3.0 overheating issue, someone shine a light please

[P415JJU]

Hi new to the forum but I have had a few surfs in the past.

My current surf P415 JJU is a 3.0 auto 1KZ, I love the old girl she’s done 180,000 and drives pretty straight for a surf, safe to go above 50mph lol

anyhow disaster struck me yesterday as she boiled on a causal 4 mile trip to get my kids from school, I limped her back home by in which time she flew up to above the H on the temp gauge.

i took the rad cap off and dumped the water as soon a shot I got back to relieve the built up pressure and allowed her to cool down, since I bought this surf (3 months ago) the interior heater didn’t work no heat came out but the car ran at a healthy temp until yesterday, so I bypassed the heater core and made sure the pipe I joined the two pipes together with wasn’t crimped.

And to avoid any other overheating issues I removed the thermostat and while I didn’t that flush the radiator and block out 4-5 times, rebuilt her back together again and...

She ran oddly at the ordinary running temp (without a thermostat fitted) and is okay so long as you keep the revs below 2000rpm, if you go above to let’s say overtake a car the temp goes up past the mid way point and prolonged high revs would certainly get her back in the red, when it does get hot if you ease the revs back slowly she does get back to a normal running temp.

(forgot to mention while the hoses where undone I fired her up and the water pump pushed the water out of the heater core hose as it should)

So any experts please, do I need a new cylinder head? I can get one for £395 from a friend that runs a company dealing in cylinder heads, but if I can save the effort of swapping one od prefer not too, I say there anything I’ve missed? Any advice would be amazing many thanks

[P415JJU]

#overheating #3.0 #1KZ #surf #cylinderhead #hilux

[wiggy]

Unfortunately not good news..you need a new head for peace of mind or get the one you have skimmed? Reason is the temp fluctuations you are having....but a question but why did take the thermostat out? Was it to test?

[Shayne van der Klei]

[FONT=comic sans ms, cursive]giday, i have a '96', 3.0ltr 5 speed. [/FONT]
[FONT=comic sans ms, cursive]a good ole girl. not a pretty but shes a got a big heart.[/FONT]

[FONT=comic sans ms, cursive]when i first got it. she was over heating. it took a couple of heads to learn the block was gone too. [/FONT]
[FONT=comic sans ms, cursive]i learned that the EGR (exhaust gas regulator) which is essentially a tube that is fitted to the back end of the exhaust manifold and is connected to the inlet manifold round the back of the tappet cover, is the mungril that pumps all that expended gas carbon and heat straight back into your inlet manifold etc etc reburn. emission control blaa blaa.[/FONT]

[FONT=comic sans ms, cursive]This means that there is a whole lot more heat around the head. more than is comfy for the 1kzte. Heat retention in this area makes for heads that die more easily.[/FONT]

[FONT=comic sans ms, cursive]I did read that the options for overcoming this heat retention problem are; 1. fit oversize turbo, 2. Fit larger exhaust, 3. Fit intercooler.[/FONT]

[FONT=comic sans ms, cursive]I looked inside to old inlet manifold to see about 5mm of carbon crap lining the walls. Bad case of colesterol. reckon this had something todo with why the inlet manifold was SO hot i couldn't touch it.[/FONT]


[FONT=comic sans ms, cursive]I removed the EGR and blocked the holes etc. got the required inlet manifold for the intercooler. fitted it. and yip. more power at the wheels. i read or was told about 25 extra horses. Fuel efficiency is definitely up. far better running.[/FONT]

[FONT=comic sans ms, cursive]Consider i have a second hand motor. not reconditioned. And had well over 100 000k's[/FONT]

[FONT=comic sans ms, cursive]No i cant remember where i learned what i offer here. sorry bout that.[/FONT]

[FONT=comic sans ms, cursive]Cheers[/FONT]

[Graham Hugh]

When my head cracked kzn130.it just blew anti freeze out the rad. Filler didnt overheat though . Tried all sorts of expensive additives. Useless. Blocked thermostat went hard in the middle of lower pipe like a snake. Also blocked and scrapped the radiator. So new head from milner. Fantastic.