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Thread: oil in one cylinder but perfect compression fresh rebuild???

  1. #1
    Forum Member Grease Monkey
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    Default oil in one cylinder but perfect compression fresh rebuild???

    Hey all,

    Still having BIG problems with my freshly rebuilt 3sgte motor. Before i pull the entire engine and gearbox again (weeps...) i thought id ask you guys...

    Theres basically WET OILY GUNK all over plug 2 within minutes of starting. It then splutters, misses under load pulling away and dies...

    Its causing the engine to miss and smoke like hell from start up hot or cold whether its revved or not. Its barely drivable and runs like a dog.

    Im thinkong valve seal or head gasket.

    its only pulling 14 hg but when i first started it a few months back was pulling 18 so i dont think its the rings because compressions pretty good on all 4 cylinders (150-165). This engines got only an hours run time on it cos of all the probs ive had with no 2 cylinder chasing down poss causes.

    From the symtoms is there any way to tell if its the Valve seals, head gasket (new cometic 1mm) or the rings?

    I made a video but am having trouble uploading it, can email it if anyone has any ideas???

    Its a st205 head mated to a st185 block, using a 3sge 9.8mm lift 252 inlet cam. HKS 9.0mm lift 256 exh cam. Ross forged pistons and rods, new accalite rings. Head was freshly rebuilt 3k ago.

    Things i have checked:

    Have re-torqued the head (ARP studs torqued first at 65ftib, then a second time time to 70 incase the thin HG hadnt sealed properly).

    Compression all good.

    Valve clearances all ok.

    Changed oil (15/40 mineral to break in)

    What am i missing???

    Seema ALOT of oil to be a valve seal. I thought if the HG was garbage id lose compression?

    Is it possibe to diagnose without pulling the head from symtoms???

    Thanks alot

    Chris

  2. #2
    Junior Member Backyard Mechanic jondee86's Avatar
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    Question Re: oil in one cylinder but perfect compression fresh rebuild???

    I think it was Homer Simpson who said... "If it wasn't for bad luck, I wouldn't have any luck at all". And you don't seem to be having any luck with this engine.

    Oil dosen't appear out of thin air, so it has to be getting into the cylinder by one of these routes...
    - Stem seals. Usually causes a wee bit of smoke on startup and then clears.
    - Head gasket leak from oil feed to cylinder. Unlikely with a new gasket that holds compression.
    - Past the rings. Can happen on a new engine if the rings are installed upside down.

    So can I ask who assembled the block with the new pistons and rods ? And were the stem seals replaced when the head was rebuilt ?

    Cheers... jondee86

  3. #3
    Junior Member Backyard Mechanic
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    Just out of curiosity, did you do both wet and dry compression check. I know it's a fresh engine so will get variation, but you have about 9-10% difference in compression which seems a borderline amount for any engine let alone new engine.
    Check, best you can for Jondee's comments. They were my first thoughts as well i.e head gasket oil way leak or valve seals.
    Cheers.

  4. #4
    Junior Member Too Much Toyota oldcorollas's Avatar
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    leakdown test? wet vs dry cyl?

    are all the other plugs clean?
    is it missing on all cylinders?

    oil could come from pressure: oil galleries, (but none are near Cyl2? looks like rear of cyl4?) turbo seals?
    or vacuum (valve seals, rings, cracked head or block?)

    if enough oil in there, would that hide a broken ring/head/block on compression test?

    hmm.. wonder if you could pressurise the oil galleries and see if it pisses out somewhere?
    "I'm a Teaspoon, not a mechanic"
    "There is hardly anything in the world that a man can not make a little worse and sell a little cheaper" - John Ruskin (1819 - 1900)

    AU$TRALIA... come and stay and PAY and PAY!!! The moral high horse of the world!

  5. #5
    Forum Member Grease Monkey
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    Hey all,

    Thamks for all the replys. Your right Jon, this engine seems to be cursed!

    I built the block myself. Pretty sure i put the rings in the right way, if not theres my anwser! When you say upside down do you mean mixing up the top 2 rings? when i gapped them i double checked everything was the right way round 18 top, 20 middle, oil rings on the bottom.... i also made sure all the "dots" on the piston rings themselves were facing up... 99.9999% sure.... i hope lol.

    One thing that does spring to mind now is after the head was rebuilt by my local machine shop it did about 1k without any problems than sat for 3 years (1st rebuild spun a bearing) so maybe a valve seal has dried out and cracked?

    The other 3 plugs look sooty but dry and fine. Just cynder 2 that looks wet and oily like its struggling to fire.

    Did a wet and dry test. Was 180-190 ish wet. Was 150 - 165 ish dry. Offending cylinder was right in the middle on both tests.

    A second thing that springs to mind is that on this build i used a 1mm hg instaed of the 2mm i used before i stripped the engine for its 2nd rebuild...

    Theres lots of smoke, all the time but its also a little intermitant too, sometimes worse than other times. Def worse when shes warmed up.

    Think im gonna change all the valve stem seals next week and see what happens. But like Jon says valve seals smoke a bit on start up not foul the cylinder constantly.

    Thanks again for everyones help. Its very appreciated and spurs me on not to give up on this car!

    Cheers

    Chris
    Last edited by Blackcountryboy; 15-10-2017 at 07:54 PM.

  6. #6
    Junior Member Backyard Mechanic jondee86's Avatar
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    Exclamation Re: oil in one cylinder but perfect compression fresh rebuild???

    Quote Originally Posted by Blackcountryboy View Post
    When you say upside down do you mean mixing up the top 2 rings?
    No... as a general comment, some (possibly all) compression rings are designed to scrape oil off the cylinder wall on the down stroke. If they are installed upside down they will scrape oil on the up stroke and into the combustion chamber. This can be the cause of high oil consumption, and is the reason why you need to install the rings with the dots up.

    Not suggesting that you installed them incorrectly, but if nothing else comes to light, it could be something worth checking.

    Before changing the stem seals, pull the intake manifold and see if there is oil dripping from the guides on the problem cylinder. Maybe a stem seal wasn't sitting right and has come off the top of the guide. That would let oil get sucked down the guide under manifold vacuum.

    Cheers... jondee86

  7. #7
    Forum Member Grease Monkey
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    Quote Originally Posted by jondee86 View Post
    No... as a general comment, some (possibly all) compression rings are designed to scrape oil off the cylinder wall on the down stroke. If they are installed upside down they will scrape oil on the up stroke and into the combustion chamber. This can be the cause of high oil consumption, and is the reason why you need to install the rings with the dots up.

    Not suggesting that you installed them incorrectly, but if nothing else comes to light, it could be something worth checking.

    Before changing the stem seals, pull the intake manifold and see if there is oil dripping from the guides on the problem cylinder. Maybe a stem seal wasn't sitting right and has come off the top of the guide. That would let oil get sucked down the guide under manifold vacuum.

    Cheers... jondee86
    Hi Jon, thanks again replying and helping me again. Hadn't even thought a stem seal might have come loose.

    Know what your saying about rings, its SOOO easy to get distracted and mess up a ring installation. Hoping tho I didnt cos I remember being over critical at the time installing them.

    Gonna get the cams out again and do all the valve seals I think and see if that helps. Your logic makes good sense.

    Even thought cos they are such high lift tap happy cams 9.8mm inlet/9.0 ext, maybe I could have disturbed/damaged a seal?

    Thanks again

    Chris

  8. #8
    Junior Member Backyard Mechanic jondee86's Avatar
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    Lightbulb Re: oil in one cylinder but perfect compression fresh rebuild???

    Quote Originally Posted by Blackcountryboy View Post
    Even thought cos they are such high lift tap happy cams 9.8mm inlet/9.0 ext, maybe I could have disturbed/damaged a seal?
    Pretty sure you would get coil bind before you came close to hitting a seal. But take a good look at the seals from the problem cylinder to see if there is anything odd... wrong stem size, lost the spring, split when installed, along those lines. If you find a problem there, it could save you having to pull the piston

    Cheers... jondee86

  9. #9
    Junior Member Too Much Toyota oldcorollas's Avatar
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    when running.. does it smoke worse:
    on startup?
    during long acceleration?
    straight after long deceleration?
    continuously?
    intermittently, and not related to accel/decel?
    "I'm a Teaspoon, not a mechanic"
    "There is hardly anything in the world that a man can not make a little worse and sell a little cheaper" - John Ruskin (1819 - 1900)

    AU$TRALIA... come and stay and PAY and PAY!!! The moral high horse of the world!

  10. #10
    Forum Member Grease Monkey
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    Its continuous from start up. Smokes like Bob Marley! Within mins the 2nd plug is covered in dark oily residue. She runs rich on start up too, 11 - 12 AFR s. The other plugs are just sooty but dry. Actually saw brand new clear 15/40 oil bubbling out ta the 2nd exhaust gasket on the flange! I'm thinking like Jon said maybe a seals come off or has gone completely. Hope it is a seal cos if I'm gonna pull the head I may as well pull the whole engine and gearbox. Surely THAT much oil couldn't get past a valve guide?

    Thanks as always.

    Chris

  11. #11
    Junior Member Too Much Toyota oldcorollas's Avatar
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    it does seem like a lot.

    whole engine? just start with head?
    or start by looking into exhaust port and see if something is visible?
    "I'm a Teaspoon, not a mechanic"
    "There is hardly anything in the world that a man can not make a little worse and sell a little cheaper" - John Ruskin (1819 - 1900)

    AU$TRALIA... come and stay and PAY and PAY!!! The moral high horse of the world!

  12. #12
    Fustrated DYI mechanic Automotive Encyclopaedia Omegaman's Avatar
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    i know nothing on the configurations of this engine. But since every avenue has been sugested above.
    Any chance the oil galleries on the st205 head is different to the st185 block. An extra gallery or something????
    Just a thought..

  13. #13
    Forum Member Grease Monkey
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    AFAIK the 205 head mates to the 185 block using a 205 gasket. Water ways are slightly different but it all lined up OK. Thinking valve seal or cracked valve guide. Just waiting on a keeper removal tool n I should hopefully get the bottom of it. Sucks I gotta take of the cam belt AGAIN lol. Good thought tho man. Keep em coming.

    Thanks again all

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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    some things to check.
    remove and plug pcv and see if symptoms persist.
    if so, pcv could be sucking in oil from a rocker cover that was left upside down and oil filled the backfire sponge.
    if ur pcv enters the plenum on the same cylinder with the issue then this is it.
    and of course, your valve stem seal theory sounds most promising. a cracked valve seal doesnt stop smoking once running, it continues to smoke untill the engine has no oil left.
    the old theory of smoke on startup is for slightly worn seals that cool down and let oil drip down the stems then the startup burns it all. a broken seal is a different story and very likely if the head sat in the open for more than a couple of weeks.

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    Forum Member 1st year Apprentice
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    Default Re: oil in one cylinder but perfect compression fresh rebuild???

    oh here u go.
    this from another forum...

    "
    ok if its not the distributor o ring or valve cover gasket, chances are, its the middle stud that holds on the intake manifold...this goes straight through to an oil return passage in the cylinder head..you need to take the stud out, and use teflon tape or gasket sealer on the stud when you put it back in.
    "

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