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micky j

Rad Pressure Build Up

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Hi

My d4ds radiator seems to be building pressure. When i take the top of the expansion bottle a gush of coolant comes out, also the top of the radiator and the top pipe are very warm but from half way down the radiator and the bottom pipe are stone cold is this normal.

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Hi

My d4ds radiator seems to be building pressure. When i take the top of the expansion bottle a gush of coolant comes out, also the top of the radiator and the top pipe are very warm but from half way down the radiator and the bottom pipe are stone cold is this normal.

The cooling system should build pressure as it warms up, the question is, is it building excessive pressure? You may have a faulty pressure cap on the radiator which is letting the pressure out into the expansion bottle, otherwise if it is building excessive pressure and forcing the pressure cap open, you may be looking at head gasket trouble.

Best bet is to check it with a cooling system pressure tester, these have provision to test both the cap and the pressure build-up in the radiator. Any good garage will have one of these.

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Hi

My d4ds radiator seems to be building pressure. When i take the top of the expansion bottle a gush of coolant comes out, also the top of the radiator and the top pipe are very warm but from half way down the radiator and the bottom pipe are stone cold is this normal.

The cooling system should build pressure as it warms up, the question is, is it building excessive pressure? You may have a faulty pressure cap on the radiator which is letting the pressure out into the expansion bottle, otherwise if it is building excessive pressure and forcing the pressure cap open, you may be looking at head gasket trouble.

Best bet is to check it with a cooling system pressure tester, these have provision to test both the cap and the pressure build-up in the radiator. Any good garage will have one of these.

Cheers any ideas on the rad being roasting at the top and freezing at the bottom?

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Hi

My d4ds radiator seems to be building pressure. When i take the top of the expansion bottle a gush of coolant comes out, also the top of the radiator and the top pipe are very warm but from half way down the radiator and the bottom pipe are stone cold is this normal.

The cooling system should build pressure as it warms up, the question is, is it building excessive pressure? You may have a faulty pressure cap on the radiator which is letting the pressure out into the expansion bottle, otherwise if it is building excessive pressure and forcing the pressure cap open, you may be looking at head gasket trouble.

Best bet is to check it with a cooling system pressure tester, these have provision to test both the cap and the pressure build-up in the radiator. Any good garage will have one of these.

Cheers any ideas on the rad being roasting at the top and freezing at the bottom?

Normal for a rad to be hot at the top and cold at the bottom with more differential in colder ambient temperatures, hot water flows into the top of the rad, cools down as it passes through. It depends on how quick it is getting hot, head gasket failure will make it get hot quicker, it may also cause an airlock in the heater (heater goes cold) and the engine to overheat when pulling hard. Symptoms get more severe depending how far gone the gasket is. If it is just starting to go, the only symptom to be noticed might be pressure build up.

Hopefully yours will be a faulty radiator (pressure) cap.

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