got a big problem
 

well here it goes...... i just threw on the turbo set up everything went great on the install did ms extra, t25, front mount the whole deal. also changed almost every seal on the engine. i go to start it up and its burning oil like crazy! i change the turbo same disconnected the drain to make sure it was flowing with the car running that was fine. im running a small enough line, with the re stricter on the turbo. change the turbo with i know was good with another one same. i notice when i pulled the turbo mani it seems like its burning the oil before the turbo int the combustion chamber. pulled the spark plugs all of them full of oil FUCK! so i did a compression test dry 185 in all OK. did a leak down test 100/96, 100/96, 100/92, 100/96 and that was cold! WTF what the hell is wrong, i check the water and no sign of oil. so im guessing the head gasket is fine, to have all plugs full of oil like that and not be in the watter i kinda ruled out the head gasket and no leaks around the engine. the only thing i can think of is valve seals, but why so much i never seen valve seals leak so much. also i check the charge pipes and no oil so im like 90% sure its not the turbo.

i mean i work at a shop i see things alot but this seemed weird to me. im not a miata guru so im ask the miata community.

shoot me ideas or what you think or if it has happend to you.

im rulling out valve seals but i never seen it this bad.....

thank for reading my small book lol

i had a bad turbo do that but you already ruled that out. Maybe try a hot test for leak down. The oil has to be comming from somewhere, turbo is the obvius choice. Pistons/HG is the next past that nothing else would do that i think valve seals would not be that dramatic i think. + they should show up on a leak down test. Try a hot test to see if it is related to expanded parts and age.

yea ill try it hot but usually the results are better... and there near perfect

what's your PCV routing look like?

not running a pcv. 180 on all cylinders compression test no blow by

Crankcase open to atmosphere? What did you do with the lines off the valve cover?

just left them open and plug ed the one on the intake mani. so i have no vacuums leaks any where. i think im just gonna yank the head get all new valve seals clean he up and slap her on and hope for the best.....

any other thoughts before i start to take the car all apart?

its obvious with your leakdown, it's not the valve seals....so why the hell would you rip the head off....

why dont you put your pcv line back....

so you just started it up and it started smoking instantly? or did you drive around and notice the turbo smoking? or the tailpipe dumping smoke? Did you get the thign a chance to burn off all the residual oil/gunk after installing?

this all could be helped if we knew how much smoke you are getting as well. for me and the way i saw what you presented it is a significant amount. IE you cant drive down the raod without being a spy hunter with a deployed smoke screen, I have been through that not fun. If you have less than this it is quite possible you have nothing wrong and just abunch of dirt etc to burn off the inside of the combustion chamber.

Oil Problem
 

I am still new to turbo charging my miata. I have a similar problem that you are having, I am almost sure on why this is happening with mine. The only difference is that you are running a t25 and I am running a 16g. Now my “guess” is that the way my turbo is sitting on the top of the manifold which is putting my oil feed line and oil return in a bad position. The oil feed line is almost at the bottom of the turbo at an angle and oil return is on the top but I am hoping that I can take the turbo apart and rotate the center peace (not sure what this is called) around to reverse this. In theory the oil being forced up into the turbo is backing up when the turbo is at low oil pressure or idle and causing it to leak past the seals and go into the Ic pipes and exhaust. Or it could be leaking on high pressure and im not seeing this until im at idle or low rpms. This may be all wrong but im going to give it a try and see how it works. If anyone can shed some light on this I would be grateful?

lol wow holy crap yeah turn that thing around (which is called "clocking" btw). That will 100% no doubt make smoke.

:nono:


that's the problem....and yes you can rotate the CHRA....


the oil feed may have pressure...however the return doesnt....so the oil you are pumping in is backing up and getting forced past your seals....rotate it back correctly (at least 10° from vertical) and your problem should go away.


btw, reattach the damn pcv.

fixed it for ya ;)

yya ya ya.

wow yeah most 16g's are in a bad spot until they are clocked (rotated) GL man.

first of all my turbo cartridge is at the right position.......
second when you do a leak down your not testing your valve seals...
the valves car completely closed when do a leak down test....
when you do a leak down test you are testing for bad rings or valves......
valve seals are completely above the combustion chamber.

y should i reconnect the PCV?
explain y that would cause oil to get in the combustion chamber

it pressurizes the crank...IE BAD. just do it and stop being an smart ass.

look man i not being a smart ass.... also did you just say the a leakdown test pressurizes the crank? if so just stop now! im looking for educated answers so you not helping too much.

and im not just going to do something with out a reason. i see no reason to put the pcv back on. if you think so give me a educated reason why. if anything i should run the pcv to the inlet of the turbo if you were to do it correctly i think it works of of vacuum and atmospheric nothing more. so my thought would be to run it to the inlet of the turbo. if im wrong educate me and explain thats what i thought forums are for

no, removing the PCV pressurizes the crank. re route it the the pipe from your Airfilter that connects to the turbo.

sorry i miss read what you wrote... but how am i pressurizing the crankcase by venting it. i mean yes it would help a lil to have a vacuum to help release crankcase pressure but i dont think its the cause of my problem.

'I believe when the crankshaft becomes pressurized it pushes oil past the rings? Don't quote me, but i think that's what happens. All i can tell you is it isn't good and it has caused smoking.... not necessarily the smoke screen style. It also leads to oil splattering all over the engine bay.

i mean you get some pressure but i dont think enough to push oil all they way up . sound like you would have to have bad rings to that witch would cause alot of blow by, oil coming out of the breather, low compression test and would have shown up on the leak down. i mean ill try the pcv thing but ill put money on it that it dont work in my application.

the car smokes bad during idle and when applied gas its smokes like crazy. all under my is black.

well re routing it is a good start... im not sure what would cause that much smoke... i'd think something to do with your routing or rings cause it's under throttle.

1: I'm still in the process of Turbo'ing my Miata, but I have turbo experience on other motors. In my experience I have had a lot of difficulty finding a PCV that can properly withstand the pressures of a turbo charger. Even stock units seem to allow seepage. I found that mid to late 80's Nissan's have a METAL one way check valve for there brake booster. This check valve is absolutely awesome in keeping boost from seeping past the PCV, I always put one between my intake and PCV and intake and brake booster. Be careful some of these check valves are PLASTIC and do not work as well, thus you'll need to hit up a junk yard to find the good one's since I'm certain that all aftermarket one's will be plastic.

Now, on to why you should have a PCV. The PCV is only removing crankcase pressure when your intake manifold has less pressure than the crankcase. When in boost it serves no purpose. Now, whenever the motor is running there will ALWAYS be some blow-by (combustive gas that seep past the piston rings). This blow-by WILL add pressure to the crankcase, this increase of pressure must be overcome for the piston to travel back downwards. If the pressure in the crankcase become too great you can blow things like your oil pan gasket (I've done it with a bad PCV before).

Now if the de-pressurizing of the crankcase doesn't happen when you're in boost, why is it important? Even a turbo motor doesn't spend 100% of it's running time in boost. Every time you shift there is a great surge of vacuum generated, this vacuum will evacuate the crankcase.

Okay, one more point to make, why it's not beneficial to vent the crank case to the atmosphere. Atmospheric pressure is around 14.7 psi (at sea level). Now assuming that that itty bitty hole for the old PCV valve can provide enough flow to equalize the pressure of the crankcase between shifts you still have 14.7 psi of pressure in your crank case. Having the PCV in place allows you to remove much more of this unwanted pressure in the same amount of time.

I hope that clears things up a bit.

2: Dow.tom, I can't PM yet, but I'm interested in the '94 ECU you have. I have a buddy with a Festivia with the 1.8 Escort GT motor (practically the same as the Miata, except it's in the wrong direction :)) that he would love to get Miata engine management on, that is until he can afford the MegaSquirt. Can you email me so we can discuss it? I know I'm probably asking for a wealth of Junk Mail from this but my email address is fastmonkeywheels @ hotmail.com

how about you simply put the PCV back on so you can pull a shit load of vacuum out of the crankcase at idle and cruise, helping the turbo drain it's oil better, and keeping your rings healthy.

and then reattach the breather line to the intake so there is constant vacuum in the crankcase during all conditions....

I'd like to ask, in eradicating the pcv....what did you do, block off both ports?

fwiw, reattaching the pcv is not going to fix your current issue...

I think you should reconnect the PCV valve and also replace it with one out of a 323GTX that can handle boost. This is something that is recommended often on this forum. The crank case vent on the right side of the valve cover can either have a catch can or a little air filter. That one I wouldnt put into your intake just because it can throw oil into the turbo, and you dont want that in there.

No, it is also highly recommended here that you do route the goddamn breather line back into the intake....

Then why do I always read threads with people saying that if you plug the breather into the intake it can throw oil into the turbo and then into your charge pipes? Is the catch can the cleaner solution?

yes, catch can isnt a bad idea. But if you have good rings, you shouldn't be getting any blow-by.

The reason I suggest keeping the breather line there is so it's harder for excess pressure to build up in the crankcase, as you keep a constant source of vacuum in the crankcase....up to 2~hg. at 10psi of boost.

This will help your turbo drain faster & keep your rings fresh.

It doesn't kill you to have a little filter on the crankcase, but it doesn't do any good either.

Removing the PCV, imho, is just silly....

This might seem like a Captain Obvious suggestion but...

You say you disconnected the drain, was this to see flow through the turbo?

If so I'm curious to know what would happen if you put a small funnel on the drain fitting (disconnected) and pour some oil down into your crankcase. If the drain is draining slower than the rate of oil that flows through the turbo, it will back up and push past the seals in the turbo. :nono:

Maybe you have a constipated drain? :eek5:

pertaining your question i took off the line off the pan and ran the car and it drained and still smoked. the thing is there is oil in the cylinders on the plugs, its burning before the turbo. so the turbo has been ruled out.

Has nobody even mentioned the cam cover seal? I found that one to be sortof tricky to get it not leaking and it was absolutely necessary to use silicone on the 90 degree corners. if its all over your plugs, thats where it has to come from right? its not like your cylinders are filled with oil right?

I highly doubt he is pushing past his rings VTA is not the end of the world but on some cars there is significant blowbye when running and this will cause a back up in the turbo's oil drain line, forcing oil into the ocmpressor and then into the intake inturn. A poorly routed drain or simply a drain that is to small etc can cause this as well. So in short order confirm the oil drain line is unkinked and has a free path to the oil pan and into it. Try a GTX pcv if this is the case. From there i gotta ask is the turbo new? If it is old maybe a good dissassembly and cleaning of the sealing surfaces inside and a carefull reasembly, or rebuild will fix your problem. There are 3 ways to burn oil guys remember Turbo, HG, and rings. My bet is on Turbom rings might not be helping it but turbo seems very likely. OF course if the turbo is new and does not have coked oil on it's internal seals from where it ws bypassed and then left opened a smidge by residue, then i :dunno:

pull your charge pipe off the TB and check for lots of oil there... it could still be your turbo. There is a seal on the compressor side just like the turbine side. Although MOST oil burning issues are caused by the turbine seal, the compressor seals are also known to go bad and toss oil through your intake.

Your oil drain test is meaningless... if you have that much oil on your plugs then it will take longer to burn off pre-existing oil than it would to run your car out of oil (spilling out the return). Very short tests do no good in finding the root cause of this kind of problem.

Another thing to consider is that our oil passages in the head are laid out in a strange way. I did, at one point, have severe oil burning issues (1 quart/ 150 miles). It was a head gasket problem. I was not losing coolant, I had no coolant in the oil, or vise-a-versa. If all your other tests suggest there isn't a problem try changing the head gasket. It isn't too expensive (ebay gasket sets are under $60) and it takes about 4-5 hours (for me... I've done it half a dozen times).

DUDE.

you did a compression and leakdown test...it suggests the internals are postively fine and everythign is WELL within specs.

That being said, your drain line MUST be corrected.

If you have oil on the threads of the spark plugs that only says your valve cover gasket is leaking and the oil is not in the combustion chamber.

if the electordes are full of oil then you know the rings are failing. But since your smart ass pulled the pcv valve to pressurize the crankcase, then i'd expect lots and lots and lots and lots of burning oil.