CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

2015 jeep high altitude

my kid lives in colorado springs. he has a 2015 wrangler 3.6. runs ok around town but he went up to pikes peak and it basically would not go near the top. motor stalled, would not start. and so on. this was on paved road to the top. no offroading/rock climbing involved. he had 1/4 tank and had to turn around. no codes that i am aware of. many jeep boards say its hit or miss. some jeeps have no issues with high altitude and some do. should a new jeep have issues like this?

Definitely not! Cars should function at 10,000 feet, especially with fuel injection to adjust the air fuel ratio.

Another FCA product with a quality issue! Who would have guessed?

Pikes Peak is 14114 ft high.

He said it would not go near the top… I guessed 10,000 feet. It still should run at 14,000 feet as well.

It seems like it should handle that altitude no problem. It’s a Jeep, right? They are made for going to high altitudes on mountain roads. I’ve ridden in a rental car to the top of P Peak before, and that car had no problem on the way up. And there were probably 40-50 other cars at the top, and many more on the way. On the way down the brakes overheated so we had to stop and let them cool a couple times, along with many other drivers doing the same. But no problem at all with the engine, except perhaps a little loss of accelerating power near the top. 14,000 foot air is pretty thin, just climbing a dozen steps or so to go inside the visitor center at the top was a huffing and puffing chore. Some other people were having problems with headaches and nosebleeds too.

The way the engine computer handles thin air is either the MAF or the MAP. I’d guess the MAF would be more sensitive to errors in the accuracy of measurement than the MAP. So my guess, the MAF is slightly mis-calibrated, perhaps b/c it is a little dirty.

I absolutely agree.
Based on the way fuel is metered on modern engines, the system should have no problem metering the proper fuel amount at high altitudes. It would appear that this system isn’t. Especially a Jeep.

The problem is either design or manufacturing related.

Actually, they are made to go off road, which may or may not involve high elevations.

he says it has happened twice going to the top. he had to stop and turn around. ran fine at lower elevation. maybe something as simple as the map sensor? the jeep does not have a maf.

I wouldn’t call a two-year-old Jeep “new,” especially if it’s been treated like a Jeep.

I suspect it might not be an air-fuel mixture problem (like I might normally assume if it wasn’t fuel injected), but it could also be a fuel sump/pump problem related to the angle of the jeep as it climbed an incline. I wonder what would have happened if he had turned around and tried to continue the trip in reverse. When you’re in the mountains, you can find yourself on an incline without realizing it if the nearby rock formations protrude from the ground at an angle.

Where was the temp gauge at? Do you know? Maybe the engine was overheating and it shut down for that reason.

I’ve been to CO countless times through many 12-14k foot passes and so on in a number of vehicles and every one of them lost some power and all ran hotter than normal.
It would be easy to ignore the temp gauge considering the terrain and with eyes focused on the drop offs.

You might do the math. A 3% horsepower drop for each 1000 feet of altitude.

That’s a good question. I was thinking it might be an oil sump issue, but I figured the OP’s son or daughter would have noticed something like an oil light, high temperature warning light, or a rising temperature gauge.

That’s correct. The excursions off road may involve high altitudes. If they do, the jeep should be fine with it.
Adventurers are often drawn to mountains. So in essence you’ve supported George’s point.

There are also a lot of steep grades and rough terrain near sea level, so going off road for adventure doesn’t automatically mean you will be driving at high altitude.
Also, there are a lot of paved roads at high altitudes, so driving in high altitudes doesn’t automatically mean you will be driving off road or even climbing steep grades for that matter.

Surprisingly the road to the top of Pikes Peak isn’t particularly steep. Just a long, slow well paved incline. I doubt the reason for the Jeep’s engine performance problem is the grade. No harm to try the experiment of backing up the hill when it happens tho, good idea actually, might provide a clue. My dad used to tell me he would have to back his Model-T up steep hills to keep it running. I think the reason was the gas flow to the engine was gravity fed, no pump, and the tank was in the back of the vehicle. If it isn’t an air fuel mixture problem for the Jeep, my next guess after that would be something temperature related. Nearing the top will be when everything in the drive-train is over-stressed & overheated the most, and I expect the radiator is less efficient at cooling when the air is thin.

How did he turn the Jeep around to go down the mountain if the engine wouldn’t start? Sounds like the fuel pump might be failing. Will you be going to the top of Pikes Peak to diagnose this?

Another possible reason is that a Model T’s transmission had a 2.75:1 reduction ratio in low gear and a 4:1 reduction ratio in reverse.

Engine lost power. Wouldnt idle. Stalled. Wouldn’t start. Sat awhile finally started. He turned around. I suppose you could assume it eventually started since he got home. He was not towed home.

If you look on Jeep forums, there are a lot of complaints about this but no resolutions that I saw.

I looked also, seemed a computer reprogram helped some, Kind if like it learned in the flatlands and wanted to stay in the flatlands.

I can see the advertisements during NFL football games now: "The New Jeep Flatlander "… lol …