What's up guys,

I have a 94 Miata with an 03 motor running MS3PNP and a Garrett T25 pushing 13lbs as of last week. After pulling it out of the garage a couple of days ago I noticed it left a couple oil spots. Unfortunately, I'm the kind of person that hates leaks more than anything. I did the valve cover gasket and replaced the copper washers for the VVT hardline. Upon further inspection, I notice that both sides of my block are somehow wet, all below the head. I get under the car and I see oil streaking down the side of the trans and collecting at the bottom. I also found oil within the slave cylinder boot.

While my tuner was working on it, it apparently spiked to 18lbs. I know for a fact the car has not overheated. Could boost spiking cause the factory head bolts to stretch enough to pop the head gasket? Should I bother getting them resurfaced if I know it hasn't overheated?

I plan on taking the head off after this holiday weekend and putting on a new head gasket with ARP studs.

Thanks guys

Here's an album of images with descriptions: https://imgur.com/a/fspoIYo

 

Didn't blow from 18lbs in itself. Probably detonation.

As for resurfacing, if head comes off, head gets resurfaced.

 

Ah alright, sure. Never taken anything to a machine shop before, how complete will I likely be able to leave the head?

Also, do you believe it was caused by the overboosting condition then or could this be detonation from a regular drive?

 

headbolts will not stretch at 18psi and certainly not on a T25 turbo.

if you are set on changing the head gasket, have it checked for flatness at a machine shop, and send it with ARP head studs.

im running original reused 20 year old head bolts on my semi built motor at 17psi, 309hp, for almost 2 years now with zero issues.

 

Ah alright. That's what I'm seeing the more I research it: factory bolts and gasket should have held...

Was mine just bad luck? Something is clearly not right if the sides of my block are wet with oil. I'm pretty set on it. Also, since I have to wait until after the holiday weekend, how much can I expect to pay for a head resurface?

 

Before pulling the head, I would get some uv dye, add to oil, let engine run for a bit and check with a black light exactly where the oil is coming from

 

Hard to tell, i haven't seen your car or your tune. I could also be wrong. But generally that's how i'd expect a head gasket to blow prematurely if not making manpants power and didn't overheat.

If you're not tuned for 18psi, and it hit 18psi and leaned out, that could/would cause detonation. A less-than-awesome tune in general could be detonating on the regular.

It's just a theory that i'm coming up with with the assumption that your diagnosis of a blown head gasket is correct.

 

In general, I don't think 18psi would take kindly to being hit so there's also that. Not hitting 18psi seems to be a safe bet for all parties concerned.

 

I'd hit that.

 

Sure it's not just your valvecover gasket?

 

I doubt it's the headgasket. They aren't really known for failing on these motors. More likely your VC gasket, CAS (or the CAS plug if you arent running a CAS), or cam seals. Any of these leaks can look pretty bad but actually be a pretty simple fix.

 

I'd be more inclined to believe it being the VCG if you had an explanation for the wetness on either side of the block below the head.

Also it's a VVT motor, I just have a freeze plug in back.

 

Put some oil dye in there and try to track it down. I've had a few mysterious oil leaks, one of which was the valve cover, that I thought for sure was a much bigger issue. It's really hard to track 'em down sometimes.

 

Well a hg usually blows in one spot on one cylinder and then leaks internally so it wouldn't really have a cascade of oil down each side evenly. The cam seals could be leaking and then that's whicking back along the head.