Rattle on the engine

[Nick K]

This promblem has been going on for about a week or so. Every time I hit 4000 RPM there becomes a rattle coming from under the hood, the rattle will continue all the way untill 4500RPM were it shifts. As soon as I let go of the throttle the sound is gone and the rattle only happens in the higher RPM's. Is this Pinging? What do you think this could be?

 

[yob_yeknom]

That sound you hear is your Explorer telling you to stop ragging it out! What reason do you have to turn 4,000+ RPM's? It's just wearing out the engine faster.

The sound you are describing does sound like a little bit of knocking/pinging. Not uncommon to hear at high RPM's, considering the weight of an Explorer is a pretty large load.

I also know exactly how to fix your problem:
Don't push it past 3,500 RPM's anymore.

 

[CADDYBILL]

I would have to agree with yob_yeknom, but you may also whant to check out your exhuast heat shields. Sometimes they come lose and make the noise you described. Happened to mine and I wraped a hose clamp around them. No more noise.

 

[Ross-N-Chicago]

i had same thing, fixed the heat shield- nope. replaced u joints-nope. it was a connector just south (toward firewall) of the coolant overflow tank. she was tucked in there and banged around under heavy loads. zip tied her down and no more noise.

 

[Nick K]

Great I'll go look and see. 4000 RPMS does'nt seem all that high. I also have a Saturn DOHC which easily revs to 4000 just coming of the line, and it red lines at 6700

 

[Alec]

I definately could be detonation though. With the intake and exhaust mods, you might need to run 89 octane. Sometimes when the stock computer is reset to take advantage of the mods, it likes a little higher octane.