1hz overheating

Submitted: Sunday, Feb 15, 2015 at 19:21
ThreadID: 111128 Views:6906 Replies:13 FollowUps:17
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hey guys. having overheating problems on the hills . changed the thermostat and top up the oil in the viscous fan but still not coping under load on the hills. should I replace the rad next??
And if so does anyone have or know anyone with a work space I can fit one round Melbourne area? any feedback is appreciated .
Sam pommie on the road round Oz
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Reply By: get outmore - Sunday, Feb 15, 2015 at 19:26

Sunday, Feb 15, 2015 at 19:26
bout the only thing left so i guess so
AnswerID: 545986

Reply By: D-MaxerWA - Sunday, Feb 15, 2015 at 20:38

Sunday, Feb 15, 2015 at 20:38
My mate had similar problems with his HiLux. New radiator didn't fix the problem. He did a really good flush of the cooling system and had a lot of gunk come out. He also removed the head and cleaned that as well. Problem has gone away.
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AnswerID: 545991

Reply By: Member - Nutta - Sunday, Feb 15, 2015 at 20:40

Sunday, Feb 15, 2015 at 20:40
What temperature does it get to exactly?

Have a look at some of these, cheers.

https://www.google.com.au/search?client=safari&rls=en&q=1hz+overheating&ie=UTF-8&oe=UTF-8&gfe_rd=cr&ei=-2XgVJSGCtPu8wfN-oGQCQ
AnswerID: 545992

Reply By: Troopyman - Sunday, Feb 15, 2015 at 20:40

Sunday, Feb 15, 2015 at 20:40
Take it to a proper radiator place . I had a leaking radiator and had it replaced with an aftermarket brass one . I get it flushed out every year for around $150 . The radiator needs to be taken out and cleaned out . Never have to worry about overheating .
AnswerID: 545993

Reply By: Steve in Kakadu - Sunday, Feb 15, 2015 at 20:51

Sunday, Feb 15, 2015 at 20:51
No ifs No buts and no maybes, it is the viscus hub on the fan.

AnswerID: 545994

Follow Up By: Slow one - Sunday, Feb 15, 2015 at 20:54

Sunday, Feb 15, 2015 at 20:54
Gotta agree steve
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Follow Up By: Sam M1 - Sunday, Feb 15, 2015 at 20:58

Sunday, Feb 15, 2015 at 20:58
well I had the hub to bits and bought new oil from Toyota . seems to be Cracking and when stopped has good resistance .
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Follow Up By: Slow one - Sunday, Feb 15, 2015 at 21:05

Sunday, Feb 15, 2015 at 21:05
Sam,
if you don't here the fan coming in when it starts to i=overheat that will be the problem. You should here it roar.
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FollowupID: 833669

Follow Up By: Member - eighty matey - Sunday, Feb 15, 2015 at 21:49

Sunday, Feb 15, 2015 at 21:49
We changed the viscous fan and it sorted our overheating problems.

Try that before putting in a new radiator.

Steve
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FollowupID: 833674

Follow Up By: Member - Tony F8 - Monday, Feb 16, 2015 at 17:52

Monday, Feb 16, 2015 at 17:52
Same on my 80, topped up the oil etc, but in the end replaced the viscous fan and have not had problems since. As slowone said, you should hear it roar when it kicks in.
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FollowupID: 833715

Follow Up By: Slow one - Monday, Feb 16, 2015 at 21:23

Monday, Feb 16, 2015 at 21:23
Sam,
if it is found to be the fan that is causing the problem, do yourself a favour and pay the extra for a genuine toyota fan hub. If it is the radiator also do yourself a favour and buy a genuine dense radiator, you can often get a good price on ebay for a genuine one.
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FollowupID: 833730

Reply By: Gone Bush (WA) - Sunday, Feb 15, 2015 at 21:02

Sunday, Feb 15, 2015 at 21:02
Do you have an aftermarket turbo fitted?

From my own experience, replace the upper and lower hoses if they are old and soft.

They could be sucking themselves shut under load.

That's what happened with my old 80 series. I fully reconditioned the viscous hub and replaced the thermostat, it still happened on long steady climbs towing my camper trailer.

Short of going for a higher capacity radiator, renewing the hoses helped a lot.

If you can, fit some sort of coiled wire into them to help them keep their shape.
I'm glad I ain't too scared to be lazy
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Follow Up By: Ron N - Sunday, Feb 15, 2015 at 21:48

Sunday, Feb 15, 2015 at 21:48
Gone Bush is on the money - but it's the lower hose that sucks flat, not the top hose.

If you haven't been maintaining your coolant quality with exceptional care, then the tubes in the radiator core become partly-plugged with a buildup of gunk.

As the water pump sucks from the bottom of the radiator and pumps the coolant through the block and head and into the top tank, the core flow blockage is where the problems start.

It's almost impossible to have a flow blockage through the block and head, as the coolant passages there are huge (compared to radiator tubes).

Bottom radiator hoses should be stiffly reinforced or contain a spring, to prevent flattening under high water pump flow levels.
If you find there is no spring and you desire to install one, make sure you select a stainless steel spring, to combat corrosion.

Bottom line is, if the tubes are partly congested, a trip to the radiator repair shop is the order of the day, to have the tubes cleaned out.

If the tubes are blocked exceptionally badly, the radiator crowd will have to unsolder the top tank and physically clean the tubes.
Usually an acid-bath dip, followed by a pressure flush will clean them out.

Cooling systems should only be filled with the manufacturers recommended coolant - or coolant additive plus pure water.

In the case of Toyotas, the proper Toyota coolant additive added in the ratio of about 40% additive to 60% pure distilled water, or clean rainwater (NOT tap water!) - and then changed out every 3 years - will ensure your cooling system stays in excellent condition.

The genuine Toyota coolant additive isn't cheap, but you have to look on it as cheap insurance.
Always carry a supply of premixed coolant for any top-up, and never add just plain water to a low cooling system.

Cheers, Ron.
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FollowupID: 833672

Follow Up By: Allan B (Member, SunCoast) - Sunday, Feb 15, 2015 at 23:40

Sunday, Feb 15, 2015 at 23:40
I would add to what Ron has said regarding radiator blockages.........

Many years ago I had serious overheating of my V8 whilst on a trip. A country radiator repairer diagnosed radiator blockage. Opened the top tank to reveal a small piece of rubber blocking each and every tube. One (or both) of the hoses had disintegrated on the inside wall to produce pieces of rubber to pass through the system. Removal of the blockages fixed the problem. Plus new hoses of course!

I had not heard of it before but it was no surprise to the radiator bloke.

My recommendation is to get the cooling system checked by a radiator specialist before doing more trial-and-error fixes.
Cheers
Allan

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Reply By: happytravelers - Sunday, Feb 15, 2015 at 21:38

Sunday, Feb 15, 2015 at 21:38
Rather than spending a lot of money guessing, take it to a reputable mechanic and get them to diagnose it. The problem could be caused by any number of different things, including a leaking head gasket. Get someone who knows what they're doing to check it over.
AnswerID: 546000

Follow Up By: Member - Gnomey - Monday, Feb 16, 2015 at 00:14

Monday, Feb 16, 2015 at 00:14
Yep. For sure. I've seen several threads on this forum and others. I've had a 1HZ with an overheating problem (cause not mentioned so far) and posted to at least two threads hereabouts.

There isn't a silver bullet, there's a whole magazine of the dang things and you need someone capable of going through the list.

Cheers
Mark
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Follow Up By: aboutfivebucks (Pilbara) - Monday, Feb 16, 2015 at 16:53

Monday, Feb 16, 2015 at 16:53
I'm with Mark.
And you may never find the problem after throwing time and cash at it.
Workout what you are prepared to spend and what you are prepared to put up with.
A compromise might be - if you have to turn off the aircon and limp up a hill, so be it. Drive to the temp gauge not the speedo.

If you are doing a lap around Australia, for more than half of it you wont see a hill (and that's the warmer half of the country).

Good luck, I hope you find a silver bullet.

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FollowupID: 833711

Reply By: Member - DOZER - Sunday, Feb 15, 2015 at 21:50

Sunday, Feb 15, 2015 at 21:50
Its most commonly the fan oil level, IF it is ok on the flat and temp rises on hills.
It could also be mud in between the rad and aircond, broken baffles in the muffler, dragging brakes, too many restrictions on the bullbar, blocked radiator, hoses pump...the list goes on and on...start with the obvious...is it getting hot, or just the gauge? Is the water level constant, or r u loosing some? What happened just prior to the problem starting??? some mud 4wding, or new brakes perhaps?? Do u have a flex joint in the engine pipe, or was that replaced with extracters before the problem started???
AnswerID: 546002

Reply By: Member - mike g2 - Monday, Feb 16, 2015 at 14:49

Monday, Feb 16, 2015 at 14:49
Hi sam, agree with other suggestions- may be solved by check radiator for blockage with gunk, piping for leaks. blockage fault often shows at altitude to city cars- there's a radiator man doing good business in Tumit as I found out once many years ago! recollect being told radiator can be 80% blocked and not be symptomatic ( on city streets) until you go into the big hills and put system under some stress. have you looked at cap ? there are different rated ones. what is history of vehicle? has tap water been used in radiator -perhaps without conditioner?
I assume you've done a good look for leaks. next step check engine performance-overheating can come from a number of sources related to engine as well.
duel fuel? check gas input (pre heater)- radiator water runs thru here as well. look under dash at internal fan heater for a leak here.
? small head crack .
MG.
AnswerID: 546021

Reply By: Member - mark D18 - Monday, Feb 16, 2015 at 16:09

Monday, Feb 16, 2015 at 16:09
Sam

Sounds like a classic blocked radiator to me


Cheers

AnswerID: 546024

Follow Up By: get outmore - Monday, Feb 16, 2015 at 19:47

Monday, Feb 16, 2015 at 19:47
yep
very much so the fan can be an issue buit hes done that - besides doing the fan can mask a blocked radiator for a bit longer but the truth comes out
new radiator is about $700 fitted approx
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FollowupID: 833723

Reply By: swampfox - Monday, Feb 16, 2015 at 17:01

Monday, Feb 16, 2015 at 17:01
HI
MANY OEM fans DONOT reach growling pitch lock up of the viscous hub.
This is not to say it has not failed .
1 check for" matched "drive belts are not dry around 80,000kms is enough
2 is plastic fan cracked , if they fly off they will destroy a radiator
3 viscous hub should stop dead with engine after a good warm drive
4 it use to be that after 1/2 hr run u could not stop the fan turning with a rag at idle
3,4 can trick u into thinking it needs replacing ,not always true
5 pressure test radiater for leaks RUNNING AN ENGINE IS NOT ENOUGH
a leak at 3 lbs pressure can hide ,A system tested to say operating pressure will show way more leaks .
The radiator will need roding out . If its a later unit alloy/plastic these run very close to the limit .
Test thermostat in a tin and boil A TEST THERMOMETER
PRIOR TO REMOVING RADIATOR USE LOCTITE RADIATOR FLUSH tHIS WILL FLUSH ALL BLOCK DEBRIS INTO RAD CORE
B4 REINSTALL FLUSH BLOCK WITH HUGE AMOUNTS OF WATER
6 remove water pump and check impellor

Use either Toyota coolant or an aftermarket complete fill type [premix ] hybrid type preffered . Valvoline make a good one .

Whilist u r servicing the replace all hoses , guenuine last a long time or there is aftermarket .Replace cap also

The bottom hose can suck in under load so see if u can source a spring for the inside

hope this helps
swampfox
AnswerID: 546026

Follow Up By: swampfox - Monday, Feb 16, 2015 at 17:06

Monday, Feb 16, 2015 at 17:06
Hi
Remember to check for blown head gasket .
Either a TK tester ,checks for exhaust in coolant [changes colour ]
pressure test cooling system to 18 psi and pull out glow plugs ,if there is water coming out when u turn over ...blown...

swampfox
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FollowupID: 833712

Follow Up By: Member - mark D18 - Monday, Feb 16, 2015 at 19:51

Monday, Feb 16, 2015 at 19:51
Swampfox

Are you sure you didn't miss anything.!!!!


Sam's Oz tour will be over by the time he gets though "THAT" list.
I will stick to Allan's Thoughts ( R A D I A T O R ) Blockage .

Cheers
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FollowupID: 833724

Follow Up By: get outmore - Monday, Feb 16, 2015 at 21:35

Monday, Feb 16, 2015 at 21:35
With a diesel if you have a cracked head you well and truly know it
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FollowupID: 833733

Follow Up By: swampfox - Tuesday, Feb 17, 2015 at 07:32

Tuesday, Feb 17, 2015 at 07:32
hi
If this were not standard procedure check list for a work shop u would not be doing your job properly.
Guessing does not happen at my work shop
There is no replacement for thorough procedure when spending someone elses money .
A comprehensive cooling service does not stop at the radiator /coolant level
Hair line fractures in the cylinder head typically do exist and cause no issues . But it will not be long b4 the head needs removal.
All the above items are carried out in a mornings work
If 95% of this list was not carried out where I work u would be sacked

swampfox

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FollowupID: 833751

Reply By: Rojac - Monday, Feb 16, 2015 at 19:59

Monday, Feb 16, 2015 at 19:59
Had that identical problem on my hz, on any incline the temp guage would skyrocket into the red.

Had a HD 3 core radiator fitted as well as getting the viscous fan recon and problem solved.

That was in 2007 and still going strong ( touch wood)

Cheers

AnswerID: 546043

Follow Up By: Member - mark D18 - Tuesday, Feb 17, 2015 at 20:35

Tuesday, Feb 17, 2015 at 20:35
Rojac

Yep its heading to one conclusion.
The radiator.


Cheers
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FollowupID: 833799

Follow Up By: Rojac - Tuesday, Feb 17, 2015 at 20:49

Tuesday, Feb 17, 2015 at 20:49
Suppose I should have added the needle still moves but rarely goes past the half way mark and then when the incline finishes reverts to its std position at the bottom end of the scale

Cheers
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FollowupID: 833802

Reply By: Sam M1 - Friday, Feb 20, 2015 at 21:02

Friday, Feb 20, 2015 at 21:02
Thanks for the info folks!! trying to process it all haha . im on my final leg of my trip .but hopefully gonna get someone to look at Rad . One garage in Canberra didnt even look in the RAD he put his hand on the front made some funny noise ,then said yeah you need a new Rad. $1200.
AnswerID: 546280

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