I understand the source of piston ring deposits. What typically causes cylinder wall scoring?
Honda K24 Valvetrain, 135K miles
- Thread starter The Critic
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I understand the source of piston ring deposits. What typically causes cylinder wall scoring?
Our '06 TSX has 230K on the clock. I don't bother to check the level between services. We gave the car to a friend last year but I still service it.
Stuck rings, certain operating conditions.
Mine ran great on M1 0/40 for 350k miles. Changed every 5k miles. 2012 Accord 5sp manual. Original clutch
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This was my 2010 K24 at 180K miles.
3qts/5k consumption. Burned exhaust valve due to carbon.
I was at the point of just dumping in whatever oil and changing the filter every 6 months.
Ironically, a new valve and valve guide seals stopped the oil consumption. Was down to ½qt/5k OCI. Drove it for another 2 years (26k miles).
Then this happened.... Several of us here know the feeling.........
3qts/5k consumption. Burned exhaust valve due to carbon.
I was at the point of just dumping in whatever oil and changing the filter every 6 months.
Ironically, a new valve and valve guide seals stopped the oil consumption. Was down to ½qt/5k OCI. Drove it for another 2 years (26k miles).
Then this happened.... Several of us here know the feeling.........
When you say it burned the exhaust valve "due to carbon", how do you know? Couldn't it have been due to a too-tight valve clearance? Did you do any valve clearance adjustments prior to this event?
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Yes, valves were adjusted at 75k and again at 150k. This thing would carbon foul the plug in cyl 2 every 30k miles. Hard carbon on electrode.
Here is a pic of the carbon which held the valve open.
It was like a piece of weld spatter on the seat.
Was that car yours the whole time? No offense intended, but it looks like that car was rode hard and put away wet, explaining the rust and maybe the valve situation.
I strongly suspect that on these newer (ish) Hondas--and perhaps other engines- a clean overhead tells you nothing about the parts of the engine that are most at risk.
Think back to that teardown video of the K20C4 accord turbo engine that was immaculately clean at 92K miles everywhere-- except the one place that it mattered: the ring pack. Stuck oil ring, high oil consumption, engine was scrapped. And in the process, all that cleanliness and low wear elsewhere in the engine was for naught.
What good is it to have little to no cam wear if your guzzling oil due to a stuck ring?
This is in my mind as I consider the relative value of oils which are known to run very clean. I'm thinking that cleanliness and deposit prevention and removal is arguably now the single most consequential discriminator between oils. Lots of oils can lubricate sufficiently. They can all prevent corrosion very well and all will cool the engine about equally effectively. We've seen engines deliver great UOAs on 20 grade, 30 grade and 40 grade. Even viscosity isn't much of a discriminator in determining engine life.
But the ability to prevent and remove deposits is quite starkly different between oils, and I think we should be placing more emphasis on these attributes (and related ones like volatility) than most other attributes-- perhaps even something like viscosity.
Think back to that teardown video of the K20C4 accord turbo engine that was immaculately clean at 92K miles everywhere-- except the one place that it mattered: the ring pack. Stuck oil ring, high oil consumption, engine was scrapped. And in the process, all that cleanliness and low wear elsewhere in the engine was for naught.
What good is it to have little to no cam wear if your guzzling oil due to a stuck ring?
This is in my mind as I consider the relative value of oils which are known to run very clean. I'm thinking that cleanliness and deposit prevention and removal is arguably now the single most consequential discriminator between oils. Lots of oils can lubricate sufficiently. They can all prevent corrosion very well and all will cool the engine about equally effectively. We've seen engines deliver great UOAs on 20 grade, 30 grade and 40 grade. Even viscosity isn't much of a discriminator in determining engine life.
But the ability to prevent and remove deposits is quite starkly different between oils, and I think we should be placing more emphasis on these attributes (and related ones like volatility) than most other attributes-- perhaps even something like viscosity.
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BrendanC
$100 site donor 2024
how bad is pulling the head off of a K24? never done it but i’m fairly certain my 400k mile K24 has bad valve seals and it burns quite a large amount of oil. i’m invested in running it until it blows but i want to replace the valve seals.
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Depends on your mechanical knowledge. Mine was in a CR-V. No special tools needed and I did it in my garage with a floor jack. Best part was the integral exhaust manifold so all 4 studs came right out! The head bolts are reusable, and I used FelPro top end gasket set. Only needed the V-TEC actuator seals from the dealer.
The timing cover is just on with RTV and my favorite is Permatex ultra Black. My timing chain was at about 70% stretch, and I just put it back in. It was a budget repair, due to tye rust underneath. Planned on selling it soon, but ended up being recalled and Honda bought it back. So it was a big win.
BrendanC
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former diesel mechanic, now engineer and part time fleet mechanic.
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You'll be good! I worked professionally on vehicles (independent garage) for a decade, but that was 15 years ago.
Good write up thanks! Looks like you got your money’s worth! Good job on the garage repair.
BrendanC
$100 site donor 2024
i was debating on not pulling the front cover. is it possible to pull the sprockets off the cams in place?
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We bought it at 60k and 5 years old. It was well taken care of and the interior looked like new when it fell apart. I live in northern Maine where we have 6 months of snow and salt. Vehicles rust away here.
Does that valve train look bad to you for 175k miles?
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No, you must remove timing chain, tensioner etc.
I'm not accusing, just asking. Does using 3 qts every 5k miles cause piston deposits like that? The tops of those pistons are ugly.
Since we're showing other K24s, mine at 200K when I last adjusted the valves. A lifetime of Castrol Black Bottle 5W-30 then "German Castrol" 0W-30 for the last 100K miles. It has 262K on it now.
Scott
That’s what happens when you never do a valve adjustment
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It consumed a lot of oil. Honestly, the dealer told me it was a piston/ring issue and many CR-Vs etc were affected by oil consumption. Honda recalled the excessive ones up to 125k miles and more than a qt in 800 mile consumption. Ours was at a qt in 1000 miles at 125k. It went up dramatically after that.
Due to its age, i just kept dumping oil in it and didn't want to pull it all apart to re-ring and possible piston replacement. Until this happened.
The Pic was before I cleaned everything up. Keep in mind I put 1 (used) exhaust valve in it, and replaced valve guide seals as they came with the FelPro kit I bought. Oil consumption went to well under 1qt/5000 miles after that. I never touched the bottom end, other than cleaning the piston tops.
Due to its age, i just kept dumping oil in it and didn't want to pull it all apart to re-ring and possible piston replacement. Until this happened.
The Pic was before I cleaned everything up. Keep in mind I put 1 (used) exhaust valve in it, and replaced valve guide seals as they came with the FelPro kit I bought. Oil consumption went to well under 1qt/5000 miles after that. I never touched the bottom end, other than cleaning the piston tops.
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