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-   -   Burning oil like theres no tomorrow (https://www.miataturbo.net/engine-performance-56/burning-oil-like-theres-no-tomorrow-92389/)

Zammish24 03-04-2017 08:07 AM

Burning oil like theres no tomorrow
 
i need advise as I'm very tempted to torch it! Mk1 1.6 with a brand new vf34 turbo
Running a megasquirt MS2pnp mapped at 270.8whp @1 bar
Okay so every morning when i start the car it smokes alittle(oil) did a compression test the compression was around 180psi across all cylinders cold and hot.
i had a play about with launch control had alot of fun for a week or so then blew the headgasket https://www.facebook.com/images/emoj...1/16/1f615.png:/ (oil and water mixing)
so when i went to remove the headbolts two of them had worked loose! (i think the head lifted) thinking the headbolts aren't good enough for my power goals i installed some ARP headstuds , got the head FULLY rebuilt and installed a cometic headgasket. turn the key and it fired up but the oil is burning so badly i couldn't see behind me!
had a poke around and spotted a crankshaft seal oil leak, fitted a new seal and great ran perfectly no smoke and no oil leak.
Feeling pretty good took it for a drive then here comes EVEN MORE buring oil!
got it home had a poke around and its still leaking oil very badly. i have no idea what to do now, any ideas whats gone wrong?
guess ill never use launch control again ;(

Ted75zcar 03-04-2017 09:14 AM

Leaking and burning may/may not be two different issues. Have you performed a leakdown test yet?

Zammish24 03-04-2017 09:41 AM

No I have not yet. After a hour of letting it cool down i went backout to start it up and now it's running perfectly no smoke or oil leaks, thinking I might of ran out of oil I checked the dipstick and it hasn't used any! Got it to operating temp and it's still running perfectly. I don't understand what's happened

3rdCarMX5 03-04-2017 10:55 AM

If it is smoking - check if you have excess flow of oil to the turbo, my quick research indicates that the vf34 has a restrictor in the feed line at the banjo bolt, if you didn't use one it could lead to what you are describing.

Zammish24 03-04-2017 10:58 AM

Its got a 1mm restrictor already everything was fine until the headgasket went. Seems to be okay now though

Zammish24 04-02-2017 01:26 PM

hello everyone again, ive started up the car and its got so much worse, ive done a compression check both wet and dry also hot and cold and the results are identical. Ive taken the turbo off now, there dosent seem to be anything obvious. the intercooler piping looks clean no signs of oil. Had a very close inspection the turbo blades look alittle rough, not much but noticeable, it has some play there but i dont think its much either. Any idea what else i can try?
https://cimg6.ibsrv.net/gimg/www.mia...84e814049e.jpg

Ted75zcar 04-02-2017 01:34 PM

Leakdown

Zammish24 04-02-2017 01:40 PM

Ive done that, it made no difference on compression test result

Ted75zcar 04-02-2017 01:43 PM

What were the numbers? Where did you hear the leaks?

Zammish24 04-02-2017 01:51 PM

Oh sorry I got mixed up i thought leak down was pouring oil down the bores.
Both hot and and cold the compression was as pictured, with a tea spoon of oil only raised the compression about 5 psi across all four. I haven't got access to a leak down tester. If the compression is good would a leak down tester result the same thing?

Ted75zcar 04-02-2017 01:52 PM

Nope ;)

Ted75zcar 04-02-2017 01:55 PM

You can have good compression with bad leakdown. Ring blowby can pressurize the crankcase which may prevent oil from draining from your turbo, especially under boost. Result... good turbo seals leak.

Ted75zcar 04-02-2017 02:04 PM

Better yet, log crankcase pressure.

Zammish24 04-02-2017 02:09 PM


Originally Posted by Ted75zcar (Post 1402916)
Better yet, log crankcase pressure.

how would i do this? I was told u remove the oil cap and if the idle increases it means bad rings. ive done this and made no difference but idk if the guy that told me this was talking out his a$$

Ted75zcar 04-02-2017 02:26 PM

Yeah, umm hmmm, not sure that is the best test. Leakdown testers are available here for rent/loaners. I bought one, cause tools are good.

I tapped the valve cover with a 1/8" npt thread, then ran a nipple/hose to a MAP sensor connected my Megasquirt. You could drill/tap a spare oil cap and do the same thing. Might even be able to use a gauge, but watching a gauge intently under full boost may not be the best plan.

Zammish24 04-02-2017 02:33 PM

Ive just bought a leakdown tester, never know when i may need it again.

Zammish24 04-04-2017 10:37 AM

i think i found the culprit
https://cimg3.ibsrv.net/gimg/www.mia...24eaeb04c1.jpg
Good thing its covered under warrenty

Ryan_G 04-04-2017 10:56 AM


Originally Posted by Zammish24 (Post 1403377)
i think i found the culprit
https://cimg3.ibsrv.net/gimg/www.mia...24eaeb04c1.jpg
Good thing its covered under warrenty

The question is why is it leaking? Just because the turbo is leaking doesn't mean the seals are bad. Ask me how I know :doh:

If you have excessive crank case pressure or a restriction in your oil drain path, like the oil pickup tube blocking 75% of the opening, your turbo will not drain effectively and push oil past the seals.

Zammish24 04-10-2017 02:42 PM

Bad news everyone! I took the turbo to the guys that rebuilt it. They attached it to their machine and the oil isn't leaking, looked into my exhaust manifold spotted 3 ports COVERED in oil 1, 2 and 3. so I took the valve seals off,replaced them with genuine replacements, still burning oil badly. So I bought a leak down tester,
cylinder one and two had 20% leaks listened out where from.
cylinder one leaks into cylinder two and vise versa.
cylinder 3 40% leaking into the crank case, so I took off the cylinder head inspected the bores and there are miniscule scratches, my nail can't feel them.
but I'm starting to think with the amount of oil leaking into cylinder 1,2 and 3 I don't think the scratches are the only cause.
could it be that the heads warped? It's been skimmed but I can feel a high point in the cylinder head in the middle, strange as it's just been skimmed?

Braineack 04-10-2017 02:54 PM


Originally Posted by Zammish24 (Post 1404901)
So I bought a leak down tester,
cylinder one and two had 20% leaks listened out where from.
cylinder one leaks into cylinder two and vise versa.
cylinder 3 40% leaking into the crank case


we already knew this...


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