Rough Idle and Knocking engine noise
 

Ok so heres the deal I just bought a 2000 explorer ohv 4.0 xlt love the truck hate the noise i have this real annoying knocking noise coming from the engine also like a rattle when its idling also when I give it some gas. The thing runs like a champ I took it to the dealer who gave me a print out direct from from ford saying that it was a natural characteristic of that engine...BULL****!!!! I've had numerous cars/trucks/suv's not one has had any noise like this unless there was something wrong I've researched all the forums I've seen the string's about the marble/rattle sound ok that maybe a characteristic... but what about the knock its sounds like a spark knock or maybe a rod knock you can hear it all the way up to 2500-3000 rpms and a mad rough idle it idles fine then seems like it's about to stall I have the esp on it all the way to 60k miles and theres only 30k on it so i'm not to worried yet but i've seen strings on this that say it's been happening for years someone give me some ammo for the service depo i wanna know the exact problem if someone knows maybe email me and ill give you the exact specs on what it's doing at what rpm's

Rough Idle and Knocking engine noise
 

If it were a 4.0 OHC then it may be the troublesome timing chain tensionsers, but I havent heard of this noise on the OHV.

Rough Idle and Knocking engine noise
 

maibe when u changed the sparks u change the fiering order i did that and was knoking my engine

Rough Idle and Knocking engine noise
 

also now I'm starting to get when i shut it off like a rattle when the engine stops this is really starting to piss me off now when I took it to the dealer they feed me a whole load of **** well I Live in detroit so I took it to Ford Hq in dearborn an they told me that the knocking was not part of the marble noise that was supposed to be a characteristic of the truck well I take it back to the dealer and they say that they have to wait untill it gets worse because they cant tell what it is wellProfanity Removed!!!! what good are these guys for if a computer cant tell them whats wrong they don't know anything I thought mechanics where supposed to be able to do that kinda thing... but whatever anyway enough of my rabbling seriously if anybody knows what this could be let me know thanx

Rough Idle and Knocking engine noise
 

Have you decided if it's spark knock or rod knock?

Rough Idle and Knocking engine noise
 

alot of the time it's carbon buildup on cyliners. alot of dealer mechanics don't check the TSBs, so you better check yourself.
i had similar problem on 3.8L , dealer wanted to tear down
engine and charge me. they didnt check TSB and i found it myself.
ended up cleaning off carbon and getting out of it spending
$50 bucks- not bad.

Tango.

Rough Idle and Knocking engine noise
 

really it sounds more like spark,rod knock is more consistent of course I've never heard it on one of my cars just on other peoples so i really dont have the first hand experience but anyway tango they didnt check anything all they did was listen to it and told me that well come on now you cant just say oh thats this without acctually checking it out a knock can be 100 different things but you say the tsb ... maybe you can elaborate I'm not the best on abbreviations and is this a easy fix or is this a big job thanx for any help

Rough Idle and Knocking engine noise
 

TSB=Technical Service Bulletin. Manufacturers send these out when they become aware of a particularly common/troublesome problem. One common cause of spark knock on the OHV engine is dirty/carboned cylinders. Seafoam is one product that's supposed to be good for cleaning out the cylinders, and should have instructions on the can.
Other possible causes for spark knock on the OHV are from the engine running slightly lean. Look for vacuum leaks, a dirty mass air flow sensor, a loose intake manifold, and anything else that can effect the air/fuel mixture.

Rough Idle and Knocking engine noise
 

Check out this link....The process is extremely simple to do, but because you do it 3 times, it takes a while. The hardest part for me was finding a dealer that would give up 3 cans of pm3. my problem by the way was a dirty maf sensor. I had to clean it with a tooth brush. Just spraying it didn't work. Good luck!

http://www.alldatapro.com/alldata/PR...93498/87891107

Rough Idle and Knocking engine noise
 

Technical Service Bulletins can be found by doing a search on the net. I haven't found the right place to view all Ford
TSBs. A close friend is a warranty claims adjuster and is an encyclopedia of knowledge and can get this info for me.

I had my 99 Expl XLS cleaned and I continue to use Fuel Injector cleaner every other fill up - and it helps keep the knocks down.

Tango.

Rough Idle and Knocking engine noise
 

ok now this link says that you get the knocking only in gear and on acceleration I get the noise only when I'm idleing only and only under 2000 rpm so I'm not sure if that would help but I guess it wouldn't hurt to try