OK, let me give you the progression of this jackhammer sound coming from under my the front end of my 2008 Yukon Denali (170K miles, well taken cared of, checked out and completely serviced not one month ago):
About a week ago, I was driving along and heard what sounded like a cross between a plastic trash can stuck under the vehicle and someone spraying high pressure water under the passenger side wheel wells. It was loud. Ear splitting loud, about 120 db without any exaggeration. The first time it happened it lasted about 5 seconds and appeared to come from under the whole passenger side. Then about 30 seconds later it sounded like it was coming from directly under the engine (just like the splash shield came down and was scraping along the road). Ear splitting loud. I pull over and see nothing under the car at all to account for the sounds.
Fast forward to tonight. I was backing up at my horse barn and heard a nasty banging noise, like someone beating on the front end with a hammer when I backed up and turned the wheel to the left. I tried to reproduce this sound by repeating the maneuver and got no banging sound. So, I straighten out and drove down the driveway and the banging sound came back, but the rate of it (about three times per second) did not change with the speed of the vehicle. The banging stopped and was replaced by a hissing-squealing sound. This hissing-squealing sound stopped the second I stopped the vehicle.
About two minutes later, there came a sound that was ear splitting loud that resembled a jack hammer that started at about 25 mph as I slowed down for a deer in the road. The jack hammer sound only stopped when I came to a complete stop. I drove on and the hissing- squealing sound continued for about 5 miles and stopped when I went down a big hill. That sound was replaced by what sounded like loose metal bars clanging together every time I hit a bump in the road, almost like a loose suspension part. That stopped about about a mile.
When I got home, I lifted the front end and inspected for any looseness in the wheels, spun the wheels to listen for bearing and CV joint sounds, etc., and did this also at the extremes of the steering. Nothing, No looseness in the half shafts/cv joints. Nothing. I then took the Yukon out of a test drive - nothing. It performed perfectly, no unusual sounds or steering issues at all. I tried to reproduce the exact conditions by going back to the barn and retracing my exact steps at the exact same speeds, etc. Nothing. Everything seems perfect.
I did, however, find a slight amount of oil seepage on the inboard side of the passenger side halfshaft/cv joint. Other than that, I can't find a single blessed thing wrong.
I've heard horror stories of people having a similar issue and spending several thousand dollars to fix the issue and the problem persists (in those instances it was either a broken parking break part or a loose brick in the catalytic converter). And I know, knowing my luck, that it is either a one-off freak occurrence or a $10,000 repair.
Anyone have any idea what is causing these sounds?
If I can get a photo to attach to the post, I'll show the oil seepage image.
About a week ago, I was driving along and heard what sounded like a cross between a plastic trash can stuck under the vehicle and someone spraying high pressure water under the passenger side wheel wells. It was loud. Ear splitting loud, about 120 db without any exaggeration. The first time it happened it lasted about 5 seconds and appeared to come from under the whole passenger side. Then about 30 seconds later it sounded like it was coming from directly under the engine (just like the splash shield came down and was scraping along the road). Ear splitting loud. I pull over and see nothing under the car at all to account for the sounds.
Fast forward to tonight. I was backing up at my horse barn and heard a nasty banging noise, like someone beating on the front end with a hammer when I backed up and turned the wheel to the left. I tried to reproduce this sound by repeating the maneuver and got no banging sound. So, I straighten out and drove down the driveway and the banging sound came back, but the rate of it (about three times per second) did not change with the speed of the vehicle. The banging stopped and was replaced by a hissing-squealing sound. This hissing-squealing sound stopped the second I stopped the vehicle.
About two minutes later, there came a sound that was ear splitting loud that resembled a jack hammer that started at about 25 mph as I slowed down for a deer in the road. The jack hammer sound only stopped when I came to a complete stop. I drove on and the hissing- squealing sound continued for about 5 miles and stopped when I went down a big hill. That sound was replaced by what sounded like loose metal bars clanging together every time I hit a bump in the road, almost like a loose suspension part. That stopped about about a mile.
When I got home, I lifted the front end and inspected for any looseness in the wheels, spun the wheels to listen for bearing and CV joint sounds, etc., and did this also at the extremes of the steering. Nothing, No looseness in the half shafts/cv joints. Nothing. I then took the Yukon out of a test drive - nothing. It performed perfectly, no unusual sounds or steering issues at all. I tried to reproduce the exact conditions by going back to the barn and retracing my exact steps at the exact same speeds, etc. Nothing. Everything seems perfect.
I did, however, find a slight amount of oil seepage on the inboard side of the passenger side halfshaft/cv joint. Other than that, I can't find a single blessed thing wrong.
I've heard horror stories of people having a similar issue and spending several thousand dollars to fix the issue and the problem persists (in those instances it was either a broken parking break part or a loose brick in the catalytic converter). And I know, knowing my luck, that it is either a one-off freak occurrence or a $10,000 repair.
Anyone have any idea what is causing these sounds?
If I can get a photo to attach to the post, I'll show the oil seepage image.
