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 :-))
Cheers
Phil
AnswerID:
99119
Follow Up By: Wayne (NSW) - Sunday, Feb 20, 2005 at 09:12
Sunday, Feb 20, 2005 at 09:12
Phil,
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.
Wayne
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.
Quote:
" 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.
Cheers
Phil
FollowupID:
357475