96 OHV Intermittent Chirp at Highway Speed

[trubbleinmind]

I think it was the fuel filter
changed it today and got a slight ping at first but then never again, took it through a battery of highway situations with nothing

here's hoping that's the end of this saga. my theory was that a clogged fuel filter was causing a lean condition when under load. I started to notice that the sound came out when the air temperature was cooler - cooler air = denser air = higher concentration of O2. Higher O2 + restricted fuel flow = lean condition = pinging

 

[trubbleinmind]

still chasing this, cute that I thought I had figured it out

driving back from out of town on the highway today it started making the sound and then spewed oil from the oil pan gasket (presumably, I know it has a leak) leaving behind a burst of oil smoke. I'm bringing it back to the transmission shop that rebuilt it in February for other things, I had hoped that this problem was with the transmission, but it seems to not be the case.

I'll probably bite the bullet and bring it to my preferred mechanic in the next few weeks, it's getting difficult and tiresome going long distances and avoiding highways.

 

[chewy012]

Just read through, so the chirp is more of a squeal type noise? And only at highway speeds under load?

Sent from my XT1254 using Tapatalk

 

[trubbleinmind]

sort of, I'd say its between a chirp and a tick, although now that the weather is 80 degrees and up it's been kind of deeper, more like a clattering tick. But yeah only around 65-75 and at about 2500 rpm. it seems to go away if I rev and let the transmission shift up, which is what made me think it might have something to do with the transmission.

I began getting the P0401 code yesterday as well, only had time to read it today. I'm going to start with the DPFE and go from there for now