Occasional bucking from the engine when cold

[PJensen]

'03 2500 HO 6 speed



I have had 2 seperate incidents when its in the single digits outside for temperature driving for the first couple of miles.



It feels like the engine just cuts out and the rpms drop and then it recovers in a second or two.



Happened twice now, only when very cold outside and truck isnt warmed up. It doesnt happen everytime when the temp is in the single digits.



Any experience with this type of problem.



Fuel filter changed at 6K miles now have around 8500 miles on it.



Thanks for any suggestions.

 

[MCornwell]

Our engines use heat to burn the fuel, if there isnt enought heat when the fuel is injected it will stumble for a sec or protest alittle.

I have also had my truck stumble alittle when i get off the peddle in a hurry from an idle, i wouldnt loose any sleep over it.



If it doesnt happen often i would consider this normal. My . 02$



-Mitch

 

[Gary - K7GLD]

AHHHH SOOoooo - the 'ol "hesitation when cold" bit surfaces on the 3rd gennies - welcome to the crowd from a 2nd genny owner...

 

[Gary - K7GLD]

Just a little more info...



Check the "hesitation with no codes" thread in the 2nd generation engine/transmission forum - it is one of the more detailed threads on the issue - seem to be a few different potential causes for the cold weather hesitation, but many still have the effect even after checking/clearing all peripheral causes - problem is most apparent with power boxes, greatly diminished or disappears when they are removed or turned off - is also more pronounced when the engine is operating under a load such as towing - very low temperatures, freezing and below gets the hesitation/surge started - usually goes away when temps rise. Perhaps the reason this tendency is surfacing so slowly on the 3rd generation trucks is due to length of time it's taken to get the power boxes on the market, and recent colder weather,



Next winter could be real interesting, as more power adders are common, and we again get into colder weather...

 

[sstanley]

Cycling of the grid heaters seems to affect my electric "throttle", causing the engine to speed up and slow down slightly. (Yes, I know diesels don't have throttles, but for conversation... ) The heaters stop cycling after so many minutes or 20? mph, but I notice this while going slowly with a cold engine.

 

[Gary - K7GLD]

The grid heaters are supposed to shut down when the vehicle gets above a set speed (I haven't driven enough in cold weather to know for sure) - and the heaters usually are pretty consistent in their on/off cycles, whereas the hesitation most see is very random and inconsistently spaced...

 

[johncameron]

The colder it gets the more they hesitate. Mine doesn't last 2 secs but it is notable. The grid heaters shut off around 18MPH and they are not consistent on their on/off cycles. when the airflow increases, the heaters stay on longer.