Bad valve seals
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Bad valve seals
Here are some of my symptoms I had that required me to change my valve seals after I spent too much time and money on other things but hopefully this will save someone else alot of aggravation and wasted money.
Car in question: 1997 A4Q 2.8L 12v, 273,000KMS, 5spd
Symptoms: 1)White/gray smoke from exhaust when idling at stop sign (only when oil temp above 70*C)-Sometimes-
2)When exhaust is smoking, revving engine up created more grayish/white smoke BUT as revs dropped towards idle a puff of blue smoke followed
3)Strong "rich" smelling exhaust fumes all the time (before smoking) and of course oil burning smell when oil temp reached 70*C or above when "blipping throttle"
What symptoms I DID NOT HAVE: 1)Plugs fouling/ oily deposits
2)Rough idle 3)poor fuel mileage 4)blue smoke "at first start up" 5)Blue smoke during driving or accelerating at high rpm
At first the white/gray smoke led myself to believe a bad headgasket (but no coolant loss) or a ruptured oil cooler dumping coolant into the oil (again no coolant loss).
High RPM 4000-6000RPM produced NO smoke but from a set of lights the smoke cloud was large enough to hide a SUV.
So when the oil is hot (thinning) and the engine is at it's high points of vaccuum (idling/ decel) oil was leaking by the exhaust and intake valve stems...
-Intake valve stems leaking gave me a small dark spot on each spark plug electrode only on one side
-Exhaust valve stems leaking produced the white/gray smoke at idle
Combine both and I got a nice smoke show at every stop light.
Oil will burn WHITE, it will burn GRAY, and it will burn BLUE it just depends on HOW HOT it is burning!
The following seems to be a common response to "rings or seals?" I gathered.
Rings= smoke DURING acceleration especially high rpm (usually starts with ONE cylinder/plug becoming fouled and oily)
Seals= smoke During extended idling NOT when driving (all cylinders/ plugs look the same) and the infamous gray/blue cloud "puff"
Of course always TEST everything first that you can (leakdown, compression, etc) but unfortuneately there is no test for failed seals except raised emissions and embarrassing smoke and failed oil control rings will still yield great compression numbers.
Car in question: 1997 A4Q 2.8L 12v, 273,000KMS, 5spd
Symptoms: 1)White/gray smoke from exhaust when idling at stop sign (only when oil temp above 70*C)-Sometimes-
2)When exhaust is smoking, revving engine up created more grayish/white smoke BUT as revs dropped towards idle a puff of blue smoke followed
3)Strong "rich" smelling exhaust fumes all the time (before smoking) and of course oil burning smell when oil temp reached 70*C or above when "blipping throttle"
What symptoms I DID NOT HAVE: 1)Plugs fouling/ oily deposits
2)Rough idle 3)poor fuel mileage 4)blue smoke "at first start up" 5)Blue smoke during driving or accelerating at high rpm
At first the white/gray smoke led myself to believe a bad headgasket (but no coolant loss) or a ruptured oil cooler dumping coolant into the oil (again no coolant loss).
High RPM 4000-6000RPM produced NO smoke but from a set of lights the smoke cloud was large enough to hide a SUV.
So when the oil is hot (thinning) and the engine is at it's high points of vaccuum (idling/ decel) oil was leaking by the exhaust and intake valve stems...
-Intake valve stems leaking gave me a small dark spot on each spark plug electrode only on one side
-Exhaust valve stems leaking produced the white/gray smoke at idle
Combine both and I got a nice smoke show at every stop light.
Oil will burn WHITE, it will burn GRAY, and it will burn BLUE it just depends on HOW HOT it is burning!
The following seems to be a common response to "rings or seals?" I gathered.
Rings= smoke DURING acceleration especially high rpm (usually starts with ONE cylinder/plug becoming fouled and oily)
Seals= smoke During extended idling NOT when driving (all cylinders/ plugs look the same) and the infamous gray/blue cloud "puff"
Of course always TEST everything first that you can (leakdown, compression, etc) but unfortuneately there is no test for failed seals except raised emissions and embarrassing smoke and failed oil control rings will still yield great compression numbers.
#3
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I also checked my guide to stem clearance and all was well, the seals were obviously bad (they felt like they were made of wood and the inner diameter was quite larger than the new ones)
On a "side note" I purchased this car 2 years ago, it had a "Canadian Tire OIL Reminder" sticker in the windshield plus the engine had a top end tick......after I changed the oil a few times with Castrol Syntec 5-40 the valve covers leaked like crazy and then the smoke from the exhaust soon followed.....I guess the Castrol actually cleaned away alot of my sludge and the tick is gone!
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Valve Stem Seal Procedure?
Hi there and thanks for the good information.
I was wondering though, how did you do the valve stem seals? I have been poking around the site and can't seem to find a posted procedure to follow for some insight.
I have read conflicting information about if you can replace them without removing the heads. My old SOHC 22r toyota could ... but these heads look a lot tighter for clearance. Or maybe not?
I was wondering though, how did you do the valve stem seals? I have been poking around the site and can't seem to find a posted procedure to follow for some insight.
I have read conflicting information about if you can replace them without removing the heads. My old SOHC 22r toyota could ... but these heads look a lot tighter for clearance. Or maybe not?
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I too would like to know how you performed the seal replacement. The Bentley's manual procedure uses a host of specialty tools to compress the springs, pull the oil seal and put pressure in the cylinder. Also, the guide to stem clearance, according to Bentley's, is measured with the head off. Of course, Bentley's isn't necessarily always right.
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Hi there and thanks for the good information.
I was wondering though, how did you do the valve stem seals? I have been poking around the site and can't seem to find a posted procedure to follow for some insight.
I have read conflicting information about if you can replace them without removing the heads. My old SOHC 22r toyota could ... but these heads look a lot tighter for clearance. Or maybe not?
I was wondering though, how did you do the valve stem seals? I have been poking around the site and can't seem to find a posted procedure to follow for some insight.
I have read conflicting information about if you can replace them without removing the heads. My old SOHC 22r toyota could ... but these heads look a lot tighter for clearance. Or maybe not?
They are easily done with the heads remaining on the engine and the only "specialty" tool you'll need is a valve spring compressor designed to compress the springs of the valves with the heads on the car and an air compressor with a fitting to thread in the spark plug hole. I actually made my valve spring compressor with some scraps laying around my shed, as well as the spark plug fitting. Other than that it's a matter of removing your valve covers and camshafts, turn the engine over by hand until the cylinder you are working on is EXACTLY at TDC, having your air compressor on and set to "auto" and the fitting threaded in. Supply 60 to 100 PSI in the cylinder, once again make sure the cylinder is at TDC and the compressor is set to automatically keep pressure supplied (dropping valves sucks). Then it's a matter of compressing the springs, remove the springs(do one valve at a time) use some needle nose pliers to pull off the old seal and then install the new seals (I used some "assembly grease" lithium grease on the valve stem and seal and very gently pushed the seal over the "keeper" grooves and finished with a 10mm deep socket to push the seal onto the guide snug). That's pretty well it, wash-rinse-repeat. I might take some flak from someone so you might want to make or purchase a plastic seal installer that covers the keeper grooves (get a 7mm) this ensures you don't damage the new seal from the grooves, but for me-adequate lubrication works .
Have fun, the keepers are a pain too, might want a small magnet pick up, needle nose pliers, lithium grease, small slotted screw driver etc...oh, LOTS of PATIENCE!.......another tip is put a rag over or in the oil returns so you don't drop a keeper down to the oil pan!! Triple check everything basically and because your cams were out hopefully you marked everything well and made a timing bar to lock your cams to set your timing......again, I built mine with a piece of 1/2" EMT and some threaded rod...presto! If you want pics of the tools, I'll put some up if you want design ideas to diy.
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They are easily done with the heads remaining on the engine and the only "specialty" tool you'll need is a valve spring compressor designed to compress the springs of the valves with the heads on the car and an air compressor with a fitting to thread in the spark plug hole. I actually made my valve spring compressor with some scraps laying around my shed, as well as the spark plug fitting. Other than that it's a matter of removing your valve covers and camshafts, turn the engine over by hand until the cylinder you are working on is EXACTLY at TDC, having your air compressor on and set to "auto" and the fitting threaded in. Supply 60 to 100 PSI in the cylinder, once again make sure the cylinder is at TDC and the compressor is set to automatically keep pressure supplied (dropping valves sucks). Then it's a matter of compressing the springs, remove the springs(do one valve at a time) use some needle nose pliers to pull off the old seal and then install the new seals (I used some "assembly grease" lithium grease on the valve stem and seal and very gently pushed the seal over the "keeper" grooves and finished with a 10mm deep socket to push the seal onto the guide snug). That's pretty well it, wash-rinse-repeat. I might take some flak from someone so you might want to make or purchase a plastic seal installer that covers the keeper grooves (get a 7mm) this ensures you don't damage the new seal from the grooves, but for me-adequate lubrication works .
Have fun, the keepers are a pain too, might want a small magnet pick up, needle nose pliers, lithium grease, small slotted screw driver etc...oh, LOTS of PATIENCE!.......another tip is put a rag over or in the oil returns so you don't drop a keeper down to the oil pan!! Triple check everything basically and because your cams were out hopefully you marked everything well and made a timing bar to lock your cams to set your timing......again, I built mine with a piece of 1/2" EMT and some threaded rod...presto! If you want pics of the tools, I'll put some up if you want design ideas to diy.
Have fun, the keepers are a pain too, might want a small magnet pick up, needle nose pliers, lithium grease, small slotted screw driver etc...oh, LOTS of PATIENCE!.......another tip is put a rag over or in the oil returns so you don't drop a keeper down to the oil pan!! Triple check everything basically and because your cams were out hopefully you marked everything well and made a timing bar to lock your cams to set your timing......again, I built mine with a piece of 1/2" EMT and some threaded rod...presto! If you want pics of the tools, I'll put some up if you want design ideas to diy.
Thanks!
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