Tapping when under load
#1
Tapping when under load
I have a 4.6 V8 in my 1998 F-150 with 125K miles. Whenever I put the engine under a descent amount of load, say accelerating normally up hill, or 3/4 throttle or more on flat ground, I get a tapping noise from my engine. It doesn't seem to loose power, but it is a scarry sound. It is definetly coming from the engine bay, and almost sure it is the engine. I did get a check engine light that has since turned off. It was the secondary o2 sensor was bad. I have not replaced it yet, but I also haven't recieved that code again for over 5K miles. Any suggestions on why it would be happening?
#5
#6
update: when I went to the gas station today, I decided to try premium gas again. Surprisingly, this has "fixed" the problem. No matter how hard I hit the gas, I wouldn't get any noises. So, I tend to agree with glc that it is probably detonation.
New question: any other areas to look into for the cause of the detonation other than 02 sensors that I will replace the first chance I have?
New question: any other areas to look into for the cause of the detonation other than 02 sensors that I will replace the first chance I have?
#7
Originally Posted by iRoushF150
update: when I went to the gas station today, I decided to try premium gas again. Surprisingly, this has "fixed" the problem. No matter how hard I hit the gas, I wouldn't get any noises. So, I tend to agree with glc that it is probably detonation.
New question: any other areas to look into for the cause of the detonation other than 02 sensors that I will replace the first chance I have?
New question: any other areas to look into for the cause of the detonation other than 02 sensors that I will replace the first chance I have?
If it doesn't fix it, fill up with 89 octane from now on, and call it a day. You'll drive yourself crazy trying to find the cause of that spark knock. Fords are known for it, and I've never seen any problems come of it. But if you spend $.10 extra a gallon, it won't even happen. A $500 service bill will buy you 90,000 miles of 89 octane fuel, if you get 18mpg.