1999 3.0 Off Road power loss & sounds like jet engine

[tpginmaine]

Hey All,
Been fixing this thing up for a couple months now, getting ready for inspection. My CEL has been on for a while & I've been trying to trouble-shoot that, but it's been driving great, so wasn't top priority. Unfortunately, this week something changed dramatically. It idles ok. Sometimes maybe a couple hundred too high? Not sure on that yet. That may be intermittent or just temp related, so spring in Maine means temps are all over the board from hour to hour. Anyway, this isn't a change compared to two weeks ago.
The problem is that under higher RPMs, approx 3k or more, it suddenly sounds like a jet engine. REALLY loud. Best I can explain it is to take the regular 3.0 engine noise and add one of those turbo hand-dryers found in public bathrooms. You can barely hear yourself think in the cab! I stood in front of the engine the other day and had my son rev it to 3k to try and pinpoint the where the noise was coming from. Not only could I not pinpoint it, it was so loud I was uncomfortable standing in front of it. Literally like too close to a jet engine. I definitely have a loss of power, too. It will purr down a straight-away at 60MPH, but hit the gas to pass & it starts screaming! It will down shift and accelerate, but feels like it's towing a boat or something.
The CEL code has been P0401, EGR flow insufficient. I cleaned the EGR valve last fall and it worked fine. I just checked that it holds vacuum, so I don't think there's a leak there. It holds vacuum from the valve to the solenoid, and there's good vacuum into the solenoid. So I thought it might be the solenoid, and I replaced that a couple weeks ago with no CEL luck.
The past couple days I've tried 1. Driving with the EGR vacuum hose diconnected, 2. Driving with the solenoid plug disconnected, 3. Driving with the DPFE sensor disconnected. No change in "screaming" or power loss.
What now?

 

[RonD]

Assuming automatic transmission from "downshifting" comments

Could be fan clutch, but you shouldn't lose power from that, but will get the louder noise

With engine stone cold, remove fan belt from crank pulley
Start engine, should be very quiet in engine bay with no fan
REV engine to get it to make the louder noise
If no noise replace fan clutch, most likely source of noise but check other pulleys by manually spinning them while fan belt is off.

You can run a stone cold engine for 2 minutes without a water pump, but no longer

If you still get the noise then best guess will be torque converter maybe transmission, which will cause power loss.

 

[Bretsk2500]

My vote is check the fan clutch as well.. as far as the CEL... did you clear the codes after changing the solenoid?

 

[tpginmaine]

Hey guys,

The ongoing CEL & sudden loss of power didn't lead me to suspect the fan, but I think you're right.
When I started messing with the fan I noticed an orange (washer) on the post, attached. I assume this is supposed to be a seal on the back side of the clutch. Also, it's supposed to spin freely with the engine off, right? It doesn't spin. So when the engine revs the fan spins full speed with the RPMs of the engine right?
I think I developed two separate problems pretty much simultaneously: fan clutch (noise) & power loss (assuming CEL related). I also suspect I need a new idler pulley & should do a new belt while I'm at it.

As for resetting the CEL code...um, no, I don't have an ODB scanner. But I did disconnect the battery when I did it & then the CEL was off for about one commute. Does that 'clear' the code, or does it needed to be electronically wiped?

Thanks guys!
Todd

 

[RonD]

The engine computer stores "active" codes in a KAM(Keep Alive Memory) similar KAM is used in a car radio to hold Favorite Channel Pre-sets and Clock time.

KAMs get power all the time, even with key off

If you disconnect battery, usually takes about 5 minutes, you will Clear the KAMs, so codes will be cleared from active memory, and clock needs to be reset, lol.

Computer also has a History memory, any codes should still be there but won't turn on the CEL because they are not "active" codes.
But if same problem that set the code before disconnecting battery is still there then CEL will come back on.
Most Codes require computer to "see" the problem a few times before is "sets the code" in active memory, which is why it can take a day or two for it to come back

Yes, you should be able to turn the fan, if it is locked then it will make ALOT of noise.

 

[tpginmaine]

Wasn't on the agenda for this weekend, but I'm taking a small trip Wednesday...so today I replaced the fan clutch, the idler & tensioner pulleys, and the V-belt. Purrs like a kitten now, better than ever since I've owned her! Took her on a long test drive, and what's strange is that 1. performance seems to be completely restored, 2. The CEL never came back on. Could a slipping belt and drag from the fan cause those two problems somehow? I expect the CEL to come back, but it sounds & drives great again.
THANKS FOR THE HELP!!!
Todd

P.S. - attached a picture of the bad fan clutch bearing race. If your bearings look like that, you've got a problem!

 

[RonD]

Good work

I don't know, might have been a bit early to change that fan clutch, looks like it would have been good for another 5 or 10 miles

Fan was "grabbing" air and that does take horse power, so............

Not sure on the codes