2007 Escape RPM Can't Exceed 4000
 

My son-in-law's 07 Escape XLT just had this weird problem: when parked and rev the engine, the RPM can't go beyond 4000. And when it reaches 4000, the engine starts to shake and the RPM just stays there. As a result, if you drive from a stop to accelerate, you feel lost of power. The scanner didn't find any code and the check engine light is not on. Did anybody here had the same problem before and know the cause of this? Please share.

Sounds like a rev limiter behaving as designed. Why would you want to rev it that high in Park?

What happens if driven normally? Auto or Standard trans?

He first told me it hesitates whenever accelerate from a full stop such as traffic lights. I then tested by just revving it up in park and thought if it can't rev up at park, it can't do it either when driving. I have a 94 Bronco and 05 Expedition, both can go as high as I want without any rev limiter in park unless they have problems. I will try to drive it tomorrow to see if I can tell anything different. Thanks!

It's automatic, BTW, and I didn't see any red line on its tachometer to set the rev limiter.

That is the rev limiter doing what it is suppose too. What happens if you power brake it. When was the fuel filter last changed, that is what it sounds like to me, starving for fuel. The rev limiter is built into the PCM and cant be adhusted, well wouldn't say cant, but you need a laptop with the software to do it.

I also asked him about the fuel filter and he said it's never been replaced. I will replace it first and let you know the result. Thanks!

BTW, rev limiter is usually set above 6000, right? My old Bronco can go higher than that and last time I found it can't go over 3000, they found cat converter meltdown caused it.

on an escape 4000 sounds about right though it will rev higher while driving. It's just a safety issue they put into the PCM programming why rev a truck to 4000rpm's in park? that is what the pcm is saying!!

I had a rental 2005 Mustang with a V6 that wouldn't exceed 3,000 RPM in Park.

How does a PCM do this? Cutting off/reducing the fuel?

Depends, making the engine run lean is dangerous so mostly it will completely cut the fuel on individual cycles to give you a solid misfire that won't result in unburnt fuel going into the cat.

Experience with other models is not really relevant, different designers may have completely different views on the protections their engines need.

As with others - don't just rev under no load - and you've immediately drawn a false conclusion.

When did it last have new plugs and COPs?

I just wonder how could that not trigger some kind of code, such as misfire. Fuel pressure low could trigger some code too, right?

Since I didn't find any code, I assume plugs/COPs are OK. But I may need to replace the plugs too since I have no idea when they were done last time.

Low FP should issue a code. Plugs/COPs don't issue a code even for quite a severe misfire, I have just replaced all 6 COPS on my V6 for what seemed a mild hesitation only apparent in tope gear cruise but changing them has resulted in about 10% better gas mileage...all with no codes thrown.

My 05 Expedition gave me #3 and #7 misfire codes now so I may need to replace COPs for those two. I did a couple before but never replace all together due to cost. Why brand did you buy?

I've used both PAT and Bosch.

Never heard of PAT before, Bosch is probably a good one (must be pricey too).