Odd "hissing", crackling, "depressurizing" sound after highway driving
This has been going for about the last 2 weeks, but intermittently so - happened today after I parked at work.<O</O
<O</O
After shutting the engine off after highway driving (say 75-80 MPH), but not necessarily always (even cruising at 40-45 MPH), Ive been getting an odd metallic crackling/hissing sound from the front end. Popping the hood and putting an ear close, it sounds like near/in/around the radiator. No dried coolant anywhere or puddles underneath. I dont see any leaks, bubbles, etc.. Cap is on tight/proper. Fluids are fine. Temp stays fine, never goes above where it should be (just below the mid-point).<O</O
<O</O
It lasts for about 7-10 seconds (if that) then dissipates. Again, sounds like something is depressurizing, but the crackling is boggling me.<O</O
<O</O
It could very well be things expanding/contracting after the drive (so ambient air temperature these past few weeks may be an issue. This is the first winter Ive driven w/o the heat shield on the stock manifold. Not sure if the additional heat vs. greater temperature differential (than say summer/fall temps) is contributing to this. Possibly other than speed and duration of the drive, I cant find any common thread so far.<O</O
<O</O
Ill try to replicate at lower speeds, less duration of driving.<O</O
<O</O
Any thoughts would be appreciated.<O</O
D
This has been going for about the last 2 weeks, but intermittently so - happened today after I parked at work.<O</O
<O</O
After shutting the engine off after highway driving (say 75-80 MPH), but not necessarily always (even cruising at 40-45 MPH), Ive been getting an odd metallic crackling/hissing sound from the front end. Popping the hood and putting an ear close, it sounds like near/in/around the radiator. No dried coolant anywhere or puddles underneath. I dont see any leaks, bubbles, etc.. Cap is on tight/proper. Fluids are fine. Temp stays fine, never goes above where it should be (just below the mid-point).<O</O
<O</O
It lasts for about 7-10 seconds (if that) then dissipates. Again, sounds like something is depressurizing, but the crackling is boggling me.<O</O
<O</O
It could very well be things expanding/contracting after the drive (so ambient air temperature these past few weeks may be an issue. This is the first winter Ive driven w/o the heat shield on the stock manifold. Not sure if the additional heat vs. greater temperature differential (than say summer/fall temps) is contributing to this. Possibly other than speed and duration of the drive, I cant find any common thread so far.<O</O
<O</O
Ill try to replicate at lower speeds, less duration of driving.<O</O
<O</O
Any thoughts would be appreciated.<O</O
D
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