- Thread starter
- #21
Hairline Cracks In Cylinder Head -- Advice Please!
- Thread starter brukshut
- Start date
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Interesting that you say that the machining sucks. You will not see the true work until the head is off. All the real machining is done on the other side. What you may be seeing is where the top surfaces are cleaned with sand paper, instead of some scotch brite material. More than likely done with a DA sander with all the shims and pucks out.
when you had the valve cover off, did you take Valve clearences to see if the valve were in Spec?
I am not trying to defend the work done, just trying to bring to light that the real machine work is done on the other side. I would not condone that someone missed the cracks as they are easily seen in the picture. But to not fix them is not right, and more than likely a choice, not a over site.
Good luck with this.
when you had the valve cover off, did you take Valve clearences to see if the valve were in Spec?
I am not trying to defend the work done, just trying to bring to light that the real machine work is done on the other side. I would not condone that someone missed the cracks as they are easily seen in the picture. But to not fix them is not right, and more than likely a choice, not a over site.
Good luck with this.
IME/O, it could very well be these cracks weren't present when the head was machined. When I see any aluminum head cracked like that (these cracks are not a heat or machining stress points), more than likely the closest bracket or fastener was overtightened on install. Like the ratchet-operator's face turning red, or more likey, with an air-hammer set at 'kill' torque. Unless the crack extends down to a head bolt or over to a cam journal, I'd either JB weld it, or take the truck to a good automotive tig welder, and have it repaired in situ. Assuming these cracks to be non structural as they appear in your pics, this repair is pretty standard, and not worthy of head replacement.
If it was me, before I call the welder-man, I'd loosen and retighten to factory spec, all the fasteners close to those cracks. Including the cam journal caps and the external fasteners.
HTH and my .02
Scott J
94 FZJ80 Supercharged
If it was me, before I call the welder-man, I'd loosen and retighten to factory spec, all the fasteners close to those cracks. Including the cam journal caps and the external fasteners.
HTH and my .02
Scott J
94 FZJ80 Supercharged
brukshut - I found a crack in the exact same place in my head 2 years ago!
The head gasket was replaced by the PO roughly 10,000 prior to me finding the leak & crack. My mechanic speculated that the crack may have been due to improper milling of the surface and/or over torqueing of the bolts. I ended up buying a used Toyota head for peace of mind and had it installed. Just a side note but I installed a supercharger on the used head too, with no subsequent issues.
Anyway, here are a few posts regarding my dilema. Maybe you can find some of the info useful.
https://forum.ih8mud.com/80-series-tech/328905-smoking-oil-leak.html
https://forum.ih8mud.com/80-series-tech/333677-odds-cracked-head.html
https://forum.ih8mud.com/80-series-tech/374875-lower-intake-plenum-cleaning-how.html (post #7)
Good luck with it and hopefully you get that thing running how you like it and out to Fire Island to catch some waves!
The head gasket was replaced by the PO roughly 10,000 prior to me finding the leak & crack. My mechanic speculated that the crack may have been due to improper milling of the surface and/or over torqueing of the bolts. I ended up buying a used Toyota head for peace of mind and had it installed. Just a side note but I installed a supercharger on the used head too, with no subsequent issues.
Anyway, here are a few posts regarding my dilema. Maybe you can find some of the info useful.
https://forum.ih8mud.com/80-series-tech/328905-smoking-oil-leak.html
https://forum.ih8mud.com/80-series-tech/333677-odds-cracked-head.html
https://forum.ih8mud.com/80-series-tech/374875-lower-intake-plenum-cleaning-how.html (post #7)
Good luck with it and hopefully you get that thing running how you like it and out to Fire Island to catch some waves!
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just to add another voice to this since you are looking for opinions, and I have been in a very similar situation with my truck:
If you have the money, time, and motivation right now to get it done right I would do that. If you look at it in terms of probability, the fact that 1. the head gasket went at such a low mileage 2. the head has cracks in it after the job was done 3. there is no documentation to speak of that validates the install, all these things would prompt me to source a good used head from a viable source, or a new one from American Toyota. The only parts within the head that should be anywhere near end of life would be the valve seals and you will need new ones when swapping everything over, all your springs and valves should be well within spec and reusable. Like I said, given what you know about this truck, I think it justifies a new head and a validated proper installation. Are you thinking about doing the work? Do you know of any reputable machinists in your area?
If you have the money, time, and motivation right now to get it done right I would do that. If you look at it in terms of probability, the fact that 1. the head gasket went at such a low mileage 2. the head has cracks in it after the job was done 3. there is no documentation to speak of that validates the install, all these things would prompt me to source a good used head from a viable source, or a new one from American Toyota. The only parts within the head that should be anywhere near end of life would be the valve seals and you will need new ones when swapping everything over, all your springs and valves should be well within spec and reusable. Like I said, given what you know about this truck, I think it justifies a new head and a validated proper installation. Are you thinking about doing the work? Do you know of any reputable machinists in your area?
Perfect timing on the info in this thread...since my head is off as well...
Thanks!
Thanks!
- Thread starter
- #27
Thanks for the input -- so here's my plan of attack.
1.) I have a friend who owns a shop in Brooklyn, I trust his advice. He recommended NOT to buy a new OEM head. He said that if I wanted to replace the head, to find a used one and have it reconditioned. He said that the new head would not be broken in, which is why a used one would be better.
I asked him what he would do if he owned the truck and planned on owning it forever. He said he would have the head pulled and sent off to a machine shop to fix the cracks and essentially recondition it. They'd be able to find all hidden cracks which aren't showing, etc. and would re-machine the mating surfaces. He quoted me labor costs around $1000, which is cheaper than a new OEM head.
He also said that fixing/remanufacturing the original head that came with the block is my best bet, as it matches the block precisely in terms of fit and mileage. I suppose that makes sense -- anyone think differently?
Manhattan Toyota (10th and 47th) quoted me a new head at $1600, but you can find them online for $1100. Kinda ridiculous, but the guys at Manhattan Toyota, in the parts department, are pretty awesome and the service there rocks, which is unusual for NYC where everyone is an a******! Ha. They gave me the numbers for some machin shops in brooklyn that they send their heads to. I can give you guys the number if you want.
I still think I'm going to follow the advice of my friend Peter, I have known him for 10 years and have seen him build up just about every kind of ridiculous car. If he knows a guy he trusts, then I am inclined to go with him.
I believe I am burning some coolant incidently; after a new thermostat, hoses and flush I am seeing some white smoke in the morning, but it abates once the engine warms up. My friend also recommended that I replace the timing chain and guides while I'm at it. Thanks to all who mentioned that I don't need new valves/springs, etc.
I did purchase a full engine gasket kit, and will be buying a new timing chain and guides (via Man-A-Fre), and plan on having the work done ASAP. My friend said that the cracks could grow as the weather around here gets colder.
As an aside, I'm noticing a rattling noise when I turn the engine over in the morning -- just when it starts up. I hear a quick rattle which sounds like the timing belt (CHAIN, yes) only on start up. I was thinking I dropped a washer or something when I did the valve cover seal! Hope that's not the case. Anyone hear any noises like this during a cold start in the morning? For some reason I think it's the timing chain.
Thanks all for the great advice and words of encouragement. Much appreciated!
You shouldn't need to replace the timing chain and guides, unless the guides are worn and/or broken (which you'll see when you open it up). Not very common at all.
If they are, you should hear the timing chain slapping against the housing, but that's a different noise than the rattle you are hearing (most likely). Many 80's have that start up rattle, it's just the top end rattling before it gets lubricated by oil. Worse in the winter as the oil is thicker, takes longer to get moved around.
The
80 has the start up rattle, mine doesn't. Since they're almost the same year and same amount of miles... 
I wouldn't worry about the rattle unless you have evidence it's something worse than the standard start up rattle that many 80's have.
As for your engine, if I had a cracked block what I (personally) would do would be to source a complete used engine from someone parting out an 80 (check the classifieds). They are not in high demand and often go very cheap. Rebuild the engine from top to bottom on a stand (including a new HG), then drop it in. That will likely be your cheapest option, and give you a like new engine.
It also minimizes your down time as you can keep driving your 80 until you do the swap.
I don't think it is important to use the same head. Any head should be machined flat. IMHO, I would get a used (undamaged) head, they aren't that expensive, and have it rebuilt. If I reused the cracked head, I would always be wondering why those cracks were there, and if the head was prone to weakness/ damage...
My head had a hairline crack in it, and I opted to replace the "core" with new OEM. Robbie (PowderPig) was the one who handled the whole diagnostics and replacement. His recommendation was to either get a new core, or have another used head sourced, reconditioned and installed. Repairing cracks in aluminum heads is a tricky business, and I agree that it should be avoided.
If money is no object I would get a new head. If money is tight, I would look for used, and take it from there. I call BS on the idea that the head already on your rig is better than one which is off of another rig. As long as the block is flat, and the head going onto it is also flat-machined, you will be fine. Odds are you are only seeing some of the cracks, and will be forever chasing your tail finding new ones with this head. IMHO the old head is nothing but a boat anchor, or a few bucks worth of ALU for the recyclers.
My $0.02 from being there, and having to make this exact decision.
Steve
If money is no object I would get a new head. If money is tight, I would look for used, and take it from there. I call BS on the idea that the head already on your rig is better than one which is off of another rig. As long as the block is flat, and the head going onto it is also flat-machined, you will be fine. Odds are you are only seeing some of the cracks, and will be forever chasing your tail finding new ones with this head. IMHO the old head is nothing but a boat anchor, or a few bucks worth of ALU for the recyclers.
My $0.02 from being there, and having to make this exact decision.
Steve
Thanks for the input -- so here's my plan of attack.
1.) I have a friend who owns a shop in Brooklyn, I trust his advice. He recommended NOT to buy a new OEM head. He said that if I wanted to replace the head, to find a used one and have it reconditioned. He said that the new head would not be broken in, which is why a used one would be better.
I asked him what he would do if he owned the truck and planned on owning it forever. He said he would have the head pulled and sent off to a machine shop to fix the cracks and essentially recondition it. They'd be able to find all hidden cracks which aren't showing, etc. and would re-machine the mating surfaces. He quoted me labor costs around $1000, which is cheaper than a new OEM head.
He also said that fixing/remanufacturing the original head that came with the block is my best bet, as it matches the block precisely in terms of fit and mileage. I suppose that makes sense -- anyone think differently?
Manhattan Toyota (10th and 47th) quoted me a new head at $1600, but you can find them online for $1100. Kinda ridiculous, but the guys at Manhattan Toyota, in the parts department, are pretty awesome and the service there rocks, which is unusual for NYC where everyone is an a******! Ha. They gave me the numbers for some machin shops in brooklyn that they send their heads to. I can give you guys the number if you want.
I still think I'm going to follow the advice of my friend Peter, I have known him for 10 years and have seen him build up just about every kind of ridiculous car. If he knows a guy he trusts, then I am inclined to go with him.
I believe I am burning some coolant incidently; after a new thermostat, hoses and flush I am seeing some white smoke in the morning, but it abates once the engine warms up. My friend also recommended that I replace the timing chain and guides while I'm at it. Thanks to all who mentioned that I don't need new valves/springs, etc.
I did purchase a full engine gasket kit, and will be buying a new timing chain and guides (via Man-A-Fre), and plan on having the work done ASAP. My friend said that the cracks could grow as the weather around here gets colder.
As an aside, I'm noticing a rattling noise when I turn the engine over in the morning -- just when it starts up. I hear a quick rattle which sounds like the timing belt (CHAIN, yes) only on start up. I was thinking I dropped a washer or something when I did the valve cover seal! Hope that's not the case. Anyone hear any noises like this during a cold start in the morning? For some reason I think it's the timing chain.
Thanks all for the great advice and words of encouragement. Much appreciated!
for the $$ quoted from the toyota dealer are they talking about a bare head (which I assume so)....
all depends on how much money you want to spend. In my view cylinder heads don't "break in" like you think about a short block "breaking in". It would be standard process to have any used cylidner head checked for cracks...(magna-fluxed) I believe is the process...
a cylinder head does not know if its sitting on a new short block or used.... If I were to buy the new cylinder head then I would want all the valvetrain assembly (new) to go with it and that would be really expensive.
you are probally well off to just find a good used cylinder head (and get a machine shop) to inspect it that deals in those type heads all the time before you buy and get it installed.
I would run toyota gaskets to include the head gasket, and would also make sure to run Toyota OEM on most anything else internal to the engine...if you plan on keeping it a long time.
I just discovered I have this exact type of crack on the exhaust side on the surface that mates to the valve cover. I've noticed a small oil leak there for about 3 months but had assumed it was just leaky valve cover gasket. I cleaned it up when the engine was hot and I could clearly see the crack and see it weep oil. Later with it cold, around 30-deg F, it was virtually impossible to see even with it spotlessly clean.
I have about 6K miles on the engine since the rebuild, with the head being machined lightly on that surface by a shop that is extremely reputable. I'll shoot some pics later but it isn't really close to a valve cover bolt or any of the head fasteners.
I have about 6K miles on the engine since the rebuild, with the head being machined lightly on that surface by a shop that is extremely reputable. I'll shoot some pics later but it isn't really close to a valve cover bolt or any of the head fasteners.
It's likely since it is almost impossible to see until it get's up to around 150+ deg F. And it really isn't the side that get's the machining attention. I'm going to see if my local machine shop guy can weld it up in place with the valve cover off. It is definitely not cool to see ANY cracks in an aluminum head! Especially after my journey....
This brings back bad memories!! Had the head gasket job done, original head out to a machine shop for inspection and light resurfacing. Said no cracks. One year later due to other issues (engine misfire...due to a pinched wire from fuel injector to ECU causing an intermitent ground fault/misfire), went elsewhere and they discovered a good sized crack at the cylinder head bolt hole at cylinder #5. No way to prove if that crack existed when the HG was done the first time or not.
Long story short, replaced the head with a brand spanking new one, along with all the associated parts, gaskets, etc. and it runs like the day I bought it if not better thanks to John and the gang at SDTRUX in San Diego. Engine has over 200K on it.
Long story short, replaced the head with a brand spanking new one, along with all the associated parts, gaskets, etc. and it runs like the day I bought it if not better thanks to John and the gang at SDTRUX in San Diego. Engine has over 200K on it.
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Here are the pics.
I had a very interesting conversation with the owner of a highly reputable engine machine shop out of Watkins Glen about how to fix this.
He was clear that there was no way this should be repaired with a weld. He said any stress, and to him it had to be heat, that was enough to cause a crack on the valve cover surface would surely have warped the head too much to allow the cams, their journal bearings, etc to be properly in line. It didn't matter that the block surface could be machined flat, it would just end up failing due to misalignment of the valve train. His advice was to try the "band-aid" approach of using epoxy on the inside but not to drill any holes or bother gouging out the crack. He then said to plan on ditching the vehicle ASAP as it was just a ticking time bomb. The only proper way to fix this kind of problem to him was get a new head or one that has never been heat stressed.
I guess that all makes sense to me at some level, but I also think there's a big gray area about little things like this and "catastrophic failure looming on the horizon".
I had a very interesting conversation with the owner of a highly reputable engine machine shop out of Watkins Glen about how to fix this.
He was clear that there was no way this should be repaired with a weld. He said any stress, and to him it had to be heat, that was enough to cause a crack on the valve cover surface would surely have warped the head too much to allow the cams, their journal bearings, etc to be properly in line. It didn't matter that the block surface could be machined flat, it would just end up failing due to misalignment of the valve train. His advice was to try the "band-aid" approach of using epoxy on the inside but not to drill any holes or bother gouging out the crack. He then said to plan on ditching the vehicle ASAP as it was just a ticking time bomb. The only proper way to fix this kind of problem to him was get a new head or one that has never been heat stressed.
I guess that all makes sense to me at some level, but I also think there's a big gray area about little things like this and "catastrophic failure looming on the horizon".
If it's truly that minor (rarely leaks, only small amounts, etc) then run it until it fails or becomes significantly worse.
It wouldn't surprise me if there are a decent amount of 80's out there with similar cracks. Most 80 owners wouldn't have their truck clean enough and enough OCD to notice that tiny hairline crack.
It wouldn't surprise me if there are a decent amount of 80's out there with similar cracks. Most 80 owners wouldn't have their truck clean enough and enough OCD to notice that tiny hairline crack.
