1kz Te Cylinder Head Crack Sealer
A few thoughts on a 1KZTE engine rebuild using a Toyota genuine short block. All relate to a 1994 KZJ78W Prado. I started this saga as a consequence of the dreaded cracked head syndrome. On removing the engine I discovered that not only was the head very obviously cracked on three cylinders but that I had come very close to total engine melt down.
HINT There are 5 types of cylinder head gasket hole number 1 to 5. Toyota 1kzte Head Gasket Thinknes Difference. Toyota Hilux 1KZ TE Repair. First introduced in 1993, Toyota's 1KZ-TE was a 3.0-litre turbo-diesel four-cylinder engine. Key features of the 1KZ-TE included its alloy cast iron block, aluminium alloy cylinder head, single overhead camshaft, two valves per cylinder, drive-by-wire electronic throttle control and indirect injection. Furthermore, the 1KZ-TE.
All of the bores were scored and the big ends had all been “wiped” but hadn’t picked up. A new head and bottom end rebuild was clearly on the cards but just to tick a box I asked our local Toyota dealer what a short block would cost. They came back with a really good price and so I decided on that thinking it would be quicker.
There have been a few issues: All part numbers are Toyota OE ones. I took the head off in the car. With the benefit of hindsight I think that taking the whole engine out is probably easier unless you have tentacles. Take lots of pictures before you dissemble, vacuum hoses can be a swine to figure out. Be careful to separate the torque converter from the flex plate before the engine comes out very far.
If you don’t there will be oil all over the floor and you risk damaging the transmission oil seal. There is a water feed union in the head that goes to the throttle body. It is a press fit and cannot be re-used. For the new head you will need to buy a screw in one: (part # ). There are two types of head, one has longer valves than the other. From researching forums like this one it appears that as a complete assembly they are interchangeable but don't try to fit long valves into a short valve one.
New short valve head is part #. As far as I know they can't be distinguished externally but you can tell when they are off. The short valve has the valves sitting in small pockets in the head but in the long valve version they are flush. The diesel return union rail on the injectors can easily be damaged unless you take the inlet manifold off first and then stop the injectors from turning with a spanner before undoing the lock nuts on the injectors. I found this out the hard way.
There is a tiny packet in the box with the new block containing a small brass plug with a hole in it and a small core plug. What's that for? The brass plug is the restrictor for the oil supply to the head and goes into the oil feed gallery at the back of the block. Leave it out and you'll have low oil pressure. It is a rattling good fit so if you turn the engine over without the head on watch that it doesn’t fall on the floor.
The small core plug is to block whichever dip stick hole you don’t use, there's one on both sides. The short block is obviously designed to be generic. The turbo water feed pipe is a press fit and cannot be removed, you will need to buy a new one (part # ). The new short block block (part # ) has larger reinforcing webs at the rear of the sump and a different bolt arrangement for the two bracing members that fit between the transmission and block. Toyota wasn’t able to say what was supposed to done about this so I ended up cutting mine to fit.
This means that there is now only one bolt fixing per side instead of two. I reckon this will be OK because a) the block is a lot stronger now in this area and b) because I don’t intend to ramp over any sand dunes. The short block is very short – pistons, rods, crank and block only so if going this route the rest of your engine needs to be in good shape. Buy lots of parts cleaner because you are going to need it! The idler gear which sits between the crank and the injector pump drive gears sits on a pedestal that in my engine was secured by two 8mm bolts. Apparently in early 1995 this was re-engineered because of some failures so it doesn’t fit the new block. You will need a new pedestal (part# ), thrust washer (part # ) and bolts (part # ) as the new ones are 10mm and the pedestal and thrust washer are changed accordingly.
Don’t be tempted to make a plan because if the thing fails it makes a huge mess. There is a dimple on the new thrust washer which faces out and goes below the top bolt. Don’t know why that’s important but that’s what the manual says.
Before you remove the idler gear remember to lock it up with a 6mm bolt if you aren't planning on inspecting its internals and even more importantly remember to remove it before you try to fit the front casing. As an observation that’s maybe obvious but still needs to be made if you are disorganised like me try to order everything at once because there can be significant delays. For example Mr Toyota only had the pedestal and one of the bolts in stock here in NZ despite there being approximately 1 billion 1KZ's here.
The other stuff had to come from Japan which took weeks so I got it from Aus. Yes the crank pulley is torqued up to that ridiculous number. Most of us don’t have a torque wrench that size or a torque multiplier so I did mine up to the maximum my torque wrench offers (210Nm) then got out my 3/4 drive power bar, put a piece of pipe on the end and pulled as hard as I could.
Hope it works. When you come to putting the thing back in the car take some time to get the engine to hang squarely. Mr Toyota's handy head hooks didn’t do that for me and caused no end of grief because there isn’t much wiggle room.
Make sure that you remember to attach the earth lead on the back of the block before you get the engine all the way in. You'll regret it if you don’t! Many of the tranny to engine fixing bolts are best tightened (or loosened) by using some long half inch extensions joined together and a universal joint so that the ratchet is near the back of the gearbox. Take the transmission dip stick off or it gets in the way.
There is a joint towards the bottom and a bracket onto the transmission. If you don't it gets in the way big time and bends. I put a scissors jack between the transmission oil pan and the anti roll bar that was very helpful in adjusting the angle of dangle for refitting and supporting the tranny whilst the engine was out.
Make sure that the torque converter is pushed all the way in before you put the engine in as otherwise it can hang up and cause problems. Also get at least one bolt in on the flex plate before the engine is fully home so that you can rotate the torque converter relative to the flex plate with a stubby screwdriver. There is no way to turn it when the engine is fully home so if the bolt holes don’t line up at that point you'll not be a happy bunny. There are a number of O rings around the timing gear train, front cover etc that will need to be replaced. Get a good manual and check where they are because they ain't easy to get at afterwards and have a talent for falling off when you try to install the covers over them.
The engine overhaul set (part # ) doesn’t include O rings for the vacuum pump, power steering pump and turbo to exhaust manifold gasket. You'll need to buy these separately. Apparently Mr Toyota can rebuild an engine without taking these things off. I had lower than normal oil pressure for some time before this rebuild and consequently had replaced the pressure relief valve spring, big end bearings and thermostat hoping for a cure. I now suspect the idler gear mentioned above.
The original thrust washer was quite worn and the gear had clearly been running at a slight angle. I suspect that it was just enough to bleed 4 or 5 psi of oil pressure off.
Install Onedrive Personal on this page. There is lots and lots of stuff about the overheating head cracking ways of this engine on this and other forums so I won't waste space pulling that one to bits. However what makes the most sense to me is the discussion around the siting of the thermostat.
Dakku Daddy Mp3 Download Free. My personal “fix” has been to fit the 71 degree thermostat (part # ), refill the fan viscous coupling and to fit a EGT gauge. Here's hoping.
Hi all, With all of the talk about the frequency of heads cracking on the 1kz-te engine, I would like to find out what definitive test can be done to determine if the head is cracked. The head was replaced on the engine before I got it on mine, but I would still like to check it to make sure. I have a rough start from cold and the occasional stutter in my idle, which I have read match some folks with this engine's cracked head symptoms. What I have read so far is that the coolant system can be pressurized, and then you check to see if the pressure remains after a period of time.
I would imagine that this test may be more accurate with a warmed up engine. I have also read that obvious clues are loss of coolant and/or bubbles coming through the coolant. Are there other ways to check for a cracked head without taking the head off for a visual inspection? Thanks for the response Maxi. I have done a compression test and all is excellent there. There is no oil in the coolant or vice versa. If I do have a poorly functioning head gasket or slightly cracked head, it is only very minimally so.
If either are the case, I would expect that while the engine is hot, a small amount of coolant is able to get into the cylinders, and so it idles rough. When shut off, some coolant gets into the cylinders as the block cools down. Then when I go to start it, the coolant makes the initial start difficult. This is all just conjecture, so that is why I would like to find a definitive test to determine that my head is in great shape or not.
Guess maybe I should just take it apart to take a look. If I do that, I will need a new head gasket, correct? The one that is in there came with the new head something like 8k miles ago. Thanks for the response Maxi. I have done a compression test and all is excellent there.
There is no oil in the coolant or vice versa. If I do have a poorly functioning head gasket or slightly cracked head, it is only very minimally so. If either are the case, I would expect that while the engine is hot, a small amount of coolant is able to get into the cylinders, and so it idles rough. When shut off, some coolant gets into the cylinders as the block cools down. Then when I go to start it, the coolant makes the initial start difficult.
This is all just conjecture, so that is why I would like to find a definitive test to determine that my head is in great shape or not. Guess maybe I should just take it apart to take a look. If I do that, I will need a new head gasket, correct? The one that is in there came with the new head something like 8k miles ago.
Does the engine puff white smoke when you cold start it, indicating coolant in the cylinder, or anything like that? Are you losing coolant? Other than rough idling, hard cold starting, are there any symptoms that make you suspect the head? Have you ensured the timing is correct, and the fuel system is up to snuff? I also thought the head issues were limited to the L-series engines, so the head would be something I would look to after I tried everything else. You could try a leakdown test as well as the compression test to make sure the engine itself is OK.
No, no real puff of white when starting. I have described elsewhere that the initial start is very rough, with the engine shaking around, but after a minute or so it changes character and idles much smoother. While idling 'smoothly' is occasionally stutters and does cough a white puff. I recently had the injectors cleaned and balanced, hoping that one was misbehaving and leaking diesel that would cause the puff, but I have not gotten to the point of starting the truck after the injector work (wiring work going on).
If I don't have a cylinder head or gasket issue, then my next step is to have the injector pump worked on. But I would really rather have a clue about the cause of the issue instead of throwing money at it Thanks for the responses. I'd really check the fuel system for 'air' tightness to make sure it's not sucking a little air in from somewhere causing this.
Also, I don't think 1KZ's have a problem with heads cracking/head gaskets leaking at all. When I was over in Afghanistan we had two hi-ace vans, both with 1KZ's. Well, the auto had a bad radiator cap and army people being kind of idiots, continued to drive it around in the red during 105+ temps in the summer. I know of 5 times at least the van overheated and two of those times I got to it afterward and poured water in it. When I poured the water in it, it would suck down a few bottles and then suddenly spew up a geyser when it all started boiling down in the bottom of the engine. What I'm getting at was this engine was HOT!! Anyhow, we eventually got a new radiator cap and continued to drive the van around for another 6+ months (until we rotated out).
I continued checking the oil and coolant for any sign of cross contamination or leaking and it never did. The engine was still running like a top (really!) when we left. I also note that in the year I was over there I never saw the oil get changed, I don't think they had a mechanism in place to do that (local nationals fixed all the civilian type vehicles on base), so the last time the oil was changed is anybody's guess. After that experience, I'm much more sure of the durability of the 1KZ engines. Thanks for giving your thoughts on the situation.
The 1kz-te does have a frequency of heads cracking, just read a few pages on hiluxsurf.co.uk. They even have a sticky about changing your head since it happens to so many of their imports. Regardless, the head on my truck had already cracked and the original swapper, paid somebody to put in a new head.
Id on't know how in the world the head could be cracked in only 8k miles or so, but the symptoms I have seem to match those he had when it had originally cracked. It has been suggested by a fellow in Australia that the front seal of the injector pump is leaking in air, and is worse when it is cold. I have not pulled the pump yet, but that may be next. I do have clear hoses all the way to the injector pump and do not have noticeable bubbles. With the messing around I have been doing with fueling components recently, I have noticed that the fuel primer does not seem to do its job, and a spare from a local buddy does not seem to do much better. The previous owner told me that the fuel filter is pretty new, but is it possible that the filter is so clogged that the primer won't do its job? A visible inspection did show it looking bad at all.
I wish it was as simple as needing new glow plugs. I previously did the test per the FSM and the glow plugs seem to check out. I am actually suspecting that the hand fuel primer is leaking air in. I have clear hose and don't usually see bubbles, but this week I did a controlled test to see what bubbles could be seen. I removed the fuel line from the hard pipe and put it and the return line into a large jar with diesel and Lubromoly's Diesel Purge. I did actually witness randomly time packets of mini bubble exit the injector pump.
I also saw some bubbles that appear to have originated from the primer. Here's the video: Additionally, the main point of this thread was not just to solve my issue, but to nail down a definitive test that can be done to determine if there is a crack in the head/head gasket (even though it seems unlikely I have a crack in this case). A cracked head is going to show itself on a cold engine. You can try leakdown and coolant pressure tests but with a diesel the cylinder pressure is so high that unless you have a really bad crack or blown gasket you aren't going to see it that way. A block test will test positive if there are combustion gasses in the coolant. The best way is to start the engine cold and give it some rpm's right away, shut it down and then see what kind of pressure built up in the cooling system. Normally it will take 5 minutes minimum to build any kind of pressure.
A crack in the head will displace all the coolant in the head and burp the system into the overflow reservoir. Typically your first sign of that kind of a problem is that you are losing coolant out of the overflow. Once combustion warms the head up the crack seals and all goes back to the way it should be until the next cold start. I just watched that video, you definitely have an air leak and unless it came from the clear hose it would have to come from the primer.