I've got a 2012 Limited. Twice in the last month I've been caught in stop and go traffic on warmer than average days (about 55 degrees). Both times, the bike has gone into the one-cylinder heat management mode very quickly. Then after 15 minutes or so, it starts knocking pretty bad unless I add some throttle.

I had a brief conversation with our dealer's head tech, who has really proven he knows his stuff in the past. He said from my description, the knocking was probably the bike going from heat management mode 1 (rear cylinder off) to mode 2 (alternating cylinders), which happens just before shutdown.

I asked him if it made sense for this to happen on such a cool day. He said he believes it's because the winter ethanol/gas mix the stations are pumping burns much hotter, and causes this kind of problem.

So....anybody else noticing this problem? And is there some kind of check the techs can do to see if their might be some kind of heat (or sensor/computer) related problem on the bike?

 

Scan the ECM I bet you have a bad O2 sensor.

 

FWIW, the current "winter" blend is actually the old "year 'round" blend we got many years ago. It's the "summer" blend that has all the additives.

The summer/winter blends came about when the EPA got involved and mandated the introduction of many chemicals to gas manufacturing in an attempt to minimize the evaporation of gasoline into the air during the warmer months.

As suggested above, I think you might have another problem related to the ECM or sensors.

Good luck!

 

Most folks overestimate the cooling effect of cold ambient temperatures, especially ET AKA CHT that governs the EITMS. Sitting still is sitting still whether its 50 degrees or 105 degrees outside temp, you're not moving so the head fins are not getting the assistance from moving air to help dissipate heat. Your 2012 is O2 controlled so with a colder denser air charge the ECM is adding more fuel to maintain AFR, the result is greater total heat released with every charge. Even though its colder outside, your bike is making more heat. With my 2006 non-O2 controlled EFI it doesn't add fuel to maintain my target map, my AFR just leans out in the winter, which also causes more heat, so I have to run a summer and a winter map. It is an air cooled motor, if you're not moving then you're not cooling. The fuel may be contributing also.

 

That's well thought out.

Concerning winter additives packages- it depends where you are- here in AZ winter blends are higher in ethanol than in the summer as much as 5 to 10% higher.

OP, is your bike completely stock?
What is the idle speed ( before eitms)- low idle means less oil pressure and volume, oil is part of the cooling system.

Is the oil cooler operating? it should be warm to the touch after a few miles operation

mike

 

loose the cat and put a tune on it.

 

I have never heard of a mode 2 heat management system. Does this really exist?

 

Yes, I believe they started in 2010 (both my SGs have it).

 

Yep, it exists, its called EITMS, has 2 modes, don't remember the trigger temps but one mode lowers idle, the other skip fires the rear cylnder.

 

I am aware of EITMS (Engine Idle Temperature Management System) which I believe shuts off the fuel to the rear cylinder when the head temperature reaches the cut off point. My bike has this on it. From what I've read on here and on HD's web site, this system is primarily for rider comfort and not for the engine.

The OP mentioned a system that alternated cylinders just before shut down. I had never heard of this system or seen it mentioned on here before.

It may be real, I've just never heard of it before now.