they're good, all you need to replace is the valves and associated bits in the heads. The machine shop will do that for you if you pay them, or they'll advise you on the parts you need and sell them to you. Check out all your options pricewise before deciding to just order a set of new built heads. For your other question, while you've got the heads off is a great time to do your timing belt and water pump service. Ship your injectors off to get them cleaned and rebuilt (I like Accurate Injector Service in Arizona, there's lots of other good companies.).

There's a good chance there's at least one person who's going to post up that you should buy a JDM motor. Don't listen to that person. Buying a used motor and not rebuilding it before you put it in is asking for trouble, and if you're going to rebuild something you might as well rebuild what you've got.
 
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Most folks here will just tell you to buy a set of heads from a junkyard engine and put those on. Call up a few machine shops and see what they recommend and what they'd charge. Can't imagine it being more than $500-1000 to get your heads resurfaced, new valve guides, valve job, etc.
 
Well, new or fix the ones you have, which will likely be a lot cheaper. Once you get them off, take them to a machine shop to get checked out for cracks or other damage. If they're good, all you need to replace is the valves and associated bits in the heads. The machine shop will do that for you if you pay them, or they'll advise you on the parts you need and sell them to you. Check out all your options pricewise before deciding to just order a set of new built heads. For your other question, while you've got the heads off is a great time to do your timing belt and water pump service.

There's a good chance there's at least one person who's going to post up that you should buy a JDM motor. Don't listen to that person. Buying a used motor and not rebuilding it before you put it in is asking for trouble, and if you're going to rebuild something you might as well rebuild what you've got.


Yeah, that was my understanding of replacement engines as well, besides, I doubt I'd be able to find an engine with this few miles on it anyway.
And thanks, I'm confident I can pull the heads off, it's just the valves and "associated bits" I really know nothing about, so if the machine shop is helpful in that area I'll feel a bit more confident.
 
Thanks Caesar! That thread is definitely saved. And I agree, it does seem really early. I know the PO had it sitting for a bit before they sold it, maybe something clogged the injectors?
[MENTION=113822]LookAtThatDog[/MENTION] it was constant man, but no overheating as far as I could tell
[MENTION=65101]BrianSD_42[/MENTION] I think you skipped the link brother, I have definitely seen you mention a few times that you had to buy new heads. The place here in town that I'm looking at to rebuild the heads is about $750 with everything, so I'm not sure if that's any better than ordering them from the same place you did.
(P.S. Yeah, no way I'm paying for 28 hours of labor on this, it might take me twice that amount of time but I'm not $100 dollars an hour)
 
So you are buying remanu heads?

The JE heads I bought are $750 each, gaskets $400. That's almost $2000.

Labor best case $750-$1000 more.

Valves going bad is pretty rare, at least on this forum. Perhaps the engine wasn't cared for.
 
[MENTION=127297]thatoneguygeoff[/MENTION] No kidding? That seems pretty good. What's was your thinking for that vs. Two rebuilt heads? Assuming my lower engine is still okay that is
 
[MENTION=65101]BrianSD_42[/MENTION] Oh sorry man, I had it in my head that you'd said in a previous thread it was $800 for BOTH, my bad.
And no, I'm gonna pull the heads and pray to the car Gods that they aren't cracked yet, the place I'd been talking to said they could rebuild them both for $750

And yes, neglect is what I'm thinking as well. It all looks so clean though! The lady even covered her mats in plastic bags! Haha sneaky old ladies are the worst.
 
So let's go back a little bit... I bought my 97 4Runner about a year and a half ago with 240,000 miles on it. After having it for a couple months on my way home from work one night there was a funny pop followed by a fluttering sound coming from the engine. It still ran fine but had is fluttering sound. The following morning I get up and dig into it to look for the issue and it ended up that my spark plug in cylinder 5 had come apart and about a third of the exhaust valve was missing. I then took the rig to my shop which happens to be owned by a family friend. He was able to get me a new rebuilt head and install it for around $600 with his shop labor. Then a month later I blow a head gasket. Guess what, it popped in cylinder 5 once again. The head gasket subsequently let loose twice more after that about a month apart all in cylinder 5. I got fed up with that motor and had him find me a nice used engine. With the cost of the engine and his shop to install it set me back $2800.
 
[MENTION=127297]thatoneguygeoff[/MENTION] Haha what in the world man, that's miserable. Did they ever say what was wrong with the old engine?
I dunno man, I still have just over 100,000 on my old engine, if it was more Id probably be more inclined towards a fresh engine.
I'm a definite novice though, so please tell me if I'm talking out my @ss
 
You can find used resurfaced heads with a warranty for $350 each online. If you are going to DIY that may be an option.

If you want to get an engine I'd think you can find one for $1200 solid and get it installed for $800. There is risk but it could be the best choice.
 
Yea it royally sucked and got expensive! Figure $400 each time he did the head gasket so there's $1600 in just head gasket replacements! Oh yea forgot to mention this, you're gonna laugh... So when he swapped out the motor, he got it all wrapped up and running, he called me and said its good to go. I get down to his shop, fire it up, screeeeccchhh. The motor seizes right there in his shop! Solidly locked up. So he calls the yard that sold him the motor which happens to be a buddy of his that he's worked with for over 20 years to tell him what happened. The guy is completely baffled and within 20 minutes he's at the shop with a new motor for me. Ended up that the motor that seized had been sitting for a while and both aft cam bearing caps (on each head) had oil that had gummed up and we're not letting fresh oil pass through had literally welded themselves to both cams! My shop had the new motor installed the very next day and he drove it for about 20 miles to make sure it was good before he called me.
 
[MENTION=65101]BrianSD_42[/MENTION] oh yeah? Do you remember where online? And why did you buy those JE heads for $750 each as opposed to the rebuilt ones for $350 each? If I can ask and bother you some more.

[MENTION=127297]thatoneguygeoff[/MENTION] No, I can't laugh man, not yet at least. That's absolutely ridiculous though. I think for the next couple of days crying is the only emotion I'll be able to utilize.
 
I guess the question is, do you have reliable transportation besides the 4Runner? If yes, do it yourself, as much as you can.

I'm not sure about 3rd Gens, but on 2nd Gens you could get new heads cheaper than used ones lol! These engines are very easy to work on compared to others so I'm sure that as long as time is not a factor you can do it. There's a lot of collective knowledge to help as well in case you get stuck.

Valves will go bad if they have been out of spec for long periods of time. I suspect that the misfire/lean condition was not an injector but a bad valve. If the valves are out of adjustment they can get worse to the point where they don't seal during combustion, causing the valves to burn and eventually need replacing. I was fighting that on my Pickup but wasn't worth the money for new heads, I did a valve adjustment which cleared up most of it. Would rarely throw a lean/misfire code though but at least it ran well.
 

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