#135306, "WTF sound keeps going after the car's OFF!?" Oct-19-11 07:28 PM by 420agreenvilleSC
two videos. the first is starting (engine is warm) and soon after, you'll start to hear the sound. Then the engine is shut off and the noise gasps for its last breath LOL. Notice that the PS/AC belt is OFF, so that rules that out. I reallyyyy don't think it's the alternator bearing, but who the hell knows. the timing side (belt, tensioner, bearings) have only about 15K miles on them. Oil pump and water pump are older. IT'S ANNOYINGLY LOUD what's weird though is that the noise persists a tiny bit after shutoff... what in the world could that signify??
the second vid is of just idling, but with the PS/AC belt ON. the noise remains and as I rev it, you can slightly hear it go away, but the noise increases to match the RPM, then gets louder again as it approaches idle RPM range.
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
#135307, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 0
What an annoying sound. I would have said it was one of the idler bearings in the timing belt pulleys, but since those are relatively new, I don't know. Try taking off your alternator belt and turning on the car for a bit to see if it disappears.
2gnt: '99 RS-T, killed by a toyota, pending rebuild... Daily: Volt Daily #2: '99 EVG ebike- STOLEN by PEDRO
#135309, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 2 Oct-19-11 10:31 PM by 420agreenvilleSC
I'll try that, but why would the sound persist a couple seconds after the engine was shutoff then (belt not spinning)? why would the alt still possibly be the culprit in that case?
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
#135310, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 3
I can't really determine if the sound is persisting long after the engine stops completely, it sounds like it's winding down as the engine is winding down. HOWEVER, if you are certain the sound is continuing after the engine is shut down, I noticed one mechanical part on your car that would keep spinning shortly after the engine stops. I see a wastegate in that video-> Could your turbo center be making this noise? How old are the bearings in your turbo?
2gnt: '99 RS-T, killed by a toyota, pending rebuild... Daily: Volt Daily #2: '99 EVG ebike- STOLEN by PEDRO
#135314, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 7 Oct-20-11 07:12 AM by 420agreenvilleSC
The turbo seals are worn and has a bit of shaft play, but im willing to seriously put $50 on it that the sound's not coming from the turbo - ill check it though. You can clearly hear the sound coming from the timing area.. specifically the water pump region
Im noticing that the noise only occurs when the car is warmed up. This makes me think more about the water pump. As I turn off the motor, you can hear the noise phase out, kinda like letting air out of a inflated balloon. I squeezed the upper radiator hose and it's firm/pressurized, but I didn't squeeze the lower (going to the pump).
Also, just to see if it was the alternator bearing, I sprayed the joint between the bearing and the alt and now there's a belt squeel that will hopefully go away soon. Ill have to still test and remove the alt belt to rule that out but it doesnt seem to be it right off hand
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
#135318, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 8
Simple enough to narrow down the spot of the noise. Have someone in the car start it up (after its warmed up) and then stand in front with a stethescope (or screwdriver to the ear) on each component you think it might be. Then shut it off and see how loud/isolated the noise is to that component.
Loudest/most isolated wins.
Captain Caveman
96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq 97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq 98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats 99 OZ 5sp Stocker 15.856 @ 85.97 99 GS stocker auto 17.7@77mph!
#135324, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 9
I would have to say the water pump also. Mine did the same thing a few months back and then got a little worse and louder when accelerating. I thought it might have been the water pump and had it towed to the dealer. It was in fact the water pump.
#135326, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 10 Oct-24-11 09:25 AM by 420agreenvilleSC
so guess what it was.. positive crankcase pressure. go figure
That's why i'm thinking the sound was coming from the crank pulley area. Once I popped up the dipstick a little, the sounded faded away.
Now I have a new issue to diagnose - excess smoke, which may be just the turbo, but potentially valve seals as well. This may belong in a diff thread but compression #s and leak-down tests pass, but leakdown wont help detect valve seals. Is there a method of testing that? if valve seals are fine, i'm confident that the smoke is solely the turbo seals. What's weird is since the crankcase pressure is relieved, the smoke appears, but when pressurized, there's no smoke..
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
#135357, "RE: WTF sound keeps going after the car's OFF!?" In response to Reply # 13
Originally posted by iamnotwhoiam what about your cam shaft/gear seals on the timing belt side... since you did hear noise from that side.
the noise is gone, it had nothing to do with the timing side.. was positive crankcase pressure causing the whistle sound
Originally posted by Slo2g What are your rings gapped at?
16 lower, 18 upper.. i really cant remember if i have it backwards but those numbers stuck to my head. one of them is 17/19 (accidentally trimmed too much). if the lower's supposed to be closed more, then that's the 16, otherwise i just said it backwards
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
Search
Printer-friendly copy
1 User in Chat
