White smoke on decel that smells like oil?

Cya

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Aug 12, 2005
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I swaped my 1j into my Mk3. I upgraded my twins to an MPT70 and am experiencing white smoke that smells like only on decel only? I'm familiar with the general rules of the colors of smoke being: white=coolant, blue/gray=oil, black=fuel. My mechanic thinks the piston oil rings but I did a compression test and every thing was even at 130 after three rotations. I did a vacuum test and the gauge is holding a solid 23 which means a good motor. Any suggestions?
 

Ryan_V

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You sure that's 130PSI?

I think it's bad if your below 150PSI

Was the engine warm when you did the compression check?



Need one of the pros to respond
 

tissimo

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For 3 cranks it sounds ok, try for 5-6 and see what the numbers are.

Most likely its just valve seals. Under high vacuum (decel) itll pull more oil through the valve seals more then normal. Is there any slight smoke at startup after the car sits for a while?
 

Cya

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Ryan_V;1307348 said:
You sure that's 130PSI?

I think it's bad if your below 150PSI

Was the engine warm when you did the compression check?



Need one of the pros to respond

As warm as it could be after taking all required items off

tissimo;1307381 said:
For 3 cranks it sounds ok, try for 5-6 and see what the numbers are.

Most likely its just valve seals. Under high vacuum (decel) itll pull more oil through the valve seals more then normal. Is there any slight smoke at startup after the car sits for a while?

Yeah there is some. Is there a way to test the valve stems with the motor assembled?

Ill re-test tommorow, any pointers on testing for compression?
 

tissimo

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Apr 5, 2005
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Cya;1307411 said:
As warm as it could be after taking all required items off



Yeah there is some. Is there a way to test the valve stems with the motor assembled?

Ill re-test tommorow, any pointers on testing for compression?

Not really a way to test. If it smokes then they're bad. Its pretty common on the JZ engines.

For the compression test, make sure the engine is at operating temp, hold the throttle open and crank so you get 5 revs out of the cyl you're testing.
 

Cya

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So I re-tested compression and got 150 across the board! My next test to confirm the valve stems will be the down hill test where you just downshift and throttle to see if the white smoke occurs only under decel, if so valve stems are the culprit. If not im not sure where to go. WISH ME LUCK!
 

Cya

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I did the decel test and it does smoke, and it looked more so in the bluish/grey area today. The funny thing about this is that when I took out the plugs there was no oil on the plugs, they must not be too far gone yet. The head will come off ASAP.