01 Pathfinder 4x4 looses power

[swanicyouth]

Today I was driving along the freeway. I went to pass someone and all of a sudden my 01 PF 4x4 lost power. By lost power, I mean would not accelerate past 30 miles an hour and gets there very slowly. This is not a situation where I "need a tune up" or "better gas". Something happened all of a sudden. There is also a wining noise that started with this, but it only happens under load - so I can't pinpoint it in park. There was no CEL light and the engine idles smooth, the problem is only under load - I had a hard time getting it home up hills, as it accelerates very slowly. But, its fine up to about 10mph - when it starts to loose power, it starts to make a "whiny" type noise, which seems to be coming from underneath or the right side of the engine. I can't pin point the noise, because it's only doing it under load.

Revving the engine in park, it seems fine. There *seems* to be good pressure at the tailpipe. I shooked the exhaust and nothing internal seemed loose or broken. But, there is that "whiny" noise from under the vehicle, hardly noticeable when revving in park, but noticeable at RPMs over 2000 when driving.

Im thinking it could be one of 3 things:

1. Power Valves

2. Exhaust / cats plugged

3. Torque converter failure

My question is, if it was power valves, wouldn't the engine make noise when revving in park and not idle right. That doesn't seem to be the case. The fuel filter was changed about 6 months ago, and this did happen suddenly, so I doubt it's that. Plugs were also changed around that time.

Any comments, advice, help is welcome. Thanks!

[IanH]

Today I was driving along the freeway. I went to pass someone and all of a sudden my 01 PF 4x4 lost power. By lost power, I mean would not accelerate past 30 miles an hour and gets there very slowly. This is not a situation where I "need a tune up" or "better gas". Something happened all of a sudden. There is also a wining noise that started with this, but it only happens under load - so I can't pinpoint it in park. There was no CEL light and the engine idles smooth, the problem is only under load - I had a hard time getting it home up hills, as it accelerates very slowly. But, its fine up to about 10mph - when it starts to loose power, it starts to make a "whiny" type noise, which seems to be coming from underneath or the right side of the engine. I can't pin point the noise, because it's only doing it under load.

Revving the engine in park, it seems fine. There *seems* to be good pressure at the tailpipe. I shooked the exhaust and nothing internal seemed loose or broken. But, there is that "whiny" noise from under the vehicle, hardly noticeable when revving in park, but noticeable at RPMs over 2000 when driving.

Im thinking it could be one of 3 things:

1. Power Valves

2. Exhaust / cats plugged

3. Torque converter failure

My question is, if it was power valves, wouldn't the engine make noise when revving in park and not idle right. That doesn't seem to be the case. The fuel filter was changed about 6 months ago, and this did happen suddenly, so I doubt it's that. Plugs were also changed around that time.

Any comments, advice, help is welcome. Thanks!

Did you try pulling over, switch off, restart and see if its gone.

Is this problem intermittent, or is it like it all the time now,
sound like its in limp home, have you read pending codes and codes ?
mine does this after hot soak once or twice a summer, still working on it !!!

[swanicyouth]

Today I was driving along the freeway. I went to pass someone and all of a sudden my 01 PF 4x4 lost power. By lost power, I mean would not accelerate past 30 miles an hour and gets there very slowly. This is not a situation where I "need a tune up" or "better gas". Something happened all of a sudden. There is also a wining noise that started with this, but it only happens under load - so I can't pinpoint it in park. There was no CEL light and the engine idles smooth, the problem is only under load - I had a hard time getting it home up hills, as it accelerates very slowly. But, its fine up to about 10mph - when it starts to loose power, it starts to make a "whiny" type noise, which seems to be coming from underneath or the right side of the engine. I can't pin point the noise, because it's only doing it under load.

Revving the engine in park, it seems fine. There *seems* to be good pressure at the tailpipe. I shooked the exhaust and nothing internal seemed loose or broken. But, there is that "whiny" noise from under the vehicle, hardly noticeable when revving in park, but noticeable at RPMs over 2000 when driving.

Im thinking it could be one of 3 things:

1. Power Valves

2. Exhaust / cats plugged

3. Torque converter failure

My question is, if it was power valves, wouldn't the engine make noise when revving in park and not idle right. That doesn't seem to be the case. The fuel filter was changed about 6 months ago, and this did happen suddenly, so I doubt it's that. Plugs were also changed around that time.

Any comments, advice, help is welcome. Thanks!

Did you try pulling over, switch off, restart and see if its gone.

Is this problem intermittent, or is it like it all the time now,
sound like its in limp home, have you read pending codes and codes ?
mine does this after hot soak once or twice a summer, still working on it !!!

Yeah, I tried both pulling codes (none) and letting it sit a while (no change). Im just wondering how the wining noise fits in. I was driving, and something "broke" thats for sure. Maybe the cat broke internally, but there seems to be decent pressure at the tail pipe.

[IanH]

there are codes and pending codes.
Most readers will read the pending codes as well. I would check this out.

So the problem is constant, I don't have any idea what the wining noise could be.

[swanicyouth]

there are codes and pending codes.
Most readers will read the pending codes as well. I would check this out.

So the problem is constant, I don't have any idea what the wining noise could be.

The "whining noise" almost sounds like a lawn mower engine. Again, it idles fine, revs fine in park, revs fine in drive w/ the E brake on, and has no SES and no codes. I had a chance to jack it up today and look around. Everything looked fine underneath. I had it idling and both cats seemed equally hot. Nothing seemed abnormally hot. When driving, I can't pick out if the whining noise is coming out the intake, from the transmission, or from the exhaust. The bad part about it is, you can't duplicate it when not moving.

This is so odd. It happened suddenly. I was able to check the linkage and the opening of the swirl control valve. Nothing external is frozen or broken. Same thing with the power valves. I opened both with the engine idling and nothing changed.

It really seems to me like something internal in the torque converter broke. It doesn't seem to be in the transmission itself, its almost like the torque converter can't transmit power above a certain speed efficiently. I check the trans fluid and its fine. I'm usually able to fix stuff like this but this has me baffled. I'm pretty sure its not the power valves, as the engine is quiet and idles and revs smoothly.

It would seem like the cats are clogged, but I've never heard of this happening all of a sudden. Also, the exiting exhaust seems normal and the cats do t seem abnormally hot. This has me stumped. I wish the was a code to send me in some direction.

It just drives like above a certain speed something is fighting the engine, almost like a seized pully, but there is no evidence of that.

Anyway, I give up. I don't want to spend a lot of money hanging parts when I have no idea what it is. Pulling the exhaust to look at the cats looks like a ton of work, I can't even see the top 6 bolts. It looks like the exhaust manifolds have to come off to replace the front cats. I have an appointment at the Nissan dealer Monday to have them look at it. I've never had to pay a dealer to fix my car before, I've always been able to figure it out myself.

If its too costly to fix in looking at a 2010 Xterra or Pathfinder. But, then again, if its catrostrophic I may not want another Nissan. The truck actually does have an aftermarket warranty that only covers limited things like engine, transmission, and driveline - not cats or emission control.

Any idea what cat replacement cost on an 01 PF?

[IanH]

mines got 105K and no real issues.

I looked on rock Auto and the Front L and R CATS are about $190 each, the under cat is the same if I am reading the parts correctly.
If they don't have the underneath CAT I am sure a universal will fit under there.

My code reader reads Pending codes, these do not throw a CEL warning light, and The guys that read your codes for free don't read these for you in my experience.

[IanH]

there are codes and pending codes.
Most readers will read the pending codes as well. I would check this out.

So the problem is constant, I don't have any idea what the wining noise could be.

The "whining noise" almost sounds like a lawn mower engine. Again, it idles fine, revs fine in park, revs fine in drive w/ the E brake on, and has no SES and no codes. I had a chance to jack it up today and look around. Everything looked fine underneath. I had it idling and both cats seemed equally hot. Nothing seemed abnormally hot. When driving, I can't pick out if the whining noise is coming out the intake, from the transmission, or from the exhaust. The bad part about it is, you can't duplicate it when not moving.

This is so odd. It happened suddenly. I was able to check the linkage and the opening of the swirl control valve. Nothing external is frozen or broken. Same thing with the power valves. I opened both with the engine idling and nothing changed.

It really seems to me like something internal in the torque converter broke. It doesn't seem to be in the transmission itself, its almost like the torque converter can't transmit power above a certain speed efficiently. I check the trans fluid and its fine. I'm usually able to fix stuff like this but this has me baffled. I'm pretty sure its not the power valves, as the engine is quiet and idles and revs smoothly.

It would seem like the cats are clogged, but I've never heard of this happening all of a sudden. Also, the exiting exhaust seems normal and the cats do t seem abnormally hot. This has me stumped. I wish the was a code to send me in some direction.

It just drives like above a certain speed something is fighting the engine, almost like a seized pully, but there is no evidence of that.

Anyway, I give up. I don't want to spend a lot of money hanging parts when I have no idea what it is. Pulling the exhaust to look at the cats looks like a ton of work, I can't even see the top 6 bolts. It looks like the exhaust manifolds have to come off to replace the front cats. I have an appointment at the Nissan dealer Monday to have them look at it. I've never had to pay a dealer to fix my car before, I've always been able to figure it out myself.

If its too costly to fix in looking at a 2010 Xterra or Pathfinder. But, then again, if its catrostrophic I may not want another Nissan. The truck actually does have an aftermarket warranty that only covers limited things like engine, transmission, and driveline - not cats or emission control.

Any idea what cat replacement cost on an 01 PF?

It almost sounds like a misfire to me !!

Let us know what the dealership says.

Good Luck....

[swanicyouth]

OK, got a diagnosis. It's the cats and the resonators - clogged. Vehicle needs complete new exhaust (which I knew), cats, resonators, and we are putting 4 new o2 sensors in it while in there. Dealer called me with a 6k estimate using all Nissan parts. Now we are down to $3800 using aftermarket parts. Since the vehicle is close to perfect, I'm fixing it. I know the price is high, but $700 is o2 sensors (Nissan) and $300 is diagnostics. I could get it towed down the street and get it done for less, but these people already have their hands in it and I just want it fixed.

Ive already put a lot of cash into the vehicle getting it cosmetically as perfect as an 01 could be. I looked at 2010s and they were kind of beat. Hoping fixing it was the right decision

[IanH]

I would ask why the CATS are blocked.

Read up on the Oil consumption problem from the PCV valve and rocker cover baffles.

I am due for plugs so will replace my PCV and maybe put in a catch can in the PCV valve line.

[terry2001]

4000 dollars for a stock exhaust .i paid 6000 for the vehical.i hope it fixes your problem