K482 shutdown noise

[Trouty56 565]

I've noticed that when I shut down my D-180 the engine lets out a long hiss or ssshhh for about 10 seconds. Just curious if this is normal or if not, what could be causing it. I do get a good bit of smoke from it and am going to try a rebuild this spring. I'm guessing it has something to do with pressure I really noticed the last time I was running it.

Thanks for any help or advice.

[TT-(Moderator) 1,128]

Have you checked the crankcase breather?

There may be a blockage causing excessive crankcase pressure - which would ultimately contribute to the smoking problem.

[Trouty56 565]

Terry, I did check the breather and it seemed to be working to me. I could blow air though the exit however there was a small amount of air that it allowed back the other way also. Does this sound right?? Could there be an obstruction elsewhere?? My nephew pointed me in this direction also from the smoking.

Thanks for the quick response!!

[TT-(Moderator) 1,128]

I won't leave you hanging, Bob, but I better look into this one before I respond again.

All crankcase breathers work on the same principal, but due to variations in manufacturer and even between spec numbers on the Kohlers, there could be something different between your D engine and the ones I have been around.

Stay tuned........ (it may not be real soon though )

[TT-(Moderator) 1,128]

OK... the 482 is the one with the breather valve on the governor housing. (the 662 has the reed-type like the single cylinder engines)

If you have checked it and you can suck air out - but not blow any in, it should be working correctly.

You should be able to remove the breather from the governor and run the engine long enough to see if it still hisses when you shut it off again. (oil may fly out of the hole if there's a lot of blow-by in your engine)

If you find it to be the culprit, A-277905-S is the Kohler part number. (they're not cheap either - around $40)

[Trouty56 565]

Thanks Terry. I'll try your method of troubleshooting and post my findings. Won't be till Wednesday though. Tough work schedule for a couple days.

Again thanks,

[rickv1957 70]

Bob,I dont recall any of my Ds making that type of noise,Rick

[Trouty56 565]

Thanks for the input Rick. I was hoping guys like TT and you would help me out here. I get through work tomorrow and I'll have some days off to check this pressure thing out. At work I noticed this tube gauge I think it is a manometer. I might borrow it to check pressure too.

Thanks again,

[Jim_M 178]

I had a 180 automatic a couple of years ago that hissed like that when you shut it off. It smoked like a freight train, the rings were completely worn out. I'm pretty sure the noise was caused by compression leaking by the rings.

[Trouty56 565]

Checked for vacuum today with a manometer. I had a 6 inch water column. I think I read in the manual where it should be about 12 inches. The breather must be working some. At least it isn't positive pressure. I'm going to check the compression tomorrow. I'm leaning towards the rings like Jim mentioned.

Today I ran it about 5 minutes but no sound. I don't think it does it every time or I would have noticed it more. It has done it several times though.

Thanks,

[Trouty56 565]

Checked compression today on this engine. 95 lbs on both cylinders. Manual says anything less that 90 or variation of 15% is a problem. Is 95 OK? Maybe the vacuum is too low.

Thanks for any input.

[gzx3sc 0]

I've not read anybody that has mentioned the valves. You should be able to check to see if the hiss is coming through the carburetor or out of the mufflers. If the engine stops with one cylinder on the compression stroke the charge could be leaking past either an intake or exhaust valve.

[rickv1957 70]

As Rob stated,the valves could be leaking or the rings, maybe even a small leak in head gasket,Rick

[Trouty56 565]

Thanks Rob. Then this noise could be just the result of pressure being released through a valve that is slightly open. If this is the case it is not from a breather problem and is not related to the smoking. I guess that is possible since it is not every time. Looks like I need to do an engine refresh. This will be new to me too. I do have a guy that will look over my shoulder and has the tools I need to do it.

Thanks for all the help.

[Trouty56 565]

I would like to bump this up for a new issue that might help you guys pinpoint something for me. This morning I fired up the tractor to scrape the 1" we got and to widen the driveway a couple feet onto the grass. I could hear a few pops so afterwards I took the air cleaner off and noticed some sludge (oil and water mixture) coming out of the breather tube into the carb. There was enough that I could take the screwdriver and dip some out. What engine condition would cause this. In this post there has been mention of breather problems, which I have checked the breather, ring problems and valve problems. I figure there should be some condensation inside but not pushing into the carb like that. Will an engine refresh fix this condition??

Thanks in advance.