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Discussion Starter · #1 ·
I have a burnt valve on my 08 jk. It has 119,000 mikes on it. Is worth replacing just the burnt valve? Or should I change all of them? My mechanic says its like doing open heart surgery on an 80 year old man. He recommends putting in a remanufactured engine. He says its not worth rebuilding the top of the engine and leaving the bottom of the engine untouched. He said I'll just burn a ton of oil.
Any advice you can give I appreciate. I'm trying not to spend a ton of money, but I don't want to waste money either. What do think is a fair price for the valve or complete valve job or even the complete jasper remanufactured engine completely installed.
 

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Burnt valve at 120k? I am not trying to sell you on anything but I am a rep for a company called BG Products. I sell to dealerships. Many of times I have had vehicles (usually Direct injected) where the shop thought they had a burnt valve. We ran a couple cans of air induction cleaner through it (special tool the shop has) and it came back, valves were just had a lot of carbon on them. They would follow this up with a can of 44k in the fuel. Again, I don't live anywhere near you, so there is nothing in it for me. If interested this would run $120-$150 and you can find a place that sells it at BG Findashop - Search for an authorized BG service center near you!

I promise this is not parts house snake oil.
 

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How did the tech determine that you have a "burnt valve". Was there a compression test done? An emissions test? I know before I would give anyone advice on something like this, I would have to know how it was determined. Carbon build up is only one of a few symptoms of a burnt valve, and it's usually as a result of one or more additional issues. If it is in fact one burnt valve, replacing one isn't the way to go. If you trust your mechanic, it's possible that there's a lot more going on to the extent that he believes it's probably more cost effective to replace the engine if you plan on keeping your JK for the long run. This is if you trust your mechanic. There's nothing wrong with you asking a few more questions. Have you asked him for prices for the types of work he's recommending so you have something to compare it to?
 

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Discussion Starter · #4 ·
Burnt valve

The mechanic did a compression check and it was ok, the number 2 plug was fouled, after just changing it 5 days ago and he put a scope in and took a picture. He gave me the picture a a well. Even said it looked like a piece if the valve was missing. But couldn't be 100 % until you open it up. Which he doesn't think I should do. I do trust him,but I don't want to spend 5 g's right now.
 

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The mechanic did a compression check and it was ok, the number 2 plug was fouled, after just changing it 5 days ago and he put a scope in and took a picture. He gave me the picture a a well. Even said it looked like a piece if the valve was missing. But couldn't be 100 % until you open it up. Which he doesn't think I should do. I do trust him,but I don't want to spend 5 g's right now.
Based upon what your mechanic discovered, you're going to have to determine what he will be able to do considering how much you can spend on the repair. I wouldn't want to have to spend 5K either. You already have over 100K on the engine. Maybe if he's willing to do a partial rebuild you might be able to extend the life of your original engine. Tough choice.
 

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There is always a reason to why it burnt up a valve... you need to get that figured out before you go and spend money on fixing the head(s).

That being said i'm a cylinder head machinist...

I see burnt valves all the time. I do a lot of work for Honda, Toyota and GM dealers.

When I get heads that have burnt valve(s) I do a full tear down and clean and grind every valve.... if the valve doesn't grind right, is starting to burn, heavily pitted, etc I replace them as well.

Doing so will result in doing a valve job with an actual cutting bit... not a stone or lapping them.

I can guarantee you will need at least exhaust valve guides as well.

Long story short you will need to do a full rebuild on that head and its up in the air if you want to do the other... Me personally would go a head and do both especially if you plan on keeping the jeep.
 

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Just an old retired engine builder. BUT if you had a good compression test then it is hard to conceive that you have a piece of your valve head missing. It would be a low reading at best. I would get a second opinion if you have another mechanic available.
 

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Discussion Starter · #8 ·
Valve burnt

Thanks guys I appreciate the feedback. I will be taking it to get a second opinion. What do think a fair price would be if I'd did either a complete head repair or if I just did the vaves if that is what comes back to be the issue.
 
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