scoobyster

My old man's 93 Primera 1.6 is getting through its coolant pretty rapidly. Can't see any leaks from the radiator so suspecting the head gasket, but there's no goo under the radiator cap which I thought was the sign to look for of the head going. Seems to be running fine but it does have well over 100k miles on the clock. Any ideas what it could be?

Cheers,

Ben

camk

It can only be into the oil or out to the world. If you drain the oil and it looks OK then its escaping to the world. Best way to test for a coolant leak is take it for a good hard run then park it up, stop the engine and stop the electric fan from running. The pressure in the system will rise and you should see the leak. If its leaking out you'll smell it.

Cheers
Cammy

MGJohn

Several ways coolant can be lost. Leaks anywhere in the cooling system could be responsible and the cylinder head gasket is part of the coolant system. Via a damaged head gasket, coolant can thus enter the engine and exit out the exhaust system as well as becoming severely over-pressurised. If all hoses, radiator, water pump, heater matrix etc appear sound then suspect: Damaged (they rarely fail) head gasket.

Here's a test I've used:

As appears the case here, in the absence of classic signs of a damaged head gasket, look for other signs. As already advised above, following a run with a warm/hot engine, allow to stand for a few minutes. Then, VERY CAREFULLY and SLOWLY (use stout gloves) remove the coolant expansion cap. If your head gasket is sound, there should be a gentle 'shuuushh' sound at some stage as the normal warm engine coolant pressure is released. If a damaged head gasket is allowing compression gases into the cooling passageways, pressure build up therein could be at a VERY HIGH level. SO BE CAREFUL in case this is what's happened to this Nissan. What usually happens then is that there is at best, an obviously above normal release of pressure immediately followed by much spilling of coolant as it bubbles up and overflows out of the expansion bottle. That is unmistakeable! Near boiling coolant under extreme abnormal pressure is obviously VERY DANGEROUS and worst case, a litre or more can be forcibly ejected at high velocity all over the place including you. Anything of this nature will confirm the head gasket is damaged. If you don't fancy checking this yourself, find someone with the necessary experience to do it. It can be risky.

Good luck.

jjones

these are infamous for leaking rads. my egt used to use water. not the head gasket, knackered radiator but you would never see it drip

scoobyster

Thanks for the replies guys. Can't smell it but it doesn't seem to be pressurising the coolant excessively either. Bought some radiator leak repairing gunk in Halfords to see if it helps at all, if so we'll see about a rad from a breakers.
Cheers,
Ben

rob carthy

dude check out www.npoc.co.uk the guys there will be able to help wth any more probs :-)

mn_angrybeats

You done a compression check yet ??