exhaust smoke after new head gaskets
March 2nd, 2011, 11:14 PM
#1
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Location: Santa Fe, NM
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exhaust smoke after new head gaskets
Hello, I recently bought a 1968 442 (w/orig drivetrain). It had not gone very many miles for several (5+) years though it had been started and driven a few miles a couple of times a month. I changed the oil when I bought it in Oct. I've been driving it about 200 miles a week since then with zero oil loss until...
A couple of weeks ago, I changed the oil and 2 days later the right head gasket blew (the left didn't look much better) so I replaced them both (also adjusted timing and leaned out the carb for high altitude). After a 150 mile trip I noticed some "ticking" (valves?) and checked the oil only to find that the shop left the oil cap off (or so loose it fell off) and oil was all over the engine compartment and I was 2 qts. low. Replaced the cap, topped off the oil, cleaned the engine compartment and air cleaner, and changed the air filter. Now when I get up to about 75 mph I smell oil and see white smoke out of the pass side tailpipe. No smoke or smell at low speed. Any thoughts?
Bill in Santa Fe
A couple of weeks ago, I changed the oil and 2 days later the right head gasket blew (the left didn't look much better) so I replaced them both (also adjusted timing and leaned out the carb for high altitude). After a 150 mile trip I noticed some "ticking" (valves?) and checked the oil only to find that the shop left the oil cap off (or so loose it fell off) and oil was all over the engine compartment and I was 2 qts. low. Replaced the cap, topped off the oil, cleaned the engine compartment and air cleaner, and changed the air filter. Now when I get up to about 75 mph I smell oil and see white smoke out of the pass side tailpipe. No smoke or smell at low speed. Any thoughts?
Bill in Santa Fe
Last edited by dr.chaos; March 3rd, 2011 at 09:28 AM.
March 3rd, 2011, 03:13 AM
#3
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Location: The Hudson Valley
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Agreed.
White smoke = Water.
Should smell sweet, like antifreeze.
Look for bubbling in radiator, coffee foaming on dipstick, and pressure test radiator.
Are the exhaust pipes separate or crossed over?
Could easily be a head gasket.
How did the head gaskets "blow" last time?
Head gaskets that won't stay intact usually means a head (or a deck surface) isn't flat.
Oil smell could just be residual oil burning off after the mess.
- Eric
White smoke = Water.
Should smell sweet, like antifreeze.
Look for bubbling in radiator, coffee foaming on dipstick, and pressure test radiator.
Are the exhaust pipes separate or crossed over?
Could easily be a head gasket.
How did the head gaskets "blow" last time?
Head gaskets that won't stay intact usually means a head (or a deck surface) isn't flat.
Oil smell could just be residual oil burning off after the mess.
- Eric
March 3rd, 2011, 05:26 AM
#4
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Location: South Portland Maine
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x2 on Eric & Yellow Statue,
Having just replaced my head gaskets, I have limited, but very recent knowledge on this.
No smoke @ low rpm, smoke & oil smell @ higher RPM leads me to think oil is getting past the rings. Is the smoke white, or more of a bluish color? How many miles on it?
Are you doing the work yourself, or having a shop do it? I once had a quick lube oil change on my dd where they left the oil cap off with similar results, thankfully I hadn't driven more than about 15-20 miles, and had an oil pressure gauge in the truck. I noticed the pressure was way too low, turned around and headed back to the shop. Thankfully no damage was done.
Having just replaced my head gaskets, I have limited, but very recent knowledge on this.
No smoke @ low rpm, smoke & oil smell @ higher RPM leads me to think oil is getting past the rings. Is the smoke white, or more of a bluish color? How many miles on it?
Are you doing the work yourself, or having a shop do it? I once had a quick lube oil change on my dd where they left the oil cap off with similar results, thankfully I hadn't driven more than about 15-20 miles, and had an oil pressure gauge in the truck. I noticed the pressure was way too low, turned around and headed back to the shop. Thankfully no damage was done.
March 3rd, 2011, 05:35 AM
#5
This may not be your problem but I had a 66 Dynamic, at high speed, above 70MPH, trans fluid would come up and out of dipstick tube and end up on exhaust manifold. Lots of blue and white smoke from the rear of the car. Did not do it at lower sppeds so I never went over 70 and all was well.
March 3rd, 2011, 05:47 AM
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Location: Dover, Ohio
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This may not be your problem but I had a 66 Dynamic, at high speed, above 70MPH, trans fluid would come up and out of dipstick tube and end up on exhaust manifold. Lots of blue and white smoke from the rear of the car. Did not do it at lower sppeds so I never went over 70 and all was well.
P.S. - Installed my new dual stainless fuel lines and new tank sending unit yesterday!
It wasnt nearly as hard as I thought it would be! I thought it would be a real "bear" to get those lines over the rear and upper brace and through the front frame all in one piece without having to bend the crap out of em. Took quit a bit of "bowing" but the stainless is rigid enough to bow a lot without bending!! Thanks God! I seriously doubt that i could have done it without the car being on the lift. Theres no way I could have gotten it from the height of a floor jack!
March 3rd, 2011, 07:04 AM
#7
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As far as the oil smell, is the PCV working correctly, also check the breather from the left valve cover to the air filter housing. I've experienced blowby causing the smell issue. The white smoke like the others mentioned could be caused by the above concerns and possibly a rich condition in your carb.
March 3rd, 2011, 09:56 AM
#9
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Location: Santa Fe, NM
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Definitely smells like oil, not coolant. Also, last night I didn't know my left from right... the blown head gasket was on the right side. The dual exhaust is separate and the smoke is on the right side.
After picking up the car from the shop that did the gasket work, I drove from Santa Fe to Albuquerque (1hr at 75mph). I kept it under 85 the whole way but was at or near the speed limit even on some decent hills. No smoke. Drove back to Santa Fe that night and noticed what sounded like some valve noise on the hills. Checked oil and found cap missing. Next morning, after replacing cap and topping off the oil, the right side would smoke at 75 mph...a lot!. So I changed the air filter and cleaned the air cleaner and now it smokes a little less. Then I cleaned the engine compartment and it smokes about the same and only at 75mph (a common speed limit around here) and above. I've gone about 400 miles since the gaskets were changed.
Before the gasket brew, the carb was a little rich (moved to high altitude) and the timing was a little off and it would ping on hills. The previous owner stated that the timing was "perfect" and that the distributor should be recurved to run on premium gas. He was running aviation gas which kept it from knocking. I had been using premium with Lucas Octane boost until the gasket blew and I had the timing and carb adjusted. The mechanic said the timing had been adjusted for "maximum vacuum" and it runs much better since he reset it... except the smoke.
Could the rings/cylinder have been damaged by the blown gasket causing blow-by? Or a damaged valve guide, perhaps? What's the diagnostic here?
Bill
After picking up the car from the shop that did the gasket work, I drove from Santa Fe to Albuquerque (1hr at 75mph). I kept it under 85 the whole way but was at or near the speed limit even on some decent hills. No smoke. Drove back to Santa Fe that night and noticed what sounded like some valve noise on the hills. Checked oil and found cap missing. Next morning, after replacing cap and topping off the oil, the right side would smoke at 75 mph...a lot!. So I changed the air filter and cleaned the air cleaner and now it smokes a little less. Then I cleaned the engine compartment and it smokes about the same and only at 75mph (a common speed limit around here) and above. I've gone about 400 miles since the gaskets were changed.
Before the gasket brew, the carb was a little rich (moved to high altitude) and the timing was a little off and it would ping on hills. The previous owner stated that the timing was "perfect" and that the distributor should be recurved to run on premium gas. He was running aviation gas which kept it from knocking. I had been using premium with Lucas Octane boost until the gasket blew and I had the timing and carb adjusted. The mechanic said the timing had been adjusted for "maximum vacuum" and it runs much better since he reset it... except the smoke.
Could the rings/cylinder have been damaged by the blown gasket causing blow-by? Or a damaged valve guide, perhaps? What's the diagnostic here?
Bill
March 3rd, 2011, 04:13 PM
#10
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How many miles are on this motor? Did they rejet the carb or just set the idle mixture. Is the choke opening up fully when it warms up? Does it have points or electronic dist? What are the timing and dwell set at and is the vacuum advance working properly. You possibly have multiple issues!! I would insure my tuneup settings are correct first. Even a poorly tuned engine can seem to run fine.
I would enure my PVC valve was in good working order, and the breather on the left side is clear and /or make sure it is connected to the air cleaner assy properly.
I would look for loss of coolant level and foaming in the radiator. And I would note the loss of any oil between changes and note how much actually leaks around the engine (valve covers, pan, etc...)
Then I perform a compression check first 1,3,5,7-2,4,6,8 dry and note the readings, and then squirt some motor oil into each cylinder and repeat the sequence and note the readings. All readings should be a bout the same dry and all readings about the same wet. If there is a dramatic drop from 1 cylinder to an ajoining or the other's in the same bank dry, it could mean a head gasket issue, burnt valve, or valve guide and/or seal issue. If the compression numbers go way up wet then it probably a ring issue.
Good luck!
I would enure my PVC valve was in good working order, and the breather on the left side is clear and /or make sure it is connected to the air cleaner assy properly.
I would look for loss of coolant level and foaming in the radiator. And I would note the loss of any oil between changes and note how much actually leaks around the engine (valve covers, pan, etc...)
Then I perform a compression check first 1,3,5,7-2,4,6,8 dry and note the readings, and then squirt some motor oil into each cylinder and repeat the sequence and note the readings. All readings should be a bout the same dry and all readings about the same wet. If there is a dramatic drop from 1 cylinder to an ajoining or the other's in the same bank dry, it could mean a head gasket issue, burnt valve, or valve guide and/or seal issue. If the compression numbers go way up wet then it probably a ring issue.
Good luck!
Last edited by oldcutlass; March 3rd, 2011 at 04:15 PM.
March 3rd, 2011, 04:25 PM
#11
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Motor was rebuilt about 5-6 years ago and only about 10k miles (half in the last 5 months) since. Carb was rejetted. Choke opens up fully when you give a little pump on the throttle. Electronic ignition (not sure the timing settings). The shop tuned it up after the rejet (post head gasket repair). Breather on left is clear and properly attached. Too soon to tell on the fluid levels issue. I'm keeping an eye on it.
Thanks for the info!
Thanks for the info!
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