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Discussion Starter #1
I've got a John Deere riding mower with the above mentioned engine. For a while it's produced a puff or two of smoke on start up, but I've always kept the oil level where it should be. It's about 5 years old.

Lately, the engine's been making a loud ticking noise. Slow at idle, and of course increases as RPM increases. I'm not an expert, but I'm pretty sure it's a valve.

If it is a valve, would it be wise of me to do a complete engine overhaul?
How much would it run for a shop to do it, and how much would it run for parts if I were to do it myself? I'd need new gaskets and seals, and two new valves... perhaps I'd need to bore the cylinder and get a new piston?

Where can I find these parts online?

Thanks!
 

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it ain't so old just to make sure check the valves. it could be that an engine mount bolt is loose or something else is loose. a valve is supposed to pop closed by a spring. i know my engine made that sort of noise. it was about 7 years old with alot of use. the engine oil loosened the mount bolts. now if it is the valves try cleaning them and make sure they seal. but it could be that something is loose. try this before you spend money. an all alluminum engine will last about 10 years with a small yard. around 8 on a huge one. and allways clean the combustion chamber by hand at least every year after you get it running right or rebuilt.
 

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Discussion Starter #3
Ok well, like I said I'm not a pro mechanic, and I'm just doing this in my spare time.

I ran the engine before I took it apart, to get a good idea of the sound. It was the loudest when I put my head near the valve cover. Does this mean it is a valve?

I've completely disasembled the engine. I found one of the piston rings was broken. It was the middle ring, one of the compression rings. No scoring I could notice in the piston bore. There seemed to be a crosshatch pattern, like when you re-bore the cylinder. Is this just from the orginal manufacture or could it be due to the broken ring, requiring re-honing of the bore?

I didn't find anything out of ordinary regarding the valves. No pitting or warping on the valves or the seats.

Could this ticking/clicking noise I was hearing be completely due to the broken ring?
 

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that sound could have totally come from the ring. the criss cross pattern was most likely done by the manufacturer. it helps on the oil lubricating the rings. if there are no scratches other than that your fine there. but do replace all the rings with the same type and size. most likely the ring had a defect in it. if it all looks good do rebuild. now on scratches when you look in the bore and the scratches look like fine criss cross scratches and no blank ones pointing toward you your fine do go ahead and replace the rings no honing required. that ring was most likely the problem for your oil puffs at start up. make sure you don't line the rings up or close for that matter on the gaps do your in for trouble.
 

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Discussion Starter #5
Thanks for the reply... I ordered new piston rings. I am really hoping it's not the valves!

One question: In the Kohler CV15 manual, it says:
Valve Stem Seals
These engines use valve stem seals on the intake
valves and sometimes on the exhaust. Always use a
new seal when valves are removed from cylinder
head. The seals should also be replaced if deteriorated
or damaged in any way. Never reuse an old seal.


I called the John Deere place near me, and they couldn't find this part.
Any ideas?

Thanks!
 

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its seals used to keep oil and gas separate by sealing the stems. that would be ordered from the company of the engine manufacturer. i'm not to good on kohlers, mostly briggs and some tecumsehs. but they should be replaced if the engine was used alot or they are worn or deteriorated.
 

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Discussion Starter #7
Well, I've got good news and bad news. Good news is that I replaced the piston, rings and both lifters. And I put the engine back together and it runs.

Bad news is that annoying noise is still there.

It's this really loud ticking/tinging noise. I know it can't be good. I looked at the valves, and they seemed fine to me, not warped or anything...What else could be wrong with the valves to make this noise?

Any ideas?
 

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its probablly the governer or its a just a gremlin. thats weird though. nothing was in the oil when you drained it to rebuild it was it because if it won't its probablly where the springs could be to strong but you'd know from looking at it. i'd run it and check the oil for any scrapings of alluminum. well check the oil and make sure the springs are at factory specs because that is weird.
 

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Once you replace sometime, like rings the compression goes up. chevk the valve lash and make sure it is correct. That sounds like were your noise is coming from.

Tony
 

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Discussion Starter #11
Could you briefly explain valve lash and how to check it? I'm not that advanced of a mechanic.

This particular engine does not have adjustable valve lash heads. The manual says some versions do, but mine are not.

Thanks again!
 

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Valve lash is the amount of free play you have between the valve and the push rod (ususally somewhere between 0.005-0.008). I'm assuming this is an L head engine...in that case, all you need to do is pop the valve cover off the side of the engine, rotate the engine over to about 5 degrees past TDC, and place a feeler gage between the valve and push rod.

If the clearance is too tight, you can remove the valve and CAREFULLY grind a small amount of material off the end of the valve. Then place the valve back in the engine and check the clearance again. Just remember to take it slow so you don't grind too much off the valve.

BTW, you are going to need to remove the head to do this properly, so it wouldn't be a bad idea to go ahead and lap the valves.
 

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put 10 w 30 oil in it it will quit the noise thing . it wont have adjustable rockers if hydraulic, might need to set the idle up a little could be the compression release , on the cam :thumbsup: i would bet ten thirty oil will pump the lifters up :thumbsup:
 

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You may well have a lifter on the way out but the correct oil is a must on many of the Command series engines. I heard that the Command oil has an anti foaming agent and after going to that oil fixed to many noisy lifters I'm sold on it. The oil is only 2.49 so why not use it. It is 10w-30. What is happening is the lifter has trapped air in it/them that can't bleed off. Try the correct oil to see if that doesn't cure the ticking. This is very common on the twin vertical Commands. The horizontals seem to bleed the air somewhat due to the lifters upright position.

Mike
 

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yeah, my roper was ticking with 30w, i changed the oil after 25mins. runtime and out 10w30 in it, didnt tick anymore, beacuase of the lower base weight, it gets inot the little nooks and crannies before the engine is warmed up as much as it would for 30w to get into there

my mom's 88 plymouth vayager ticks, thats becuase it has been using oil from bad valve seals, it has 20w50 in it, if it was probably 15w40 rotella, it wouldnt tick, it ticks beacuase the thicker base weight cant gert into the little cracks when the metal is cold
 

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i have also seen the valve seats work loose from the head and that will make some noise i guess you might call that the valve seat seat (lol) seen a couple briggs engines do that also --- real hair puller chasing that one down , but you can take a sharp punch and go around the seat and make a few stamps near the seat edge in the alumnium and that will hold the seat in ,,,, just my 2 cents hope it helps a fellow tech-- :thumbsup:
 

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Discussion Starter #20
could it be the fuel pump?

i noticed the arm on the fuel pump (the arm the camshaft moves) had some wear on it. could the pump be bad, causing this noise?


good thing it's winter and i don't need the tractor right away!


thanks
 
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