TCEd
SILVER Star
I know that is a broad title but from what I can find the engine is good except for a potential to crack heads. Any comments are greatly appreciated. Ed
1-KZT thoughts ? (1 Viewer)
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Recommend going into it with the intention of replacing it with a new updated head part number, most likely sooner than later.
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For any kind of hard work; towing, off roading, extended overland travel, I would definitely avoid it.
While I have never owned one, I have been a Hilux and Hilux Surf owner for many years. Most Hilux Surfs have the 1KZ-T/TE and if you join the (mostly UK based) FB group and search terms like 'overheating' or 'cracked head' you won't make it to the bottom of the list of people whose 1KZs have died. And that's in a place with a very mild climate and nothing you could really call a mountain pass.
I suspect many of these cases are from poor maintenance, but there are also stories of people doing everything right (new head, all of the cooling system replaced) and still cracking the head.
On the other hand, there are people who run them without issues. In Australia I don't think they have such a terrible reputation as in the UK. But there is clearly a serious flaw with these engines.
If the engine is in a perfect JDM cruiser that you just want to polish and keep in the garage, or drive gently at weekends, go for it. If you are keen to get into diesel Landcruisers, this is in my opinion the worst diesel Toyota ever put in one.
While I have never owned one, I have been a Hilux and Hilux Surf owner for many years. Most Hilux Surfs have the 1KZ-T/TE and if you join the (mostly UK based) FB group and search terms like 'overheating' or 'cracked head' you won't make it to the bottom of the list of people whose 1KZs have died. And that's in a place with a very mild climate and nothing you could really call a mountain pass.
I suspect many of these cases are from poor maintenance, but there are also stories of people doing everything right (new head, all of the cooling system replaced) and still cracking the head.
On the other hand, there are people who run them without issues. In Australia I don't think they have such a terrible reputation as in the UK. But there is clearly a serious flaw with these engines.
If the engine is in a perfect JDM cruiser that you just want to polish and keep in the garage, or drive gently at weekends, go for it. If you are keen to get into diesel Landcruisers, this is in my opinion the worst diesel Toyota ever put in one.
I got a screaming deal on a 1KZ-TE powered Prado. Did a lot of reading before hand, and was hesitant precisely because of these head issues. Wanted a 1KD, but it'll be a couple more years before those can be imported. Between not being sure if the 25 year loophole will still be open when 1KDs are available, and the ridiculously good deal I got, I decided to move forward.
The Aussies don't seem to have nearly the head problems with the 1KZ, despite working them harder and in a much harsher environment. Maybe they just know they're in a harsh environment and keep their cooling system in better order than folks in the UK? Intercooling seems to help a lot also.
I'm amazed at how fast I start getting heat out of the vents after a cold start, no wonder they overheat so fast with any kind of cooling system issue. Someone here said that coolant is as important to these engines as oil, and I believe it. I've moved small block Chevy powered stuff around the driveway and yard without coolant and no issue, but I absolutely wouldn't do that with this engine.
I'm also not thrilled with the fuel economy, indirect injection definitely has a penalty. Once 1KDs are available for import, I'll be looking to upgrade.
The Aussies don't seem to have nearly the head problems with the 1KZ, despite working them harder and in a much harsher environment. Maybe they just know they're in a harsh environment and keep their cooling system in better order than folks in the UK? Intercooling seems to help a lot also.
I'm amazed at how fast I start getting heat out of the vents after a cold start, no wonder they overheat so fast with any kind of cooling system issue. Someone here said that coolant is as important to these engines as oil, and I believe it. I've moved small block Chevy powered stuff around the driveway and yard without coolant and no issue, but I absolutely wouldn't do that with this engine.
I'm also not thrilled with the fuel economy, indirect injection definitely has a penalty. Once 1KDs are available for import, I'll be looking to upgrade.
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They stopped cracking heads in the 2000's, but by then most markets were using the 1KD. All of the ones built in the 90's crack heads. All of them.
The 1KD is ~20% more efficient. So that much more power and that much better economy.
The 1KD is ~20% more efficient. So that much more power and that much better economy.
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I think there are a couple of things different in Australia - though these are just thoughts as I've never lived there. Firstly, in the UK, Hilux Surfs and light duty 70 Series Cruisers with the 1KZ are dirt cheap, so appeal to people who can't afford to maintain them properly. I believe cars in Australia are relatively more expensive. Also, I am not sure how popular the 1KZ was in Australia where the heavy duty Landcruisers are pretty common (I believe). In Europe where, let's face it, very few people need a 2+ tonne Landcruiser, the smaller, more economical models are much more popular.
Interesting. Was that a clear design change, or it's just that they crack heads after a certain age, which the 2000ish models have not yet reached?
mudgudgeon
Resident galah
I would guess Hilux would have outsold Landcruiser many years. Maybe not always.
Hilux was the work ute of choice for tradies for a looooong time
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Ah, in the UK we never got the 1KZ in the Hilux. Looking now and putting your comment together with Dougal's, I think we can say that the UK mainly got the 1KZ (via grey imports) in pre-2000 JDM Hilux Surfs whereas Australia saw the 1KZ mainly in the KZN165 etc from about 2000 onwards, when the UK had the 2KD.
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Here in New Zealand we have more 1KZs than anywhere else - thanks to our hunger for Japanese imports. They're here in 70 and 90 series prados, Hiluxes, Surfs and Hiace vans. There are literally thousands of them. I have even seen them on stern drive, shaft drive and Jet Drive boats. It is not an exaggeration that i would see at least a dozen 1KZ powered vehicles a day here.
They do have a reputation for doing heads and gaskets. It's usually a when not if scenario. Maybe if you're super anal about maintenance then you'll get away with it. Personally having owned 2 (both of which didn't have an issue) i wouldn't have one again - it was always in my head that it could let go at any stage.
They do have a reputation for doing heads and gaskets. It's usually a when not if scenario. Maybe if you're super anal about maintenance then you'll get away with it. Personally having owned 2 (both of which didn't have an issue) i wouldn't have one again - it was always in my head that it could let go at any stage.
That's a shame. I just got rid of a Subaru as a daily driver, and swore off ever getting another because of the head gasket issue. Out of the frying pan and into the fire, I guess.
With Subaru head gaskets, there's a lot of warning. Mine smelled of coolant from the day I bought it, and I eventually had the head gaskets done due to oil leaking on the exhaust system and filling the cab with smoke, not because they were leaking combustion gasses into the cooling system and vice versa. It drove to the repair shop under it's own power without issue. Does the 1KZ go the same way and give lots of warning, or does everything seem perfectly fine until you're walking home?
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The engines don't grenade, usually you just get overheating/coolant pressurisation. Unlike your Subaru, the head gasket will be fine, but you can be 99.9% sure that the head is cracked.
If there is a change in head design that can be linked to the observation that it's the pre 2000 models which have the issue, then that, as @OGBeno said, may be your solution.
If there is a change in head design that can be linked to the observation that it's the pre 2000 models which have the issue, then that, as @OGBeno said, may be your solution.
GTSSportCoupe
2LTE abuser
In general, all Idi turbo diesels get hot when worked . It's a function of the tech. That's really all there is to it!
I've got no idea of any design changes. I just know a lot of people who had to change heads. The two 1KZ's I know built after 2000 (hilux and prado) did high km without head failure.
I'm not aware of repeat failures once a head is replaced. But I also don't know anyone who did the original km again to test.
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I noticed something similar in the UK - the early to mid 1990s 2LT, which came mostly in grey import Surfs, used to crack heads quite commonly. The later models of the same engine (technically 2LII-T) in the 1998+ LN165 seemed not to do so.
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Both of the trucks i mentioned had north of 300,000KM. They didn't use coolant or get hot, and i was fully on top of maintenance. Maybe i listened to the scaremongering too much but I found them worrying to own.
How many kms were on the trucks when you bought them? The heads might have already been done.
If I bought a Subaru with 300k kms with no head gasket issues, guarantee it would be because the head gaskets had already been done.
