Isuzu Trooper Owners Club UK™

[carlinscairn]

97 trooper 3.1. temp goes high till i put the heater on full blast at hot this brings temp back down . took the stat out, flushed out  the rad still  overheating. replaced the water pump today, still overheating. It is not using any water, what i noticed is that the top hose is pretty warm but the bottom one is stone cold, could the rad still  be clogged after flushing it ?  i put the garden hose in one end for a while then in the other end for a while dont know if this flushed it properley,
the rad is about 3 years old. any ideas.

[Google]

[Browndoff]

I've had similar problems with my 3.0 Trooper. Sadly it DOES seem that your radiator is still blocked. As you've replaced the pump, we can assume the new one is putting plenty of pressure into trying to push water through the Rad. The bottom-hose should be COOLER - but NOT cold!

I, too, have replaced my Thermostat - with no change in the overheating. In my case the Viscous-Fan-Clutch isn't working - so I'm going to replace the viscous fluid [easy and cheap!]. More relevant to YOUR problem - I'm also running a Radiator-Cleaning chemical through the coolant-system - to help to flush the gunk out of all the pipework!

That stuff is easily available from Builder-Suppliers - as a flushing-compound used in domestic Radiator-Systems. Just drain the whole system, then close it and re-fill with a mix of plain water and the Flushing-Compound [correct-proportions on the bottle]. Leave it run in the vehicle for a week, or two, while you drive around normally. It should dislodge the crud that builds-up within and then just flush it out as before. Use your hose to make sure it's all gone and then close it and re-fill with 50:50 water and anti-freeze.

Good Luck!

[Browndoff]

Further information - I've drained my own radiator [after running it with the rad-cleaner mix for a fortnight] - and I was shocked that it FAILED completely to remove any crud from the collant-system!!

It's unlikely that my Trooper's system is so spotless inside that there was NOTHING there to come out - but the stuff drained-out almost as clean as it went in!! I attached my garden-hose to the heater-matrix pipes and THEY ran clear too!

If the overheating-problem persists, I'm going to have to remove the damn radiator and fill it with VINEGAR [ends blocked, of course!] for a few days, to remove the calcium-carbonate deposits [limescale] which are 'furring it up' on the inside. That's a messy job I was hoping to avoid!

[carlinscairn]

problem sorted.got some rad flush followed the instructions flushed the rad out, it ran rusty red for fifteen minutes must have been lots of gunge in it. temp now sitting at about third on the gauge. thanks for the help
       carlinscairn

[Browndoff]

I'm delighted to read that your thermometer is now 'behaving' itself since you flushed-out all that rust!

What's a bit more surprising, is that MINE is definitely better too! I'm not sure if it will now allow 80 MPH uphill for miles on end, but a short spin THIS AFTERNOON on a motorway hill [which ALWAYS used to cause overheating!] caused no visible flicker on the temperature-guage! I even pulled over and got out a thermal-scanner [it WAS a test-run - I don't ALWAYS go so well-equipped!]. The scanner showed the same temperature-range across face of the rad [and the sides of the engine-block] as it had last week after a 4 mile run in traffic! There was NO spot any hotter than 'normal' values!

We're both winners this time!