80 series overheating problems

Submitted: Monday, Mar 18, 2013 at 23:22
ThreadID: 101173 Views:3832 Replies:5 FollowUps:2
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Hoping someone may be able to help!!

I have an 80 series, auto 1FZFE on gas. Recently I have been having overheating issues which I cant seem to workout.
It only overheats when working under load - ie low range in heavy sand, towing up long hills or if let idling for a long time on hot days with the air con running.

I have replaced the radiator, viscus fan and thermostat and the water pump appears to be working normally. The auto trans has been serviced recently and has its own cooler.

So .... whats next ... motor issues I am presuming but not sure where to start

Any help would be appreciated.

cheers.
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Reply By: philldeb - Tuesday, Mar 19, 2013 at 07:46

Tuesday, Mar 19, 2013 at 07:46
ignition timing
AnswerID: 507093

Reply By: olcoolone - Tuesday, Mar 19, 2013 at 08:03

Tuesday, Mar 19, 2013 at 08:03
Have you only replaced the radiator or did you also replace the other stuff mentioned.

Check the AC condenser to see if the fins are blocking air flow.
AnswerID: 507095

Reply By: Member - Keith C (NSW) - Tuesday, Mar 19, 2013 at 08:55

Tuesday, Mar 19, 2013 at 08:55
Do you have clear passage for air to get to the radiator?Driving lights across the front will block airflow and cause overheating when working hard, also using gas in these situations will cause this. I have an 80 manual on dual fuel and gas always causes temp to rise under heavy load, eg, towing up steep inclines for prolonged periods, I have'nt had any issues in sand at all, We crossed the Simpson last year using both fuels ok. Getting plenty of air into the radiator works for me. Regards Keith
AnswerID: 507100

Reply By: howesy - Tuesday, Mar 19, 2013 at 10:09

Tuesday, Mar 19, 2013 at 10:09
So you replaced the fan and hub I hope,, and also was it an ebay one? have seen some blokes buy new ones that don't cut the mustard I like to pull hubs aapart and put more silicon oil in them.
Also how is the fan cowling?? It is an important piece to the puzzle to draw air.
Also like he said some 80's owners have reported removing large driving lights from the front and solving the issue. Get that timing checked too,, dont do it yourself unless you know which pins to bridge on the diagnostics port before checking otherwise you get a false reading and incorrectly timed vehicle.
AnswerID: 507112

Reply By: lost in the dust - Tuesday, Mar 19, 2013 at 23:13

Tuesday, Mar 19, 2013 at 23:13
thanks for the replies - I am wondering if the fan is working as it should

There is nothing blocking the radiator and up until a couple of months ago I had no problems at all - but started having issues whlich resulted in the new fan and thermostat, because they were easier to replace, but it ended up being the radiator.

I was looking at the fan today and it doesnt seem to be drawing much air through. It is an aftermarket fan, a genuine one is priced at over $500.
When hot should the fan continue to turn when the engine is shut down or should it stop immediately - ive never really taken any notice.
The fan cowling is as before so I cant see that being an issue

Didnt realise timing could be an issue with overheating so I will get that checked out properly as suggested

Thanks for the suggestions - the search continues!
AnswerID: 507176

Follow Up By: olcoolone - Wednesday, Mar 20, 2013 at 12:12

Wednesday, Mar 20, 2013 at 12:12
The way we test viscous engine fans on the vehicle is to rev the engine to 1500-2000 rpm when at normal operating temp and then turn the engine off quickly without dropping the rpm.... the engine fan should do no more than 3-4 revolutions and stop....... if it keeps on spinning then it's stuffed.

Viscous fans will never lock up more than about 70-80% and are designed to free spin even when engaged.

The other way of testing the fan is with an external heat source onto the hub.

The factory Toyota hubs are rebuildable.

One question...... how did you know it was overheating?

And is your fan shroud intact!

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FollowupID: 784399

Follow Up By: lost in the dust - Wednesday, Mar 20, 2013 at 22:59

Wednesday, Mar 20, 2013 at 22:59
The temp guage never used to go above 50% - even middle of summer bashing around sand dunes it would stay at 50%. Then we were going on a trip and I had it looked over at mechanics and had the hoses replaced - and they flushed the engine and replaced the coolant.
3mths later I started having overheating issues, gauge would get up to the red on small hills and normal driving - hence the parts replaced. Finally I removed the radiator and it was 60% clogged, radiator was "cracked" around the top lip so I replaced it rather than try and get a dodgy seal.
The inital high temps dropped back to the usual 50%, but now it creeps up to the red if working hard at low speeds.

The shroud is all good, no cracks and not loose - how do you test the hub with an external heat source?

Might just have to lash out on a genuine fan or pick up a second hand one and see if that fixes it - wish I had kept hold of the old one now!

cheers
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FollowupID: 784452

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