Bad Rings or Valve Seals?
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Mountain Pass
Joined: Aug 2014
Posts: 144
Likes: 1
From: Front Range & Gunnison
Bad Rings or Valve Seals?
Morning folks. Still basking in the glow of my turning signal success. Now back to school.
Symptom; about 30 seconds after cold startup, my truck starts smoking like crazy. Thick, blue smoke. BUT, only from the right side exhaust. There is a small, almost undetectable amount of the same blue smoke from the left side. After about 3-4 minutes, the smoke stops.
Questions:
1) does this smoke, pattern, and timing indicate bad rings or bad valve seals? Or something else?
2) does the right side only smoke indicate something other than a bad....whatever on the right side, and not on the left?
3) could the answer to #1 be "both", possibly? Aside from having a compression test done, how could I tell if the rings need replacing (or a whole engine job)?
Thanks fellas,
Mac
Symptom; about 30 seconds after cold startup, my truck starts smoking like crazy. Thick, blue smoke. BUT, only from the right side exhaust. There is a small, almost undetectable amount of the same blue smoke from the left side. After about 3-4 minutes, the smoke stops.
Questions:
1) does this smoke, pattern, and timing indicate bad rings or bad valve seals? Or something else?
2) does the right side only smoke indicate something other than a bad....whatever on the right side, and not on the left?
3) could the answer to #1 be "both", possibly? Aside from having a compression test done, how could I tell if the rings need replacing (or a whole engine job)?
Thanks fellas,
Mac
Lead Driver
Joined: Jun 2006
Posts: 5,627
Likes: 957
From: Near Yosemite CA
Blue smoke on start up, = bad valve seals/guides, the oil used to lubricate them runs down and pools on the piston. Upon start-up, all that oil starts burning off. If it was smoking non-stop, then you would look towards rings, crankcase pressure pushing the oil up past the rings. If you coast down a hill, when you give it gas, do you see a puff or so of blue smoke? The vacuum is drawing the oil down the valve guides/seals.
You CAN change valve seals whilst the engine is still in the truck,,, did it once,,, better than pulling heads, or engine, but still a bit of a PITA.
You CAN change valve seals whilst the engine is still in the truck,,, did it once,,, better than pulling heads, or engine, but still a bit of a PITA.
Thread Starter
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Mountain Pass
Joined: Aug 2014
Posts: 144
Likes: 1
From: Front Range & Gunnison
Thanks for your help.
Another question; why just on one side? I mean I now know the cause, but why would one side be so much worse than the other?
Mac
Laughing Gas
Joined: May 2006
Posts: 1,140
Likes: 13
From: Port Orchard Wa
Hard to say. I have found valve guide seals in little bits floating around on top of the head (which can then plug oil channels). So anything is possible.
Postmaster
Joined: Oct 2010
Posts: 4,656
Likes: 4
From: Northern and Southern Cal
Before you do anything involved, pull the offending side valve cover and check the drain backs at the back of the head.
Is it clogged?
If so clean it real well, put your cover back on and see if you're still smoking.
Oil can pool way up in here and go down the guides very easily.
Good luck.
Is it clogged?
If so clean it real well, put your cover back on and see if you're still smoking.
Oil can pool way up in here and go down the guides very easily.
Good luck.
Lead Driver
Joined: Jun 2006
Posts: 5,627
Likes: 957
From: Near Yosemite CA
Good point Marc,,, I got busy after my facetious response
and forgot to come back with a serious response.
and forgot to come back with a serious response. Before you do anything involved, pull the offending side valve cover and check the drain backs at the back of the head.
Is it clogged?
If so clean it real well, put your cover back on and see if you're still smoking.
Oil can pool way up in here and go down the guides very easily.
Good luck.
Is it clogged?
If so clean it real well, put your cover back on and see if you're still smoking.
Oil can pool way up in here and go down the guides very easily.
Good luck.
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Thread Starter
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Mountain Pass
Joined: Aug 2014
Posts: 144
Likes: 1
From: Front Range & Gunnison
Mark,
Thanks. I'll take off the valve covers and look for a clog or if there's any noticeable difference between L and R.
One thing comes to mind; a couple months ago I noticed some oil dripping from what I thought was the valve cover. So I cranked both the L and R covers down tighter. It seems like the smoking got noticeably heavier on the right side after I did it.
I'll check and report back.
Love this forum.
Thanks. I'll take off the valve covers and look for a clog or if there's any noticeable difference between L and R.
One thing comes to mind; a couple months ago I noticed some oil dripping from what I thought was the valve cover. So I cranked both the L and R covers down tighter. It seems like the smoking got noticeably heavier on the right side after I did it.
I'll check and report back.
Love this forum.
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Thread Starter
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Mountain Pass
Joined: Aug 2014
Posts: 144
Likes: 1
From: Front Range & Gunnison
Did some more research and found the quote below from:
https://www.ford-trucks.com/forums/1...st-fouled.html
"I ran into this same type of thing ~20 years ago. Got a 71 F100 from a freind who was convinced the engine was toast. Smoked badly most of the time, and had a dead miss at idle. Perfectly clean on the outside. I just needed a truck, and was very low on funds, as my son was only 3 days old (be 20 in ~ 6 weeks).
I put dual exhaust on to replace the nearly rotted off stock single, and only the pass side smoked, and then only if the truck wasn't parked in a nose-down position.
Popped off the right hand valve cover, spilling ~1/2 qt of oil, and rodded out the drain hole. No more smoke. Ever.
The miss was just #6 exhaust valve burned.
Got another ~60K miles out of that 360 before selling the truck with 175K on the original 360 and C6 still running like new."
This is very encouraging, as the symptoms sound very similar to mine. Getting excited to tear into it....
https://www.ford-trucks.com/forums/1...st-fouled.html
"I ran into this same type of thing ~20 years ago. Got a 71 F100 from a freind who was convinced the engine was toast. Smoked badly most of the time, and had a dead miss at idle. Perfectly clean on the outside. I just needed a truck, and was very low on funds, as my son was only 3 days old (be 20 in ~ 6 weeks).
I put dual exhaust on to replace the nearly rotted off stock single, and only the pass side smoked, and then only if the truck wasn't parked in a nose-down position.
Popped off the right hand valve cover, spilling ~1/2 qt of oil, and rodded out the drain hole. No more smoke. Ever.
The miss was just #6 exhaust valve burned.
Got another ~60K miles out of that 360 before selling the truck with 175K on the original 360 and C6 still running like new."
This is very encouraging, as the symptoms sound very similar to mine. Getting excited to tear into it....
Thread Starter
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Mountain Pass
Joined: Aug 2014
Posts: 144
Likes: 1
From: Front Range & Gunnison
Before you do anything involved, pull the offending side valve cover and check the drain backs at the back of the head.
Is it clogged?
If so clean it real well, put your cover back on and see if you're still smoking.
Oil can pool way up in here and go down the guides very easily.
Good luck.
Is it clogged?
If so clean it real well, put your cover back on and see if you're still smoking.
Oil can pool way up in here and go down the guides very easily.
Good luck.
Front drain back
Rear drain back
Sorry for the poor image quality. It was a blind shot.
Any more suggestions before I begin valve seal replacement 101?
Fail or not, this is pretty fun.
And thanks as always.
Mac
Postmaster
Joined: Oct 2010
Posts: 4,656
Likes: 4
From: Northern and Southern Cal
Yeah those aren't bad at all.
Oil still pools pretty well in there. You may have a bad seal. Or any one of ten other things it could be.
The most important thing is you're having fun.
Oil still pools pretty well in there. You may have a bad seal. Or any one of ten other things it could be.
The most important thing is you're having fun.
Postmaster
Joined: Jan 2013
Posts: 3,512
Likes: 3
From: Panama City
If you have an air compressor you can buy an adapter(or build your own) to go in the spark plug hole. Hook compressed air to it and it will hold the valves up while you replace the valve stem seals. Not that big of a job really. Probably can borrow a tool from your parts store to depress springs. And as a bonus it will give you an indication of what kind of shape your rings and valve seats are.
Laughing Gas
Joined: May 2006
Posts: 1,140
Likes: 13
From: Port Orchard Wa
If you have an air compressor you can buy an adapter(or build your own) to go in the spark plug hole. Hook compressed air to it and it will hold the valves up while you replace the valve stem seals. Not that big of a job really. Probably can borrow a tool from your parts store to depress springs. And as a bonus it will give you an indication of what kind of shape your rings and valve seats are.
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