Overheating 3F(FJ80 landcruiser) when idle

Submitted: Tuesday, Mar 30, 2004 at 19:08
ThreadID: 11682 Views:7723 Replies:16 FollowUps:0
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My engine seems to overheat only when idling for long periods of time (shorter periods if air-con is on). The engine has been overheating like this since i bought it a few weeks ago, since then i have replaced the radiator, fan and fan clutch, thermostat, checked for vacuum leaks, etc. It had a new water pump when i bought it. These have made the engine run a bit cooler but nothing has STOPPED the overheating.

I was thinking that it could be ignition timing (however checked this and adjusted it to no avail), I then considered the problem might be that the engine has overheated before and there could be problems with the head, however the engine (i believe) is running to smoothly for this to be the case.

The engine has had a gas conversion, and it does overheat (the same) on both.

I dont seem to have a HAI (Hot Air Inlet) valve on my air intake so i doubt that it is recycling exaust air and this causing the overheating,

however the normal (cold-air) intake is sourced from the inside of the front fender. This whole area gets extremely hot when the engine is running especially when it gets close to temp on the temp gauge the red area, so i was thinking that maybe it is just getting to hotter air, and this causes a loop

Hot air -> hotter engine -> hotter air -> hotter engine -> hotter air again, etc.

Is this normally where the air intake is ?

NOTE: If the bonnet is up the engine does not overheat... only when the bonnet is closed.

I am using a 15W-40 grade oil, many books recommend 10W-30 so could the 40 (ie hotter running oil) be making the engine overheat like this ? (I am just about due for a oil change so i'll post that back here whether it makes a difference or not)

N.B. - the engine does backfire OCCASIONALLY(really only on petrol), if this helps in anyones diagnosis.

Thanks any sugesstions welcome,

Kallum
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Reply By: Patroleum - Tuesday, Mar 30, 2004 at 19:28

Tuesday, Mar 30, 2004 at 19:28
Hot Air intake as you describe won't cause overheating. Backfiring is caused by lean fuel mixture and lean fuel mixture causes extremely high combustion temps.

Generally as you say that it only o-heats stationarry this would indicate an air flow
problem. Reccomend rechecking fan clutch and restrictions in a/c condenser.

Steve
AnswerID: 52588

Reply By: howesy - Tuesday, Mar 30, 2004 at 19:53

Tuesday, Mar 30, 2004 at 19:53
What you describe still says not enough air flow but there are tyhings you need to consider.
Is it actually overheating or is it just that the guage shows hot. get a thermometer and run it at idle with the cap off and the thermometer in the water. You will not only see what temp it gets to but it will also show at what point the thermostat opens. Wouldn't be the first time a new thermostat is faulty. if this checks out find someone who has an industrial fan and set it up in front of the radiator at idle that will dispell an airflow problem. Lastly Check that it is the right thermostat as in some vehicles it has a foot attached which is designed to close off a galley when it opens so all the water goes through the radiator and if you have the wrong one in this instance then you have problems. also check the installation of the water hoses for the LPG as a lot of fitters take them all off to facilitate the LPG and put them back without taking into consideration the directional flow of the block and it inhibits water flow at low engine revs.
Good luck and make sure that clutch has a good deal of resistance thats the usual culprit.
AnswerID: 52591

Reply By: Member Eric - Tuesday, Mar 30, 2004 at 23:26

Tuesday, Mar 30, 2004 at 23:26
have you done thesimple things like checked your radiator cap ? If you radiator cap dosnt hold pressure , it will cause this problem , If you have done all you say , and the radiator cap is ok , just looking at head gasket
AnswerID: 52601

Reply By: Coops (Pilbara) - Wednesday, Mar 31, 2004 at 09:25

Wednesday, Mar 31, 2004 at 09:25
for the sake of ten bucks I would replace the radiator cap and do so every year or so.
Also check the lube oil in your fan
AnswerID: 52617

Reply By: Kiwi Ray - Wednesday, Mar 31, 2004 at 16:06

Wednesday, Mar 31, 2004 at 16:06
Hi
I know this may sound silly but, is the fan oftted the correct way round.
It is quite a common problem
Ray
AnswerID: 52663

Reply By: Kiwi Ray - Wednesday, Mar 31, 2004 at 16:19

Wednesday, Mar 31, 2004 at 16:19
Hi Callu,m
I should have typed is the fan fitted the correct way round and also is the fan shroud fitted.
Ray
AnswerID: 52665

Reply By: Member - Jeff M (WA) - Wednesday, Mar 31, 2004 at 18:44

Wednesday, Mar 31, 2004 at 18:44
Yeah I would really check the shroud, my mate had no shroud on his HQ Kingswood, he put in a big arse radiator and it will cruise at 120km/h all day with no probs, as soon as he goes into a drive thru for some tucker it jumps up to 130c!!
My surf had two bolts missing out of my shroud and I was having cooling probs, it also had some pin hole size holes in the radiator top tank that I hadn't even noticed causing pressure problem when running hot, check those, see how you go!
AnswerID: 52690

Reply By: Member - DOZER- Wednesday, Mar 31, 2004 at 20:18

Wednesday, Mar 31, 2004 at 20:18
I bet you have a blocked air cond condenser. (mud)
Its the only thing that explains why it doesnt overheat on idle with the bonnet up.
The backfiring thing on petrol would suggest the flange gasket is leaking, it should backfire on gas if anything.
I suggest you have check up at the general mechanic. He will put a special cap on the rad and check for blown head, aswell as a vacuum gauge on the inlet to check for leaks if you ask.
Andrew
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AnswerID: 52707

Reply By: Member - Royce- Thursday, Apr 01, 2004 at 00:11

Thursday, Apr 01, 2004 at 00:11
A fine crack in the head?
AnswerID: 52743

Reply By: Kallum - Saturday, Apr 03, 2004 at 14:01

Saturday, Apr 03, 2004 at 14:01
Hey guys,

Thanks for your responses, some of the things you suggested did make a slight difference however did not STOP the problem. I had a detailed look at my Haynes Repair manual, and in the basic engine componenents explanation it shows a that there should be Underhood electric fan for 2F and 2F engines. (I assume the gas fitters took it out, as it is supposed to be where the cas converter is)

I have rung around and cannot seem to find one at the wreckers, some people don't even know what i'm talking about, the the ones that do say that as soon as one comes in it goes straight out again, i don't want to get one from $$TOYOTA$$ but it looks like i will have to. I have on old intercooler fan lying around and i am going to try and fit that somehow first.

Thanks again
AnswerID: 53063

Reply By: Kallum - Saturday, Apr 03, 2004 at 14:01

Saturday, Apr 03, 2004 at 14:01
Hey guys,

Thanks for your responses, some of the things you suggested did make a slight difference however did not STOP the problem. I had a detailed look at my Haynes Repair manual, and in the basic engine componenents explanation it shows a that there should be Underhood electric fan for 2F and 2F engines. (I assume the gas fitters took it out, as it is supposed to be where the cas converter is)

I have rung around and cannot seem to find one at the wreckers, some people don't even know what i'm talking about, the the ones that do say that as soon as one comes in it goes straight out again, i don't want to get one from $$TOYOTA$$ but it looks like i will have to. I have on old intercooler fan lying around and i am going to try and fit that somehow first.

Thanks again
AnswerID: 53064

Reply By: Kallum - Saturday, Apr 03, 2004 at 14:01

Saturday, Apr 03, 2004 at 14:01
Hey guys,

Thanks for your responses, some of the things you suggested did make a slight difference however did not STOP the problem. I had a detailed look at my Haynes Repair manual, and in the basic engine componenents explanation it shows a that there should be Underhood electric fan for 2F and 2F engines. (I assume the gas fitters took it out, as it is supposed to be where the cas converter is)

I have rung around and cannot seem to find one at the wreckers, some people don't even know what i'm talking about, the the ones that do say that as soon as one comes in it goes straight out again, i don't want to get one from $$TOYOTA$$ but it looks like i will have to. I have on old intercooler fan lying around and i am going to try and fit that somehow first.

Thanks again
AnswerID: 53065

Reply By: Kallum - Saturday, Apr 03, 2004 at 14:01

Saturday, Apr 03, 2004 at 14:01
Hey guys,

Thanks for your responses, some of the things you suggested did make a slight difference however did not STOP the problem. I had a detailed look at my Haynes Repair manual, and in the basic engine componenents explanation it shows a that there should be Underhood electric fan for 2F and 2F engines. (I assume the gas fitters took it out, as it is supposed to be where the cas converter is)

I have rung around and cannot seem to find one at the wreckers, some people don't even know what i'm talking about, the the ones that do say that as soon as one comes in it goes straight out again, i don't want to get one from $$TOYOTA$$ but it looks like i will have to. I have on old intercooler fan lying around and i am going to try and fit that somehow first.

Thanks again
AnswerID: 53066

Reply By: Kallum - Saturday, Apr 03, 2004 at 14:01

Saturday, Apr 03, 2004 at 14:01
Hey guys,

Thanks for your responses, some of the things you suggested did make a slight difference however did not STOP the problem. I had a detailed look at my Haynes Repair manual, and in the basic engine componenents explanation it shows a that there should be Underhood electric fan for 2F and 2F engines. (I assume the gas fitters took it out, as it is supposed to be where the cas converter is)

I have rung around and cannot seem to find one at the wreckers, some people don't even know what i'm talking about, the the ones that do say that as soon as one comes in it goes straight out again, i don't want to get one from $$TOYOTA$$ but it looks like i will have to. I have on old intercooler fan lying around and i am going to try and fit that somehow first.

Thanks again
AnswerID: 53067

Reply By: Kallum - Saturday, Apr 03, 2004 at 14:01

Saturday, Apr 03, 2004 at 14:01
Hey guys,

Thanks for your responses, some of the things you suggested did make a slight difference however did not STOP the problem. I had a detailed look at my Haynes Repair manual, and in the basic engine componenents explanation it shows a that there should be Underhood electric fan for 2F and 2F engines. (I assume the gas fitters took it out, as it is supposed to be where the cas converter is)

I have rung around and cannot seem to find one at the wreckers, some people don't even know what i'm talking about, the the ones that do say that as soon as one comes in it goes straight out again, i don't want to get one from $$TOYOTA$$ but it looks like i will have to. I have on old intercooler fan lying around and i am going to try and fit that somehow first.

Thanks again
AnswerID: 53068

Reply By: Rod E B - Saturday, Apr 03, 2004 at 14:55

Saturday, Apr 03, 2004 at 14:55
I have a 1985 cruiser with a 3F motor.
The temperature gauge normally runs at about 1/4 of the scale , before the red bit
But ,
the engine bay is always hot , i think too hot , but do not know if this is normal
The gauge does not move if the car is idling etc.
The car is a petrol automatic and on long trips the gear change housing and the shift stick inside the car can get hot , sometimes to hot to have your leg constantly in contact , sometimes it does not get hot ???? . I am told this is the hot air from the engine bay passing through.
The transmission temperature light does not come on , it does at ignition ( so it must work ).
I feel the bay should be cooler , but what is the standard.
My engine manual , Toyota genuine , is a 2F ( unfortunately ) but does not have a fan in the engine bay listed .
I will follow your post with interest

Rod
AnswerID: 53071

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