steven17

I have a 1990 Mazda Miata that i have had for 6 months now, it has a greddy turbo with an intercooler, bipes, larger injectors. It has been noticeably been burning oil ever since i got it and every time i top it off i have to put more oil in it. I checked the spark plugs recently and they were completely corroded with burnt oil so i got new ones and thought it would fix my problem. My problem is that it has been losing bottom end power ever since i got it(0k-4k rpm). It has gotten to the point that it does not even have the guts to get up my driveway. I was thinking that it may be the oil rings. Can anyone help me to figure out what is wrong with my car?

steven17

if you guys could direct me to look for certain things that would be nice.
I hope my engine isn't toast

Slacker2223

do a compression test.... doesn't sound good though. do all the plugs have oil or only some?

steven17

ok i was planning on doing that anyways i just need to find a compression tester

steven17

all of the plugs were coated in oil

steven17

ok i just ran a compression test and i had 150psi in all of the cylinders
Could this mean that it is my valve seals that are leaking?
If so what is the fix?
Should i just get a new head?

steven17

HELLO can somebody help?
i need my car in order to get to school

flounder

May be unrelated but if all four plugs are soaked with oil your valve cover gasket may be shot.

150 psi is on the low side though.

aug

iTrader: (7)

The actual PSI is not as significant as a consistent reading between the four cylinders.

SKMetalworks

iTrader: (7)

Do you have a catch can?

steven17

no i do not have a catch can
if it were the v.c. wouldn't it be leaking onto the block and such, there are no visible oil leaks and it has never dripped any oil where i park it.

flounder

There are four rubber grommets between the cover and the plug bores, this is a common failure. If you look down into the holes, you can tell if they are leaking. You'll find oil all around the bores.

And yes, it's more important to have all the cylinders balanced but I think the min spec on compression is 145psi so as long as your testing it correctly, your motor is just worn out.

steven17

OK i will go check, would this be creating the complete lack of power though

steven17

Ok i went looking for those 4 rubber gromets and i was not able to see any.
Do i have to take off the valve cover in order to see them?
With the valve cover on there are 3 bolts in between the spark plug bores are these what you were talking about?
I appreciate your help

sixshooter

iTrader: (12)

Do the vacuum hoses from the valve cover go to the intake manifold? You might should be running them to a catch can and see if that helps. You might have a lot of oil transiting those hoses and right into your intake manifold. Give it a try and see if they spit a bunch of oil into your can due to excessive blowby. Old engines can have a lot of blowby, especially when turbocharged.

It is easy to make a DIY catch can if you are poor. Search here and also google for more ideas.

steven17

yes it does go to the intake manifold
if i make a catch can what difference would it make?
Would it just be releasing the pressure or would it bring the oil into the oil pan because if i remember it goes valve cover to can and then to the oil pan.

flounder

The o-rings are between the cover and the head, you can see them if you look closely inside where the plug wires go. Use a flashlight.

If you still can't see them, you can pull the cover but once you do, you may as well replace the vcg.

sixshooter

iTrader: (12)

It would help to keep oil from going into your intake manifold and then down into your cylinders. All motors have blowby. Old motors have more blowby. Old turbo motors can have LOTS of blowby. Blowby is crankcase pressure created by the rings not keeping all of the cylinder pressure in the combustion chamber when the mixture is burned. When your engine is old/tired/suffering from increased cylinder pressure due to being turbocharged, it allows more blowby. This blowby force carries oil droplets and oil vapor that can make its way into the intake manifold. Having those little hoses go to a can with some volume will allow the oil to collect in the can and not be burned in your engine. That is what we are shooting for here.


Yes it will be releasing the pressure into a container with some volume. The volume allows the gasses to slow down and lets the vapors settle and/or condense to liquid and rest in the bottom of the can. There is no reason to get complicated with adding a return to the oil pan. There will be things (like water vapor) that will be collected in the catch can that you will not want to reintroduce to your oil pan. The contents of catch cans will often look like chocolate milk because of the mixture of oil and water. The common way that catch cans are handled is that they are drained through a built-in bottom drain or simply removed and dumped out periodically. This is the normal way they are handled.

shlammed

iTrader: (8)

burning oil and no power do not always correlate.

how is your fuel pump?

do you have a 323 gtx PCV valve, or a factory miata one? ->try capping your intake manifold port completely and just leave the valve cover open to air for now and see if that stops the oil burning.

has the oil burning issue been consistant, or has it gotten worse?
was the oil that you observed on the spark plugs burnt oil, or oil on the white ceramic part?

p51hellfire

iTrader: (28)

do you notice any smoke out of our exhaust?? haven't noticed anyone mentione rings?

I just did a comp test and came up with these numbers 210 200 190 170 i see white smoke every now and then, I believe my head gasket might have a slight leak....