I put a whole can of Seafoam through my brake booster line. It did the usual smoke screen, etc.. Now I have a high idle. Sometimes it will idle normal, but most of the time its idling around 1500+. It really does this after highway use. My plugs are new, as well as injectors. The truck (98 F150 w/ 5.4L) runs smooth, besides the high idle. Any ideas. I did a search and couldnt find any answers. My IAC, MAF, & TB are all clean.

 

If you look at the instructions it says 1/3 can.
You hit the Ox sensors pretty hard, the cats and the monitiors.
Everything else is before the point of introduction.
Why did you do this if the engine was running ok?
I just used it in a 5L and gave no smoke at all or improvement in performance on a 150K mile motor as I thought it might.
The rest went in the fuel and a bit in the oil.
I have an 02 150 with 38k and won't even think of adding anything to a fine running young engine and bring on problems.
Over doing it, over does it sometimes.
It may, after some time, settle down for you.

 

spray004,

I have the same problem as you. I have replaced the IAC and the Throttle Positioning sensor, which I did on Saturday afternoon. I have not driven the truck any distance since, but I'll know tomorrow morning when I get off of the highway. I'll be sure to let you know.

If it is the O2 sensors, that makes a lot of sense. I only used the 8oz of Seafoam and I may have covered the O2 sensors as well.

They probably need changed anyway.

Hunt4Fun

 

OT, but after seeing your oil pressure guage, I would suggest you get rid of the nylon line. If you ever had one bust on you and cover your leg with hot oil, you know why. You can use a metal line, and it won't burst.

 

A shot in the dark but try resetting the computer.

I've used from less than 1/2 can to more than a full can and never had any problems.

 

I'll try resetting the comp later today sometime. This is the only time I've ever had any problems with the product. I used a full can on my 4cyl Accord and had no problems at all. My O2 sensors are new and arent throwing a code. I'm stumped.