Yes, it's official.

It is consuming about a quart in just over 500 miles.

I also get a puff of smoke out the tailpipe when I get on the gas aggressively once the engine is warm.

Compression test was 180 psi on all four.

The engine has 164.000 Km on it.

Do you think its ring related as I think it is indeed the culprit?

And,

What do you guys think I should do?

I can do a basic hone, with new rings, bearings and a head gasket. That would be the most economical way to go. (I would change the stem seals, as well, while I get in there, of course.)

I really do not want to (and can't) go the whole way with a full bore, new pistons, etc..

Any thoughts, ideas?

Thanks.

 

I had the same issue with my 99. Went ahead and did a ring and hone job and had the head cleaned up along with new seals before I ordered my turbo kit.

In all honesty it didn't do a damn thing. I used to go through a quart every 200 miles with 190psi across the board, now I go through a quart every 350 with 205psi across the board. I wanted to have new guides put in while the head was off but the machine shop said they all looked great and it wasn't needed. I also don't see a lot of blue smoke either and I don't have a cat.

I'm noticing a lot of 99's having the same problem.

My engine runs great and I've been boosted for about 3 months without any issues except the comsumption. Mine isn't a daily driver so it isn't that big of an issue for me to add a quart every few weeks or so. When I do take her out, I drive the **** out of it though with lots of high revs. I may see better consumption #'s taking it easy.

I also replaced the pcv system and searched for any leaks but so far I can't find ****.

When I pull the drivetrain out for a new clutch in the winter I may end up swapping motors. I have 117k on this one with about 4k on the rebuild.

 

You need to figure out exactly why the car is eating oil, and not just assume that its the oil rings without having any real proof.

I have NEVER heard this before, and do not believe it for a second. My car and many 99-00's owners I spoke with don't have oil consumption issues at all.

My stock motor didn't eat oil for about a year, and only about a month or two before it blew did it start eating oil, and only a LITTLE bit. Like a 5th of a quart between oil changes. Since the build it hasn't consumed a drop of oil.


All I'm saying is do a whole lot more investigating and hopefully find out 100% the problem before doing anything drastic.

I'd also recommend throwing in h-beam rods in there while you're in there. It just makes sense. rods+cleaned up stock pistons+chromoly rings+new gaskets= nice mild build that should definitely run like a champ for a while.

 

Search on miata.net, cr, mt and you'll find a few 99's with this issue. I have a very early edition of the NB #7477- 2/98. I'm not sure if that has anything to do with it or not? No issues with the #4 thrust bearing either.

I'm not saying it should be a recall or anything but it is happening. I'm hoping to find the rear main leaking when pull the trans, but I'd imagine with that much consumption the clutch would have been slipping like crazy by now.

 

My 99/00 had 190,000 on it when I put the 05 engine it and it never used a drop. The last 2000 miles it was used for nothing but an autocross car.

 

wanna trade?