Hey guys, I've been doing some research on the symptoms of a cracked valve seal VS a bad piston ring. At this point, I'm still not 100% sure what the problem is.

To start off, I have an n/a 01' with 144k. Intake, header, exhuast, test pipe.

Symptoms include: Excessive amounts of smoke at WOT. Smells like oil/burning smell at stop lights. Definitely consuming alot of oil. I have not yet directly defined how much oil per 1k miles, but I estimate 1qt every 800-1k miles. I use Royal Purple 10-30w.

I do not see any smoke at a cold start up.
Sometimes, I see a puff of smoke at a downshift.
I do not see any smoke while decelerating.

I just did a compression test today and the numbers were 210 across the board.
Spark plugs #1 and #2 were squeaky clean, #3 and #4 were dirty inside of the pin.
I can definitely say cylinder 4 is burning/consuming more oil compared to the others. Is this because its the last cylinder to receive air thru the intake? #1 cylinder would receive the most air, being closest to the intake, therefore #4 would not get as much air? Is theory true?

My question to you is, what is the next step? Should I open the head and check the valve seals? Is there another way to pin-point my problem?

Thank you,

 

Symptoms sounds like valve seals fella. IT WONT SMOKE ON COLD, BUT WHEN WARMED UP ON TAKE OF IT WILL THROUGH A PUFF OF SMOKE.

If your compression is showing 210 it wont be you piston rings for sure all so piston rings let out blue smoke from a mixture of fuel and oil.

COMPRESSION TEST
WARM THE ENGINE
TAKE THE COIL PLUG OR FUSE OUT THE FUEL PUMP FUSE OUT
MAKE SURE BATTERY IS GOOD
THROTTLE ALL THE WAY DOWN
AND TURN ENGINE TILL THE NEEDLE STOPS ON THE COMPRESSION TESTER
RELEASE THE PRESSURE ON THE GAUGE BEFORE TESTING THE NEXT CYLINDER
BEST TO GO OVER IT TWICE

BUT YOUR COMPRESSION SEEMS GOOD

 

+1. Rings would show low compression on the problem cylinder(s). Your compression, while a little low, is consistent across the board, which is what really matters.

Valve oil seals on the other hand, won't affect compression. Valve seats would show up on compression test, but not valve seals. But valve seats by themsleves wouldn't cause oil consumption (though evenually they would wear out seals and that would cause oil consumption).

You can replace valve seals without removing head (involves using compressed air to hold valves in place).

Sent from my SM-G920P using IB AutoGroup

 

Thank you for your replies,

Car analogy, I thought valve seats is another term for valve seals?
I plan on doing a leakdown test this week to see if anything comes up.

I've been thinking about switching to a part synthetic 10-40 oil to see if my oil consumption decreases.

Already bought new valve seals and retainers, going to have my mechanic replace them hopefully sooner than later.

 

Valve seal seals out oil from getting into combustion chamber and consuming oil. They seal against the valve stem, in the area where valve springs reside, under the valve cover.

Valve seats are where the valve seals the cumbustion chamber. They seal the intake and exhaust, so combustion can take place in a sealed chamber. The cone shaped backside of the valves big end seals to the matching shape of the cylinder head. This is the valve seat.

Valve seat issues will affect Compression, but not directly cause oil consumption.

Valve seal issues will not affect Compression, but will cause oil consumption.

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Yes Change those! also I would DEFINATELY do a catch can and switch to Castrol Edge titanium. its proven to many owners to not use barely any of that stuff.

 

I wonder if tight valves that don't seat all the way could cause problems to the valve stem seals by allowing combustion gasses to get into the head?

 

I would assume so. But at that point you have a burned valve and you should replace the stem seal anyways when redoing your valves.

 

only a bad compression ring would show on a compression test. a bad oil control ring would not show on a compression test. so oil can get around your rings and you can still pass a compression test.

 

I think I'm definitely past due on a valve adjustment, I can hear the valves ticking, (not my tct); is it possible that a valve is so tight that it can break a seal?

I pray that it's not a piston ring or an oil ring.
I plan on switching to a half syn 10-40 as a temporary bandaid until I can get my mechanic to replace my retainers and valve seals.
Should I go ahead and replace the valve guides as well since I'm right there anyways?

Thanks guys