Cylinder head replacement - questions

[LS-4Runner]

I have a cracked cylinder head between the valves on cylinder 2, the motor has a very good compression on all cylinders, averaging ~198 PSI.
It's a 2000 4runner with 186k miles on it.
Dealer recommendation is to replace the motor , but I don't want to do that, I would like to replace the the damaged cylinder head, and I have the following questions:

1. Any recommendations for where to buy a cylinder head?
2. New or used/remanufactured?
3. Should I replace the good cylinder head as well?
4. Should I replace anything else while I'm in there already?
5. Any recommendations for good head gasket kit?

 

[jbtvt]

They want to replace a motor for a single bad head?? How are they justifying that? What's your mileage? Absolutely just do the head regardless. I've always just rebuilt mine so can't say whether brand new heads are available with valves pre-installed or not. If they are it will surely cost you but should be less likely to have valve issues. Personally I'd get a set off rebuilt off ebay, but I've had 2 different local shops mangle my valve/seat cuts, coming out with worse leak downs than they went in with, so if you value your compression you must do a leak down after installation. Save the old head gasket and bolts for this so you don't ruin a new one only to find out the valves leak, like I have in the past. You can also spot bad leaks doing this before even putting it on the engine. Fluid is naptha

Pressure testing a cylinder head - YouTube

Some shops say they pressure test their assemblies after installing valves, I'd message before buying something like "hey I always leakdown test after installation to ensure valves are seating correctly, just wanted to confirm that you do bench test your heads so I can be confident not to get any leaks from my results, thanks" if they don't respond then they're probably bluffing to make more sales. Would still test either way.

Ishino Stone is your OEM gasket, 209Yota1 sells kits at a good price. If you've got some miles on the heads I'd probably do both sides for the couple hundred extra it'd cost but reasonable people may disagree.

ETA you should of course also check valve clearances while you're in there

 

[clearock]

what r ur symptoms? There r any # of people on here driving around with cracked heads that have no clue, 3.4L with cracked heads are not uncommon. If ur having a real issue then replace, if not drive as is... as to where to get a head I would just pull from another 3.4L and take it to a machine shop and have it gone through and depending on ur mileage I would due the same with ur non-cracked head. Not sure what u mean about replacing the cylinder.

 

[19963.4lsr5]

Yotashop has a head replacement kit with everything you need to replace a set of heads. Even valve stem seals and headbolts.

I’d replace both heads. I found that removing the exhaust studs from the heads allows you to not need to remove the exhaust system.

It’s a lot of work, and bent over the fenders torquing those head bolts is a workout.


Sent from my iPhone using Tapatalk

 

[mtbtim]

I'd say try the head replacement instead of going straight to the replacement engine unless your engine has a ton of miles on it. If it's got in the neighborhood of 300k, your money and time might be better spent just replacing the engine, because how long is the lower end going to hold up? It could hold up for a long time, and then again, it might not and you just spent a bunch of time and money for very little benefit.

If you're definitely going for the replacement head, this guy did a really good job documenting a head replacement on his 1st Gen Tacoma which has the same 3.4 liter engine.

<iframe width="560" height="315" src="https://www.youtube.com/embed/voLBRDZL9fE" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

 

[LS-4Runner]

what r ur symptoms? There r any # of people on here driving around with cracked heads that have no clue, 3.4L with cracked heads are not uncommon. If ur having a real issue then replace, if not drive as is... as to where to get a head I would just pull from another 3.4L and take it to a machine shop and have it gone through and depending on ur mileage I would due the same with ur non-cracked head. Not sure what u mean about replacing the cylinder.

The truck has lost it's power and I have multiple misfires.
I'm leaning toward taking the good head to machine shop for check up as well.
I meant replacing the 2nd cylinder head, not cylinder lol.

 

[LS-4Runner]

I'd say try the head replacement instead of going straight to the replacement engine unless your engine has a ton of miles on it. If it's got in the neighborhood of 300k, your money and time might be better spent just replacing the engine, because how long is the lower end going to hold up? It could hold up for a long time, and then again, it might not and you just spent a bunch of time and money for very little benefit.

If you're definitely going for the replacement head, this guy did a really good job documenting a head replacement on his 1st Gen Tacoma which has the same 3.4 liter engine.

<iframe width="560" height="315" src="https://www.youtube.com/embed/voLBRDZL9fE" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

It's got 186k mile and driving strong, I'm going to do the head replacement, now just need to find a good one.
I did watched this guy series on the head replacement, he did a great job on it.
I also like your channel a lot and using it frequently - thank you Tim for filming and documenting these.