Hey Guys, 97 Ford F150 XL/w air, 4.2L V6., 168K I need some advice

I am a newbie here and have and have done some searches but think my problems might be unique and maybe related.

Here is the skinny... Two symptoms possibly related.
1. Chattering noise under the hood on acceleration. Strange noise, not like a lifter, stops immediately after trans downshifts. like a plastic ball in a tube kkinda sound or baseball card in the spokes of a kids bike, beats me. I cant reproduce it in park. This started a couple months ago but doesnt seem to affect preformance, I just know something isnt right.

2. Multiple misfires durring rainstorms or wet conditions. Almost seems like she is runnin on 4 cylenders. When its wet out it worst. Next morning shes fine. Also happens in drive at times at a long stop light but it recovers on acceleration or if I put it in neutral.

Background:
Purchased used at 97K in 2000. Not much service records prior to me.
Stock engine other than a cold air intake added at 130K.
Changed the coil pack, plugs and wires at about 105K (2001?) .
Intake right bank manafold and timing cover mild leaks noted at about 110K seemed to be fixed with Barsleak, no more coolant loss. But I have been afraid to flush the coolant since then.
Regular oil and lube every 3000 since I have owed her.

Took her to my mechanic last week he said plugs looked fine, wet the wires no miss, and the only codes she threw were Multiple misfire, O2 sensor (prolly from the missfires) and missing intake sensor which is from the cold air intake. He couldnt get it to misfire. Said bring it back when it does. but thats tough cause it does it intermittently. Otherwise she runs stong as an ox.

I am afraid it might be a timing chain or possibly a cracked coil pack? But I am open to any and all thoughts. I love this truck but cant afford a new engine. Any ideas to try? Thanks for your time and knowlege.

DOC

 

Cracked Coil pack-as for the noise high rpm,I would check the cat might be clogged,run it hard @ night look for the glow!!Sounds like too much back pressure on the valves, little different noise then lifter.

 

Awesome, thanks so much for the tip. I used a clean out typa stuff on the cat after I bought the truck in '00 called Gold Touch or some such thing, IV bottle drip thing that put out all kinds of smoke and got me passed emmisions. Maybe I will try that again or just replace the cat. Thanks for the help.

 

Ok guys here is the update.
Old plugs and wires looked pretty good, no obvious damage to the coil pack.
The only trouble codes I could pull were a misfire on 4 and 5 and an unpluged MAF sensor.

Just put in Bosch platnuim plugs, new plug wires, and new coil paick. Cleaned the MAF sensor as besrt I could, PCV valve, and ran some LUCAS injector cleaner through the gas tank. All in all about a $150 day and three hours work.

Sitting in line at Taco Bell in drive, waitin to order the truck misfired and threw a misfire on 4,5 again. Damnit. Any other ideas?

 

I can only think of one thing that might be causing this;your lower intake gasket going bad.Its possible that very small amounts of coolant are starting to pass the gasket and getting into the cylinders.

 

Well another feller suggested that to me and I did have a small external leak in that bank a few years back. My concern is at almost 170K how much more can I expect to get out of her if I have the manafold done? Last I read if I have Ford do it that its over $800. Are there any better options?

 

Ford charges 3-4 hours labor for this job.They will also clean your intakes,which means cleaning the EGR passages.Try other dealers near you;I bet you can get it done for $400-$500.Ask around about local independant shops that have a good reputation;they could be cheaper then Ford.

 

Thanks alot BOF, I think I am going to look into that before I have a half ton paper weight. Also I have been looking into the EGR side of the problem. The code has mysteriously dissapeared now. Maybe the computer just needed time to reset, I didnt pull the ground cable off before I drove it. She runs pretty good now, seems a little "tight" if you know what I mean, no miss, just doesnt feel just quite as peppy as before. Plus I still get just a little struggle at long lights or sittin in drive with my foot on the brake. The chattering noise seems less too, I have heard it once or twice, but only when the motor was hot and I was driving it hard. I am wondering if this is "detonation" that I am hearing. I was unframilliar with the term before doing research. Now I am looking into the EGR system to see if it is faulty or my DPFE is bad.

BUT the gaskets need done and if they will clean the EGR passages as well, maybe its best to set aside the money and get it done. If I can get her done for less than $750 it will be worth the gamble just for the peace of mind not worrying about hydrolock every morning. LOL

 

If you think it's detonation, try a tank of premium gas. If it goes away, that's what it is.

 

Ok Fellers,

I just put a tank of 93 octane in her and so far so good. Man I hope that wasnt detonation I was hearing cuz I let it go awhile. Most of the summer. It has gotten gradually worse from time to time but I have read it is VERY bad on the engine. I would think spark knock would be alot louder than the noise I am hearin but who knows. time will tell.

On the intake note, I found a guy that said he used to work on Ford Fleet vehicles and maintained 144 trucks in one fleet. Says he knows the issue and will do the intakes for $300 labor and prolly $50 on the gasket set he said so I will do that when I get caught up the end of this month. I will keep you posted on the outcome.

DOC