How difficult a job is replacing head gasket?

[wesayso]

I'm a skilled mechanic, and have done engine rebuilds on several Toyota truck engines, but never a Land Cruiser. And, given my age, I'm not looking forward to the project. Anything unique to worry about? What's a fair price for a shop to charge for the job?

 

[TurboDennis]

To do it right - a few grand in parts alone. Head, OEM gasket set, new head bolts and a lot of other misc parts that you should replace "while you're there". If your HG went, then the head is most likely warped out of spec and will need to be repalced with new. The heads CAN NOT be machined on these trucks. If you want to do it right, that is.
Probably 10-20 hours labor depending on what exactly you're doing. There is nothing particularly difficult about this job on 1FZ for a skilled mechanic.

If you want to do a hack job - machine the head, order misc gaskets from rock auto. Can probably do it under $1000 total. There is a pretty decent chance that it might even run for a year or two after that.

 

[Malleus]

Easier than splitting the atom, harder than boiling an egg. Nothing out of the ordinary, as far as general engine work is concerned, though.

You didn't specify the year, so you get the first one I could reach
I would not buy a new head, before I verified that the old one was unusable. See page EG-33, for the inspection procedure.

 

[jpoole]

A good way to get a better idea of what's involved could be to watch related videos and read threads on the forum here. A few members have shared a lot of good photos and information about their HG replacements.




The work took me weeks but I did it in small installments and I did a lot of "while in there" tasks. Cleaning generally and cleaning the intake manifold specifically took some time as I recall. I had a local shop inspect and service the head, including surfacing, and my truck has run great for years since HG replacement. I've seen numerous cases of folks doing a HG replacement on this forum without finding their heads warped. My opinion is that the overall length of the deck along with the HG design and different composition of the block/head (iron/alu) lead to HG failure on these more than warping does. I'd be optimistic about your head until you learn otherwise from the machinist.

Don't forget to replace the valve stem seals while you are at it, they are likely leaking at this point. Consider using all new head bolts vs. reusing even if yours are original.

 

[Malleus]

As an aside, FSM procedures are always written as a compromise between the original design specifications and the available repair methods. When writing these FSMs, Toyota expected their dealerships to be able to do a lot, which they typically don't (for reasons of their own). While it's perfectly reasonable for a dealership to be expected to have all the tools and methods necessary to perform any and all repairs on a Camry, Land Cruisers were intended to be used, and available for use, in extremely harsh environments, which means that the expectation was that when they failed, they likely wouldn't be near a dealership with access to all the gee whiz stuff we have come to know and love here in the land of opportunity.

Milling heads has long been an accepted practice, and I'd bet Toyota knows that. Either they didn't allow enough wall thickness between the lower side of the bottom galleys near the bottom surface of the head, or they didn't think that machine shops would be readily available and replacement parts are certainly easier to deal with than machine work. I would have to think long and hard about dumping a head that was 0.002-inch over the warpage limit. It would certainly be interesting to see a trashed head milled in 0.005-inch increments to see exactly how much meat is available on the lower face.

Maybe @Onur has some insight on this.

 

[TurboDennis]

As an aside, FSM procedures are always written as a compromise between the original design specifications and the available repair methods. When writing these FSMs, Toyota expected their dealerships to be able to do a lot, which they typically don't (for reasons of their own). While it's perfectly reasonable for a dealership to be expected to have all the tools and methods necessary to perform any and all repairs on a Camry, Land Cruisers were intended to be used, and available for use, in extremely harsh environments, which means that the expectation was that when they failed, they likely wouldn't be near a dealership with access to all the gee whiz stuff we have come to know and love here in the land of opportunity.

Milling heads has long been an accepted practice, and I'd bet Toyota knows that. Either they didn't allow enough wall thickness between the lower side of the bottom galleys near the bottom surface of the head, or they didn't think that machine shops would be readily available and replacement parts are certainly easier to deal with than machine work. I would have to think long and hard about dumping a head that was 0.002-inch over the warpage limit. It would certainly be interesting to see a trashed head milled in 0.005-inch increments to see exactly how much meat is available on the lower face.

Maybe @Onur has some insight on this.

Metal thickness on the bottom has very little (nothing?) to do with the fact that these heads should not be milled/machined.

The main reason Toyota says that these heads must never be machined is this:

When you remove the head, measure the block mating surface and it measures out of spec (lets say 0.010"), its not just that surface that is warped. The whole head is warped (twisted), and the "top" (where the cam journals are) is warped by the same amount. If you were to machine the bottom so that it's perfectly flat, the top part would remain warped. This is critical, because installing a head like this will introduce a new, bigger problem than what you were trying to solve by milling the bottom - the cam journals will now be out of alignment, and the journal oil clearances will completely go to s*** - some will be off by up to 0.010" that you took off the bottom of the head. Considering that the spec for the cam journal clearance is ~0.001-0.002", this will be catastrophic in the long term.

Personally, if i was doing a HG job on a budget and the head warpage was a few thou over the max limit (per FSM), i would clean it up as best i could without machining, and reinstall as is. By doing so, the head bolts will essentially straighten the head when its fully torqued down, and you won't be introducing the issue described above. Yes, it's not ideal because the head gasket surface of the head will not be perfectly smooth, but the OEM HG is pretty forgiving in that department unless you got serious pitting there.

 

[Malleus]

Metal thickness on the bottom has very little (nothing?) to do with the fact that these heads should not be milled/machined.

The main reason Toyota says that these heads must never be machined is this:

When you remove the head, measure the block mating surface and it measures out of spec (lets say 0.010"), its not just that surface that is warped. The whole head is warped (twisted), and the "top" (where the cam journals are) is warped by the same amount. If you were to machine the bottom so that it's perfectly flat, the top part would remain warped. This is critical, because installing a head like this will introduce a new, bigger problem than what you were trying to solve by milling the bottom - the cam journals will now be out of alignment, and the journal oil clearances will completely go to s*** - some will be off by up to 0.010" that you took off the bottom of the head. Considering that the spec for the cam journal clearance is ~0.001-0.002", this will be catastrophic in the long term.

Personally, if i was doing a HG job on a budget and the head warpage was a few thou over the max limit (per FSM), i would clean it up as best i could without machining, and reinstall as is. By doing so, the head bolts will essentially straighten the head when its fully torqued down, and you won't be introducing the issue described above. Yes, it's not ideal because the head gasket surface of the head will not be perfectly smooth, but the OEM HG is pretty forgiving in that department unless you got serious pitting there.

A reputable machinist would not just skim the bottom flat, knowing the cam journals have a dimensional relationship to the mounting surface.

 

[TurboDennis]

A reputable machinist would not just skim the bottom flat, knowing the cam journals have a dimensional relationship to the mounting surface.

That's what they do. There is really no "feasible" way around it.

 

[toyofan]

"skilled mechanic" should have no issues doing the job, but mentioned your 'age' , and that would be a concern. I am 6' 4'' and had a hard time reaching into certain areas and my back did hurt after working on it. I ended up putting a board in the engine bay and crawled up in there to be a little more comfortable

If your LC is not lifted it may not be that bad, but mine with the lift and large tires made the reaching issue worse

 

[flintknapper]

Metal thickness on the bottom has very little (nothing?) to do with the fact that these heads should not be milled/machined.

The main reason Toyota says that these heads must never be machined is this:

When you remove the head, measure the block mating surface and it measures out of spec (lets say 0.010"), its not just that surface that is warped. The whole head is warped (twisted), and the "top" (where the cam journals are) is warped by the same amount. If you were to machine the bottom so that it's perfectly flat, the top part would remain warped. This is critical, because installing a head like this will introduce a new, bigger problem than what you were trying to solve by milling the bottom - the cam journals will now be out of alignment, and the journal oil clearances will completely go to s*** - some will be off by up to 0.010" that you took off the bottom of the head. Considering that the spec for the cam journal clearance is ~0.001-0.002", this will be catastrophic in the long term.

Personally, if i was doing a HG job on a budget and the head warpage was a few thou over the max limit (per FSM), i would clean it up as best i could without machining, and reinstall as is. By doing so, the head bolts will essentially straighten the head when its fully torqued down, and you won't be introducing the issue described above. Yes, it's not ideal because the head gasket surface of the head will not be perfectly smooth, but the OEM HG is pretty forgiving in that department unless you got serious pitting there.

^^^^^^

Agree.

Cam bore alignment on an aluminum overhead cam head is the MOST critical area. But that doesn't mean that 'replacement' is necessarily the answer UNLESS the cost to replace is less than the cost to repair (where possible).

Aluminum heads (particularly long, inline six heads) respond well to thermal treating to straighten them. Good, well equipped machine shops can do this. But the critical area to be addressed are the cam bores. They need to be as straight and aligned as possible. Generally IF the cam bores can be brought back into alignment the mating surface of the head will also have been straightened and any small irregularities there can be addressed with minimal surfacing and a good head-gasket.

 

[flintknapper]

"skilled mechanic" should have no issues doing the job, but mentioned your 'age' , and that would be a concern. I am 6' 4'' and had a hard time reaching into certain areas and my back did hurt after working on it. I ended up putting a board in the engine bay and crawled up in there to be a little more comfortable

If your LC is not lifted it may not be that bad, but mine with the lift and large tires made the reaching issue worse

Yes, I wouldn't even consider doing the job without benefit of a 'belly board' or some other type of support.

 

[tacocat]

I find @jcardona1 ’s thread most helpful.

Builds - Evolution of a Land Cruiser: My 80's build thread

CLUSTER LEDs Today I also installed a new set of cluster LEDs I purchased from member 'lilevo'. All 4 of the main bulbs for $15 shipped. I got the white color. Very nice improvement over the sad, dim little OEM halogen bulbs with plastic green covers. The light is nice and crisp. :clap: Did...

forum.ih8mud.com

 

[JM74]

Took me like 4 months lol. But most of that time was waiting for parts. The disassembly and reassembly is pretty easy to be honest.

My head was also around .20thou out of spec and had 2 or 3 cracks... but block was still on the verge so I ended up ordering a new head from mr.T and truck drives nice now and runs great! (Knock on wood)

New head wobbled a little on the block but I’m attributing that to the lines of FPIG for the timing cover and once tightened down the cams turned nicely.

It really isn’t that hard of a job, I think my biggest worry if having to do it again is the time down waiting for parts... but hey I’m in Canada and getting parts takes time...

Best of luck!

 

[tacocat]

Oh yeah, what’s the nature of this repair? Is it PM? Did the truck overheat and the HG blow? Is it a slow external leak, or internal leak?

 

[Bludozer]

Shouldn't this just have been answered with a specific number of emojis?

 

[wileetoyote]

Blew my HG back in 2014 towing my popup... knew it immediately, limped it back home 50 miles pulling over every now and then to prevent it from overheating adding water to Rad a couple times iirc. I bought the Toyota OEM HG Kit, Toyota Rad Fluid, new belts and hoses, etc. and got started within 2 days as it was my daily driver at the time...

I removed the hood, air filter assy and any other items that prevented me from sitting in the engine bay to remove things (2.5" OME lifted)
I had the Head and Intake assy on the bench by that first evening, spent that night and the next morning cleaning everything up and it was back running by day 3 (albeit long days).
I did use my Bendpak car lift to remove the head and intake assy as one piece but that could be done with an engine hoist. To stay organized, I ziplock bagged and tagged every set of nuts and bolts and misc brackets I removed keeping them in the white box in last pic which made re-assembly much easier. IIRC, I did use the car lift to tighten the exhaust pipes to the exhaust manifold. I would think under normal circumstances, most folks could get it done within 3-4 days or a couple weekends if they were motivated to do so... since you mention age, at the time I was a spry 48 yr old
In hindsight, I should've had a valve job done but as I said it was my daily driver so I approached it simply as a 3 ( to 4) repair.

 

[wesayso]

Oh yeah, what’s the nature of this repair? Is it PM? Did the truck overheat and the HG blow? Is it a slow external leak, or internal leak?

It hasn't overheated. A couple weeks ago, I noticed a rough idle when cold starting, that would disappear in 5 -15 seconds. Recently I've noticed steam coming from exhaust. Yesterday, I had to add a half gallon of coolant. I believe one of the cylinders is collecting a little coolant when the truck sits for a while.

 

[JM74]

It hasn't overheated. A couple weeks ago, I noticed a rough idle when cold starting, that would disappear in 5 -15 seconds. Recently I've noticed steam coming from exhaust. Yesterday, I had to add a half gallon of coolant. I believe one of the cylinders is collecting a little coolant when the truck sits for a while.

The half gallon of coolant is a sign in my opinion.. But if you live in a cold climate you’ll have steam coming from your exhaust a lot on startup. It’s just moisture.

Not sure on the rough idle. Might just be quirk if the truck. All cruisers I’ve been around have them.

Mine will steam white for a good while until around 130f on a -15C morning. Once warm it still is a little wet exhaust but It’s clear.

 

[jpoole]

How long since you last checked and topped up your coolant level? Losing some over a longer period of time may not necessarily indicate a failed HG as you know. Evaporation, small/hidden leaks like through hoses or small seeps that evaporate/etc. could all add up, though 1/2 gal is a lot. I'd consider a HG test kit, Blackstone oil analysis and/or spark plug inspection and cylinder scoping before I decided the HG is failed.

I did my HG as PM which isn't a bad idea in my opinion/experience but if your 80 is running well otherwise and has been taken care of you may want to hold off if the above checks indicate that you don't have a HG failure. If it's a relevant leak it should show in the oil and/or a steam cleaned cylinder/plug pretty easily.

Keep in mind that for every gallon of gas burned more than a gallon of water is created. All of that has to pass out of your tailpipe. These things burn a lot of gas, and run pretty rich when cold typically, so that along with the long/weighty exhaust is pretty ideal for creating steam.

 

[Azca]

I am older, have a bad back, big hands, not slim and not double jointed. I decided to pull the engine and trans to tackle the job rather than attempting to work on it in the rig. If you can't comfortably reach something you can damage it or just give up and rig something. Ultimately, due to some pitting on the block, I wound up rebuilding it anyway. So, it would have been very frustrating going through all of the contortions necessary to pull the heads in the truck and have to yank it anyway.

Even if I had not rebuilt it, I recomend pulling it. So much easier to properly work on it and now you can replace repair practically everything you want without killing yourself to get to it. Yes it will take longer, but, it is MUCH easier on the body. Items such as the PHH and power steering hoses and components, as well as all the rubber, are easily reached.