overheating problems 1hz

[mule75]

my 1hz turbo is having overheating problems big time. cant keep it cool under load at all. new thermostat, checked water pump(ok), aussie desert coolers triple flow rad(never been happy with it i don't think it was any better than my old stock one with crimped and welded cores everywhere) has a front mount cooler, spotties and hi mount blocking air flow but these are not new. also been turboed for about 8 years well before this problem. shows no signs of head gasket apart from getting hot, doesn't use water, has a good fan shroud. dont run a pyro but nothing has been changed as far as boost and fuel since well before this prob.

next i'm going to pull the triple flow baffles out of the rad if that doesn't solve it maybe an ali rad. don't want to but i'm out of ideas.

anyone had similar probs?? any ideas??

it only gets hot when i give it a hard time or over 90kph otherwise its fine

[Z()LTAN]

check your viscus clutch on the belt driven fan, they always stuff up.

Just change it for a new one, they are fairly cheap

[blownba]

I agree with you the aussie desert cooler rads are junk IMO. The tripple flow looks good in theory but barely works in practice.
Are you sure your head is not cracked??? Or gasket leaking???
Are you noticing any coolant loos but not seeing it on the ground?
If you have changed everything you said and you are not experiencing coolant loss at all and it overheats while on the move (IE enough air flow) I'd say that your radiator is partially blocked.
If you get it out and send it to a rad joint they will tell you in a percentage how blocked it is.

[mule75]

just got a new viscous hub gonna put in in today 37 degrees today and tomorrow should test it out. putting another temp guage on to see what the water temp is comming out of the head. still going to get the baffles taken out of the radiator to make it work normal.

[Tapage]

Get a Pyro and check your EGT .. how much boost you are running .. ?

I will start with this .. just my .002 cents.

[me3@neuralfibre.com]

I had / have a similar problem. I reckon it's the viscous, but can't be sure. I put an aftermarket one in, but no significant change. Swapped a genuine one in for $430 last week (OUCHIE). Takin trailer for run this weekend, so you'll know if that helped on by Monday.

Is yours an Auto?
Is the cooler an intercooler or trans cooler?
If auto, do you have the extra cooler in the radiator, or just the single trans cooler?
If intercooled, is it a 1/2 width of full width core?
Have you blcked off the gap at the bottom between the A/C and Raditor cores?


Paul

[mule75]

Get a Pyro and check your EGT .. how much boost you are running .. ?

I will start with this .. just my .002 cents.

i'm runnin 16psi with pump dialed to suit but it has been like that for years with no problems. the overheating is only a new prob.

[Dzltec]

Has anything changed on the vehicle ie fitting of accessories to front of vehicle?

How did you test the water pump? Did you do a pressure and cavitation check? Is the guage reading accurately? Does it boil, are you loosing water??


Andy

[mule75]

I had / have a similar problem. I reckon it's the viscous, but can't be sure. I put an aftermarket one in, but no significant change. Swapped a genuine one in for $430 last week (OUCHIE). Takin trailer for run this weekend, so you'll know if that helped on by Monday.

Is yours an Auto?
Is the cooler an intercooler or trans cooler?
If auto, do you have the extra cooler in the radiator, or just the single trans cooler?
If intercooled, is it a 1/2 width of full width core?
Have you blcked off the gap at the bottom between the A/C and Raditor cores?



it's a man with front mount intercooler but it has been like that since before the prob. have not blocked gap between cooler and rad, is this good? bad? my cooler is only about 10-20mm of the rad. cooler is about 50mm thick and 400hx700w
took rad out to get it looked at and get those shit baffles out and will be back together on weekend with the new viscous hub.







Paul

[mule75]

Has anything changed on the vehicle ie fitting of accessories to front of vehicle?

How did you test the water pump? Did you do a pressure and cavitation check? Is the guage reading accurately? Does it boil, are you loosing water??


Andy

nothing changed with accesories. took water pump out and just checked visual, looked perfect. i replaced it about five years ago and my truck doesn't do many miles. always use coolant and change it every 12-18 months. it boils if i really push it but it takes a fair bit. don't seem to lose water but it only really does short trips except for once a year so hard to tell. i'm really sus on the triple flow rad so i'll see how it goes with the baffles out.

[mule75]

oh yeah, while the rad is out i'm putting a new temp guage in with the sender in the top tank near the hose.

[Tapage]

Mechanical water temp gauge .. could be anice option to start just to know if your problem it's real.

Other thing could be your ijectors .. much time without rebuild ( change ) and bad injection pathern could affect your temp .. due to much diesel in your pre cubs . .

[mule75]

i've owned the car for about 300,000km and never done injectors. maybe it's time to

[Z()LTAN]

i've owned the car for about 300,000km and never done injectors. maybe it's time to

whoopsy, even if it does not fix your temp problem, its totally time to do them!

[ROCKRASH]

I've only skimmed this thread-sore eyes. It may be mentioned above but, thermostat partially opening sounds feasable. Boil it and see what it does.

[dow50r]

You said under load it heats up...that is indicitive of the viscous fan...it is very common, they dont kick in when getting hot and not enough gets pulled through....friend had exactly thesame only on hills with trailer on the back, and we put a vl dunnydyre electric fan up front to prove it was the viscous...and it made the temp gauge come back down when switched ion....come to think of it, i still havnt got it back because his handbrake loves the cooler airconditioning

[Z()LTAN]

I've only skimmed this thread-sore eyes. It may be mentioned above but, thermostat partially opening sounds feasable. Boil it and see what it does.

new thermo bro

[mule75]

my rad is ready to p/up tomorrow so i will know more on the weekend when i get it back together.


thanks for the help

[mule75]

went to p/up rad he said you cant pull the triple flow baffles out so time for an alloy. best price so far $850 for an alloy rad 50mm longer than standard (can go 50mm longer because of body lift) with a one week turn around. can anyone beat this???????!!!!!!!!!!!!!! will ring race radiator in dande for a price tomorrow (ran out of time to call them).

[playtime4x4]

Mule, do yourself a favour, go to your nearest Toyota dealer and get yourself a tube of silicone oil for the coupling.Have done this mod for a couple of 75's now which had the same symptoms as your describing and after a good radiator clean out and engine flush you will find a huge difference. I did this to our 75 and have not looked back.As far as the radiator goes ring PWR Radiators and get a price. I have fitted one of these (75's) to my FJ45 to cool a 400 chev and and it now sits on half in 40 degree in traffic. This radiator is actually a 2 core with cooling fins designed to draw air in as opposed to Toyotas 5 core. Feel free to call the shop for more info on 9740 6300. Good luck,,
Dave @ PlayTime 4x4

[me3@neuralfibre.com]

Mine is a factory 2 core alloy job, same radiator in V8, Factory TD and 1HZ.

I put in a new aftermarket fan clutch 6 mths ago for $160, no fix. I know about the silicon oil, did it in the Surf. Works a treat, but the fan runs too often after that. Didn't want to hear the thing all the time round town. 1HZ is noisy enough already.

I put in a new factory fan cluth for $430 trade (OUCH) and new thermostat when I did the alternotor last week. Took the trailer for a 500km run this weekend, about 1.5ton total, dual axle, wire cage. Reasonably large wind resistance.

Overheated up the range on the way there at night (Blackbutt range). Temp rose on every major hill today with A/C on and warm / hot day. Had to back off to no more than 50% just before it touched the red. Sits on 100 fine, but hills are not nice. Medium hills I get to the top before it cooks, big big suckers get me first. I can hold 3/4 @ 2200RPM and 9PSI at 550EGT and it will rise to 3/4 stable for a few minutes. More revs or more fuel sends it climbing.

Motherf*cker. Coolant is new, cap is good, radiator has been flushed. Doesn't overheat in slow going, offroad etc. Has factory alloy bar and 2 Hella 4000's fitted. It's a pretty basic car.

EGT has to be 600+ before it overheats. Saw it crak 800EGT at 4200RPM on top of range, just as the temp cracked the red and it boiled. I backed off after that. 10PSI boost, no I/C.

Car is auto, but auto temp light never lit. I felt the auto cooler, and whislt hot, it wasn't roasting. I don't think the auto is contributing significantly.

It's gotta either be
a) Incorrect injection timing / pattern etc
b) all turbo'd 1HZ's are dodgy, but most ppl drive them too gently.

Anyone else got a turbo'd 1HZ and can you verify it bulletproof? Care to tow my trailer to prove it?

Thanx
Paul

[dow50r]

Paul
With two new fans on there, im swayed to believe you have that part covered. although i know the symptoms are thesame....
So, lets look at this from another point....your motor is a heat pump...more fuel equals more heat...hills kill it, but runining normally it keeps up....this all points to an inadequite heat exchange, and the reasons can be blocked rad internally or mud external, water pump impeller stuffed, bottom hose sucking in, partially open thermistat all the time, or blocked muffler, bad injection timing.
Mule, id be putting in a std rad to try...all that stuff up front shouldnt make any difference....a std one is roughly 400...both of you can try this...wind down windows and turn heater on full when it gets hot...see if that reduces the temperature of the coolant....you will get hot feet....
Another thing to do is physically check temperature of motor....sometimes, if the motor is not earthed to the chassis, you will get a false reading on the gauge...u could both try an earth wire from head to firewall...

[me3@neuralfibre.com]

Paul
With two new fans on there, im swayed to believe you have that part covered. although i know the symptoms are thesame....
So, lets look at this from another point....your motor is a heat pump...more fuel equals more heat...hills kill it, but runining normally it keeps up....this all points to an inadequite heat exchange, and the reasons can be blocked rad internally or mud external, water pump impeller stuffed, bottom hose sucking in, partially open thermistat all the time, or blocked muffler, bad injection timing.
Mule, id be putting in a std rad to try...all that stuff up front shouldnt make any difference....a std one is roughly 400...both of you can try this...wind down windows and turn heater on full when it gets hot...see if that reduces the temperature of the coolant....you will get hot feet....
Another thing to do is physically check temperature of motor....sometimes, if the motor is not earthed to the chassis, you will get a false reading on the gauge...u could both try an earth wire from head to firewall...

Rad has been cleaned inside and out. Few butterflies on the front this weekend is all. Bottom & top hose is new and under plenty of pressure. Red on the gauge = boiling over into overflow bottle. Normally sits solid on 1/2 in nearly all conditions except towing on large hills. Thermostat is new. Exhaust is 2.5" mandrel w/ straight thru can and boost behaviour and noise tend to indicate free flow. Heater doesn't help, not big enough to influence. Water pump is a possible, but I kinda doubt it.
I'm going for either injection timing / spray pattern, or simply that indirct injection dumps too much heat into the head. I need another to compare to be sure though.

Paul

[hdj105]

EGT has to be 600+ before it overheats. Saw it crak 800EGT at 4200RPM on top of range, just as the temp cracked the red and it boiled. I backed off after that. 10PSI boost, no I/C.

Paul,

If that's 800 deg C you won't have to worry about the overheating issue for long! Is that pre or post, still HOT either way.

Retarded timing will cause EGT's to be higher, out of cal pump or restricted filter can cause that. At 4200rpm the fuel should be being cut back as you're approaching redline, and EGT's should decrease.

[me3@neuralfibre.com]

EGT has to be 600+ before it overheats. Saw it crak 800EGT at 4200RPM on top of range, just as the temp cracked the red and it boiled. I backed off after that. 10PSI boost, no I/C.

Paul,

If that's 800 deg C you won't have to worry about the overheating issue for long! Is that pre or post, still HOT either way.

Retarded timing will cause EGT's to be higher, out of cal pump or restricted filter can cause that. At 4200rpm the fuel should be being cut back as you're approaching redline, and EGT's should decrease.

Stays under 720 under all throttle conditions until temp climbs beyond 3/4. Climbs to 750 then. As revs go above 3700 quickly climbs from 750 to 800. Only hold that for 4-5 seconds. All pre turbo on Autometer electronic gauge.

I know yours is the 1HD-FT Greg. Is it possible to overheat it that you know of?

Thanx
Paul

[hdj105]

[
I know yours is the 1HD-FT Greg. Is it possible to overheat it that you know of?

Thanx
Paul

I've never "overheated it", but I have twice had the temp gauge rise above half when towing, once when towing on a 42 deg January day and the a/c cut out - gauge no higher than 3/4. Another time on a more moderate day when towing the 40 series on tandem up the Hume Hwy and deliberately pushing it to see what it would do, EGT, temp, boost, etc.

[Dzltec]

Test your water pump by this method. http://www.allhead.com.au/technical.html

Is the temp gauge accurate? Has the fan coupling been rechecked. The only way we know to test these properly is via fan blade and coupling speed.



Andy

[mule75]

put the new viscous hub on and put an old rooted stock radiator in and it is already heaps better. on a hill sitting on 120 the temp crept to just(maybe one mm) over half and at all other times it was sitting on about a third on the guage but it was a pretty cold night last night. i'm gonna stuff around with my old rad before i order an alloy. i'm not too keen on shelling out the coin unless i really have to. i'm thinking about putting thermo's on my intercooler too. it seems that because of all the stuff on the bar it is blocking allot of air flow.

[Z()LTAN]

yeah, 100% sure its the viscus hub aye

[simkell]

mate you say your rad is a two core, mine is three core .

i would say you have to much fuel to start with, then possibly a air flow restriction though the rad, either air can't get in or can't get out.
as sated before the engine is a heat exchange pump, more fuel more heat.