Moparbustet
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My 69 rr smokes on hard deceleration any idea what it could be motor runs great
Smoking bird
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Smokes the whole time you are on the throttle? If so I would say rings....
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Tire smoke is good.
Moparbustet
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Lots of tire smoke but smokes out exhaust after turning her up to bout 5500 rpms only on decel
Wietse
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Normally with deceleration the vacuum inside the combustion chamber (due to throttle is closed) can pull excessive oil and fumes in from the crankcase past the piston rings if they are worn out.
Think that another option could be valve stem seals as well.
Could try and do a pressure test on all cylinders to see what you get.
Think that another option could be valve stem seals as well.
Could try and do a pressure test on all cylinders to see what you get.
BB BELLA
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decel i'd put my money on valve seals / guides!
Big Bad Dad
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valve stem seals
alfaitalia
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Blue smoke under power?...rings/bore wear....Blue smoke under hard deceleration or when blipping the throttle after a couple of minutes idling? .......usually accompanied by a big puff of blue smoke on the first cold start of the day?.....valve stem oil seals.
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Do a compression test and if the numbers are somewhat low, squirt some oil into the cylinder and test it again. If the numbers rise, your rings could be the problem....
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Valve seals, or you have an unshielded PCV valve installation and are sucking oil on decel like all the '18 F150 x 5.0's!
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If you get a cloud of smoke when you fire it up in the morning, valve seals. If it's ONLY on deceleration, I'd go with rings.
Wietse
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Personally i don't think there will be sufficient oil being pulled through the valve stem seals, how much can be there? Just a drop here or there, it's not that they are submerged in oil and pull a lot through.
Compression test is easy to determine what the condition is of the rings.
Compression test is easy to determine what the condition is of the rings.
alfaitalia
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You would be surprised.....my old V6 Capri used to give a huge ball of blue smoke after deceleration or idling and on a cold start. Most of the stem seals had split due to age hardening. New set cured the smoking completely.
PRHeads
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If the motor is mostly stock(or an older stock type rebuild), 1/2 the valve seals are probably in the pan.
Having to replace valve seals on high mileage engines was pretty commonplace in the 60’s, 70’s, 80’s.
Having to replace valve seals on high mileage engines was pretty commonplace in the 60’s, 70’s, 80’s.
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