Hoping someone here can help, because nothing else has...
154,000 miles on vehicle. Regular oil changes. Nothing but highway miles. Now the car has almost NO power and stutters/stumbles until 3k rpm, then explodes with power like a rocket up to cruising speed. When trying to pass another vehicle however, the engine revs up like normal (3k-4k rpm) and the transmission shifts down, but it feels as if no power is actually making it to the wheels because the speed does not increase. This same problem happens when driving up hills. Yet again though, if the rpms drop below 3k, the car stutters/stumbles. Car operates absolutely fine when not in gear, and seems to shift like normal (no hard shifts, erratic shifts or tardy/extended shifts) Checked the fuel pressure, and it is within range. Replaced plugs/wires, fuel filter, EGR valve, cleaned throttle body, replaced Body Control Module.
EDIT: Checked Tranny fluid (stupid sealed transmission BS) and it was up to the drain plug.
Last edited by hypageck; 09-10-2011 at 11:00 PM.
Reason: Tranny info
Now the car has almost NO power and stutters/stumbles until 3k rpm, then explodes with power like a rocket up to cruising speed.
No real help but an idea:
Maybe it's not an engine problem at all but transmission trouble.
It kind of sounds like a more severe case of what several folks have been reporting on here with erratic operation in the lower gears.
If that IS the case, visiting one or more transmission shops for an "evaluation" might give you a better perspective. If that is the problem, it might be time to consider a trade-in.......as getting the tranny fixed would likely cost more than the car is worth.
I'd like to say a restricted exhaust, maybe clogged catalytic converter but you say over 3 grand it explodes with power. Kind of doesn't fit very well with restricted exhaust but keep it in mind. Did this happen all of a sudden? No check engine light? Engine stutters and stumbles, sounds like misfire, should trip the check engine light really. Can you feel the stumble/stutter at idle in gear and not moving?
I haven't been to a shop yet, but I have an appointment with one this week.
It did throw a MIL light once, Advanced Auto read that the EGR threw the code, so I replaced it.
The problem started about a month ago. I replaced the plugs and wires, and it went away till about a week ago. I've checked all the plugs and wires, and they test ok.
The car does not act weird in neutral, park, or while in gear and stopped. I lifted the car today, and it does not act oddly while in gear and off the ground. The problem happens in any gear, too.
New update though, I can hear a hissing noise coming from the front drivers side of the vehicle when the problem is ongoing, then it completely goes away at 3k rpm. Sounds almost the same noise as if I was riding my brakes ( they relax at 3k?) or as if there is a vacuum leak (sucks closed at 3k??) RPMs are slow to rise while trying to take off from a stop, until you hit 3k... it never fails to stop occurring at 3k rpm.
I wonder if there's some kind of second path in the intake system that is controlled by the ECM. One where it's a long path during low RPMs and a shorter path higher up. If there is it could be that the mechanism is obstructing the path (or both paths) during low RPMs and then the movement at 3000 clears it.
In the 90's Ford used a system like that and I believe other manufacturers did or do as well.
Just a thought...
'11 LTZ, born Aug 2010, Fairfax, KS
V6/A6, Red Jewel Tintcoat / Cocoa-Cashmere, Sunroof
Mods: WeatherTech mats, CHMSL Pulser
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