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After finishing a bunch of general maintenance on my 93 MX3 sohc 1.6 including fixing a valve cover gasket leak and degreasing the engine, a neighbor pointed out a lower oil leak on my engine.

He said it was the head gasket throwing a little oil out and that it probably became a worse leak after I replaced the valve cover gasket due to increased pressure. He also said the leak would look worse when the car was not in use due to block retraction.

I have had no real problem with the way the car runs, smoke, water or oil consumption thus far.

How serious a problem is this small leak?
If repairing this what other parts of the engine would it make sense to overhaul at the same time? Lastly, is this a job big enough that it may make sense to spend time on a BP engine swap instead of taking time disassembling the SOHC?

THX
GRA

If your head gasket it leaking, even a little bit, replace it ASAP. It may not seem a big problem now, but it will only degrade. A blown head gasket is a very good way to force yourself into an engine swap whether you want it or not.

If you're wanting to do a swap and have the resources available, go for it. But it's a lot more expensive, time consuming, and difficult than replacing a head gasket.

Graphixv wrote:After finishing a bunch of general maintenance on my 93 MX3 sohc 1.6 including fixing a valve cover gasket leak and degreasing the engine, a neighbor pointed out a lower oil leak on my engine.

He said it was the head gasket throwing a little oil out and that it probably became a worse leak after I replaced the valve cover gasket due to increased pressure. He also said the leak would look worse when the car was not in use due to block retraction.

I have had no real problem with the way the car runs, smoke, water or oil consumption thus far.

How serious a problem is this small leak?
If repairing this what other parts of the engine would it make sense to overhaul at the same time? Lastly, is this a job big enough that it may make sense to spend time on a BP engine swap instead of taking time disassembling the SOHC?

THX
GRA

you probably have a front or rear main seal oil leak. The oil spins around on the flywheel or pulleys while driving and splatters up to the top part of the transmission or all over the other side of hte motor depending on which side. Generally an oil leak is not indicative of a head gasket...

And by not in use, I assume he means after the block has sufficiently cooled a few hours later... as opposed to your block will ummm 'retract' more because you don't drive it for a week. If it's the later, stop popping your hood for him.

you probably have a front or rear main seal oil leak. Generally an oil leak is not indicative of a head gasket...

the oil didn't look splattered on the engine, it had a small amount on the lower left front seam area where the head gasket should be. It appeared to be seeping out of the seam.

And by not in use, I assume he means after the block has sufficiently cooled a few hours later...

Yep, he said while running it probably leaked very little.
Is there a guide for what should be overhauled when replacing the gasket?

This guy is has tons of experience with Mazdas (i.e. Mazda mechanic) and has seen the head gasket leak many times before?? I can see a Neon or something, but I would have hoped Mazda would be better than that.

You've replaced the distributor gasket as well?

I have an odd oil leak on mine that I'm leaning towards being the rear main seal now (searched some old threads like this). Where it's coming from and where it looks like it's coming from can be very misleading. Of course, mine doesn't just 'seal' up and go away when the engine is warm and I'm driving. It's there all the time and it's very minor and it's never bothered me.

If it's some flaw with original machining, gasket material, and/or head warpage of sorts and it is the head gasket.... I'd save up for the BP. To do it right, I'd deck the head, lap the block, fix a bunch of other little seals and so on so forth while there. Swapping in a BP with a 90 day warranty from a wrecker, even on your stock F series trans, would probably be more time and potentially cost efficient. Of course, for me, I wouldn't even fix the rear main if it is the problem on my sohc. If I'm going to spend that time just to replace a seal, I'm inclined to make it better than it was before and put a new seal on the BP I end up putting in.

Yeah, it is on the opposite side of the engine than the distributor.
It could be something else but there is so little oil there I am inclined to think the oil is slowly seeping right from the spot. i would be happy indeed if it was the distributor gasket!

Perhaps I should clean the area up and take a picture of it when a little fresh oil appears.

I don't mind working on the engine, I just want to make sure my labor effort on the sohc would be worth it. Money isn't the issue, time well spent is.