I Hear You Knocking

A "glamour shot" of my vehicle that I found somewhere on the Internet a long time ago. (From www.autonet.hr, I think)

My car has a knock and it is driving me just about out of my mind.

Those of you who are regular readers of this blog already know that I am notoriously fussy about some things.  One of the things about which I am most fussy is my car.  I like it to be clean, comfortable, and in excellent working order at all times.  Come to think of it, that’s pretty much how I like to be too.

If a dashboard light comes on, I immediately stop and look into it.  If something is spilled inside the car, I will pull over to the side of the road wherever I am and clean it up.  While it is impossible to keep the exterior spotless during a Maine winter, I do hit the automatic car wash as often as I reasonably can during the winter months, and can be seen washing and waxing almost every weekend once the weather gets above freezing.

So, you can imagine my horror a month ago when a strange sound started coming from what sounded like the passenger side of the undercarriage whenever there was a slight side-to-side motion of the car.  Given the pothole quotient during spring in these parts, and the fact that my car is an SUV with a fairly high profile, I was hearing it quite a bit.  It was a gentle knocking sound, as though something dangling underneath was bumping up against something else.  The car, a 2007 Hyundai Santa Fe with about 70,000 miles on it, has had very few problems in the two years I've owned it, so this was cause for concern.

Frankly, I did not want to shell out a bunch of cash to a mechanic if I could solve it myself, which I hoped was the case here.  My vehicular mechanical skills are much like my computer troubleshooting skills: intuitive.  I don’t really know how to explain what is wrong or how to fix it, but I can generally dive right in and take care of it myself in many situations.  If I had to teach someone else how to do it or describe what I just did to fix the problem, I’d be totally lost for words (which would be really something for me).  I instinctively knew that this sound from below the car, while irritating, was not something serious that would impede operation of the car in any way.  The only way the knock would knock was when influenced by a side-to-side motion.  It was not, for example, a faulty CV joint, since I've been there before with a prior car, and my bank account has the scars to prove it.

I did the most obvious thing first.  I went through the interior of the car to see if something was loose and knocking around.  I crawled under the seats and looked in all of the storage compartments, finding nothing that would be prone to movement.  I don’t tend to store a lot of “stuff” in my car anyway.  Just to be sure, I took every single thing out of all nooks and crannies of the car, from the papers in the glove box to the spare tire and everything in between.  Then I went for a quick drive around the block.  The knock was still there.

So much for Plan A.

The next step was to jack up the car and crawl under.  It was still mud season at the time, so this was a miserable thing to do.  There wasn't really enough room in my garage to easily jack it up and have room to get underneath, so I had to do it outside in the wet, muddy driveway, where there were likely earthworms and God knows what else.

I didn't use the small emergency jack I carry in the car, since it was both flimsy and also neatly packed away again after the failed Plan A.  Instead, I got out the allegedly heavy duty hydraulic “SUV jack” (note the quotation marks), which I kept in the garage.  I had not actually used it on this particular vehicle before, though it had always worked fine on my previous vehicle, which was a lighter car.  There was no reason to think it wouldn't work on this one, since it was supposed to be a jack capable of lifting SUVs, and my current vehicle is indeed one of those.

Wrong.

I positioned the jack carefully and started moving the handle up and down, up and down.  This went on for several minutes, and I was starting to get a bit winded.  “Wow,” I thought, “the suspension on this thing must be terrific if it takes this long to get the wheels off the ground!”  Come to find out, the jack couldn't handle the weight of my vehicle, and all my jacking was for nothing.  I proceeded to cram the car, the jack, and myself into my tiny garage and tried the whole process again on a cement surface, but still nothing.  This “SUV jack” was just not going to jack my SUV.

Moving the car back into the driveway, I shimmied underneath it without benefit of a jack.  The undercarriage does sit fairly high off the ground, but it was still a tight squeeze for me to get underneath to inspect things and commune with the earthworms.  Every move required contortionist-like skill, which is no easy feat for a guy like me.  The idea was to muckle onto a few things underneath and gave them a gentle shake to see if I could replicate the knocking sound.  After slightly burning my hand on a still rather hot exhaust system, which had been the primary suspect, I concluded that it was not the problem.  It moved a little bit, but made more of a metallic sound. 

Every shake dislodged a winter’s worth of dirt, most of which landed on my face and in my hair.  Nonetheless, it seemed like most everything under there was pretty solid.  I was just about to crawl out from under, pick the squished earthworms off my back, and go shower for several days when I tried one last thing.  There was a conduit for what I believe is a brake line that seemed like a possible culprit. Sure enough, it did have a side-to-side movement and bumped slightly into some other thingy nearby.  It sounded like the knock I had been hearing, and so I thought I had found it.  With much effort, I maneuvered my way out from under and went to get some plastic ties to secure the conduit in such a way that it wouldn't bump the other thingy.  After doing so, I took a quick spin around the block in the car.

The car still knocked.

Dammit.

I crawled back under, carefully avoiding the now very hot exhaust system, and saw that the ties had come off somewhere on my short drive around the block.  Still convinced that I had pinned down the problem, I got some more plastic ties and fit them more tightly than the last set.  I didn't want to make it too tight, for fear it would damage the conduit.  Another trip around the block, and still the knock persisted. 

They say the definition of insanity is doing the same thing repeatedly and expecting a different result.  In spite of that, I crawled under the car yet again and readjusted the plastic ties in such a way that there was no possible way the conduit could knock against anything.

People were starting to look out their windows as I drove around the block for a third time, probably wondering if I was stalking them.  The crazed look on my face as I continued to hear the knocking sound in spite of my efforts probably only heightened their fears.

So apparently the brake conduit was not the culprit after all.  I was done for the day, and decided to just keep the radio turned up loud to drown out the knock until I could get a second opinion.  I was going to dinner with my brother not long after that, so I figured we would take my car and he could hear the sound for himself.  He didn't.  Claimed he didn't hear a thing.  Of course, he has two young children and a large dog, so his cars are constantly rattling, clanging, and bumping from all manner of detritus left behind by the youngsters and the pooch.  My car probably sounded like a sailboat on a glassy sea in comparison.

A few weeks have passed, and my delusion that the knock would just resolve itself miraculously has long since fallen by the wayside.  I've crawled under that damn car at least three other times in hopes of finding that which has eluded me for nearly a month, but to no avail.  The knocking persists.  As much as I hate to admit defeat, I think it’s time to make an appointment with my mechanic.

I can almost see how it’s going to go:  He’ll call to say the car is ready.  I’ll stop by to pick it up, and he’ll hand me an empty bottle of Ibuprofen or something similar he found rattling in some compartment I missed in my previous searches.  Then, with a smarmy grin, he’ll hand me a bill for several hundred dollars, and I’ll wish that bottle of Ibuprofen had a few tablets left.

I still have one plan left, although it might have a few flaws.  Since the knock can only be heard when the car is in motion, I am thinking that I can get someone to hang suspended by bungee cords underneath while I drive around on some rough streets.  The aforementioned “someone” would thus be able to pinpoint the source of the knock, and will then tell me what it is as soon as they are released from the hospital. 

Any volunteers?  Might be a free beer in it for you.

YouTube Video: A live version of the classic "I Hear You Knocking" by the incomparable Dave Edmunds. You have no idea how much I hate this song now.