226 replies to this topic

[REDA9X]

I would certainly do the research in getting the cast impeller pump, but before you spend any more money, have a good look at the basics of the system, do some testing. It sounds like you had a pre-existing problem before you fitted the radiator.
Will the car get hot driving around town constantly moving? Will it get hot just sitting still in the driveway?
You originally said at 80km it gets hot after 15 minutes of driving and you said with the fans going full bore it takes ages to bring the temp back down, but is that when you pull up? The way read it you are pulling up the fans are going and slowly the temp comes back down?
If the thing keeps cool just sitting there it's not a fan issue, however you said you have no controller, I would fit a switch under the dash so if you know you're going to be stopped you can turn the fans on long before it starts getting hot. Later model cars have a low speed relay so when the speed drops the fans kick in regardless.
Get yourself one of those lazer thermometers and run it around over the hoses and radiator and block and check it against your guage as well so you can get an idea of how hot it really is getting if at all.
At the end of the day all we are doing is pumping water around an engine and radiator. You have a pump, hoses, a block and radiator. The Thermostat is basically there to get the system up to temp, removing it will not make the system work any better unless the thermostat is the actual problem.
What size is the radiator you bought? Is it a decent brand or a cheap one? Also, going bigger isn't always better as you have more cores for the air to travel through, and the water capacity isn't increased that much either. For example, going from a factory V8 Torana 2 core radiator to the factory 3 core as used in the air con cars increases the capacity by less than 200ml.

[RallyRed]

Yeh, agree with S pack above.
I wouldnt be ripping it apart just yet...one thing at a time.

I'm certainly no engine guru,....but if we take our time, most things are simply sorted..

remove the thermostat ( for a day or two) and see if the problem still occurs.
if yes - then it is NOT the thermostat causing issues
if no - then hey presto, you have a dodgy thermostat, problem sorted.

Another logical thing to check.....with the thermostat still removed..
Start the car from cold with the radiator cap off....is the water moving in the top rad. tank?
If yes = then it would appear you have flow, i.e. the pump is doing some work.
Rev the engine , does the flow increase? ..if yes then the pump is doing more work.
if no - then the cavitation issues refered to in earlier post might be occuring.

Hopefully they are simple , sensible quick, free checks.
regards

[REDA9X]

Always good for a dig darky, but while that old stock taxi may have produced little power, a power increase relative to heat generation would at best be equivelant to the underbonnet heat generated by something like a late model V8 Holden with a mass of accessories like air con, power steer etc. A good example to keep it close would be a VT with the last of the Holden V8's with the 220i stroker. Similar block and pump, radiator is only the same size and so is the capacity, no 5 core radiators there, the big difference is the twin thermo fans which are similar to those on the AU. This thing shouldn't be getting hot at 80kmh regardless of what type of fan you have anyway.
He has the AU fans and the aluminuim radiator. I doubt the car is making anywhere near 400HP, the 220i is roughly 300hp. I would suggest there are lots of people out there who have 308's generating a lot more HP that still have the standard cooling system with no problems.
For the record, GMB pumps are shithouse unless they have improved dramatically in the last 15 years. I know there is a company that makes them with the cast impeller, i just can't remember which company it was but I looked into it not that long ago.

[hanra]

I fitted a Gates water pump to mine. Can't bloody remember what the impeller was like......

[REDA9X]

Hey REDBITS, yep just a dig as I seem to recall you once finding the root cause of your 80km overheating issue was the tin impeller pump, not the 3 core radiator.

actually, no....

http://www.gmh-toran...hl__ longwinded

[S pack]

I took the pump back off and the Thermostat,I looked all over town for a useable Thermometer but nothing of any good anywhere!!!!??. I bit the bullet and bought another Water Pump, the right one with the cast type Impeller and also one of those Hi Flow Thermostats that was suggested TRIDON TT2000-180.

The box of the new pump with the correct type Impeller says " POWERMAX" on it , Im going to go fit this new gear up tonight but unfortunately I cant test the Thermostats ( correctly)

Did you try a kitchenware shop or the kitchen sect at a department store? Should be able to find a digital probe type cooking thermometer at one of those places. Reece plumbing supplies also stock digital probe type thermometers, approx $50.

[REDA9X]

Yes, it certainly can if it's not holding pressure. Make sure you get the correct pressure rating too

[hanra]

Do u have a recovery system?