My '08 Ram with 6ooo miles becomes very sluggish during hot summer days. I got it last Dec and it drove fine thru the winter and spring, in fact it was a very quick truck. It still runs great after its parked overnight in cool temps (50 deg, we live at Tahoe)

The problem is on hot days, after the truck warms up 10 miles or so, there is a sudden major loss of power and the engine makes a lot of rushing sounds when the gas is hit, but does nothing. The tach is also slow.

The dealer admits something is strange, but cannot nail it down. They replaced the cat, did the hotline with Chrysler, all codes are good, and now they say that that's 'normal'. Say what?? There is just too much of a drop in performance to be normal!

Any ideas?

 

When you say rushing sound, is it more like a roaring or sucking sound. It sounds almost like fuel starvation or vapor lock. I know that computers and fuel injection should not allow this but computers tend to hide problems. Faulty knock sensor? (not sure if our trucks have a knock sensor.) Make sure the truck is not overheating as well.

It's a long shot, but you might have a plugged fuel filter.

Just spit balling if ya know what I mean. Let us know how it goes.

 

I am right now looking to find the knock sensor harness so I can unplug it, which is supposed to be located by the #8 coil (rear pas side) but it ain't there, or at least I cannot see or feel it.

The engine makes a rushing/roaring sound with a dull whistle on the passenger side when I punch it. Not overheating. FYI I already tried disconnecting the EGR. Runs great until the engine compartment heats up.

 

For anyone that may have an interest in a 4.7 losing power on hot days, my truck went back to the dealer today with disappointing results.

I was told by the head service tech that they acknowledge the issue, the truck really does lose a LOT of power when the under hood temperatures are hot, but they say that this is normal! They also said they did a comparison with another '08 that came in on trade and it behaved the same way, now that is indeed troubling.

I cannot imagine Chrysler making a vehicle that runs like a sports car on steroids on cool days then loses so much power when it gets warm that it is unsafe to drive. What if a person lived in Phoenix?

Anyway, does anyone out there owing a 4.7 have this problem? Could this really be a legitimate issue? I would most appreciate hearing from anyone else experiencing this.

 

Kinda Out there but maybe try an E-Fan mod ?
prolly robbing a few horses and when the clutch engages the fan will make a whoooosh while pulling air at higher rev's,,,,

 

Thanks for the suggestion. My first thought was the viscous fan, but it is not locking up, that is I can free wheel it even with a hot engine. Still, the horsepower difference is major, more than turning a locked fan.

This is my third new Ram with the 4.7 and none of the others did this. My '02 had 75k on the clock when I traded with no such issues.

As much as I have liked my Dodges over the years this new one goes on Craigs list if they can't, or won't, fix it.

 

yea i dont blame you i dont see how anything could make that much of a difference "on purpose" something is wrong and they just dont want to look like idiots is my guess...if its as significant as you say it is.

 

Thanks for the support, I'll post whatever the outcome winds up to be.

I can't help but wonder if anybody else out there with a new 4.7 has experienced the same thing, seems if my truck is this way there must be others. The fact that, besides my own experience with past Rams, the head service tech agrees the problem is real makes me believe that Dodge hopes it will just go away without a fix. If that is so, it's a **** poor way to save a buck. How do they expect repeat buyers?

 

I have a 2008 4.7 which just turned over 10,000 miles. I have not noticed any power problems so far and living in FL it can get pretty hot here. Even when getting off the interstate on hot days it wants to get up and go in traffic.

Sorry to hear about your problem.

 

My 5.7L ram is exactly the same...in the winter when its like -20c holy CRAP does she move due to the dense cold air....in the summer it feels like a completely different vehicle....hot air isnt good for performance.