No oil pressure Kohler M18 Help! Help!!

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mfowler
Posts: 23
Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

I finally got to tear this engine down to see why no oil pressure.
I got this engine a few years ago to replace a dead KT 8 1/2 ( old timers will know what that means!). I installed it, and immediately saw there was no oil pressure on the gauge. Removed the gauge feed line and saw no oil flowing out of that either. Also removed the oil filter hoses--no oil flowing there. I then removed the front closure plate and made sure that the oil pump was spinning--yes it was, and then i ran a wire thru each hose port back to the pump--everything was clean. Well that was all I could do until I had time to split the case--which was today.
Still, nothing obvious. The oil pick up screen had a little gunk on it, but not enough to prevent oil from being picked up. I shot some carb cleaner thru the tube bother ways--to the pick up and then to the channel to the pump. Everything is clean.
There are no obvious signs of problems with the case. Has anyone ever seen where the RTV would not seal and allow air to be sucked into the oil pump? Seems like a long shot to me.
For the record, the main bearings all look fine. I haven't done the con rod big ends, but expect to see nothing unusual, there.
So I am stumped.
Do I invest in gaskets and time to put this back together "hoping" that I will have oil pressure?
Anything that you can see that I might have missed? I can use all the help--even odd-ball stuff.

Meanwhile, the barrels are soaking in solvent so i can clean out the gunk clogging the cooling fins.

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Jlaws
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First and Last Name: Jess Laws
Location: Independence , Ky

Re: No oil pressure Kohler M18 Help! Help!!

Post by Jlaws »

Mike , its been a while since I've rebuilt a M-18 so bear with me . I know that when you put them back together you have to be very careful with the RTV . A very small bead , like pencil lead size bead so that it doesn't clog oil passages when you put them back together . Was this a rebuilt engine ?
I see a lot of cub cadets while going down the tracks , its a shame I can't pull over and ask about them .

mfowler
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Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

UI can't say for sure, but I don't think it was previously rebuilt. I did not not see globs of RTV in that oil channel from the pick up to the pump chamber. I's like to find some way to test out the seal before committing to spending any more money.
I have the old KT that I can disassemble and see if it looks any different. They are very similar motors.

mfowler
Posts: 23
Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

Well, i got the M18 fully apart. I won't saw that the main and con rod bearings are "perfect", but they are not far from it. No perceptible ridges--fingernail won't hang up on any of them. There is a slight hint of color--like one of the conrods was just starting to get too warm, but nothing I see that causes alarm.
I think i will RTV the case together with just the crank and cam installed, then put on the oil pump and front cover. If I spin the crank, I "should" see oil flow--if there will be any oil flow---to the remote filter ports, and the cam and rods in the engine. The only problem is I have to ten tear it all apart and reassemble with conrods and pistons. No way I know to test it then other than running it.

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dag1450
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Joined: Fri Apr 01, 2011 3:16 pm
First and Last Name: Dave Gibson
Location: Chalfont, Pa

Re: No oil pressure Kohler M18 Help! Help!!

Post by dag1450 »

Just thinking out loud....two things. Oil pump can spin and not make pressure (worn)? And...I think there is a pressure relief ball/ spring that could be bypassing ....idk
127, 1650, 1572, 1872, 2072 . A mower, blower and blade for each.

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dag1450
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Joined: Fri Apr 01, 2011 3:16 pm
First and Last Name: Dave Gibson
Location: Chalfont, Pa

Re: No oil pressure Kohler M18 Help! Help!!

Post by dag1450 »

IMG_20170910_195042588.jpg
IMG_20170910_195042588.jpg (4.33 MiB) Viewed 7577 times
127, 1650, 1572, 1872, 2072 . A mower, blower and blade for each.

mfowler
Posts: 23
Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

I appreciate the reply. The ball and spring were present, and clean. Pump gears do not appear worn. When i first had this problem, I swapped in the pump gear set, ball and spring from my dead KT17 that had good oil pressure---no improvement.

mfowler
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Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

I made up a little plexiglass cover and RTV and bolted it in place over the channel from the oil pickup to the oil pump. I spun the drive gear and I saw oil being pulled up that channel and toward the pump, then i saw oil dribble out the oil pump relief hole. Installed the ball and held the spring in place and spun the gear ( need more hands) and oil came out the remote filter adapter. But even after plugging the outlets, no oil made it up to the gauge port. I removed the remote filter adapter and saw that the gasket was missing a chunk. Could that be it? The pump was just recirculating the oil back to the pan? Where, exactly is that oil returbn? It looks like it must be behind the oil pump drive gear--the big plastic one. Is that right?

mfowler
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Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

I have oil pressure!!!
Just reassembled the case and jugs, and used the starter to spin it over, and the gauge i installed shows almost 40 psi at cranking speed.
I am happy, and relieved.
No oil to the valve train yet. Looks like the valves get oil from around the lifters which would come off the cam. I suppose there is not much oil that comes, or is needed. Anything I need to check before buttoning it back up for good?

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dag1450
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Joined: Fri Apr 01, 2011 3:16 pm
First and Last Name: Dave Gibson
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Re: No oil pressure Kohler M18 Help! Help!!

Post by dag1450 »

Nice! So...what do u think was the issue?
127, 1650, 1572, 1872, 2072 . A mower, blower and blade for each.

mfowler
Posts: 23
Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

Not really sure...perhaps there was a leak in the RTV sealant on the suction side of the pump--the RTV was very thin. I can't know for sure.

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dag1450
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First and Last Name: Dave Gibson
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Re: No oil pressure Kohler M18 Help! Help!!

Post by dag1450 »

So....what tractor is this for.......or is this just a "Big Mike project"? an engine with no real purpose :? . Give us some details. Glad it's solved anyway. The plexiglass takes the cake. Any pics of that setup?
127, 1650, 1572, 1872, 2072 . A mower, blower and blade for each.

mfowler
Posts: 23
Joined: Sun Feb 21, 2016 6:51 am
First and Last Name: Michael Fowler
Location: Littlestown, PA

Re: No oil pressure Kohler M18 Help! Help!!

Post by mfowler »

Sorry, no pics.... It is a good idea, but I just didn't.

Engine is for a Red 782.
It is the key to my tractor project list...
First get it running, then add a 3 point hitch from Xtreme, and then fabricate a rear box blade with scarifiers to help maintain the gravel road on which i live. It is a shared road, but not maintained by the local township...and it is FULL of pot-holes. In two weeks I will go to the AACA Fall meet at Hershey--the biggest antique car event anywhere. Somewhere among the thousands of vendors, i will find the best deal on a Mig welder AND a Plasma cutter, along with a few other things--like 20 ton shop press, and a floor mounted drill press---all needed so I can fabricate that box blade. ( Eastwood is my initial choice--but I need to see what others might have)
Hershey is an annual pilgrimage for me. I started going when a high school classmate and his dad invited me along in 1965. There were a few yeas I didn't make it due to college and grad school, and then work and family, but except for last year, I haven't missed being there since about 1985. Last year my wife had an unplanned surgery that needed to be done right at the end of September, and I needed to stay home for her---but she knew how much Hershey meant to me, and arranged to have a friend stay with her one day so I could at least go for a few hours.

dwilke
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Joined: Sun Nov 17, 2019 7:51 pm
First and Last Name: Don Wilke
Location: Parkton

Re: No oil pressure Kohler M18 Help! Help!!

Post by dwilke »

I'm coming in late on this topic, but want to because of what may be the same problem I need help on.
I have a 1987 1806 Cub Cadet with the Kohler Magnum M18 engine. The Tractor has been in storage for 20 years, I got it to run but it has no oil pressure. I have oil in it up to the full mark. Even with the filter hoses disconnected, no oil is coming out of the connectors. Are there Checks I can do to diagnose the problem before I open the engine. Also Where can I find a good set of instructions on opening the engine and replacing the oil pump. I downloaded a manual for the engine but pictures are terrible and it doesn't describe the oil pump replacement.
Don

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