Do I have a blown gasket?

VanMan2007

I checked the oil level yesterday and noticed it was down slightly. Then I noticed at one corner of the engine block, there was a hardened "rubberized" piece of oil. Beneath that there were signs of an oil leak.

I have noticed that the engine has seemed to "misfire" occasionally, but this this does not happen often and has been happening for a few months (I only do 3-4K miles a year). All other things on the car - temp, coolant levels, seem okay.

We were due to go to London today (Weds), but if it is a blown or near-blown gasket - and I think I've probably answered my own question - then that trip is probably not a good idea?

It will disappoint a few people not to go, so I just wanted an "expert" opinion before calling the trip off.

attila_

Check the following:

Underneath the oil filler cap for signs of white cream.

When the engine i running is there any sign of white smoke coming from the exhaust

Where is the leak coming from? Inline with the head gasket?
If the cylinder head went and was burning oil, i would bot have thought ot should misfire as oil burns, unlike coolant. When coolant enters the combustion chamber then it should misfire.

VanMan2007

attila_ wrote: »

Check the following:

Underneath the oil filler cap for signs of white cream.

When the engine i running is there any sign of white smoke coming from the exhaust

Where is the leak coming from? Inline with the head gasket?
If the cylinder head went and was burning oil, i would bot have thought ot should misfire as oil burns, unlike coolant. When coolant enters the combustion chamber then it should misfire.

Thanks Attila. As you look down on the head, the leak is at about 11 o clock. Will check under petrol cap when light. No thick white smoke from exhaust. I noticed yesterday when I started the engine, it almost died before picking up to full revs, which is unusual; but thinking back it has happened a couple of times recently.

I've decided to cancel the trip now anyway. The more I think about it, it just isn't worth the risk. I'll take it to my local garage and have it checked out. Something is amiss.

If the head gasket does need replacing, what is a ball park figure for cost? I have a 2.0L 24V Mazda Xedos 1998. I do have a mate who may be able to do it, but better prepare myself for the worst!

attila_

Check the oil filler cap not petrol cap! Also worth checking the coolant header tank to see if the water is dark. I know on VW this should typically be red for example.

Not sure about the cost on a mazda. It will depend whether the head needs skimming (this is needed if the head is warped under the heat. Very rough estimate as cost would be £400 perhaps? Someone with better knowledge will correct.

VanMan2007

attila_ wrote: »

Check the oil filler cap not petrol cap! Also worth checking the coolant header tank to see if the water is dark. I know on VW this should typically be red for example.

Not sure about the cost on a mazda. It will depend whether the head needs skimming (this is needed if the head is warped under the heat. Very rough estimate as cost would be £400 perhaps? Someone with better knowledge will correct.

Yeah, I meant oil cap, not petrol, sorry. Coolant still normal colour, checked that yesterday. Hopefully, I've caught whatever is wrong early and can be dealt with before any serious damage to engine, etc has been caused.

Checked under oil cap, no white cream. On second look, did notice more oil around bottom left quarter of head.

citykid5

it sound more like a rocker cover gasket failure to me rather then i head gasket fail? if so shouldn't cost anymore then about £50 to be replaced by a garage.as for the missfire.probably down to the low miles,needs driving a bit harsher,lower gear ,higher revs every now and again

reeac

VanMan2007 wrote: »

I checked the oil level yesterday and noticed it was down slightly. Then I noticed at one corner of the engine block, there was a hardened "rubberized" piece of oil. Beneath that there were signs of an oil leak.

I have noticed that the engine has seemed to "misfire" occasionally, but this this does not happen often and has been happening for a few months (I only do 3-4K miles a year). All other things on the car - temp, coolant levels, seem okay.

We were due to go to London today (Weds), but if it is a blown or near-blown gasket - and I think I've probably answered my own question - then that trip is probably not a good idea?

It will disappoint a few people not to go, so I just wanted an "expert" opinion before calling the trip off.

Check the cooling system to see whether it's under pressure when cold due to combustion gases getting into it. I had that once as the only symptom of gasket failure. Re. misfire - change plugs?

VanMan2007

citykid5 wrote: »

it sound more like a rocker cover gasket failure to me rather then i head gasket fail? if so shouldn't cost anymore then about £50 to be replaced by a garage.as for the missfire.probably down to the low miles,needs driving a bit harsher,lower gear ,higher revs every now and again

citykid5, thanks for that. I think all things considered, it is ONLY a leaky gasket of some kind, rather than a "blown" gasket. (Note to self: a little knowledge is a dangerous thing!) I was just concerned about trashing the engine and being stuck on the M1 with me old Ma!

I'll either get my mate to look at it, or take it to the garage. I've wiped down the head, so I'll see any further leaks in the meantime, and will keep an eye on oil levels.

Re the missfire: it is only occasionally, so probably a red herring in the blown gasket scenario. And yes, I rarely take the car above 3000 revs!

I'm also going to get my mate to do a full service, so that should iron out any further wrinkles.

Thanks to all you guys for your replies.
:T