High rpm and gear hold.

[3leggedlamb]

Hi,

I have a 2014 trail addition with 12000 miles. Drives around the town the car performs fine, but I have notice when I’m climbing a up-hill road such as hwy or paved trail between 60-75 mph the gear holds to long on the 4th between 3000-3500 RPM. It sounds like it's straggling.The only time that it will change the gear to the 5th is when I punch the gas pedal little further then it change to the 5th gear otherwise it stays on the 4th gear the duration of the clime.

What concerns me is the long hold on the 4th. Is this normal for this kind of engine?

 

[borfoo3]

Yup, its smart enough to know what its doing

 

[marshal]

There is this thing called a load sensor, it tells your transmission when to downshift. If your climbing a hill, your engine is under load. The computer is designed to downshift at a certain load level to maintain speed, and to not place too much extended pressure on the internals of the engine.

 

[NoDak]

There is this thing called a load sensor, it tells your transmission when to downshift. If your climbing a hill, your engine is under load. The computer is designed to downshift at a certain load level to maintain speed, and to not place too much extended pressure on the internals of the engine.

but on the flip side of this, if you let the ecu do this while on cruise control, it takes forever to shift back to 5th (even on level ground or slight down hill).

to get around this, either pop it into sport mode before it downshifts or take it off cruise control.

 

[3wbdriver]

but on the flip side of this, if you let the ecu do this while on cruise control, it takes forever to shift back to 5th (even on level ground or slight down hill).

to get around this, either pop it into sport mode before it downshifts or take it off cruise control.

Twice during my long trip in April it downshifted into 4th and just stayed there. Both times in mountains where it had been doing up/downshifts regularly for an hour or so. I assumed the trans was getting hot, but was prepared to stop by a dealer to have it looked at. On both occasions putting the shifter in S mode and manually upshifting to 5th was the only way to get it done. It hasn't done that since, so I guess it may just have been a bit overworked from those mountain roads.

 

[3leggedlamb]

Thanks all for your response and your advice. Very informative.

 

[03_4x4Runner]

Kicking down to 4th gear at 3000-3500 rpm is nothing. Wait till you get to a really big hill and it kicks down to 3rd and 4500-5000 rpm. I run into that in the mountains in the west trying to run the speed limit of 75-80 on the interstates. I eventually just slow down so the engine does not blow up. At least it sounds like it should.

 

[Jeremy556]

Kicking down to 4th gear at 3000-3500 rpm is nothing. Wait till you get to a really big hill and it kicks down to 3rd and 4500-5000 rpm. I run into that in the mountains in the west trying to run the speed limit of 75-80 on the interstates. I eventually just slow down so the engine does not blow up. At least it sounds like it should.

You could run the engine at 5000rpm for days on end and the coolant needle* wouldn't even move, let alone anything blow up. It's a relatively modern, dual overhead cam, VVTI engine, it needs to rev to make power.

*disclaimer: the coolant needle is not a linear or accurate representation of actual coolant temp, but it will go up above 1/2 way when you start getting near overheating temperatures.

 

[3leggedlamb]

Kicking down to 4th gear at 3000-3500 rpm is nothing. Wait till you get to a really big hill and it kicks down to 3rd and 4500-5000 rpm. I run into that in the mountains in the west trying to run the speed limit of 75-80 on the interstates. I eventually just slow down so the engine does not blow up. At least it sounds like it should.

That's how I feel when I run into the hills. It's feels like the engine is about to give up. Last time I experience this was when I was climbing around 8 thousand feet.

 

[Jeremy556]

That's how I feel when I run into the hills. It's feels like the engine is about to give up. Last time I experience this was when I was climbing around 8 thousand feet.

As altitude increases, there is less oxygen, all engines are affected by it. 8k ft? Wait until you get to some big mountains, you'll really be hurting.

 

[3leggedlamb]

As altitude increases, there is less oxygen, all engines are affected by it. 8k ft? Wait until you get to some big mountains, you'll really be hurting.

Thats what I thought too at that time, but I was not sure. I thought I was doing something wrong. Good to know.

 

[m85476585]

Power decreases by about 3% per 1000 feet above sea level. The computer is smart enough to shift accordingly, and they do test these things at all different altitudes. When I drove up Pike's Peak (14,000 feet) there were some BMW prototype cars at the top. They seemed to be testing the high altitude capability of the German engineers they sent out to drive the cars! It's probably part of the initiation process for new hires.

 

[marshal]

Power decreases by about 3% per 1000 feet above sea level. The computer is smart enough to shift accordingly, and they do test these things at all different altitudes. When I drove up Pike's Peak (14,000 feet) there were some BMW prototype cars at the top. They seemed to be testing the high altitude capability of the German engineers they sent out to drive the cars! It's probably part of the initiation process for new hires.

Don't forget that the power decrease is exponential. Every 3% isn't 3% of the total, it's 3% of the remaining.

 

[NoDak]

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