Hi folks, my little daily driver SWB Landcruiser with its 1kz-te power plant has decided to start using water.We all no what that means right.Its got about 220,000ks on it, so its getting to about the right age for it to happen, and I have been watching it closely looking for signs.I do 120k's a day in it to work and back, and everyday for the last few weeks, the level in the overflow tank has been dropping down about 10mm below the line on the tank. I fill it up in the morning to the line on the tank, do the commute, then check and fill the next morning.What's unusual is that the radiator level is always good, so its drawing back from the tank as it cools. Its also not pushing excessive amounts of coolant out into the tank, it looks just like the normal amount you get from expansion.There is no white steam on start up. It starts first flick and idles smoothly.Oil is clear, no bubbles in the coolant when cold.

• 1kz Te Engine

1kz Te Engine

When hot, its all circulating pretty furiously in the top tank with the cap off, maybe circulating to much, it is a bit messy, and very hard to see bubbles. Yet, its not chucking water out into the tank.I have been round and round the engine bay looking for coolant leaks from hoses, radiator, tanks etc. Cant find anything. Its much more like a coolant leak from a hose or radiator, except that with that sort of leak, you generally loose coolant from the radiator and the expansion tank stays steady.Its got to be the head right?? Just the early signs of it, with out the bubbles in the coolant, throwing water out into the expansion tank, white steam from the exhaust and rough idle on cold startAny tips or tricks on diagnosis??And any advice on sourcing a head, bolts and fittingCheers,Pete. Yep, I think I will go get it tested.I had a brain wave ( very rare ) when I got home from work. While the engine was hot, I put a big funnel on the top of the radiator filler and then filled it up with water.I was then able to better see if anything was going on with the engine hot.

Sure enough the water was aerating as I increased the rev's, a fine mist of bubbles coming through as opposed to a stream of bubbles. After idling for a few seconds then giving it a rev It would push out a decent bubble, then an aerated mist would start to come through.So in theory, a test when hot should pick up exhaust gas in the water.What this space.As for heads, this is all new parts, cam, valves etc from Kiwi Cylinder Heads:And this is a new head with as far as I can tell, second hand genuine parts fitted to it from Cylinder Head Supplies. They want old head in exchange:Any feed back on either of these places, good bad or otherwise??I'm leaning towards the Kiwi Cylinder Heads one, as there is a place in Hamilton and I like the idea of new parts hahaBoth offer a 12 month unlimited K's warranty, which is good for me as I expect to do about 30,000k's in it over a year.

Hey guys,As kbushnz says find the actual cause first. Do a cooling system pressure test, and a TK style combustion gas test to identify what is actually happening first.I've also seen the genuine waterpumps on 1kzs leak from brand new, yet the aftermarket repco ones are perfect.If you do determine its a head failure you can either replace the head or chemically seal what is currently there. I use 2 cubes of sealwel in a diesel and it'll lock it tight for years.If you want to replace the head there are 2 options I'm aware of:1.

Genuine yota. There's a short valve and a long valve head. Long valve is slightly thicker in the casting and is all I ever use when doing them. I also put a cooler genuine thermostat and run the genuine yota coolant and I've been very happy towing 3T behind the surf all day.2. Anything else.

Includes kiwi heads and STA parts etc. Some of these heads have been tested soft brand new. Good paperweights but hardly worth your good hard earned cash. Some people have found them ok for light use. But when I've seen a STA head literally melted after 10,000km you gotta wonder.

Have also seen kiwi back away from a warranty claim after a head failure so check the fine print.My 2c. I've heard good things about AMC cylinder heads. Spanish made.These guys are only a small ditch away.I read many years ago that the genuine (original) Toyota heads were made in China anyway. Not made in Japan, but out-sourced to China way back then even (in relation to my '96 Prado RX).They were just made with any old alloy scraps melted together and cast in the mould.

Probably why some heads die early, and some have no problem. If you were lucky Toyota sold you a Prado, etc that had a decent alloy mix in the head's construction.There was a write up about this on a UK Cruiser site. Told all about the dodgy heads, and recommended AMC heads.If my Prado ever poops itself I'll get an AMC head for sure.

Pull each injecterThis should show signs of water as 1 will be way cleaner and brighter than the others.I know this is the case with petrols and spark plugs.Altho ive owned a couple of 1kz motors ive never worked on the motor so unsure on how easy or practical it is to pull the injecters out. But if its not to hard it should give an indication on faulty cylinder and confirm the water loss at the same time.That said there is a lot of boom going on in those cylinders so would of tbought a bit of rad pressure would of shown up.Have you put a second bottle onto the rad overflow tank bottle. This will show the overflow bottle over filling and dumping water as well. Zed wrote:Hey guys,As kbushnz says find the actual cause first. Do a cooling system pressure test, and a TK style combustion gas test to identify what is actually happening first.I've also seen the genuine waterpumps on 1kzs leak from brand new, yet the aftermarket repco ones are perfect.If you do determine its a head failure you can either replace the head or chemically seal what is currently there. I use 2 cubes of sealwel in a diesel and it'll lock it tight for years.If you want to replace the head there are 2 options I'm aware of:1.

Genuine yota. There's a short valve and a long valve head.

Long valve is slightly thicker in the casting and is all I ever use when doing them. I also put a cooler genuine thermostat and run the genuine yota coolant and I've been very happy towing 3T behind the surf all day.2. Anything else. Includes kiwi heads and STA parts etc. Some of these heads have been tested soft brand new. Good paperweights but hardly worth your good hard earned cash. Some people have found them ok for light use.

But when I've seen a STA head literally melted after 10,000km you gotta wonder. Have also seen kiwi back away from a warranty claim after a head failure so check the fine print.My 2cIs Zed still lurking??I'm starting to have to top up the Radiator as well as the overflow tank now, so time to get serious.What's required to fit the long valve head to a 1994?? I assume it would have the early short valve head??