Engine rev's oddly on hills, what do you think?

[treepete]

Hey guys,

I think I remember someone post on this forum about their engine revving weirdly at times, and I think I am developing the same problem.
I have a nice long uphill climb for about a mile near my house and my truck seems to rev weird when I go up this hill.
I try to keep my RPM low for mileage sake, and when I get to this hill the engine is under a bit more load. RPMs will be at say 1400 and then slightly change up to about 1600 or so ( normal, I think, cause im going up the hill)
but then it'll go to about 2000, then to 1400 then to 1600, etc and it bounces around in there. I feather the throttle a little bit and I can make it change slightly, but I dont think this is normal. if I had to make the 5 seconds worth of the sound of it, it would be like this:

rrrrrrrrrrrrrRRRRRRrrrrrRRRrrrrRRRrrrRRRRRRRRRRrrrrr

what do you guys think of that? Am i over-reacting, or is something starting to go wrong. I dont want to lose my proactive edge from upgrade-mode to repair-mode, so I thought I would bring it up early.
thanks in advance for your thoughts.

Pete

 

[96ProCompTahoe]

checked your trans fluid lately?

sounds like its shifting in between gears going up the hill.

 

[Rebound]

I've got an '07, but that's what mine does. $tealer "couldn't find anything" wrong.

 

[Stargazer]

sounds like its shifting in between gears going up the hill.

That's what I think, too. It's hunting for the right gear. I would either give more throttle to go up the hill at a higher speed, or push the Tow/Haul mode button (if you have one) so that it stays in gear longer.

 

[Whippled2dr]

It's probably your torque converter unlocking and locking. It's pretty normal.

 

[Rollin Thunder]

I (a couple of weeks ago) made the round trip from hear to chicago, threw west va mountains, and kentucky. Mine did rev up to about 3500 (sometimes even 4000 rpms to maintain 85-90) but did not ever vary like yours. I cant help you, just posting to give you some food for thought.

When i was just cruzin along at 65-70 I would jump to 2500 when climbing hills. But it was always, no matter what RPM, was a solid monotone rumble, never varied. But apples to oranges here. IN some cases, same tranny, different engine, and my truck only has about 3500 miles on it. (2k of those miles are my trip)

 

[treepete]

OK maybe im freakin.. I will check the tranny fluid to see where its at,.. its just weird. like its hunting around for the right gear, and even at steady uphill climb, it can't seem to find the proper gear to sit at.
ok yeah, thanks for all your thoughts on that one, guys. I appriciate it.

Pete

 

[Rebound]

It's probably your torque converter unlocking and locking. It's pretty normal.

That's what the mechanic at the dealer said.

I discounted it, as they are more interested in making money than they are in helping their customers.

 

[Stargazer]

I try to keep my RPM low for mileage sake

like its hunting around for the right gear, and even at steady uphill climb, it can't seem to find the proper gear to sit at.

I live at the top of a mountain and have a long steady climb, too. I find that under 2000 rpm, the transmission has a really hard time finding the right gear. I know it's supposed to have 417 lb.ft. of torque, but it's not there in the low rpms. It's OK when you're on the flats, but not when you're climbing.

It'll hold the gear until about 2300 rpm, shift up, drop down to 2000 rpm, loose momentum, shift down and repeat. Maybe I'll follow my own advice and try the tow/haul button one of these days .

 

[mygreen98]

try putting the truck in 3rd gear before you get to the incline and see if i stops hunting for a gear.

 

[treepete]

OK ill try that tonight on my way home and see what happens

 

[treepete]

ok yeah, I tried that hill in "3" which is one below "d" for my truck. and it does the same thing.
any other thoughts, or am I overreacting?

 

[Rollin Thunder]

ok yeah, I tried that hill in "3" which is one below "d" for my truck. and it does the same thing.
any other thoughts, or am I overreacting?

go a gear further:thumbsup: try 2 if below 45-50 mph.

 

[mygreen98]

it sounds like the lockup converter is engaging/disengaging. what speed are you doing? lock up engages around 45 mph.

 

[95TwinTT]

Something to try, when ever it is happening, ride the brakes just enough to turn on the brake lights, but not enough to slow you down. The brake being applied, will disengage the TC lockup. If it continues to do the up and down thing with the brakes slightly applied, I would rule out the locking TC......

 

[Whippled2dr]

Something to try, when ever it is happening, ride the brakes just enough to turn on the brake lights, but not enough to slow you down. The brake being applied, will disengage the TC lockup. If it continues to do the up and down thing with the brakes slightly applied, I would rule out the locking TC......

I agree.

 

[treepete]

ok sorry for the delay i was jagging around in a permit to carry class this weekend and then it was raining. ( what that has tto do with anything I dont know)
OK didnt check tranny fluid yet. forgot.
I tried up the hill in "2" instead of "d" and the revving thing DID NOT change. i got it up to about 45 mph and the RPMS were kinda high, so I didnt continue with that test.

Del, Ill try that braking idea of yours next time up the hill. maybe it is the TC and that would be cool if it was normal.