North American Turbocoupe Organization



blue smoke on decel
bang4thebuck Offline
Senior Member
#1
I dont know what its from but all of a sudden I get some blue smoke at deceleration! Its annoying and I dont think it is valve guides or seals. The car only now has 70000 miles on it so could it be pcv or something? If I hold it at 2500 for 10 seconds and let go it does it too. Im stumped so what could it be??
1987 TC 5 speed. To date: AGP 50 trim T3/T4 .63 stage 2 turbo, Ebay bov, 28psi, 255hp pump, Kirban FPR, Ebay Front mount, Full 3 inch Exhaust, Ported Bob's Log, Megasquirt, 55lb. injectors, boport 1.5 cam, boxed lower control arms, Methanol Kit, Ram HD Clutch, front lowered 1/2 inch and E.T. Streets for the track. Best so far 12.5 at 110.8. still tuning.
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Pete D Offline
Administrator
#2
See if there is oil in the bottom of the IC or in the TB. Also check how much oil in the VAM hose
Pete Dunham


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Jeff K Offline
Administrator
#3
Why do you think it isnt valve guides / seals? 70K miles and 16+ years is enough time / mileage to harden up valve seals and wear guides, especially if it was mistreaded by a former owner (too long between oil changes, etc).

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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 23 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 04 Taurus Duratec (wifes car)
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
11 Crown Vic Interceptor
14 Toyota Camry (wifes car)
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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PetzJC Offline
Senior Member
#4
"Typically" when driving, blue smoke during decel is an indication of worn rings. I would be surprised if the rings are worn with only 70k miles, unless the car was abused by a previous owner......

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88 Silver T/C, original owner, 261,800 miles.
Loaded with everything except leather & auto trans.
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched.
Spec-II/III combo clutch assembly.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16's.
Former owner of 88 Silver T/C, loaded (except leather & A/T), original owner, 294,815 miles!!!
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched, spec-II/III clutch combo.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16
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Pete D Offline
Administrator
#5
I agree with John on the decel smoking being possibile bad ring(s). It's always possible that an oil control ring was defective, or got tweaked during installation (real rare)
Pete Dunham


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PetzJC Offline
Senior Member
#6
Also, if it were bad valve guides/seals, you most likey would see a puff of blue smoke at startup (especially after sitting overnite).

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88 Silver T/C, original owner, 261,800 miles.
Loaded with everything except leather & auto trans.
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched.
Spec-II/III combo clutch assembly.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16's.
Former owner of 88 Silver T/C, loaded (except leather & A/T), original owner, 294,815 miles!!!
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched, spec-II/III clutch combo.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16
Reply

martin0660 Offline
Posting Freak
#7
I just went through the smoke on decel thing, and it was bad valve seals for the most part. The seal on #3 Exhaust was off the guide. I replaced them all, and it is much better. There is still a little if I really use a lower gear to hold the car back, but it isnt anywhere near as bad as it was.

I suspect I have a worn guide on the valve to make the seal pop off. I will know more in November when I park the car, or sooner if I pop a head gasket first [Image: biggrin.gif]

Bob Myers

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My 88 Thunderbird TC Pictures, Updated 5-8 with a few drag pics
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PetzJC Offline
Senior Member
#8
Valve guide seal is an easy (and inexpensive) replacement. Try that first, especially if you suspect the seals are original. I believe valve seal replacement is covered either under a Tech Article or in FAQ.

------------------
88 Silver T/C, original owner, 261,800 miles.
Loaded with everything except leather & auto trans.
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched.
Spec-II/III combo clutch assembly.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16's.
Former owner of 88 Silver T/C, loaded (except leather & A/T), original owner, 294,815 miles!!!
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched, spec-II/III clutch combo.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16
Reply

bang4thebuck Offline
Senior Member
#9
I hope its something stupid! It never does it on startup or when flooring it. ONLY when decelerating. Thats why I am brainstorming. Maybe a seal did pop off a little or something like martin0660 said. Oh yea the prob comes and goes too sometimes it will and sometimes it wont! It just started recently so I guess im going to check the pcv system and look at the valve seals while replacing the valve cover gasket!

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88 TC, 67k miles, T-3 super 60 .63exh., 3"downpipe, Bobs log, 255hp pump, kirban FPR (48psi), 2&1/2 exhaust, gillis 20psi, HKS filter, Dawes a/f meter, big tci trans cooler, supra intercooler, Automatic, 75 shot. Future mods: Got an alcohol injection kit to put on, maybe some porting!
1987 TC 5 speed. To date: AGP 50 trim T3/T4 .63 stage 2 turbo, Ebay bov, 28psi, 255hp pump, Kirban FPR, Ebay Front mount, Full 3 inch Exhaust, Ported Bob's Log, Megasquirt, 55lb. injectors, boport 1.5 cam, boxed lower control arms, Methanol Kit, Ram HD Clutch, front lowered 1/2 inch and E.T. Streets for the track. Best so far 12.5 at 110.8. still tuning.
Reply

bang4thebuck Offline
Senior Member
#10
replaced the pcv and it still does it! I guess its time to think about looking at spark plugs and then valve seals!!! I hope thats it! How common is it for the valve seal to pop off the guide a lil? also how common is it for the exhaust seal in a new turbo to go out and leak oil into the exhaust?? could it be my breather? should I just put a regular breather on it?? villager check valve for pcv??? anyone??
1987 TC 5 speed. To date: AGP 50 trim T3/T4 .63 stage 2 turbo, Ebay bov, 28psi, 255hp pump, Kirban FPR, Ebay Front mount, Full 3 inch Exhaust, Ported Bob's Log, Megasquirt, 55lb. injectors, boport 1.5 cam, boxed lower control arms, Methanol Kit, Ram HD Clutch, front lowered 1/2 inch and E.T. Streets for the track. Best so far 12.5 at 110.8. still tuning.
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