2185 oil use WAY up this year

[CJ-8_Jim]

Ford Tractor.... What's the engine model # and serial # on the sticker on the side of the engine?

My 1992-2010 Service Manual covering 18 hp shows valve guides.

 

[Ford tractor]

Ford Tractor.... What's the engine model # and serial # on the sticker on the side of the engine?

My 1992-2010 Service Manual covering 18 hp shows valve guides.

From the sticker on the engine.

Family: SKH624U1G2RA
Model: CH18S
Spec: 62588
Serial Number: 2731107521

I DL'ed the manual from Kohler and it does not show any press in guides and the procedures are to buy valves that have larger stems and ream the holes to fit.

 

[CJ-8_Jim]

From the sticker on the engine.

Family: SKH624U1G2RA
Model: CH18S
Spec: 62588
Serial Number: 2731107521

I DL'ed the manual from Kohler and it does not show any press in guides and the procedures are to buy valves that have larger stems and ream the holes to fit.

Strange, I just looked up the CH18S service manual at Kohlerengines.com and that service manual shows valve guides.
In fact, page 1.3 (or pg 5 of the pdf) uses "CH18S" as an example of how to read the engine identification numbers.

Here's a link to the service manual for the CH18S: http://www.kohlerengines.com/onlinecatalog/pdf/tp_2428_b.pdf

- page 1.14 (or pg 16 of the pdf) lists valve guide specs
- page 3.2 (or pg 24 of the pdf) lists reason for excessive oil consumption.
IMHO, investigate each of these starting with the easiest ones first. For you, the next easiest one to investigate is "#6 worn valve stems/valve guides"
- page 10.8 (or pg 191 of the pdf) discusses how to inspect valve guides.
NOTE: The intake valve guide also has a rubber seal on the oil side of the head. It's possible that this seal has gone bad too and is leaking oil.

 

[Ford tractor]

Strange, I just looked up the CH18S service manual at Kohlerengines.com and that service manual shows valve guides.
In fact, page 1.3 (or pg 5 of the pdf) uses "CH18S" as an example of how to read the engine identification numbers.

Here's a link to the service manual for the CH18S: http://www.kohlerengines.com/onlinecatalog/pdf/tp_2428_b.pdf

- page 1.14 (or pg 16 of the pdf) lists valve guide specs
- page 3.2 (or pg 24 of the pdf) lists reason for excessive oil consumption.
IMHO, investigate each of these starting with the easiest ones first. For you, the next easiest one to investigate is "#6 worn valve stems/valve guides"
- page 10.8 (or pg 191 of the pdf) discusses how to inspect valve guides.
NOTE: The intake valve guide also has a rubber seal on the oil side of the head. It's possible that this seal has gone bad too and is leaking oil.

I already had that manual (but thanks for the link in case I didn't!:thumbsup.

But, as I posted previously, the guides in the head are simply drilled holes in the parent material of the head and not replaceable. Some Kohler engines have the ability to push out old guides and push in new ones. The ONLY way to correct a loose stem to guide on the CH18S is to buy larger diameter stem valves and ream the hole larger to match. It would have been nice to have a replaceable guide, but sadly I don't have that easy option.

Yeah, the stem seal could be toast. But with the low compression, I'm thinking probably the rings have failed too. Maybe broken or possibly just worn out. But with under 400 hours, being worn out would be sad. The piston could be scored, etc too. It looks like an overhaul is needed, but I won't be starting that until the grass is dormant and the leaves are up. ( I use the mower to "rake" the leaves 'cuz I'm lazy)


Thanks for the input, I appreciate it!

 

[CJ-8_Jim]

But, as I posted previously, the guides in the head are simply drilled holes in the parent material of the head and not replaceable. Some Kohler engines have the ability to push out old guides and push in new ones.

Sorry to pursue this more... but I'm really, really intrigued.

I guess it's possible that Kohler doesn't reference in their service manual a head design that doesn't use valve guides. I would hope their service documentation is better than that. If this is the case, someone needs to provide feedback to Kohler.

When you say your head has "simply drilled holes in the parent material of the head", do you know this by taking the valve cover off and inspecting the head? Do you have a photo of what you saw?

I ask because when my valve guide shattered, it left a "simply drilled hole in the parent material of the head".

 

[Ford tractor]

Sorry to pursue this more... but I'm really, really intrigued.

I guess it's possible that Kohler doesn't reference in their service manual a head design that doesn't use valve guides. I would hope their service documentation is better than that. If this is the case, someone needs to provide feedback to Kohler.

When you say your head has "simply drilled holes in the parent material of the head", do you know this by taking the valve cover off and inspecting the head? Do you have a photo of what you saw?

I ask because when my valve guide shattered, it left a "simply drilled hole in the parent material of the head".

No problem:thumbsup:. Being intrigued is how we learn and there is always the very large chance that I'm mistaken! :laughing:


I went to section 10.8 of the manual you linked. It has this paragraph:

The maximum (I.D.) wear on the intake valve guide is
7.134 mm (0.2809 in.) while 7.159 mm (0.2819 in.) is the
maximum allowed on the exhaust guide. The guides
are not removable but can be reamed 0.25 mm
(0.010 in.) oversize. Valves with 0.25 mm oversize
stems must then be used.

I used bold on the relevant passage. That seems to mean that the guide is like ones on most auto engines I'm familiar with (50's, 60's & 70's vintage) where the valve guide is a hole in the head honed to a precise value.

I did take the rocker arm cover off and it was hard to tell with the spring in place, but I didn't think there was a press in guide there. It will be coming apart this winter. Will give me a project to occupy my time (like I need that!).


I also copied this from the same manual on page 10.9

Ring failure is usually indicated by excessive oil
consumption and blue exhaust smoke. When rings
fail, oil is allowed to enter the combustion chamber
where it is burned along with the fuel. High oil
consumption can also occur when the piston ring end
gap is incorrect because the ring cannot properly
conform to the cylinder wall under this condition. Oil
control is also lost when ring gaps are not staggered
during installation.
When cylinder temperatures get too high, lacquer and
varnish collect on pistons causing rings to stick, which
results in rapid wear. A worn ring usually takes on a
shiny or bright appearance.


Since I dumped a boat load of light machine oil into the spark plug hole, the oil consumption seems to be lower. Hard to tell for sure what if anything of the stuff I did helped. It has been given new 15w40 oil, new filter, de-carboned the engine, degreased the vent valve with brake cleaner and the light machine oil in the cylinder. Will have to keep a close eye on it. Maybe will dump some more oil into it after the next mowing. I sort of hate to do it, because then I feel the oil needs to be changed and it really (REALLY) puts out a lot of blue smoke when started!

 

[CJ-8_Jim]

I'll try to remember to take photo of my bad head Kohler replaced for me (i.e., supplied parts... the labor was mine) for you to compare to your head.

I'm betting it's your valve guide and not rings -- especially since it has only 400 hrs on it and as I understand it, the excessive oil consumption did not build over years, but over one year.

Separately, yes the valve guides are pressed-in (not cast) and yes, they can not be ordered separately... you need to buy a new ~$200 head or machine and add thicker valves.

HOWEVER, it is possible to replace the valve guide. Here's one guy who did it: http://www.mytractorforum.com/showpost.php?p=1273747&postcount=2
"I had a local machine shop do my heads for me and he found an off the shelf guide that fit well after a light knurling on the O.D.; the I.D. was under 7mm so he was able to ream to standard stem size. That engine ran great for a year plus after the rebuild and was strong (and did not use oil) when I sold it."

I still think it's your head and not rings -- the head is a lot easier to inspect and positively diagnose than pulling apart the top-end to inspect the breather reed or pulling apart to inspect/replace rings.

Just food for thought.


P.S. The "smoking when idling up and idling down" that you mentioned in one of the first posts could be from an overly rich fuel mixture resulting from a clogged air filter &/or pre-filter. I have a bizarre occurance every now and then when after 2 mowings (3 hrs total) on a cleaned prefilter, I'll notice it "smoking" when idling down or shutting off. I'll go and examine the prefilter and sure enough, it's packed with grass and dust and sufficating the engine.

 

[Eagleview]

Two things :-

1/ All heads with non renewable valve guides can be restored without using oversize valves by reaming and fitting K liners . They are Bronze inserts that renew the guides .

2/ If your lack of compression is due to sticking rings , some carb cleaner or similar poured down the spark plug hole and left for a while may free them . It will eventually get into the sump so an oil change would be required before starting .

 

[Ford tractor]

I'll try to remember to take photo of my bad head Kohler replaced for me (i.e., supplied parts... the labor was mine) for you to compare to your head.

I'm betting it's your valve guide and not rings -- especially since it has only 400 hrs on it and as I understand it, the excessive oil consumption did not build over years, but over one year.

Separately, yes the valve guides are pressed-in (not cast) and yes, they can not be ordered separately... you need to buy a new ~$200 head or machine and add thicker valves.

HOWEVER, it is possible to replace the valve guide. Here's one guy who did it: http://www.mytractorforum.com/showpost.php?p=1273747&postcount=2
"I had a local machine shop do my heads for me and he found an off the shelf guide that fit well after a light knurling on the O.D.; the I.D. was under 7mm so he was able to ream to standard stem size. That engine ran great for a year plus after the rebuild and was strong (and did not use oil) when I sold it."

I still think it's your head and not rings -- the head is a lot easier to inspect and positively diagnose than pulling apart the top-end to inspect the breather reed or pulling apart to inspect/replace rings.

Just food for thought.


P.S. The "smoking when idling up and idling down" that you mentioned in one of the first posts could be from an overly rich fuel mixture resulting from a clogged air filter &/or pre-filter. I have a bizarre occurance every now and then when after 2 mowings (3 hrs total) on a cleaned prefilter, I'll notice it "smoking" when idling down or shutting off. I'll go and examine the prefilter and sure enough, it's packed with grass and dust and sufficating the engine.

Two things :-

1/ All heads with non renewable valve guides can be restored without using oversize valves by reaming and fitting K liners . They are Bronze inserts that renew the guides .

2/ If your lack of compression is due to sticking rings , some carb cleaner or similar poured down the spark plug hole and left for a while may free them . It will eventually get into the sump so an oil change would be required before starting .

Good points guys. I may be understanding the situation better with your assistance, but won't know for sure until I go and take it apart! While the guides may be suspect, I don't understand how they could make the compression dry be 40 psi and wet be 140 psi. That seems to be a symptom of rings, at least to me!

Next trip into town, I'll get a can of carb cleaner and maybe some ATF to soak the rings. As long as I don't crank it, it will only need to have the oil dumped and filled. No biggie.

 

[Eagleview]

You are correct , a compression increase of that sort with a squirt of oil does indicate a ring problem . That's why I suggested trying the carb cleaner in the hope they were just stuck in the ring lands and it may free them .

I was merely informing yourself and others of the existence of K liners to re new worn guides if the need ever arises . Even worn replaceable guides can be re newed with these .