HJ75 Troopy - Overheating underload

firstly, have you come across the Troopyoz group at Yahoo?
http://groups.yahoo.com/group/troopyoz

Secondly, I had very similar problems in my troopy, new radiator and hoses BUT, they only tested and did not replace the thermostat, a $20 part caused me so much grief. Could be a simple solution.
Dave

Check the fluid in the clutch fan , it should be the right grade and the right amount so that it kicks in at the right time. Had a similar problem with my Cruser work ute, ended up being the rong grade fluid(I think it is a silicone base oil???)

I've got a similar problem with my fj73. It runs hot after a few km's of lo range.

But mine can run hot in sticky traffic.

So far I've replaced the themostat, and removed and flushed the radiator. The fan clutch is fine which is leading me to think the water pump might be faulty. Another suggestion is that it may need a second cooling fan (suggested on another forum).

Rossco after 400,000km I would put new oil in the fan hub. You should be able to buy it from any Toyota dealer for approx $20.00. This has been an ongoing problem for years with the 2H and 1HZ engines that I know of and most dealers know about it and have the oil on hand.
Regd's Darryn

Rossco
Of course a good operating fan is important however keep in mind that the fan is only of use for cooling your vehicle while it's stationary or pushing along at low speed.-If the vehicle is overheating on highway runs it wont be down to the fan.-
Once the vehicle is cruising the airflow through the radiator will be the same with or without a fan.-As a suggestion you could get the system pressure tested, it's cheep and easy, and as suggested by Dave change the thermostat.-You haven't mentioned when the water pump was last changed, could be the impella corroded away- With the engine up to temp and top radiator hose off check that its pumping out water.- If you do want to check the fan, with the engine off, it should spin free when the engine is cold. Once up to temperature it will have a lot more drag-Good Luck-Ken

Rossco,

I read a while back that Toyota thermostats can be quite unreliable, especially in the earlier models.

My engine went nuts today. It went from cold to red line hot in less than 10 mins of suburban driving. Having spoken to some powers that be, they say to take the thermostat out and go for a short drive. As long as I'm not tearing down the highway, this won't cause any probs. If the overheating doesn't occur, its pretty clear that its the thermostat thats faulty. If it remains the same, I'll need to get the radiator re-checked or replaced.

How quickly is yours overheating?? How high is it going??

Matt

My troopy has always been hot - the after-market guage (good one) shows a reading close to the redline on any long highway drive. It is generally around 90* around town during the hotter months and down into the 80*'s in the cooler weather up here. I often have to turn off the air con when towing in warmer weather (a real pain). I replaced the thermo today and by the look of the old one it may have let the wax go through what appeared to be a busted 'o' ring. For $28 bucks from Toyota it is a cheap experiment. The advice I got from a mate in the radiator game was to buy genuine as it is cheaper than alternatives. The hot running has never bothered the car really. I have had some form of tojo for the past 26 years up here in the NT and have not experienced any major drama's with overheating before. I used to do a lot of heavy beach work and although the temp got high the car always ran the same. I am going to do my injectors,replace the original exhaust and put on extractors to breath some new life in the troopy - who knows, I may squeeze another 100,000 out of it (and do a hill in top gear) Cheers

Rossco,

Have heard the same about buying genuine Toyota parts. Worth the higher outlay.

How is she running now??

Keep trooping!

Rossco, (and any other 2H owners interested), I had a LC wagon with a 2H engine and was looking at getting it turboed. One of the modifications was to to have the top radiator outlet moved to the passenger's side so it was diagonally opposite the bottom inlet. This supposedly makes more efficient use of the radiator. Didn't get it turboed so I didn't get it done. However it sounds as though it may improve cooling. What was the road to Gurig NP like? When I was last there the graders finished the road as we drove out. It was fantastic. Not what it is usually like apparently. Mal T.

Rossco, I had a 2H 60 series (just parted with it this year) and I always used to drive according to the temp gauge; I replaced the radiator with an Australian core after about the 3rd fix which I was told finally by the radiator repairers was caused by a faulty thermostat. What they reckon was happening was it would open late and water would hit the tank in a rush causing fine fractures, eventually then leaking. I have heard that the standard radiator top tank design is not the best for using the whole core for cooling your water, as someone else pointed out. The radiator guys also said the good news is that thermostats can give up at almost any time. We did the silicon oil in the fan hub fix (twice) and ran without aircon on hot days whilst towing. I put in a new water pump, changed the coolant and made sure the fan belt was right. I tried a drive without the thermostat and it didn't come close to getting hot. Everyone says the 2H is a great motor, but it has a reputation for running hot and cooking heads. However, it will almost last forever if you do regular oil changes, filters etc.. It never let us down, but I drove the family nuts nursing it. It was one of the few vehicles I have owned where you could watch the temp gauge move according to how you drove it; I almost considered taking the spotties off to let more air through. This might sound like a bit of a wank but I notice that the ARB catalogue recommends that you don't fit a bug screen across the front of the grille of a 1hzt, which is what we drive now and I was told not to fit the electronic type dual battery management gizmos because they can die in the heat under the bonnet. I decided against fitting new spotties, just in case, and hope I don't have to do too much night driving! Probably haven't added ant great intelligence to the discussion but I can relate to the overheating situation!
Bye

I have a bug screen that I will remove as per your advice. I also have spotties ('cause the headlights must be off a T model ford). I also have a warn winch on the front and this may also restrict some airflow. I replaced the thermo and the temp behaved itself without the air con on. on the return trip it got hotter once the air was on. I'll keep chipping away until it gets better. Thanks to you and everyone else out their for the good advice. Rossco