[ceaudiophile]

Does anyone get this weird clicking/popping mechanical sound in their car but only during freeway speeds? It sounds like as if you made a popping sound with your tongue at the top of your mouth. I only get this problem under these conditions:

1. Only on 5th gear at around 2000 to 2500 RPM within 65 to 75mph, pedal about 1/2 to 2/3 to the floor
2. Mainly when I'm climbing, but have heard this when I reach level ground after the climb. The climb can be gradual (i.e. rolling terrain like I-80 Fairfield to Sac, Sunol Grade) or climbing to Lake Tahoe and Reno. The noise will start as I place my foot down more on the pedal to match my existing speed or attempt to increase it. We're only talking 65-75mph range, and it ends once I go above 80mph.
3. Tends to happen during longer drives at about 20miles or more, but that's also when I start climbing from where I live :scratchchin

If I downshift to 4th during the climb it will go away, but if I shift back to 5th it will be heard instantly when the shift is complete.

The sound duration is irregular and unpredicatble, but can be described as 2 to 3 consecutive pops instantly when I shift to 5th during the climb. Then it becomes a single pop every couple seconds as I continue to stay in 5th; or if I stayed in 5th in the climb.

The sound location is also very hard to figure out but it varies around the front to the center front and sometimes near the shifter. I have a hurst short shifter installed, but I think the sound just travels near the shifter because it's the easiest place for sound to travel.

I've done a lot of reading about clicking and popping but it seems like nobody has had this situation. I've read theories from spark plugs, detonation, and to the fuel popping? And then go figure when I drove it with a Ford mechanic we never heard the sound so no warranty work. :so

Any ideas?

 

[Whitelitning]

sounds to me like detonation. use higher octane fuel and try to replacate the problem where/how it happened before.

 

[Whitelitning]

I think your car is equiped with a knock sensor which adjusts ignition timing based on the computer detecting an audible "ping" from the engine.

 

[ceaudiophile]

I think your car is equiped with a knock sensor which adjusts ignition timing based on the computer detecting an audible "ping" from the engine.

I'll give 91 a try. I've used 87 and 89 and both haven't made a difference.

Can you elaborate on the knock sensor?

 

[Whitelitning]

the knock sensor adjusts ignition timing based on power demand vs fuel effeciency vs emissions. When you step on the gas espesially under high loads (5th gear uphill) there is a lot of fuel being introduced in to the cylinders. At lower RPMs it is possible fror the fuel to ignite befor the spark actually occours, due to compression creating an audible ping. The sensor backs up timing to prevent this, but perhaps cant back it up enough to satisfy the performance requested and prevent the detonation. Higher octane fuel resists ignition more so if this is the problem it should help. This is how i understand the system to work. if i'm way off someone let me know.

 

[ceaudiophile]

Time to update my old post. So I just changed my oil using Royal Purple and I've noticed that the detonation has stopped so far. I wasn't expecting this to happen but I'm not complaining either! I can't really confirm whether having good oil will stop something like this, is it really possible? I just know that places and situations where it happened aren't happening anymore.