One Hot Troopie

Submitted: Saturday, Feb 19, 2005 at 11:25
ThreadID: 20572 Views:2089 Replies:3 FollowUps:2
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Over the last few months I have had the temp gauge in the Troopie go a bit high.

Checked the over flow bottle and it was low, fliied the bottle, problem should be fixed.

Troopie runs great for a while and then starts to over heat again. Check the over flow bottle again and again it is low. Refilled bottle, and again the Troopie runs great.

Last weekend had to do some gardening which involed using the winch on the Troopie. When I moved the vehicle I noticed a puddle of fluid under the front of the vehicle.However when I traveled to and from work there was no sign of a puddle.

Today I let the vehicle warm up in the driveway and when it got hot, coolant was pouring out of the bottom radiator hose.I tightened the clampand the coolant stopped leaking.

The cooling system was completly checked and the top and bottom tanks cleaned by so called radiator experts,but they could not tighten a clamp.

That type of workmanship really get me going. I hate paying for work to be done then have to check and fix things that have not been done rihgt in the first place.

When I checked the temp gauge it was just below half, normal running temp, but I didn't drive the vehicle. When the vehicle was driven that the temp would go up a little higher.

I felt the top hose and it was warm, felt the bottom hose and it was cold and was hard, under pressure. That is why the hose was leaking when warmed up with out driving. This is why there was no puddle when driving to and from work.

At last the question,

Would this mean that the thermostat was not opening soon enough?
Driving the vehicle brought the temp up quicker and therefore the thermostat opened quicker and less pressue on the bottom hose.
Is this normal or should I change the themostat?


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Reply By: Richard Kovac - Saturday, Feb 19, 2005 at 17:08

Saturday, Feb 19, 2005 at 17:08
Take the thermostat out and check the opening temp should be 74-78 oC also the valve lift should be 10mm and check the jiggle valve is not blocked or stuck closed this may explain the lose of coolant out of the expansion bottle.
The radiator cap should also be tested standard opening pressure 14.9 psi 13.5 - 17.8 psi for a FTE
Minimum opening pressure 8.5 psi 11.4 psi for a FTE
the rad mob should have checked all this out if they were asked to
To test the cooling system for leaks it should be hand pumped up to 17.1 psi and should hold that pressure
All figures stated are Toyota 1HZ 1HD-T 1HD-FTE
I would also recommend using Toyota replacement parts

AnswerID: 99084

Reply By: Member - Phil G (SA) - Sunday, Feb 20, 2005 at 00:07

Sunday, Feb 20, 2005 at 00:07
Hi Wayne,

Unfortunately, I think you've got a bit more problem solving still to do :-((
I don't believe there is any problem with your thermostat.

So, just to be clear about what's happened to date (please correct anything that is wrong). I think your Troopie is a '97 model ex-ambulance (high mileage?) with the 1HZ motor.

So the sequence is, that you've not long had the vehicle;
#1 You've had the temp gauge go high in hot weather
#2 As a result of this, you've had the radiator removed by a radiator specialist and "rodded" to clean it out (which would largely remove the radiator as a cause).
#3 Your water leak from the lower hose is now fixed, but it sounds like you had not lost much water - I'm assuming that you also removed the radiator cap and the radiator level was full. If this is the case, then loss of coolant did not contribute to overheating.
#4 I assume you're asking the question again as you're temp gauge is still rising higher than it should?

Other info I gleaned from 70scool and your members profile:
#1 You have an aftermarket turbo fitted
#2 You have a heap of accessories, many of which are heavy
#3 You run Lightforce 240 driving lights and a hydraulic winch which may reduce airflow.
#4 You have an underbonnet shower hooked into the heater hoses in the correct manner, so the heater valve is still operational.

So where to from here?
#1 Replace the radiator cap with a new Toyota genuine cap (they are cheap)
#2 Remove the thermostat and test as per Richard's suggestions. I expect it will test fine.
#3 Consider the viscous fan, as these sometimes cause the type of overheating that you're experiencing. Do you hear the fan cut in (big wind noise) when the motor's running hot? If not, it needs to be checked, and the silcone oil refilled if its not working.
#4 Check the tension of the twin fan belts
#5 Check the radiator for obstruction by mud, grass, insects etc
#6 Cool down with a beer :-)
#7 Restricted exhaust system??
#8 Handbrake dragging?
#9 Any sign of a leaking head gasket (bubbles in radiator when running and failed pressure test).

If all of the above is a big negative, then we'll probably assume that your overheating is caused by a combination of factors:
#1 The poor underbonnet air flow of the 75series
#2 Fitting an aftermarket turbo
#3 Obstruction to airflow by the driving lights and winch
#4 Carrying all that weight around.

Then I guess the final step would be to spend some money and upgrade the radiator core to the heaviest duty core you can get.

Sorry about the heaps of lists, but if you get stuck, redo step #6 and seek some help from a cooling specialist.

Phew, think I'll do step #6 myself :-))


AnswerID: 99119

Follow Up By: Wayne (NSW) - Sunday, Feb 20, 2005 at 09:12

Sunday, Feb 20, 2005 at 09:12

97 Troopie, 167,000klm. the rest of the info is correct.

The previous owner who purchased the Troopie from the auctions had set the vehicle up with most of the gear. He also had 240 Light force and all the other gear that you mention. He also towed a Kimberly Trailer and told me that he had the radiator cleaned and checked.

From September last year until last month the Troopie has been fine. In that time I have done a Simpson crossing and a couple of runs to the Snowy Mtns. Even when I was going fromTom Groggin to Thredbo in early Janurary the motor didn't get hot. The vehicle was well loaded and the day was very hot.

I have tightened the bottom hose clamp and at this time I have not driven the vehicle because I am I in the middle of replacing a broken exhaust flange stud.

The way I see it at this stage is that because the bottom hose was not that tight and was allowing water to leak while at idle, that under very hot condictions it would allow the pressure to drop in the radiator. This would cause it to over heat.

After I have fixed the stud in the exhaust I will take it for another run to Lithgow and back, the run up Mt Vic should sort it out.


FollowupID: 357471

Follow Up By: Member - Phil G (SA) - Sunday, Feb 20, 2005 at 09:46

Sunday, Feb 20, 2005 at 09:46
Hi Wayne,

Thanks for the extra detail.

" The way I see it at this stage is that because the bottom hose was not that tight and was allowing water to leak while at idle, that under very hot condictions it would allow the pressure to drop in the radiator. This would cause it to over heat."

This isn't correct. While the water leaked out under pressure, it would only cause overheating if there was significant loss of coolant.

The pressure in the radiator doesn't improve cooling. Its there to raise the boiling point of the coolant, so there is a greater margin should the temperature rise above normal. And of course, the temp in some parts of the motor will be higher than the usual 82 degrees at the thermostat.

Anyway, hope you get it sorted.

FollowupID: 357475

Reply By: bundyman - Monday, Feb 21, 2005 at 09:16

Monday, Feb 21, 2005 at 09:16

I had the same problem on friday with my 96 HZJ75. I have a work 4x4 and so don't drive mine that often. Took it for a 300km round trip to Nyngan for a fishing trip. I leave home and pull up at the srvo before leaving town (2km) and walking back to my ute I see a puddle under the front - YEP bottom radiator hose leaking. Whipped out the socket set and gave it a tweak and no dramas again. It hasn't leaked in the previous 5 months I've owned it and I haven't touched the radiator hoses - so ??? Your probably right about the hose not leaking once up to temp and under full pressure - once it heats and expands it doesn't leak. Which is why I'd say I saw mine leak for the first time.
I know my old cruiser (same model) which got stolen, had a mystery coolant loss for ages. I had it pressure tested, replaced cap, checked head gasket and it would still loss water over time. Never found out what was causing it before it was flogged.
Sorry not much help to you but hope you sort it out.

AnswerID: 99279

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