i posted this in the "how high do you rev your 22re" thread but didnt get much response so instead of thread jacking that one i figured i would make my own. so please help me out because it driving me nucking futs!

if i take my engine over 4100 RMPs it sounds like its coming apart. i cant tell if its noise coming from the intake/exhaust or actual noise from inside the engine. it just sounds bad like a metal rattling sound. it also seems like it looses power if i go any higher then 4300 RPMs. the engine is basically new with less then 6000 miles on it.

my first instinct was timing chain so i pulled the valve cover again yesterday just to make sure the chain guides were not broken and the chain was tight. i also looked at the valve cover to make sure the rocker arms went hitting the cover but everything was good inside. i had the valves checked after 2000 miles and they were all fine. one thing i noticed too is free reving it while parked it doesnt seems to make the noise but, while in gear and under load it does.

so a few days ago, coming home from work i wanted to see what the engine sounded like up high again to try and pinpoint it. so i took the truck up to about 4900+ RPMs (highest its ever gone) at a gradual rate not WFO in 2nd gear and it was SCREAMING loud! right as i got to 4950 the truck bogged down pretty bad like i tapped the brakes and i let off instantly.
the truck still runs fine and it didnt make any odd noise other then the loudness it was already making. i didnt try to duplicate it but it scared the hell out of me. any ideas what would cause it to do this?

 

What other thread are you referring to? Is there any discussion/info there already covering your problem I could read?

 

Oh.....that one.

I'll be back later.

 

Okay....all I can think of at the moment....and since I'm not there to hear what's going on....is that you might be running too lean. I would think you'd get an O2 code, but maybe not.

If it seems normal at regular or light load, it maybe that while under load you're not getting enough pressure to compensate for manifold pressure. So, check the fuel pressure and check the operation of the fuel pressure up switching valve. That would/should be located on the rear/top side of the valve cover. It has a two wire electrical connectore with one vac line going to the fuel press. regulator. The other line goes to the intake manifold.

The noise maybe spark knock and/or the fuel pulse dampener may be kaputs.

Go ahead and read this and we can go from there:
http://www.autoshop101.com/

One more thing....check the condition of your spark plugs/what color they are.

 

check the timing

 

Good point!

 

Above 4k RPM's there's a power drop.. so it would feel like it's reached it's limit - cause it has.

 

timing is set at 5* i will pull the plugs tomorrow and look at them. i get no code when ECM is jumpered. will also check that switching valve too.

 

ok, pulled the plugs today and here is what they look like.

in order from left to right gaps were kind of off (26, 29, 30, 30) so i cleaned them up with a wire brush and re gaped them.

 

They look good....very normal.

Kaydon is right, though. The ECU has a rev limiter. So, when hitting high RPM's where engine damage could occur fuel is cut creating the drop off in power you're seeing. From what I understand, it's usually when you're redlining, but I don't really know enough to say one way or the other.

As far as the rattling, if there's anyway you could get a audio clip that would help tremendously. Otherwise, I'd check to see if you don't have something loose that's bolted on or around the engine....like the exhaust pipe or heat deflectors.

If you really believe the noise to be coming from the motor itself internally, I'd suggest getting an oil analysis. That way you could tell if the bearings or thrustwashers are wearing inappropriately creating crankshaft play. That's what I'd do short of pulling things apart again.

 

i understand the rev limiter in the ECU but i shouldnt be hitting it at 5000 RPMs if the redline starts at 5600. thats why it concerned me.
i will try to record it on my camera today but i dont know how well it will pick the audio up.

 

The noise you describe only occurs at high rpm AND under load?

IOW, you can't reproduce the sound in your driveway.

 

best i could do for now as far as recording the sound. although you cant really hear it all that well.

 

I put on headphones even and it hear anything particularly abnormal. wondering if maybe your valve may be starting to float from weak springs.

 

i was going to go buy a new set of feeler gauges today and recheck my valves but with 50mph wing gusts and so much sand and dirt in the air the sky is brown, i think i will wait until the weekend.

how could i tell if the valve springs were worn?