9 replies to this topic

[BigDave99]

Hello

At the moment iv got a major problem with my 1995 SPI mayfair overheating, the cooling system is constantly air locked and am forever bleeding the rad! A lot of the time by the side of the road! This is air is coming from somewhere and im sure everyones first thought is the head gasket! But i have checked the compression and its uniform for all four cylinders. Could the head gasket be blown and letting air into the cooling system but still be giving me the correct compression?

Also she is misfiring, shes running stupidly rich and i clean my plugs weekly but she misfires a lot, could this also be water getting into cylinders because of the head gasket?

All help appreciated

Dave

[998dave]

Sounds quite badly set up.

Head gasket would produce low compression, one would think, have you tried flushing it through, and do you get bubbling in the radiator with car running?

As for missfire, probably related to running rich, try setting this correctly. You may also have ignition problems, have you checked the rest of the system is well serviced?

D

[mr_apples]

if its the gasket letting water in the combustion chamber the spark plug would be clean in the cylinder that leaks, basically steam cleaned, also the exhaust can be steamy as well.

and when you start it the cooling system will pressurise up quickly, due to combustion pressures.


have you checked the thermostat is opening, bowl of boiling water to see if it opens?


the miss firing is probably due to how rich its running, rich enough to foul the plugs.

i guess it smokes when its running, what colour though, blue or black?

blue is oil, black is too rich a mixture

[Rhys]

Have a look under the oil filler cap for a mayonnaise looking gunk. This is a classic sign on head gasket failure.

Rhys

[mike.]

Have a look under the oil filler cap for a mayonnaise looking gunk. This is a classic sign on head gasket failure.

Rhys

But that can also be caused by lots of short journeys so not the best way to tell.

[mr_apples]

Have a look under the oil filler cap for a mayonnaise looking gunk. This is a classic sign on head gasket failure.

Rhys

only if the gasket has gone in such a way for water to get in the oil, doesn't always happen

[BigDave99]

hey

no mayonaise, checked this first! Yeh when running with cap off i have constant air bubbling up through the water and then the water overflows every now and again! All the plugs were black apart from cylinder 1 which had a weird beigy colour on most of it, im guessing this is the cyclinder thats misfiring! The exhaust is smoky black not blue, i dont think im burning oil. you can smell how rich she is running as well! I need to sort out the fuelling but the issue at the moment is the overheating as i can only do really really short journeys!

Cheers

Dave

[BigDave99]

Oh and thermostat was changed a few months ago. When driving i can get her stay at the right temp by pulling over and releasing the pressure when it builds up every now and again!

[mr_apples]

sounds like head gasket on no1 cylinder, gone through the fire ring to one of the water galleries

if you put your location up someone who is near you may be able to see your mini and say for sure.


if the head gasket has gone i would sort that as soon as possible.

sort the running rich afterwards

[DaveRob]

If its runnig rich on an SPi then the chances are the Coolant temp sensor is fubar....this is a common fail and screws up the fueling to such a point if you dont fix it it then destroys the Lambda sensor due to all that fuel and then does the cat in....where fitted......... where does your temp gauge on the dash show when its up to temp?

Rob