Garden tractor smoking

hayden · Mar 16, 2003

I've got an odd problem with JD garden tractor. It's an LX188 powered by a Kawasaki 17HP V-twin liquid cooled engine.

Frequently when I first start it, it will belch white smoke for the first minute or two that it runs. Sometimes it even runs on one cylinder for the initial smoke period.

I haven't noticed an appreciable drop in either coolant or oil level, but I *think* the smoke smells more like antifreeze than oil. Once the smoke burns off the tractor runs fine. Subsequent restarts will be smoke-free unless I leave the tractor for a week or so, then the first start will smoke again.

I'm guessing some sort of coolant leak into one of the cylinders. Any thoughts from the gang?

Now in case you thought this would be easy, there's actually a longer story and another problem behind this. When I first bought the tractor, during the first few minutes of operation the oil light would come on and off. We replaced the sender unit and other external parts, but the problem persisted. The dealer I bought from was a complete theif, adn JD was no better in helping. The JD phone support rep first told me that I was supposed to run the engine at full throttle from initial cold start (despite all good reason and despite what the manual says), and then to top it off he told me that they'd be happy to remove the warning light bulb if this continued to bother me.

Subsequent oil pressure tests with external mechanical guages confirmed that indeed the pressure was dropping to zero for multi second periods of time during warm up. Conclusion - the problem is real.

I finally gave up on the dealer and JD and just kept mowing my lawn finguring that I had a well documented case if the engine failed. A year or so later I found a good dealer and a service manager who took this on as a challenge. He ended up tearing down the whole engine looking for problems, but everything checked out. They replaced the oil pump and lower unit casting, and put it all back together.

Guess what? The oil light problem continues to this day (7 years later), and the smoking problem started right after I got the tractor back from the teardown repair. I've had the tractor back to the dealer since and they claim they can't find anything wrong with the tractor (what a surprise), and there is of course a new service manager.

I've just given up on these problems and am going to run the thing until it blows up at this point. JD sure isn't going to make good on it.

So I thought I'd tap the wisdom of TBN to see if anyone else had had problems like these two (which, by the way, I think are independent problems).

Any ideas?

Peter

Anonymous Poster · Mar 16, 2003

Hello Hayden,
You are right on with your diagnosis of antifreeze causing the white smoke. most likely, the leak is very small and is sealed temporarily when the engine gets some heat in it.

Perhaps when the service man reassembled the engine, he did not use new gaskets, or he used a defective gasket. Before you use the tractor next time, pull both plugs, one will most likely be wet with coolant. There is your leak. Continuing to run the engine with this problem could gall the piston or cylinder sooner or later. I have not worked on a Kawasaki, but most small engine head gaskets are fairly simple to change. Talk to your service person to find out for sure./forums/images/graemlins/tongue.gif

Your other problem is probably related to the viscosity of the oil when it is cold. Cold oil does not flow well and the oil is pumped into the engine faster than it can return into the crankase. As soon as the oil is warm, it flows back into the crankcase faster and the oil light stops coming on. What type of oil does your manual reccomend? Does it list a thinner oil for colder weather versus hot weather? Another remote possibility could be that the dip stick is improperly made or marked and results in a low oil level. Does your manual tell you the capacity of the crankcase?

A simple way to test the oil problem is to add an extra 1/2 quart of oil before you start the engine and see if the oil light still comes on. If this solves the problem, turn the machine off and drain the oil into a clean pan. Make sure that the oil is not full of bubbles or is foamy. Either of these will mean that there is to much oil,/forums/images/graemlins/frown.gif absence of bubbles or foam means your OK./forums/images/graemlins/smile.gif

Good luck and keep us posted.

Logan · Mar 16, 2003

I have an LX178 with the 15 hp Kawasaki engine that is seven or eight years old. It has been smoking the same as you describe since it was new. It has never used any oil or coolant. I always thought it was a bad valve guide seal, but don't know for sure. The dealer checked it once and said it wouldn't smoke for them. It has been a great mower.

BillyP · Mar 16, 2003

Years ago I had a Datsun pickup. One deer season it started puffing white smoke at startup. Just like your JD, it would quit after a few of minutes.

It was a blown head gasket. I kinda figured it was, by the smell.

mrcaptainbob · Mar 16, 2003

I'm wondering....from what all the posts say about this, and even though you've had a replacement block, the problem still exists and is common within others as well. Could it be a manufacturing defect? Slight, but possibly in the gasket surface of the head? Or of the block? I'd recommend a real close check on those two surfaces. Maybe even havin' them trued up just to be on the safe side.

hayden · Mar 18, 2003

I think you are on to it here.

A gasket seems like the most likely cause, but wouldn't it get worse over time? Some time when I've got the time and the machine is not being used weekly, I'll pull it apart and replace the head gaskets.

Re the oil, it does get better if I over fill the oil by 1/2qt or so. I've wondered about the dipstick too, but when filling the crankcase it does take the specified qty of oil.

Anonymous Poster · Mar 22, 2003

Hello Hayden:

When you have the engine apart, you might check the oil pump pickup if it has one. It could be to high and cause your problem until the oil is warm. If there is no pickup screen or tube, then look at the pump system, I.E. how it is routed, any connections between the pump and block, any gaskets?

If the oil is not being whipped by the crankshaft with the extra 1/2 quart of oil, leave it in there, could save some bucks on a rebuild or a new replacement mower down the line.

Did you get a chance to pull the plugs and check for rust or moisture? I don't mean to be a nag, just curious as to what you found.

Good Luck