powerranger262

You can put adhesive backed weatherstripping on the tray, where it is supposed to seal up to the case. Here's the link.

https://www.f150forum.com/f4/bog-dow...solved-166431/

jshillin

iTrader: (1)

I paid attention to my idle today for once... My warm/hot idle was between 530-550 rpm's.

Snoopaloop

powerranger262,
I checked my foam in the filter tray. It appears to be in good condition still.

Everyone else,
When I brought my truck into the shop for service, I had the mechanic check for vacuum leaks. He said there were none, not that I didn't believe him, but I wanted to see for myself. When I took it home, I did a very through inspection of any lines that appeared to be related to the vacuum pressure. I didn't find any leaks.

I ordered a new fuel filter and tool yesterday, based on summers22's advice, I am going to order new O2 sensors as well once I get the chance to sit down.

I appreciate all the help. Hopefully one of the two above solves my problem.

Summers22

iTrader: (2)

I would normally say to do the fuel filter, then wait to see if that cures it. But due to your mileage, the O2 sensors need replaced. Please report back if they cure your issues.

Snoopaloop

Oh, and I made a small observation while driving home tonight. It seems to get worse/ more erratic with my heater on. Is it normal for the rpm at hot idle with the heater on at medium heat and speed to go up a little bit? Better yet, should my rpm change at all when my heater/ac is on?

Summers22

iTrader: (2)

My rpm's change when I have the defrost/floor combo on, but stay steady in any other setting.

jake_85

yea i seen that link powerranger262, i just re asked the question because the pics dont come up, thank you, ill figure it out, its not rocket science haha

Summers22

iTrader: (2)

Back on track. To the OP, the "foam" is on the tray that holds the air-filter. Any standard foam where one side had sticky tape will do. Usually 1/4" will suffice. I used the same on my 3rd brake light to replace the factory seal. Works like a charm.

jake_85

Thank you, and to add, i would also recommend fuel filter. I just did mine about a month ago and the fuel in the old one was naassttyyy. Also check the fpdm on the driver side above the spare on the frame cross bar. Theres lots and lots of threads about them if you have further questions. Good luck!

Especial86

iTrader: (1)

Your rpm should rise slightly with a load on the motor to stabilize/maintain alternator charging output..

The rough idle is likely an air/lean issue if things smooth out nicely at cruising speeds.. Seafoam will help cure this by removing carbon on the valves that is soaking up the fuel your combustion chamber is supposed to be burning.. The CMCV plates will also benefit from this induction cleaning removing carbon from them as well.. I'd also run a bottle of techron fuel system cleaner in the tank for extra cleaning power..

Otherwise I would still try the battery reset, and if the rough idle goes away and then comes back, I'd now suspect the throttle body or TPS...