Engine Knock

[latinsazon]

I have a 2000 XLS 4.0 OHV with 71K miles. I bought it at 30K in 2002 and the rest is highway. When I start it up, it makes a knocking noise at idle. When I shift into gear, it goes away and doesnt reappear until I put it in park/neutral. It doesnt sound like it's coming from the valves, but more from the core of the engine.

I have changed the oil - it never leaks and everything is stock (except for my K&N). It's tuned up (sparks and wires). I use 87 gas as well.

Can anyone help me identify what this may be or if this is normal?

 

[jimbo74]

it actually sounds like you may have a bad cat heat shield or a bad skidplate or something else is loose under there......

 

[latinsazon]

I checked for all loose items under and over...but it still sounds internal. Could that recal for the 4.0 SOHV apply to my engine as well? Could it be that this "rattle" means something is loose internally?

 

[jimbo74]

the sohc rattel is a cam chain tensioner, and if you have the ohv, that is not present at all as you dont use a cam design....

 

[X~FACTOR]

Do you happen to use FRAM filter? I have been using FRAM filter FOREVER and after reading a recent thread here I switched to Motorcraft. Low and behold, the knocking was gone at start up! This might not be the case for you but I though I had to share this experience. I couldn't believe a damn oil filter could cause this.

 

[latinsazon]

Yea, I have tried different oil filters, too - and still the same thing. It doesnt sound like piston-slap ( I know what that sounds like since my 88 Cougar 3.8 had that). It's not leaking anything, nor burning - its jsut annoying and the noise is very non-steady.

 

[jimbo74]

i had a problem like this with my explorer... only made noise in park or neutral... well it ended up being that my skidplate was smashed into the tcase, and it would only hit it if i was in nuetral or park.... during the gears, there was too little vibration to make it clunk

 

[00XLS]

You say its non-steady? Non steady in terms of the rhythem or the times it occurs? If it doesn't always happen I wouldn't suspect something internal.

 

[latinsazon]

Non-steady meaning it happens all the time, but the noise does not have a continuous rhythm.

 

[jimbo74]

are you used to fords? all fords have a little engine gurgle to them.... do you have any modifications on it?

have you tried using higher grade gas?

 

[latinsazon]

This is my first Ford product since my 88 Cougar LS. That car really made me loose coolness-points for ford. But, I took a chance and in 2002 is when I found this one. It's got the sport package and all the XLT options (overhead console, rear air w/radio, towing package, ect.) so it was a nice buy for me being that it's also my first SUV. When I first bought it, it was extremely quiet. No modifications were done to the engine except the K&N, which howls extremely loud when it's hot outside in the LA area. OMG, it's to the point of embarrasment. But I love my Explorer - absolutly no problems at all - except this noise in the engine.

 

[gnasher70]

i had the same noise but now its doing it all the time so bad i am not using the car untill i find out what is making the noise havent had any luck yet i do suspect a cracked drive plate