2001 Ford F-150

Noises problem
2001 Ford F150 V8 Four Wheel Drive Automatic

My '01 f-150 4.6l has begun to make a rattaling noise during idle. When I first heard the noise I expected lifters or springs, (I changed the oil filter and oil and added an addative.) But in listenning and inspection it does not seem lto me like that problem due to the fact the knocking does not increase w/ rpm, but more so disipate. It stays consistant on idle during cold start and full tempature. The noise is like a metel rattle on the right side mostlikely in front lower region (tensioner, ac and pully area). We thought maybe bearings. I checked for movement of pully, tensioner, crank shaft, alt. And water pump with belt off and didnt really notice any. I am afraid it may be timing chain related. During idle it seems to stay mostly steady with times of ranging tempo and volume. Any ideas of my trobleshooting or any ideas of what it maybe or even were to start? Other problems with fuel ratio, low idle, almost stalling after deceleration, eratic Rpms on idle, shortage of power and spark plug missfire were also recently an issue. I belive I have fixed those problems with new spark plugs, new pcv valve and fuel filter, but however I have not driven only ran the motor after these fixes. Whats your take on this?
March 11, 2010.

If RPM's don't seemto be related to the noise, I have to ask if the rattle could be from a bad catylatic converter or a heat shield?

Later this evening I thought about checking that in the morning. Would I test that by taping the cat. Converter with a rubber malat or such? Would any of the other recent symptons I mentioned be a cause of the bad cat. Converter? I did also have an error code of catalyst eff. Below threshold in bank 2. I was going to change O2 sensors. When you said " or heat shield" meaning inside the cat. Converter? Or thinking now the shield over the cat. Converter? I apriciate you response aswell as further comments.

Mar 11, 2010.
Yes, take a rubber mallot and tap on teh exhaust system to see if there is any noise coming from it. As far as the heat shield, they are on the outside of the cat. They always come loose and make noise, but the inside of the cat can come loose too causing many troubles.

Jake and Nick,
Thank you again for your advice and suggestions on these matters. Before I spend money I dont have at he shop I am trying to diagnose and fix any problems that I can. I will gladly donate more to you for your continued advice.
Today I drove to the parts store and after my work to the vehicle yesterday it seemed to drive better other than the rattle noise. The Rpms still seemed low to me (around 500 in gear and 750ish in park and neutral). Shorttly into my drive at a stop the engine seemed to start surging or stumbling but without an rpm change. Then hesitation and not wanting to produce power during acceleration. At speed it seemed to have a slight shake. Seemed more like fuel surge maybe. I have installed a new fuel filter, used fuel system cleaner, and installed a new pcv valve. My errors prior to working on it were: Cyl. #7 misfire, system to lean bank 1 and 2 and catalyst eff. Below threshold bank 2 (4 total errors) after oil change, spark plug change and the previous mentioned repairs I cleared the codes and the did not return after numerous engin starts and run time. But later after the problems arising today the check engine light returned w/ only the cyl. 7 misfire detected. I am going to pull it and check it again, but dont understand what would cause it to start missfiring again. (My engine has an electronic ignition system. No plug wires or dristriputer, but individual coils over each plug.)
As you mostlikely know I am no mechanic but have some knowledge and experiance around engines (and a haynes manual). My knowledge is on earlier chevy engiens so a lot of the newer components are new to me. Your take on the symptoms and minor repairs I have done are greatly appriciated. Also advice on next checks and replacements before it goes to the shop or I take to long at getting the valves and timing chains.
As I mentioned I will donate more if you are able to continue giving your knowledge. I know its practicly impossable to diagnose with out physicly inspecting, but at this time I can not afford a mechanic (being new to Va I also have no conections.) And need to keep my truck runing to work.

Sorry for the long e-mail,
And thanks in advance,
Eric Rich

Mar 12, 2010.
I'm here to help. You don't need to make additional donations. I want you to check something for me. Based on the codes you mentioned, I have seen a simple problem that has caused them before. Behind the throttle body (Near IAC) there is a 3/8" vacuum hose that has a 90 degree bend in it. At the bend, they dryrot causing lean mixtures, loss of power, misfires. Just for the heck of it, check it and let me know its condition.


I am unable to check that tonight due to the amount of rain coming down, but I will deff. Check first thing in the morning. I mentioned that the cpv valve had to be replaced and that was from dry rot or major deteriation at both rubber elbows (of the intake and at the pcv valve) so that deff. Makes since.

I did however lissten more for the rattle noise. Using a wooden dowel I tried more places to narrow down the origin. The most distinctive sound that matched the adable sound seemed to come from a canaster connected to the radiator with metel hoses (it looked like a filter, but am unable to find any parts matching or pictures) it is located on the right side down near the wheel well.

While I wait to check the vacuum hose; what is your take on that.

I cant thank you enough!

Mar 12, 2010.
I'm glad to help, but we haven't fixed it yet. As far as the part you mentioned, it sounds like the charcoal canister for the emissions system. I have a 99 and just walked out and looked. The only canister on either side of the radiator is the over flow on the driver's side and nothing on the passanger side. If you can take a picture of yours and upload it for me to see, it would be helpful.

As far as the rain you are getting, you must be west of Pittsburgh. We are to start getting it tonight. Two feet of snow melted this week and now the rain. What a mess we're going to have. When I walked out to look at our vehicle, the wind is picking up. You should just keep it and let us dry out.


Sorry dont want to keep the water We're in the same boat as far as wet. Northern Virginia and same thing our 2' a snow just melted.

Well I checked all the vacuum hoses and rubber connections connecting to the throttle body and intake manafold that i could find. I didnt find any cracks, could see thru them and blow air easily thru.
I got a picture of what i mentioned It sets level with the tensioner just below the right side valve cover.
It doesent seem like this could make that kinda noise, but like I said when I listened to different parts thru a dowel that gave me the most prevelent sound. Audibly you here it the most destinctive from under the front right.
I am going to try to stop today and pick up a vacuum and pressure gauge while were out (have to go see the future inlaws).
No luck with the pic. upload page. it says "Web site cannot display this page. Page maybe under construction." after I try to upload.

Opps just had to resize.

Mar 13, 2010.
It think that is an AC component. Does it run to the other side of the radiator?

Yes actually it runs to between the radiator and grill. (For the life of me I cant think or the name) then under the engine block, but I loose it from there.
When I was first looking at it I thought maybe something to do with cooling the oil.
I am assuming that I need to check the voltage to all fuel systems and spark plugs and also check amount of vacuum?
I have voltage meters, but not knowing much of the elec. Systems of motors thats not one of the first things I check. The haynes guide can vaguely
walk me thru. How to check for proper ohms. If you can let me know which components to begin with; If that should even be my next step.
As far as the part in pic. That would have anything to do with the fuel pressure regulator or fuel charging would it?
Sorry to many questions. Just not able to do much with the rain. Yall still getting bad weather?
--thanks Joe (sorry I said Jake and Nick in an earlier post)

Mar 13, 2010.
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