1. Home
  2. Ford Trucks
  3. 99 F150 4.6 engine rattle

99 F150 4.6 engine rattle

I'm getting a bit of rattling when I apply a little gas until the engine is fully warmed up. It sounds kind of like preignition from bad gas or timing but it goes away if I apply more gas or let it warm up a little more. I haven't tried a higher grade of gas as the truck was designed to run on regular and dammit I don't want to pay for premium at the prices we have these days.

Any suggestions? Some of the things I am thinking of before I give up and take it in for a tune up are plugs, fuel filter, air filter. From the sounds of it, I'm looking at $2-300 for a basic tune-up. Do any of the of the shelf injector cleaner additives work?

Thanks for any inspiration you lend me.

Stephen

Reply to
Stephen
Loading thread data ...

Try giving the MAF sensor a good cleaning. You will need a tamper resistant torx bit to remove it. I believe it is a T20 size. It has the center drill to accommodate the head of the screws. You will need a residue free electrical cleaner to clean it.

See here:

formatting link
Lugnut

Reply to
lugnut

Thanks for the tip on the MAF, I did clean it along with the other things I did for a tune up (plugs, fuel and air filter, oil etc.). The low-load rattle is gone now but I am not sure which of the things I did made it go away.

The plugs were clean and a good colour but the gap had widened from .054 to a range of .075 to .090. I could believe that the extra wide gap might have been causing the rattle as it would affect timing and quality of ignition. I think they are the original plugs and the truck has

130,000 Kms (80,000 miles) on the clock. Fliters were a little dirty but not too bad. I'm interested to see if I get any improvement in milage.

On the MAF tech tip site above, I was wondering why he didn't just clean the MAF element by opening the air box. When I changed air filters the MAF was right out in the open and very easy to clean. You would have to follow his procedure if you wanted to take it right out but that should not be necessary just to squirt some contact cleaner over the element.

Incidentally, I also did my rear brakes and changed oil. I was quoted $100 labour for the brakes and $160 just to change the plugs. Brakes took 20 minutes, and plugs about 45 minutes (pretty tight getting in there). Oil change is a 5 minute job. Flat rate, book pricing is the biggest scam going!

Stephen

Reply to
Stephen

Looks like you won all the way around. Thanks for the feedback.

Lugnut

Reply to
lugnut

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.