Would not go above 2500 rpm (this was a post by someone else but eerily similar issues)


#1

My car will not exceed 2500 RPM in any gear. In first (or any other gear) gear I can drive up to 2500 RPM and then must shift into 2nd (or the next gear) if I want to go faster, if RPM goes above 2500 the car stops accelerating and the RPM drops to 2000 at which time the car starts to accelerate again. The engine is running at a very high rate when I come to a stop as if the idle is set too high. The car does not lose electrical power when this happens. I have driven the car more than an hour in 5th gear going 45 to 50 mph keeping the RPMs between 2000 & 2500. I can get around town with easily as long as I am staying in the 2000 to 2500 RPM range. This problem started late Saturday night when I was in Phoenix and had to get to the airport to pick up my daughter and then get back home to Prescott, AZ. Since the dealers were all closed on Sunday I just went home at 45-50 miles an hour all the way back to Prescott. It was a long drive but we enjoyed ourselves. The car ran fine except for the RPM problem. Please Advise…Thanks so much.

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VDCdriver

February 2013

Since we don’t know the make, model, model year, maintenance history, and odometer mileage of your mystery vehicle, much of the advice that you receive will be guesswork. But…here goes with my first guesses:

If your catalytic converter is clogged, that would cause the engine to be unable to gain speed.
Another possible cause might be a partially-clogged fuel filter or a weak fuel pump.

If you post back with the missing information that I mentioned above, we might be able to be more helpful.

Stoveguyy

February 2013

Whew! Car will not rev over 2500 but u continue to drive it? Is your reasoning such that “it’s not on fire”, so it must be ok to drive it?

Caddyman

February 2013

As VDC said, we need some basic information to be able to help you…

KatFur

February 2013

I appreciate you your input and sorry for lacking info. My car is a 2004 Kia Rio Cinco with 82,000 miles, 5 speed with self-adjusting clutch. All regular engine and transmission maintenance has been done on schedule. Everything else with the car is working well. I made sure that I was monitoring the systems as I was trying to figure out just what the symptoms where. If it where a clogged catalytic converter or fuel filter would there not be some sputtering? There has been none, really not even a little bit.

Caddyman

February 2013

A clogged fuel filter should cause some mis-firing but a clogged converter may not…If the car will coast along normally without any noticeable drag slowing it down (dragging brakes) then a restricted exhaust becomes more likely…have a shop put it up on a lift for a visual inspection and a simple exhaust back-pressure test…If this problem is constant, then any competent mechanic should be able to run it down quickly…

KatFur

February 2013

Since I have never experienced anything like this I was feeling pretty unsafe about taking to a mechanic about the problem because they could have told me anything and I would not have been able to spot a good lie. I feel much more confident in engaging a mechanic and asking questions…THANK YOU

Caddyman

February 2013

To test for exhaust back pressure, the front oxygen sensor is removed (its screwed into the exhaust pipe ahead of the converter, looks like a spark plug) and the exhaust back-pressure measured at that point. 2-4 psi is normal, more than that, something is plugged up…

$100 should more than cover the diagnostics on this and a decent shop might credit this towards the repair if you have them perform the repair. Always ask “Do you guarantee your recommended repair will cure my problem?” Don’t pay for guess-work…

the same mountainbike

February 2013

“This problem started late Saturday night when I was in Phoenix and had to get to the airport to pick up my daughter and then get back home to Prescott, AZ”

Since the problem occurred suddenly and has all of the symptoms of a dropped vacuum line, allow me to suggest that you pop the hood and look for any free-hanging disconnected rubber line going toward the throttle body area or from the vacuum booster. You might get lucky.

Ultimately, it may turn out to be something like a dying fuel pump or a collapsed cat converter honeycomb, but it’s worth looking at the vacuum lines. It’s free.

db4690

February 2013

May we assume the check engine light is or was on?

circuitsmith

February 2013

First, a clogged converter will not cause a high idle, so let’s rule that out.
I’ll share my experience with similar symptoms long ago.
The timing belt on my 1975 Civic jumped ahead a tooth.
I guess a combination of being loose and parking in gear twisting the engine backward.
The engine would reach a certain RPM an “gag”.
I didn’t know what RPM because it didn’t have a tachometer.
So you might want to get the valve timing checked at some point. My vehicle is an 06 dodge ram 1500, and the odometer is just under 116000miles on it. Soo any ideas?


#2

Idk to much about past maintenance, but since I’ve owned it, ive maintained it properly has had the oil and spark plugs changed recently, I was dropped off at the airport after it acted up on the way there and my friend drove it back and now it stopped but the check engine light is still on.


#3

The other suggestions you listed are viable reasons why your car won’t rev over 2500 rpm BUT they shouldn’t be so precise. Clogged fuel filter, cat convertor, ect. Plus many of these would light the Check Engine light.

I have a novel idea… Maybe your clutch pedal switch is stuck in the ON (depressed pedal) position. Some cars will not allow you to rev the engine up, abruptly release the clutch and spin the tires so they limit RPM when the clutch is pressed. Software in the engine computer may prevent the RPM from going over, in your case, 2500 RPM if the clutch is depressed and the only way it knows this is if the switch is activated. Check, or have checked, the switch.


#4

Only thing is it’s an automatic there’s no clutch I’d have to put in neutral.


#5
My car is a 2004 Kia Rio Cinco with 82,000 miles, 5 speed with self-adjusting clutch

So this isn’t yours? What, exactly is your car, the mileage and the options?


#6

I did not bother to read through all of that as the longer the post the more difficult it is to remain focused and remember everything said.

Since it bogs at 2500 I would suggest checking for an exhaust restriction; say a clogged catalytic converter, etc.


#7

Make, model, year, and miles? It is impossible to tell what parts of your post are your own or are copied and pasted from other threads.

How about posting with information about your car only.

Ed B.


#8

Edb 1961 sorry for all that I didn’t realize I had all that extra until after I posted it Stuff there But the very last specs are my vehicle the dodge ram


#9

I would have to believe both the check engine light and electronic throttle control warning lights are on.


#10

What year Dodge Ram…What engine size ? These are basic basic details any and all need to assist. As soon as we know these simple items to convey…troubleshooting can begin.

If your Check engine light is illuminated…which I seriously think it is…We can use the engine codes. Simple stuff here.

Blackbird


#11

It’s a dodge ram 1500 year 06, 160000 miles 4.7L engine and only the check engine light was on, also the airbag light has been on for quite sometime now. But other than that it’s in a clean bill of health


#12

The fault detected by the Powertrain Control module is the reason the rev limiter was reduced to 2500 RPMs. The answer is in in your vehicles computer, read the fault codes.

BTW, if you click on the gear in your original post you can edit/delete the unrelated information that came from other posts, it would make it easier to read.


#13

I believe your car has gone into “limp” mode. This is related to your check engine light, which at some point might have been a “flashing” check engine light. This occurs when the computer detects a major problem which could harm the motor if it runs at full speed. The computer allows the motor to limp along at a lower rpm. This is to allow the car to get either home, or off the highway until the problem is fixed.

The Ram truck needs to get to a mechanic and hooked up to a scan tool to see what fault codes are stored in the trucks computer.


#14

OK…the engine light is on…what is the code ? Trust us…that is info you want.

Blackbird