Obligatory C5 Thread
- Acid666
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Could be that the condensor is a little loose or something and activating it pulls tension and tightens it all up? I dunno. Like you, I can't see how the two are related, especially if it's valve train noise.
- ChrisoftheNorth
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Well, I'm wondering if it's not actually valve train noise I'm hearing? Maybe it's some other put-put-put noise? From inside, it can almost sound like an exhaust leak. Is something loose/disconnected in the HVAC system that isn't an issue when the AC is on?
I'll check the condenser to see if maybe it's loose against the radiator...but the noise seems to be closer to the engine/rear of the engine.
- ChrisoftheNorth
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Or maybe I'm just a and it's all in my head. Could it be that the AC on is making white noise in the cabin that drowns out the valve train noise?
I'll be driving the car home with the top off tonight, I'll play with the ac on/off to see if there's actually a difference.
I'll be driving the car home with the top off tonight, I'll play with the ac on/off to see if there's actually a difference.
- Desertbreh
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From my understanding, the "sewing machine" valve train was only for LS7s. I've got a few buddys with HCI C5zs and they have some decently quite top ends. Nothing compared to LS7 ticking. It feel like ticking could be coming from somewhere else. Just my thoughtsDetroit wrote: ↑Thu May 23, 2019 9:21 am Ok gents...a bit stumped on a new one here. This'll be some ADVANCED level C5 discussion...
Been driving my car more lately. Enjoying it a lot. Since doing my heads/cam, I've had noticeable valve train noise. "Sewing machine", "typewriter" are common descriptors. VERY common on these, tuners said it was normal, I just nature of the beast, whatever. It's mostly noticeable with the windows down, next to walls or other cars...but it can be detected inside with the windows up. Again, whatever.
So it got warm and humid overnight, and I decided to drive the car today. Flick the A/C on and as I'm driving notice how quiet the valve train is. Roll the window down, and indeed I swear it's quieter. I haven't driven much with the A/C on, this is the first time I drove a long period with it on.
I start racking my brain trying to figure out how the hell the two could be related, and I'm coming up with nothing. Is the extra load on the engine doing something? Is the noise not valvetrain and maybe something else?
Any thoughts from the best Corvette forum on the net?
- goIftdibrad
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thats a hydraulic lifter engine right?Detroit wrote: ↑Thu May 23, 2019 9:21 am Ok gents...a bit stumped on a new one here. This'll be some ADVANCED level C5 discussion...
Been driving my car more lately. Enjoying it a lot. Since doing my heads/cam, I've had noticeable valve train noise. "Sewing machine", "typewriter" are common descriptors. VERY common on these, tuners said it was normal, I just nature of the beast, whatever. It's mostly noticeable with the windows down, next to walls or other cars...but it can be detected inside with the windows up. Again, whatever.
So it got warm and humid overnight, and I decided to drive the car today. Flick the A/C on and as I'm driving notice how quiet the valve train is. Roll the window down, and indeed I swear it's quieter. I haven't driven much with the A/C on, this is the first time I drove a long period with it on.
I start racking my brain trying to figure out how the hell the two could be related, and I'm coming up with nothing. Is the extra load on the engine doing something? Is the noise not valvetrain and maybe something else?
Any thoughts from the best Corvette forum on the net?
brain go brrrrrr
- ChrisoftheNorth
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Nah, the sewing machine is well documented on all LS engines...especially cars with aggressive ramp rate cams. Mine isn't LOUD, but it's noticeable if you listen for it. I am starting to wonder if it's coming from somewhere else, just not sure where.Purpc5z wrote: ↑Thu May 23, 2019 1:15 pmFrom my understanding, the "sewing machine" valve train was only for LS7s. I've got a few buddys with HCI C5zs and they have some decently quite top ends. Nothing compared to LS7 ticking. It feel like ticking could be coming from somewhere else. Just my thoughtsDetroit wrote: ↑Thu May 23, 2019 9:21 am Ok gents...a bit stumped on a new one here. This'll be some ADVANCED level C5 discussion...
Been driving my car more lately. Enjoying it a lot. Since doing my heads/cam, I've had noticeable valve train noise. "Sewing machine", "typewriter" are common descriptors. VERY common on these, tuners said it was normal, I just nature of the beast, whatever. It's mostly noticeable with the windows down, next to walls or other cars...but it can be detected inside with the windows up. Again, whatever.
So it got warm and humid overnight, and I decided to drive the car today. Flick the A/C on and as I'm driving notice how quiet the valve train is. Roll the window down, and indeed I swear it's quieter. I haven't driven much with the A/C on, this is the first time I drove a long period with it on.
I start racking my brain trying to figure out how the hell the two could be related, and I'm coming up with nothing. Is the extra load on the engine doing something? Is the noise not valvetrain and maybe something else?
Any thoughts from the best Corvette forum on the net?
- ChrisoftheNorth
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Big Brain Bradley wrote: ↑Thu May 23, 2019 1:42 pmthats a hydraulic lifter engine right?Detroit wrote: ↑Thu May 23, 2019 9:21 am Ok gents...a bit stumped on a new one here. This'll be some ADVANCED level C5 discussion...
Been driving my car more lately. Enjoying it a lot. Since doing my heads/cam, I've had noticeable valve train noise. "Sewing machine", "typewriter" are common descriptors. VERY common on these, tuners said it was normal, I just nature of the beast, whatever. It's mostly noticeable with the windows down, next to walls or other cars...but it can be detected inside with the windows up. Again, whatever.
So it got warm and humid overnight, and I decided to drive the car today. Flick the A/C on and as I'm driving notice how quiet the valve train is. Roll the window down, and indeed I swear it's quieter. I haven't driven much with the A/C on, this is the first time I drove a long period with it on.
I start racking my brain trying to figure out how the hell the two could be related, and I'm coming up with nothing. Is the extra load on the engine doing something? Is the noise not valvetrain and maybe something else?
Any thoughts from the best Corvette forum on the net?
But these things are known for a somewhat noisy valve train, especially with a cam like mine.
- goIftdibrad
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I could see it being timing chain noise. with a bigger cam in-between power strokes the chain might be loosening and tightening under light load generating your noise. With that little bit of extra load this effect will be less.
brain go brrrrrr
- ChrisoftheNorth
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This did occur to me. I should get a stethoscope to test.Big Brain Bradley wrote: ↑Thu May 23, 2019 2:03 pmI could see it being timing chain noise. with a bigger cam in-between power strokes the chain might be loosening and tightening under light load generating your noise. With that little bit of extra load this effect will be less.
- ChrisoftheNorth
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- ChrisoftheNorth
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Well, to wrap this up, turns out I'm a
I forgot how loud the 2nd fan is that turns on with the A/C OR when the car gets hot. Car rarely gets hot, so it's not on often unless I'm running the A/C. It's a loud enough white noise that it masks the valvetrain noise.
I forgot how loud the 2nd fan is that turns on with the A/C OR when the car gets hot. Car rarely gets hot, so it's not on often unless I'm running the A/C. It's a loud enough white noise that it masks the valvetrain noise.
- Desertbreh
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Sending you a bill for the time I spent reading about your "advanced" C5 issue. Cash or cashiers check please.Detroit wrote: ↑Fri May 24, 2019 12:32 pm Well, to wrap this up, turns out I'm a
I forgot how loud the 2nd fan is that turns on with the A/C OR when the car gets hot. Car rarely gets hot, so it's not on often unless I'm running the A/C. It's a loud enough white noise that it masks the valvetrain noise.
- ChrisoftheNorth
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Oh shit, that should actually take care of the bill I sent you about the ridiculousness of your wheel saga on the mobile.Desertbreh wrote: ↑Fri May 24, 2019 2:58 pmSending you a bill for the time I spent reading about your "advanced" C5 issue. Cash or cashiers check please.Detroit wrote: ↑Fri May 24, 2019 12:32 pm Well, to wrap this up, turns out I'm a
I forgot how loud the 2nd fan is that turns on with the A/C OR when the car gets hot. Car rarely gets hot, so it's not on often unless I'm running the A/C. It's a loud enough white noise that it masks the valvetrain noise.
- Irish
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Detroit wrote: ↑Fri May 24, 2019 3:10 pmOh shit, that should actually take care of the bill I sent you about the ridiculousness of your wheel saga on the mobile.Desertbreh wrote: ↑Fri May 24, 2019 2:58 pm
Sending you a bill for the time I spent reading about your "advanced" C5 issue. Cash or cashiers check please.
- Desertbreh
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Detroit wrote: ↑Fri May 24, 2019 3:10 pmOh shit, that should actually take care of the bill I sent you about the ridiculousness of your wheel saga on the mobile.Desertbreh wrote: ↑Fri May 24, 2019 2:58 pm
Sending you a bill for the time I spent reading about your "advanced" C5 issue. Cash or cashiers check please.
- Irish
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Detroit wrote: ↑Fri May 24, 2019 3:10 pmOh shit, that should actually take care of the bill I sent you about the ridiculousness of your wheel saga on the mobile.Desertbreh wrote: ↑Fri May 24, 2019 2:58 pm
Sending you a bill for the time I spent reading about your "advanced" C5 issue. Cash or cashiers check please.
To both....
- wap
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Detroit wrote: ↑Fri May 24, 2019 3:10 pmOh shit, that should actually take care of the bill I sent you about the ridiculousness of your wheel saga on the mobile.Desertbreh wrote: ↑Fri May 24, 2019 2:58 pm
Sending you a bill for the time I spent reading about your "advanced" C5 issue. Cash or cashiers check please.