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Discussion Starter · #1 ·
I've run into a little issue here. Ran just fine for a while, then decides to do this the next day.

Ok, so, hard startup, no smoke at startup, but it does blow chuncks of black carbon out and also looks like theres a little water?(could be just moisture in the exhaust) I saw bubbles at the exhaust manifold where it attaches to the block and oil all over. Goes through A LOT of oil. I've always been fighting oil on spark plugs as i've gone through 3 sets already (being an idiot and avoiding the fix). It only seems to smoke blue when I get heavy on the gas, pull up a certain psi of boost, then when I hear the fuel cut sounding stutter leaving me no power and the whole car having a machine gun missfire. Looks like a little oil leaking from the outside of the valve cover but not inside and not in spark plug wells. Drives fine regular driving other than rough idle at times. Air Fuels are ok (little lean at times under boost but thats because I need a tune). If you guys need any more info let me know.

Valve seals? Rings? I have less than a month to have this fixed for the supra nationals!
 

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Discussion Starter · #3 · (Edited)
Compression reading. Front to Rear. Cyl 1-190psi, Cyl 2-180psi, Cyl 3-182psi, Cyl 4-135psi, Cyl 5-170psi, Cyl 6-180psi. Leaky piston ring or valve on Cyl 4? The reading for Cyl 4 would go up, down a little, up, down a little, up and not go past 135.
 

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2JZ swapped!
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Throw a small amount of oil in #4 and retest. If the number goes up it's the rings.
 

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stop playin wit mah name
2022 Alpina XB7
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1,934 Posts
You're looking for consistency with the compression test and Cyl. 4 & possibly 5 are the problem areas. You also shouldn't be getting more than a 14psi between cylinders. It's time to do a leakdown test to see whether it's the rings or valves. My guess is the rings since you stated you're getting oil on the plugs.
 

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The Great Kruso
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Btw... looking at your sig it looks you've got a NA-T. There are three on going threads about this same/ similar issue. Use the search feature and you'll find the answer you're looking for.

Kruso
 

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Discussion Starter · #7 · (Edited)
Tried the oil test on Cyl 4 forgot to add that. Didn't increase the psi so it must be a leaking valve? Mabe a seal?
I found the oil on the spark plugs was coming from the valve cover gasket so i've got one of those on order.
 

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stop playin wit mah name
2022 Alpina XB7
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1,934 Posts
You're just guessing now-do the leak test.

Make sure the cylinder you're testing is at TDC, or you can take the valve covers off and make sure the lobes aren't in contact with the buckets. Take out the oil dipstick as well and listen for leaks.
 
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