Honda K20 engine - 100k mile, check valve clearanc

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My maintenance minder just came on with B14. 4 is to change spark plugs and inspect valve clearance. I was wondering if K20 DOHC is what some call, shim-over-bucket design? I also heard that it is harder to adjust these engines compared to the screw type, however shim-over-bucket design keeps specs longer and thus probably require no adjustment at all? I am just debating if I should even spend the money to have a shop open it all up to check at 100k. Can I get by with just replacing the plugs? My driving summary would be around 80 miles on the highway each day and very little city. Ratio would be around 90/10 hwy/city. Always synthetic oil. Redline maybe once every 2 weeks.
 
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Have it done for peace of mind. I had my K24 done at 100K miles. It quieted down some, the K20 and K24 like to get tight more than they like to get loose, which can lead lead to burnt valves.
 
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Well your oil maintenance is a huge waste of money, and you should still get the valve clearance adjusted. Nothing really to discuss. Oil has nothing to do with it.
 
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Originally Posted By: wing0
I was wondering if K20 DOHC is what some call, shim-over-bucket design?
No, it's your standard Honda screw-and-locknut type.
Originally Posted By: wing0
I am just debating if I should even spend the money to have a shop open it all up to check at 100k. Can I get by with just replacing the plugs?
Do the valves. It's cheaper to adjust good valves now than it is to repair burnt valves later.
 
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What are other people's experience with this engine? Some engines have valve heads recede into the valve seats, hence leading to clearances close up and possible burnt valves, while others wear on the contact between the rocker and valve stem, leading to increased clearances. I'd do them just to find out if you are getting reduced (= bad) or increased (= not bad, just noisy) clearances.
 
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Originally Posted By: gregk24
Have it done for peace of mind. I had my K24 done at 100K miles. It quieted down some, the K20 and K24 like to get tight more than they like to get loose, which can lead lead to burnt valves.
^^^^^^ Did mine @ 192k and as the 2nd owner I don't know if they'd been done before. They were all tight, but not far off. Not a hard job, really.
 
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Originally Posted By: Pavlov
Some engines have valve heads recede into the valve seats, hence leading to clearances close up and possible burnt valves, while others wear on the contact between the rocker and valve stem, leading to increased clearances.
Years ago, Honda had a brief run of defective B-series CR-V heads which suffered from severe valve seat recession. This was covered by a TSB. Normally, valve clearances tend to go out of adjustment BOTH ways. It's never much, maybe a thou or so either way over 30,000 miles, but leave it long enough and you could pay for having done so.
 

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Thanks for all the comments. Looks like I will do this for sure and I've watched a couple videos and DIY online. Doesn't seem that difficult, just takes time. I have the service manual and it looks like it wants me to put liquid gasket on 4 points on the valve cover when I put it back on. This is just Hondabond HT or 4 right? Also, would it make taking off the valve cover more difficult and destroy the gasket along the way?
 
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Originally Posted By: wing0
Also, would it make taking off the valve cover more difficult and destroy the gasket along the way?
No. Assuming our 2.0's have the same design it isn't really a gasket, but a pretty thick rubber seal running the "diameter" of the cover. I'm pretty sure mine is original and the cover's been off twice with no damage to it. 220k miles. As far as the old gasket maker I used a razor blade to scrape it off before applying new gasket maker.
 
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I adjusted the valves on our K24 about a year ago. It wasn't close to the mileage number yet, but I enjoy doing that type of work. It's pretty easy to do. YouTube is definitely your friend here. Report back when you've got it done and let us know how it went.
 
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Originally Posted By: wing0
I have the service manual and it looks like it wants me to put liquid gasket on 4 points on the valve cover when I put it back on. This is just Hondabond HT or 4 right?
You can use Permatex Ultra Grey. It's pretty close to Hondabond and is available anywhere. Those 4 points are sharp bends. You need VERY little sealant, just the lightest skim right on the points. Sparing application of the sealant will not affect how the valve cover comes off. You may find the cover to be difficult to remove anyway. One point: before putting the cover back on again, I'd advise a new OE gasket, and wipe the mating surfaces clean of all oil. Any oil left on the mating surfaces will result in seepage of oil past the gasket over time, which will make a mess of your engine.
 

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Originally Posted By: Tegger
Originally Posted By: wing0
I have the service manual and it looks like it wants me to put liquid gasket on 4 points on the valve cover when I put it back on. This is just Hondabond HT or 4 right?
You can use Permatex Ultra Grey. It's pretty close to Hondabond and is available anywhere. Those 4 points are sharp bends. You need VERY little sealant, just the lightest skim right on the points. Sparing application of the sealant will not affect how the valve cover comes off. You may find the cover to be difficult to remove anyway. One point: before putting the cover back on again, I'd advise a new OE gasket, and wipe the mating surfaces clean of all oil. Any oil left on the mating surfaces will result in seepage of oil past the gasket over time, which will make a mess of your engine.
Thanks for the suggestions. I don't have ultra grey so I'm debating if I should just get Hondabond 4(based on a pdf I read from Acura. It looks to be the one for metal/metal, metal/plastic uses. From most of the DIY/Youtube, most people reuse their gasket since they notice no tear or damage to them. You're right though, maybe I should just put a new gasket just to be safe since I only do this every 100k.
 
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Originally Posted By: wing0
From most of the DIY/Youtube, most people reuse their gasket since they notice no tear or damage to them. You're right though, maybe I should just put a new gasket just to be safe since I only do this every 100k.
The problem with re-using the valve cover gasket is primarily one of oil seepage. Re-used gaskets are slightly deformed from, and slightly harder than, new ones. Re-use isn't a guarantee of leaks (I've re-used before), but seepage is more likely with a re-used gasket. Also, I did a bit of searching, and it appears that I might be wrong in saying that Hondabond or the Permatex formulations are acceptable for this application. The factory manual calls for part # 08718-0009 as the sealant for the valve cover gasket in the two specific locations; that's a substance called "Ultra Flange II". I found this web page: http://www.ephatch.com/forum/showthread....-the-difference Hondabond, Ultra Grey, and Ultra Flange II look very similar, but maybe there's a difference that would affect seepage. What PDF do you have from Acura? Does it have a number?
 

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Went ahead and took out sparkplugs and removed valve cover to do the valve adjustment. After 170k km, sparkplugs are still in pretty good shape. Too bad I already got new ones and will just put those in. Engine is really clean, no varnish anywhere. I'll stick with my synthetic oil change =) I use mainly Motomaster F1 Synthetic(from X'mas sale), PP/Synpower(both 1 OCI each). Both intake and exhaust valves clearance got tight, I do agree that it is a good idea to do the adjustment on time. I'm down to my last cylinder to adjust, then clean off the mating area and put in new gasket. Throw in new sparkplugs and wait a bit before(according to Honda - 3hrs with hondabond) firing up the engine. I am going to use ultra grey as an alternative.
 

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After driving for a while. I seem to think the engine is a bit more noisy than before. More ticking noise at idle and acceleration? Could be my mind. I found almost all valve to be tighter than minimum specs on both intake and exhaust sides. So i adjusted to the middle of the spec which has a range of 0.0 3inch. Say the intake should be within 0.008 to 0.01inch. I did it as close to 0.009 as possible by using the go/no go method with 0.009 and 0.01 feeler gauge. I also saw lost of fuel economy, but I did this just before temperature got cold so not sure if winterblend gas or longer heating time is causing it. Can all these things I'm noticing be attributes of a bad adjustment?
 
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Your valves were on the thight side that's why they were quieter than now, since you put them on the looser side it's normal for them to be a bit louder. However that doesn't mean it's bad, actually the opposite. Loose valves, even outside of recommended spec and even though they may be louder, will operate without problems, however the valves on the tight side, quiet as they may be, may burn up since they don't seat properly for good heat transfer to the head and you will loose compression. Remember, the slack, or looseness is there to accommodate for expansion of metal once the engine if up to operational temperature. If that slack is smaller than minimum spec, the valve will not close all the way when the engine is warmed up, but it will be nice and quiet during this self distracting process.
 
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wing0

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Originally Posted By: KrisZ
Your valves were on the thight side that's why they were quieter than now, since you put them on the looser side it's normal for them to be a bit louder. However that doesn't mean it's bad, actually the opposite. Loose valves, even outside of recommended spec and even though they may be louder, will operate without problems, however the valves on the tight side, quiet as they may be, may burn up since they don't seat properly for good heat transfer to the head and you will loose compression. Remember, the slack, or looseness is there to accommodate for expansion of metal once the engine if up to operational temperature. If that slack is smaller than minimum spec, the valve will not close all the way when the engine is warmed up, but it will be nice and quiet during this self distracting process.
That's good assurance. Does looser gap also mean I am losing compression and overall power? Technically, if this is adjusted on the tighter side, the valves will open larger right? So thr engine can breath easier? Not sure if this will be significant enough to be noticeable through fuel economy.
 
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Originally Posted By: wing0
Technically, if this is adjusted on the tighter side, the valves will open larger right? So thr engine can breath easier? Not sure if this will be significant enough to be noticeable through fuel economy.
Not enough to matter.
Originally Posted By: wing0
Always synthetic oil. Redline maybe once every 2 weeks.
That sounds awfully expensive.
 

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Originally Posted By: yonyon
Originally Posted By: wing0
Technically, if this is adjusted on the tighter side, the valves will open larger right? So thr engine can breath easier? Not sure if this will be significant enough to be noticeable through fuel economy.
Not enough to matter.
Originally Posted By: wing0
Always synthetic oil. Redline maybe once every 2 weeks.
That sounds awfully expensive.
What do you mean it sounds expensive? Redline as in hitting the redline on the tachometer...not the oil.
 
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