Overheating and coolant everywhere

[kamhol Lurker Find all posts View Profile Close kamhol]

Hi all,
One week out of our 300000k service and we have broken down for the first time. 2004 1KZTE 3.0 Diesel . Oils and filters done every 5000km.
We were driving on the highway when I smelt the coolant boiling, I looked over to the dash (wife driving) and the temp gauge was on H and the Check Engine light was on. We pulled over straight away.i popped the hood and could see coolant just below the Low mark in the reservoir. We noticed no loss in power and change in engine performance.

We towed the prado 10k back to home. Filled the reservoir up and tried to start the engine, after having the key turned for about 10-15 sec, the engine started with a whole heap of black soot from the exhaust. It sounds like it is running on two cylinders. You can hear air coming back out the snorkel. The oil level is fine and there is no signs of oil contamination. We can not find any water running out of the radiator.

So maybe a head gasket? But what would cause the overheating to start with?

Thanks

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

You're smelling the coolant burning on hot metal so it has to be leaking out of somewhere. The header tanks on the side of the radiator can blow their seals. Coolant will leak under pressure. It may not be visible until you drive at speed or you attach a pressure tester to the radiator. Hoses could be ruptured and core plugs could be corroded or fall out. If it was head gasket you wouldn't necessarily have the smell of boiling coolant. The gaskets have been known to fail allowing coolant to travel into the cylinder bore. Water pumps also develop leaks. There's a lot to check. Check all the heater and radiator hoses and then have a look at the radiator next with a pressure test.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Not the heater core and leaking onto floor under your matts ???.......Cheers Steve

[kamhol Lurker Find all posts View Profile Close kamhol]

Seems as If the coolant just came out of the overflow in the reservoir because it overheated. Maybe the head gasket blew which then caused the coolant to heat up. Is It common for the head gasket to go for no apparent reason ? Its a challenge when I live three hours from the nearest mechanic

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I am hesitant to use the C word on this forum but have you checked for a cracked head? Quite a common problem with the 1KZ motor. If you search here you find quite a few threads about it and recommendations from people who know what they are talking about.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

You may find the heads gone which would pressurize the cooling system with exhaust gasses which then pushes the coolant into overflow bottle and then once that fills up it will overflow and it will keep doing so till the coolant gets low then obviously it will start getting hot due to lack of water/coolant in the system. The only way to tell yourself is fill every thing back up, go for a run at higher speeds like 90/110 k making it work then check over flow bottle. If full you know what's wrong. But double check every thing else first like thermostat, radiator cap is holding pressure, no hoses sucking them selves in etc. I did all this but deep down new it was the head gone. Cost me 4k at the time.... Cheers Steve

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Sounds to me like a classic cracked head/head gasket issue, as previously said its not unheard of with the 1kz. Its probably a bit of the chicken and the egg thing whether a problem with the head or gasket caused it to get hot or it got hot for other reasons and if so has likely caused a head issue anyway.

Sounds as though taking the head off is a minimum for you, getting the entire cooling system checked at the same time would also be a must, otherwise you risk doing the damage again.

Cheers Andrew

[kamhol Lurker Find all posts View Profile Close kamhol]

Thanks fellas for the info. I ended up sending it into Toyota, (three hour trip on a truck). They did a pressure test on the radiator today and it held 100psi for an hour, so seems as though there is no leaks in the cooling system.

[kamhol Lurker Find all posts View Profile Close kamhol]

Recon Head or 2nd Hand Engine??

Hi all,

The head was tested and was it was found the "the integrity of the metal has been compromised, it is soft and beyond recon". The Toyota mechanic is concerned that if the head got this hot, that maybe the block/bottom end is also compromised even though there is no scoring on the bore and it can be turned over. He is recommending a 2nd hand engine or a brand new one!! $$$

Two other trustworthy mechanics I know are telling me to just put a recon head on it.

Remembering that the motor is obviously not ceased because we noticed no loss in power on the highway and we could start it the next day even though it only ran on 2 cyl. What should I do!?

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

Thanks fellas for the info. I ended up sending it into Toyota, (three hour trip on a truck). They did a pressure test on the radiator today and it held 100psi for an hour, so seems as though there is no leaks in the cooling system.

I think that would be 10psi...

[Rick NZ Member Find all posts View Profile Close Rick NZ]

A toyota mechanic pulled it apart without leakdown and compression tests - thats silly
Bottom end on 1KZ is pretty tough - Id be fitting a new head if bores looked ok

Heads are dam cheap, aftermarket bare heads are around the 1k mark or new Toyota for around $1600 ( all NZ dollar )
$3-400 for fitting of valves and setting valve clearances, plus a gasket set
10-12hrs labour and some coolant and its done

[kamhol Lurker Find all posts View Profile Close kamhol]

Hey Rick,

Awesome, I appreciate that advice. I'm leaning towards just a new head. Perhaps the Toyo mechanics just see it as a risk they want to avoid.

The mechanic said the first thing they did after a pressure check on the radiator was a compression check and only one cylinder had a tiny amount of compression. THey said they couldnt start the car. However at home before I took it in I could start it, it ran rough and took a while to start though.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

I'd be a little concerned in regards to no/low compression ??? I wouldn't want to wack a
new head on and the cost associated with it all to find the bottom end stuffed. Can you or is there another way if having it double checked ?? Yes the bottom end of the 1kz are strong but just how hot and for how long ?? If your going to keep the vehicle it may pay to do a full rebuild and cut the losses and enjoy it, if intending to get rid of it anytime soon I'd be wacking one in it from a wreckers (at least you get months warranty from a wreckers) then get rid of it. Problem is from a wreckers is was the motor serviced as good as yours was, will the head go on it outside the 3 months ?? Then your up for it again. This is just my opinion. I had the head go on my 1kz cost me 4g to repair but I got it before there was any overheating issues. Mine only had 103 k on it when it went and was serviced every 5k using all genuine parts. And never towed anything heavy and wasn't flogged so luck of the draw. I sold mine to a lady on here who knows the full history and to date still has it and hasn't cost her a cent more in repairs. That was nearly 3 years ago. I sold it as I wasn't happy with the over all performance or economy so I went back to petrol (3rd Prado now) cheers Steve

[Rick NZ Member Find all posts View Profile Close Rick NZ]

a cracked head or blown head gasket will show lower readings. If it ran after overheat then its got well over 400 psi still
Thats why they should of done a leakdown - esp when they noted lower compression

Ill bet they are covering there butts, by not recommending just a head fitted. Otherwise any issue with rings/block etc would become their problem
- and you can guarantee if it was one of their own cars - theyd just fit a head to it

[allenz-1203 Junior Member Find all posts View Profile Close allenz-1203]

Coolant pump

Hi I justhad a similar problem and it was the water pump from the radiator that failed the pressure test

Regards

M