Temperature spikes in 4BD1T

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Originally Posted by rijidij

Thanks Bojan,
The system actually holds pressure even after sitting for days, so I don't think there is a leak anywhere. I will test the cap as you suggest. The fluid loss is deffinately out the overflow at the cap. Anyway, a cap is such a low cost item, it might be worth getting a new one.
I've got the radiator from the truck my engine came from. I'll have a look at the rating on that cap just for interest.
Can anyone tell me the rating for the pressure cap on a factory Isuzu 110 ?

Cheers, Murray

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The one that I have on mine is 15psi - it looks as aged as the rest of the car, so it could be original. It's made by Unipart, and has a part number "BRO 9132" stamped on it.

On a side note, when you say "The system actually holds pressure even after sitting for days" do you mean it stays pressurised for that long?

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Originally Posted by Offender90

On a side note, when you say "The system actually holds pressure even after sitting for days" do you mean it stays pressurised for that long?

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Yeah, after the County has been sitting for a couple of days, I've undone the cap and it was still pressurised. Not as much as at running temp of corse, but enough to gurgle coolant up to the header tank.

Murray

Does your county run a full flow heater?
My rangie does, but my truck engine was originally intended to run a bypass heater. So I have the bypass hose from water pump to thermostat blocked off.

Seems to work for me.

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Originally Posted by Dougal

Does your county run a full flow heater?
My rangie does, but my truck engine was originally intended to run a bypass heater. So I have the bypass hose from water pump to thermostat blocked off.

Seems to work for me.

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What is the difference between a Full Flow Heater and a Bypass Heater. I hooked up the standard Rangie system to the water pump of the 4BD1.

Glenn

As I understand, the full flow heater in rangies has the full flow of water though the heater core at all times - one reason why it is hot inside during summer. The air, not water is regulated by the hot/cold heater control.

This allows the pump to circulate some water through the engine (but not radiator) before the thermostat opens.

Quote:

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Originally Posted by Dougal

Does your county run a full flow heater?
My rangie does, but my truck engine was originally intended to run a bypass heater. So I have the bypass hose from water pump to thermostat blocked off.

Seems to work for me.

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The heater hoses are hooked up the same as they were in the truck, I think it's a full flow system.

Quote:

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Originally Posted by rijidij

I've got the radiator from the truck my engine came from. I'll have a look at the rating on that cap just for interest.
Can anyone tell me the rating for the pressure cap on a factory Isuzu 110 ?

Cheers, Murray

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The only number stamped on the pressure cap that was on the truck rad is 90, does anyone know what it indicates ?

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Originally Posted by rijidij

The only number stamped on the pressure cap that was on the truck rad is 90, does anyone know what it indicates ?

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Murray, 90 Kpa, or 13psi in the old speak:p

JC

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Originally Posted by rijidij

The heater hoses are hooked up the same as they were in the truck, I think it's a full flow system.

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In that case you've got two bypasses which could be either sharing water flow or having water circulate from one through the other.
The Isuzu truck cab heater is a bypass, it shuts off water flow when not needed.

Take off that short hockeystick hose, block it and see if your problem disappears.
BTW, that little hose matches a mini part exactly.

I converted mine to a recovery system so the header tank is always full,just fitted a recovery cap to the header tank and a overflow bottle alongside,it has stopped air pockets forming in the cooling system as the top of the heater core is higher than the bleading plug on the thermo housing.I don't have any temp spikes