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Discussion Starter · #1 ·
I recently completed a head swap- a 99 head and intake manifold (with Summit Racing rev switch to control the VICS butterflies) onto my 97 with manual transmission, AC and P/S, along with a Begi coolant reroute, timing belt tensioner and idler, front main seal, all new hoses and CAS and cam seals,99 fuel rail and injectors, and a Protege valve cover. I also installed ARP head studs. I bought the head used, and had it hot tanked with a valve job, new 949 Racing seals, stock 99 exhaust cam and MSM intake cam. My engine had previously used no oil and ran strong, so I didn't do a compression test. Now I am losing oil somewhere (Mobil 1 10W-30) at about a quart in 150 miles with no external leaks that I can find. My tail pipe is black and oily. I'm thinking of pulling the top off of the intake manifold to see if itps oily inside (I also removed and blocked off my EGR). I'm wondering if the culprit might be something to do with the Protege valve cover. I installed a new Pcv valve and ran the vent from the back of the valve cover under the intake manifold to the stock connection on the intake crossover. Any ideas?
 

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If muffler is oily, then you have a leak in your exhaust valves. Best thing is compression check first. Valve covers are just that, valve covers. If valve cover is leaking, you'll definitely see a leak around it
 

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Damn that is fucked up.

I would not say its the VC that is ALOT of oil to go through the chamber you would be seeing smoke.

I would start with the head.
 

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Discussion Starter · #6 ·
I'm not seeing ANY smoke. Just a little of the normal water vapor, and very faint, on cold startup. That's what's puzzling me- it should be smoking if it's burning that much oil, and it's not.
 

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i have something similar. No smoke and my compression check was good. When we did a wet compression everything went up only about 10. I was told just start replacing gaskets form the top to the bottom.
 

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Discussion Starter · #8 ·
What I was thinking about the valve cover was that perhaps I was somehow building pressure and pushing oil through the venting system. I recently found some pictures and an article about this problem that led them to add steel wool in stainless mesh filter bags to stem oil loss from the VC venting system and it seemed the venting system in the Protege VC was not as good as the stock Miata VC.
 

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Discussion Starter · #9 ·
i have something similar. No smoke and my compression check was good. When we did a wet compression everything went up only about 10. I was told just start replacing gaskets form the top to the bottom.
I just DID replace every gasket above the oil pan except the water pump with brand new high quality gaskets. The PO said the water pump was new when I bought the car 2 years ago
And every seal except the rear main. And it didn't use a drop of oil until I did the head swap.
 

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STILL that is a ton of oil to blame on the PCV. Build a catch can and then see? There has to be some sort of leak you are missing. The oil filter could be and that would be hard to spot
 

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Discussion Starter · #11 ·
STILL that is a ton of oil to blame on the PCV. Build a catch can and then see? There has to be some sort of leak you are missing. The oil filter could be and that would be hard to spot
Good thought- I think I'll take to a friend's shop and put it on his lift for a more thorough examination. I have to root around and find some short lengths of 2X- he has on old 2- post and I have to put it up an inch or so since I dropped it an inch with FM 2.5.
 

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Discussion Starter · #13 ·
Well, the good news is- no leaks.

The bad news is- yes, it IS smoking. Damn!

I put in a can of engine restore and will put some miles on it, hoping that it is stuck oil rings and that they'll get unstuck, but I think the odds are against me. So I'm probably looking at eventually pulling the engine, boring, pistons and better rods. I'm getting too old for this!
 

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If it smokes all the time it's you're piston rings, if you get a puff of smoke on start up or just mainly when you take off from a stop it's probably you're valve seals. That and make sure you're PCV system is working properly. See if you have excessive oil, or any pooled up in the throttle body or air intake.
 

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Discussion Starter · #20 ·
I replaced the valve cover with one from a Protege, which has no cover over the cam pulleys. The vent that runs from the side of the valve cover to the passenger side of the crossover in the stock configuration now originates at the rear by the coil pack and runs beneath the intake manifold and up by the alternator to the crossover. I modified the coil pack mount (had to, as there is no provision for mounting the coils on the Protege VC, but now I can remove the VC without having to bother with the coil pack) to give room to put a brass ell (NPT to barb where the vent exits straight from the VC on the new cover). The PCV valve is new and tests good. With the 99 intake manifold, the connection to the PCV valve is nearly a straight run of about 2" (I swiveled the ell connector on the intake). So if I am losing oil through the venting system, it would just about have to be the rear vent, and when I pulled the connection to the crossover, it was dry with no trace of oil. The PCV shows oil, but that would be normal, so I guess my idea of losing oil through the venting system is busted.

Before I installed the head, I vacuumed out the bores and wiped them out with carb cleaner while turning the engine over by hand several times to make sure I got any debris removed, then wiped the bores with oil and immediately put on the head. There was some light carbon at the top of the bores and pistons, but I just left it.
 
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