Surging while towing

[Riccochet]

Like the title says I get surging while towing. Or maybe it's missing. Either way. I have almost 41k on my truck. I tow a 19' bass boat that's maybe 3500# loaded boat/trailer/gear. On slight inclines it feels like the engine is either surging, missing or the trans is slipping? Have it in tow/haul mode, so not MDS. Doesn't matter the speed. Could be going 30 or 60. No codes, no lights, nothing. Just doesn't feel right. Not smooth at all.

Anyone ever experience this? What could it be? I really don't want to take it to the dealer since it only happens when towing. I'll be damned if I'm going to leave my $50k bass boat in their hands to test with.

 

[Andy578]

6 speed or 8 speed? if it's the 8 tow/haul does not disable MDS, you need to use the manual gear selection for that. either way MDS shouldn't be kicking in up hull tho

 

[Riccochet]

6 speed. Last time I had torque pro going and didn't see any stumble in RPM's. But it sure feels like a misfire.

 

[7777xm]

If it were misfiring, it should be throwing a code.

As mentioned above, MDS does kick in during tow / haul mode. Possibility feeling it pop in and out of MDS?

Sent from my Nexus 6 using Tapatalk

 

[Riccochet]

If it were misfiring, it should be throwing a code.

As mentioned above, MDS does kick in during tow / haul mode. Possibility feeling it pop in and out of MDS?

Sent from my Nexus 6 using Tapatalk

It shouldn't be while going uphill under tow load. Just to maintain speed, say 50 mph, it'll feel like it's shuddering/missing.

ECM also won't throw a misfire code unless it's consistent. To prove that go pull the wires to the coils for one cylinder and drive around the block.

Might be time to take it to the stealership and let them **** me.

 

[Andy578]

should still be under warranty anyway

 

[Riccochet]

should still be under warranty anyway

And the dealer miss out on charging me a diagnostic fee? I don't think the powertrain warranty covers diagnostic charges like the 3/36 bumper-to-bumper does.

Either way, I'm sure they'll tell me it's plugs which are wear items. Charge me for the diagnostic, labor and parts and then it still not be fixed. I love when they start throwing other peoples money at problems.