Thick white smoke at startup

tillboy2001 · Apr 5, 2005

The last 3 or 4 times I've started the tractor I've noticed VERY thick/heavy white smoke from the exhaust for literally about 4 or 5 minutes. I rev it up and it sounds like it's just running a little rough and the white smoke continues to pour from the exhaust. After a combination of light reving and letting it idle, it smooths out and the smoke goes away.

Tractor has about 22 hours on it.

The book says if the engine emits white smoke, these are the possibilities:
- Improper type of fuel.
- Low engine temperature.
- Defective thermostat. See your John Deere Dealer.
- Faulty cold advance device.

So what do you think is going on? After it's warmed up it's fine and will startup fine and only emit a puff of black smoke when it does it's initial rev after starting.

RoyJackson · Apr 5, 2005

Probably best to contact your dealer on this...especially since there's only 22 hours on the tractor.

Could be you'll find out it's the nature of the beast...or any one of those items listed in the Owner's Manual.

Good luck...let us know what your dealer says...

tillboy2001 · Apr 5, 2005

I just talked to the mechanic from the dealership. He had come out before to replace the seat belt and he's a really nice guy. Country boy to be exact...nice as can be. Anyway, he said they've had several calls from other customers asking about the smoke. He said because of emissions laws the thermostat tells the engine how to run most efficiently and sometimes it causes the white smoke when the engine is cold. It seemed to be a little more complicated than that, but that was his explanation for it. I'll agree with him on this one because after it's warm it runs great and won't blow white smoke anymore.

SkyPup · Apr 5, 2005

White smoke is unburned fuel at startup.

KennedyDiesel · Apr 5, 2005

There has been a running change in the Powertech engine increasing the Compression ratio by .5 to aid cold starting. I'd consider plugging it in when cold to help this...

Av8r3400 · Apr 5, 2005

Does your motor have glow plugs? Sounds like you may have a bad one or one came unplugged.

tillboy2001 · Apr 5, 2005

It does have glow plugs (from what I understand). You can activate them longer than usual by pressing in on the key.

tillboy2001 · Apr 12, 2005

Update on this:
Dealer is replacing the coolant temp sensor this week. They came out to look at it and said the white smoke is much worse than they thought (from my description) and we'll see if that fixes it.

Oh by the way, I love this dealer's service dept (Bowen Farm Supply - Gardnersville, KY). I called the mechanic on his cell phone on another problem (fuel tank leak near the fuel gauge sending unit) and he just looked up on the computer what's involved with the sending unit (a cap and o ring) while I was on the phone, he ordered it and setup to come out today to fix it...and he did /forums/images/graemlins/smile.gif Now he's gonna come back to replace the coolant temp sensor I guess within a day or two.

SkyPup · Apr 12, 2005

The coolant temp sensor causes the fuel pump to inject larger volume of fuel on cold startup, less fuel when warm. Don't know which it defaults to when it is defective.

Actually, you'd have more horsepower if it was still injecting the cold setting fuel amount once the engine warmed up to operational temps although then you may end up with more black smoke.....

tillboy2001 · Apr 12, 2005

I wasn't home when he came, but I think that's what he said he was going to replace. I got the info from my in-law. I hope that fixes it. I swear it never did that this winter when it was much colder. Maybe it only showed itself as a problem once it warmed up outside this spring? Not sure.