325 Convertible drinking water.

[enviropc]

My 325 is drinking around 1ltr of water every 300 or so miles.
Ive always thought it felt slightly underpowered since ive owned it and even more so after the water pump failed.
Their is no water in the oil and no white smoke but it has blown the expansion tank off of the radiator 3 times in the last few months since the water pump fail.

Could this be head gasket related?
How can i find out for sure?

Many thanks in advance for your help.
Justin

[brettski]

Are there any signs of oil in the coolant?
Is the engine running hot?
Was the thermostat changed with the water pump?
Did the replacement water pump have a plastic impeller?

[enviropc]

Hi Berttski
No oil in the coolant.
The engine over heats in traffic only (left on tickover without moving)
I doubt the thermostat was replaced with the water pump.
I have no idea if the pump had a plastic impeller.

Regards.
Justin

[harryinsaudi]

Sounds like the head gasket, leak between a cylinder and the water passage, overpressurises the system and blows at the weak link wherever that may be...

remove the spark plugs when the engine is hot and the cooling system is pressurised. (I bet the hoses feel hard!) you may find water leaks into one/more of the cylinders after a while.

Head gaskets aren't too bad a DIY fix but get the head checked to see if it's in need of a skim.

[theluis]

Another way to check for a bad head gasket is to remove the coolant filler cap and start the engine. let it run till it gets up to operating temp and then see if there is bubbles in the coolant.

[enviropc]

bit of an update.
The mechanic rang me yesterday and has said that he thinks that all that is wrong id the radiator and thermostat.
Hes had the plugs out and they are all fine and look the same, also the oil and water are all good.
Perhaps its not the head gasket after all...only time will tell (about 100 miles or so)

[witeshark]

Glad to see that!