knocking sound from my 4.0 ohv

[00sport4x4]

I started hearing a knocking or rattle type sound from my X 4.0 ohv. To better describe it ya know when you change your oil and start it up you get the little engine noise before the oil pressure hits? well I get that sound when I turn it off? Well I took it to the dealer and the said that the catalyst converter has gone bad it will be replaced next week. Anyone ever heard of this problem? And I guess since there gonna put a new cat on it perfect time for a new exhaust opinions?

"Engines dont leak its just sweat from all that horsepower"

 

[MyExpWork]

I think a few people here have complained about that same type of noise and it being the cat.

Mine makes the same noise but my lifters are going bad. I doubt that is your problem cuz you prolly have a OHC.

Good luck with your new kitty.

Brian

 

[Dutches]

00sport4x4,
did you get that cat replaced? I have the exact same pop knock and it seems to be coming from the cat just wondering if this solved your problem. Thanks a lot

 

[Runnin'OnEmpty]

I also have a noise similiar to what you describe. It is only noisy upon a cold start-up, and quietens down when the engine gets warm. It dosen't sound like an engine noise, but more like it's coming from the exhaust. I'm hoping mine is just a loose converter shield.

 

[00sport4x4]

the new cat is on but it didnt solve the problem,So it went back to the dealer they looked at it and gave me a a dandy little flier saying alot of the 4.0s make this noise "it's known as the marble noise" and Ford has done a highmilage test on it and it does nothing to hamper the engine other then sound like crap! The noise sounds like a diesel engine but only when in park or nuetral when you put a load on it " in gear" it doesnt make it? I have taken the problem to my esp "employee support program" at the Visteon plant where I work we make alot of motor parts for the 4.0 they helped me with my F250 so we will see. I told them if it cant be fixed then replace the motor cause it's under warranty. Thanks for your replies.

 

[91Exploda]

Hey you guys. Did you know that Cats don't usually go bad on there own. Something happenes to make the cat go. Like for instance too lean. Some upper intake gaskets go in the middle of the manifold letting the two inner cylinders suck in air. Then if you pull those plugs you will find them carbond up. The comp sees the lean and dumps fuel to make the difference. The comp tries to a point to fix it but if it can't it throws the "SES" light. I'm not sure but are your 4.0s SOHC. You probably already know the recall on the cam tentioner.

 

[Jason_25]

If it's a knocking or "diesel noise" at little or no load (sitting still in drive, parked) I know what you mean. My old OHV did it (before the engine replacement), and my "new" OHV at 50K miles does it now too. I think it's just a normal wear and tear noise and I ran my old one for atleast 20K miles with the knocking sound and it didn't break anything.

 

[00sport4x4]

why was your engine replaced? would the noise had anything to do with it?

 

[Jason_25]

No it was replaced because it was hydrolocked. It looked perfect when it was opened up otherwise.

If you have the OHV, dont worry about any knocking noises (unless it's really loud), if you have the SOHC, then you should look at having the Ford extended warranty replace your tensioners, chain guides, and o-rings.

 

[00sport4x4]

My motor is an ohv, After the dealership took the cat off they did say the platinum was loose inside and just incase you dont already know the catalyst converters are covered by ford until 80,000 miles.