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It's been a while since I last posted anything. I've had my 03 STR for quite some time now and with the valuable insight offered on this forum, I've been able to manage most repairs myself without too much back pain.
That being said, I've recently developed an issue which perplexes me beyond any of the past ones. This issue relates to a very loud, high pitched whine from the engine compartment after the vehicle has been driven for a while. Doesn't happen until the car has been driven for at least an hour non-stop and engine is warm.
Occasionally I've heard it sooner when the engine is warm and I'm driving more sporty than usual. The first time I noticed it was after a quick and hard acceleration. As soon as I lifted off the accelerator pedal, I heard I weird high pitched whine or scream. As soon as I pushed the pedal down again it disappeared and reappeared when lifting off accelerator.
In quick sucession my thoughts jump simultaneously from one, to the other, to the worst case scenario on WTH this could be. Maybe my girl has finally had it but I'll be damned if I don't fight for her one last time before I take my ring back.
My immediate thought was pressure related. I checked the PCV valve. Seemed to be functioning properly best I surmised. I attempted to relieve excess crankcase pressure by lifting dip stick while it was parked, running and making the high pitched sound. Not sure if this would even do it but was my immediate thought as I've seen this done before. I also read it could be the supercharger actuator valve but it just doesn't seem to be the case as the engine was making this demonic sound without boost (could be wrong, not dismissing this).
I have P0171 and P0174 codes that predate this issue relating to a crack in the accordion looking part of the EGR tube. I will be fixing this as soon as I get the EGR pipe in, not sure if it would cause this sound though. I don't think this is a belt, pulley, or alternator --- all of which can make high pitched whining sounds. I've recently replaced both belts and pulleys seemed to check out. Alternator would be more consistent of an issue in my mind. It seems to be coming from passenger side of engine compartment but it's so deafening that it's really challenging to pin point.
I once again look to you esteemed folks of the forum to save my peace of mind. I have a video of the sound attached. Please let me know your thoughts.
Im thinking belt squeal. Try testing it with the AC off as that can slip when its really hot out. Is the motor greasy? Grease or oil on pulleys can nake belt slip. Try some degreaser and belt dressing
It seems to be coming from passenger side of engine compartment but it's so deafening that it's really challenging to pin point.
Time to buy a new tool! I highly recommend a Steelman Engine-Ear for isolating sounds. The wand has a highly directional microphone in it. You move it around the suspect area and it will narrow down the source. I once used it to find a leaking AC evaporator. This thing is that sensitive and was able to pinpoint the virtually imperceptible sound of a refrigerant leak. I've also used it to isolate a noisy bearing in an alternator:
Steelman makes two version. Be sure to get the older style with the larger ear pieces. The newer style has smaller ear pieces that don't block out ambient noise nearly as well.
Can you duplicate the fault while parked? In your video, the noise seemed more electrical than an air leak, but that was just my hunch. Does it vary at all with engine RPM or other factors? I didn't hear any change in pitch, but don't know the recording conditions. With the fault active, try loosening or removing the serpentine belt briefly. Don't run the engine very long like that, as you'll have no coolant flow, but it should be okay for a minute or so.
Im thinking belt squeal. Try testing it with the AC off as that can slip when its really hot out. Is the motor greasy? Grease or oil on pulleys can nake belt slip. Try some degreaser and belt dressing
Have you heard the sound clip by chance? I am almost certain it's not belt or pulley related. It's a very deafening sound that stays in your ear for quite some time afterwards. Somewhere deeper in the engine (maybe around or below throttle body). There doesn't seem to be anything I've found on the forum that aptly describes the sound or location other than possibly a supercharger actuator valve from the XK posts.
Time to buy a new tool! I highly recommend a Steelman Engine-Ear for isolating sounds. The wand has a highly directional microphone in it. You move it around the suspect area and it will narrow down the source. I once used it to find a leaking AC evaporator. This thing is that sensitive and was able to pinpoint the virtually imperceptible sound of a refrigerant leak. I've also used it to isolate a noisy bearing in an alternator:
Steelman makes two version. Be sure to get the older style with the larger ear pieces. The newer style has smaller ear pieces that don't block out ambient noise nearly as well.
Can you duplicate the fault while parked? In your video, the noise seemed more electrical than an air leak, but that was just my hunch. Does it vary at all with engine RPM or other factors? I didn't hear any change in pitch, but don't know the recording conditions. With the fault active, try loosening or removing the serpentine belt briefly. Don't run the engine very long like that, as you'll have no coolant flow, but it should be okay for a minute or so.
Ill give the stethoscope a go. Now that you mention it, it does sound very electronic, the sound. But it occurs only when the engine is hot after extensive use. Once it starts it won't go away until I turn the engine off. I've tried to alter the sound in different gears, including park and neutral, all to no avail.
I have a video, not sure how to post it but I'll try to figure that out.
There doesn't seem to be anything I've found on the forum that aptly describes the sound or location other than possibly a supercharger actuator valve from the XK posts.
How difficult would it be to unplug the connector on this mythical valve? I looked for it in the wiring diagrams but didn't see anything even vaguely related to that name. See figures 03.5 and 03.6 here:
How difficult would it be to unplug the connector on this mythical valve? I looked for it in the wiring diagrams but didn't see anything even vaguely related to that name. See figures 03.5 and 03.6 here:
Are you sure the S-Type has such a valve? Maybe the "Air Cleaner Solenoid Valve" on 03.6 towards the bottom left?
the supercharger bypass valve as it's called in the following thread is vacuum operated. Not electrical. Despite the sound in question sounding electrical in tone. I'm not even sure if this " SC bypass valve" is even the culprit.
Have you heard the sound clip by chance? I am almost certain it's not belt or pulley related. It's a very deafening sound that stays in your ear for quite some time afterwards. Somewhere deeper in the engine (maybe around or below throttle body). There doesn't seem to be anything I've found on the forum that aptly describes the sound or location other than possibly a supercharger actuator valve from the XK posts.
no I hadnt. I just downloaded it and will report back
Ok scratch what I said earlier. Definitely not a belt squeal. It sounds like one of those buzzers. Are you in europe? Could it be the passive sounder thats mounted under the fuse box by the antilock brake controller? Definitely electrical though
Ok scratch what I said earlier. Definitely not a belt squeal. It sounds like one of those buzzers. Are you in europe? Could it be the passive sounder thats mounted under the fuse box by the antilock brake controller? Definitely electrical though
No, I'm in Canada. I'll check into this passive sounder but doubtful because of the circumstances in which the sound begins. The first time it happened, it went away with higher rpms. But as soon as I let off the throttle and began to slow down it was back.
I'm not sure what it could be. Maybe even engine over heating and very hot air coming out somewhere under very high pressure.
Unfortunately, I can’t get the sound clip to play on my phone, but maybe you’d have more luck.
I dont think this is the culprit but its worth a shot. Ill see if I can somehow get a video posted for a more insightful review of the engine and sound. Hate to use YouTube but I might have to.
Very unusual sound and from your video it's definitely coming from the engine/under hood somewhere.
Sorry but I have never heard anything like that before.
Not belt squeal to me either but I would still be tempted to remove one belt at a time JUST to rule out anything rotating. This is so simple that's why I recommend it.
When you start/stop the engine it cuts the sound immediately so it is connected to the engine running/turning over.
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Very unusual sound and from your video it's definitely coming from the engine/under hood somewhere.
Sorry but I have never heard anything like that before.
Not belt squeal to me either but I would still be tempted to remove one belt at a time JUST to rule out anything rotating. This is so simple that's why I recommend it.
When you start/stop the engine it cuts the sound immediately so it is connected to the engine running/turning over.
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Yes, im planning to remove the drive belt and SC Belt. Should be ok to run for a minute or so.
It's a tough one though. I've never in my own experience, ever heard and engine making that sound. I'm not sure if it's related to the check engine light and RP I currently have due to the hole in the EGR pipe. I am doubtful though as I've normally just cleared the codes and driven without an issue while waiting for the parts.
Haven't given up just yet. My gut tells me, my initial prognosis was accurate. I still believe it's crankcase pressure related. I am going to try and change over the PCV valve from my 06 RR with the same size and style PCV to confirm, hopefully tomorrow. I will however, get the engine warm today, replicate the sound, and remove each of the two belts one at a time to rule this out.
08-11-2022, 07:27 PM
High Pitched extremely loud whine
honestly you're not wrong lol!