possible head gasket leak at #4 cylinder
 

The car in question is a '97 Miata that is stock as far as the engine and currently just above 102k miles. So I just removed the spark plugs since they have some miles, might be the stockers, and noticed that the spark plug from #4 cylinder(rear most cylinder) look to have water/coolant on the threads which at first I thought maybe I spilled some coolant at some point but then I saw on the "shoulder" of the bolt that it had a sort of milky stain to it and the spark plug hole on cylinder #4 had water/coolant at the edges.

All four plugs, 1-4 from left to right
https://www.miataturbo.net/attachmen...ine=1422409852
http://i21.photobucket.com/albums/b2...5e5c34aa_1.jpg

cylinder #4 plug
https://www.miataturbo.net/attachmen...ine=1422409852
https://www.miataturbo.net/attachmen...ine=1422409852

I did a compression test, never a leak down though, when I bought it in Sept. '13 and it had just under 93k miles(all cylinders were 170-180 range) and it currently has 102,296 miles. I took a couple pics of the spark plug(s) and tried to get one of the spark plug hole but none of the latter turned out. I appreciate any input because I obviously don't want to go ahead with a turbo setup with a leaking head gasket but even if it is leaking hopefully it won't side track me for too long. Thanks again in advance for everyone's help/input/advice! :party:

I have never seen a head gasket put coolant on top of the spark plug, i would check the the coolant hoses going to the heater for a pinhole, valve cover gasket to see if you are getting some condensation from the crankcase leaking to the spark plug tube...
You would have water in the oil, oil in the water, coolant loss, white or blue smoke if your head gasket was the problem.

Thanks for the quick response Harold and hopefully I am being overly cautious but better safe than sorry right? Looking into it doesn't cost anything but time and gray hair development. ;)

All the coolant hoses(radiator, auxiliary and heater) were in excellent shape and I have never seen any other signs of coolant leaking. The valve cover gasket look to have a few small leaks so the o rings for the spark plugs is a possibility but other than the recent hood louvers, there would be no other reason for water, that I can think of, to be on top of the valve cover. No water in the oil or vice versa and never any noticeable coolant loss and never a smell or colored smoke to make me think head gasket.

Water from above is my guess, not HG. Dear god those plugs look old, please change them!

Hood louvers, say no more...
If the car is running well and it has good compression I would clean everithing, put new plugs and keep an eye on it after you wash it or have the car sitting in the rain or snow.

Well they are the Singular Motorsports hood louvers so they are further forward like so...
https://www.miataturbo.net/attachmen...ine=1422464063


.....and the car is garaged 95+% of the time, so I am not real sure how much, if any, of the blame could be put on the louvers especially since I have only had them on about two months. Either way it seems I have just jumped ahead of myself and HOPEFULLY I am just being super paranoid. Appreciate yall's help! :wavey:

Louver placement for those was specifically designed to not leak water onto the valve cover, like some of the more universal solutions do.

-Ryan

Thanks for that information Ryan! I do not believe the louvers to have anything to do with water on the valve cover either but thankfully it looks to be just that, water on the valve cover that got down into the spark plug well and sat, more than likely from washing the motor some time ago.