What is this rattle from the engine compartment?
#1
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pinging.mp3
Car suddenly started making the noises in the audio. This was recorded when the engine was fully warmed up, the blips are to 1300-1400 rpm.
It's in the shop right now and the mechanic can't pin point it yet. Any pointers would be appreciated.
- It's not doing it while cold. It's intermittent and happens only once it heats up, past 165-170F coolant temperature.
- It's doing it with the accessory belt removed so it's not the accessories.
- It seems to be tracking the rpm roughly, not exactly and it's almost never doing it on idle.
- Mechanic had the stethoscope on it from the bottom of the engine, on the front, rear and the cylinder heads and it doesn't seem to be coming from anywhere there.
- Car runs fine, full power, no codes, doesn't burn oil, exhaust tips are clean, last oil analysis was 300 miles ago and was stellar.
What could it be? Evap solenoid?
Thanks.
edit: I should mention it's a 2007 C2S.
Car suddenly started making the noises in the audio. This was recorded when the engine was fully warmed up, the blips are to 1300-1400 rpm.
It's in the shop right now and the mechanic can't pin point it yet. Any pointers would be appreciated.
- It's not doing it while cold. It's intermittent and happens only once it heats up, past 165-170F coolant temperature.
- It's doing it with the accessory belt removed so it's not the accessories.
- It seems to be tracking the rpm roughly, not exactly and it's almost never doing it on idle.
- Mechanic had the stethoscope on it from the bottom of the engine, on the front, rear and the cylinder heads and it doesn't seem to be coming from anywhere there.
- Car runs fine, full power, no codes, doesn't burn oil, exhaust tips are clean, last oil analysis was 300 miles ago and was stellar.
What could it be? Evap solenoid?
Thanks.
edit: I should mention it's a 2007 C2S.
Last edited by dbv1; 06-02-2017 at 09:55 PM. Reason: Added info
#2
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odd question: does the sound or frequency increase / decrease at all depending on clutch position? i.e. is it louder or more consistent when, say, clutch pressed?
#3
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I don't have the car handy any more but I don't remember the clutch making any difference. I'll mention it to him. BTW, evap and the exhaust have been eliminated as possible sources.