So I can be a little, let's say sensitive, yeah that's a good word. Another way of putting it is I like to over think stuff and every now and again it pays off. It all started after I did my HPFP and started staring at fuel pressure. I noticed the pressure would drop at idle sometimes in the mid 200's. It seemed to only do it under parking lot maneuvers but I wasn't able to recreate it consistently, I would just notice it in the min/max on the access port. So this sent me down a rabbit hole. I was starting to think the PRV was starting to fail. The car has pretty low miles for being 13 years old but, still it's 13 and now making more pressure. I found a post on this forum talking about this valve and some of the things it will do when failing and how to check it's operation. So, I did the test, I drove the car and got it to operating temperatures and the parked it KOEO and watched the access port. It got to 1800psi and then the valve released pressure. From what I have read on here it should hold to 1850 before releasing. Still not 100% convinced it was bad, I had no other symptoms other than me being "sensitive" to weird things. Anyways, I kind of just shrugged it off and sorta kept an eye on fuel pressure. Well fast forward and my VVT starts rattling so with the help of @Rokusek and his post on the process of replacing the timing set I was able to get that job done. First start up the car made a chirp noise that almost sounded like the VVT. I thought maybe it had to do with it not having oil in it at start up because it was a very short noise and happened a second or two after the engine started. I'll post the video. EDIT: I'll post the video when I figure out how from my phone I could not replicate this noise for the life of me so about a month goes by and there it is again! That fucking chirp noise! I could only get it to happen on the first cold start and not everytime. It almost sounded like a serp belt slipping for a split second. I replaced the belt along with the idler pulley. Belt looked original and the pulley was in rough shape. I took the dust covers off the bearing and it was bone dry so, I figured I found the source. Again I drive the car for a week without hearing this sound and then it happens again... This time I was able to get it to happen more frequently. I took the serp belt off and started the car and it chirped, that eliminates anything on the accessory drive. I have my wife start the car while I poke at things with a stethoscope. It sounds like it's coming from the front of the motor but I can't hear it anywhere with the scope. So I start digging around on the internet and found a short video on YouTube that had the exact same sound, the title was something along the lines of "PRV chirp". So back out to the garage and put the scope on the PRV and that little fuck is singng away! Then just because, I take it for a drive and get it up to temp and do that test again. Low and behold it releases pressure at 1750 this time. Order a new valve from Edge Auto sports, install valve and all better . I'm guessing the next thing will be injector seals since I'm currently going through the tuning process and I'm pretty sure more boost is just gonna find those soon.
Just in case the chirp returns, look at starter. Sometimes the bendix will stick, and once the engine flywheel gets faster than starter rpm can cause this. I usually only see in boat starters that get corrosion and bendix "axle" which is part of starter motor shaft will allow gear to stick in the starter rotate, engagement of flywheel teeth, then not disengage on engine firing up.
Good point! I'm pretty confident that this was the noise. When I put my stethoscope on that valve and had my wife start the car it was clear as day. If it does return I will keep this in mind.
Here is a link to the noise it sounds slightly different from outside, here is the video I came across on YouTube Edit:I know the two videos sound different but the second one was what I was hearing outside of the car....
Those are good videos and info for others who run into this issue man good job!!! I know if I had that issue it would drive me nuts trying to hunt it down. Love videos of quirky issues cuz it's a huge help to others. Great job man!
Glad I could help you out. And happy you figured out the chirp. Still haven't found my digital shop manuals
Check the metal member section they're all hosted there https://mazdaspeeds.org/index.php?forums/mazdapeed-owners-manuals.193/ Atleast I think this is what you're after?
