I just posted on here a couple days ago and RPM problem I was having, and I followed some of the advice y'all gave on here and it fixed some of the high idling problems, so now I'm just going to give a full overview of what's going on and what's been worked on on this truck so I can try to hammer the big problem out.

1997 f-150
4.6l
4 wheel drive220k on truck and "120k on newer motor"

I have to admit I probably did not make the best decision buying this truck as a work truck or at all, but I'm not a top level mechanic and I think in the end this guy hit a lot of stuff for me. To start off the guy sold it to me with no cats which I didn't know was illegal, but I'm a welder and it only cost me an extra 200 bucks in cats and I welded everything back up so I figured that's why I got this truck for as cheap as I did. It also been broken into before so I know they replaced the steering wheel, and the dash was pretty beat up it was all together with duct tape but I didn't care about that I figured that was also why it was fairly cheap.

Pretty sure the guy erased the check engine light codes cuz after I drove it for a little bit the OBD sensors code popped up and then I found out there were no cats. I put on some magnaflow cats and those codes went away.

The alternator literally fell off one time and I had to replace that. It had sheared the bolts because the dude took the top mounting plate off which I have fabricated and put another one on since then.

Then I started having high idle problems and in neutral sometimes it would just skyrocket up to like 3 or 4K, that kept getting worse and it seemed to pull without putting any gas on it and I could just cruise at like 20 30 mph going down the road not even pressing on the gas pedal.

I got another po 340 or 430 code which is the camshaft position sensor.
I then have replaced the cam position sensor, the crank position sensor, thoroughly cleaned and tested the EGR, replaced the IAC sensor, found a possible slight leak in a line and tightened that, and found a short (bare wire spot) in the cam position sensor and insulated and fixed that.

When I test drove this truck I punched it and everything sounded pretty good, but when I put my trailer on it it seems like once I get to second or third gear and give it some it really starts to rattle, and this is even with an empty thousand pound trailer. It's a lot a lot a lot less noticeable at higher RPMs and first and second gear or with no trailer, but is very noticeable at low RPMs. There's a hill I have to go up and it's very bad, I also can't drive over 40 with the trailer or else it's pretty bad.

Below are two YouTube links to videos of the sound, and a little bit of a shifting problem which has gotten a lot better since I replaced a bunch of stuff that I mentioned.

https://youtube.com/shorts/S8Jghd_xXoM?si=k90wANw2zJCeEivW
https://youtube.com/shorts/1g_SZLAfJOQ?si=0ukz04ZlGU3z_vPE

I just started my business and in this as my only mode of transportation and a work truck, so I'm just trying to do my best in make this work. Kind of had to pay my dues with this one.

 

Automatic or stick shift?
You check out the driveshaft?

 

I have not, and probably wouldn't really know what to look for as of now. Suggestions?

It is an automatic.

 

Get under and look at the u joints on the driveshaft, front and rear. Take your hands and push the shaft up and down. Or sideways.
If there is movement at the u joints they might need replacing.
I dont know your truck but some also have a center support bearing for the driveshaft to check.
If anything you can eliminate the driveshaft that way,and an easy check.

 

JJust checked and everything is tight
I also just cleaned the throttle body and while there is saw I have a coolant temp dangling... But there are two coming off the same wiring loom and one is in the hole.

 

Okay it's been awhile since I could get back on here but I've been doing a bunch of things you guys have said and seeing if I could get the light to go off, and here's what's happened.

One of the two ports that come out from the EGR into the throttle body was completely clogged so I cleaned that, that helped a little bit.

Then I found two bare wires that came from the camshaft position sensor, I insulated them. Then I took it to a shop and had them do a diagnostic and they said that all they could find was that the fuel pump was only giving 6 PSI of pressure and it should be at 30 to 35, so just today I replaced that. Now I don't have any problems with hard starting but I'm still hearing some rattle, I've only had my battery unplugged for about half an hour but the check engine light went off. I've done that before and the check engine light sometimes came back on immediately sometimes not so I need to drive another hundred miles or so to see if it comes back on, but I am still hearing the rattling on high acceleration although it seems to have been getting a little bit better. The lady at the front desk of the shop I took it to said that she has heard on forums that f-150s do just kind of have a bit of a rattle to them, I don't know how true that is and I've never heard a truck that sounds like this so I still can't understand if it's the Clack of the valves or pre ignition or something else like a bad pulley, because the last time I took it to that shop they changed out two pulleys that they suspexted where the problem.

Does anybody else have any other ideas? This is the vehicle I I bought for my business and it's kind of eating up a lot of my money but I need to figure out what's going on so I don't get totally stranded, I'm willing to try just about anything although it might take a little time because I'm working 80 to 100 hours each week trying to stay afloat, but even though these posts are taking a little long to get back to I am working on this thing as much as I can.

 

I just took it to another mechanic to see what's going on and, they said they got done underneath it and that it is definitely coming from the transmission, I've never done any transmission work before can anybody shed some light on maybe what I can run into or what I should be thinking about?

 

According to what's wrong with it the transmission may need to be rebuilt.

 

i just took it to a transmission shop this morning and theyre saying bring it back for further diag. guy said the computer thinks its in reverse when its in park. i dont know what the hell that means but im sure its gionna be expensive. ill be back on monday on here when they tell me exactly whats going on