RaptorD

My C6 (2005, stock + Skip Shift Eliminator, manual, 23,000 miles) had never given me problems until early this summer, when it started having intermittent electrical problems. It ran fine, but once in awhile it would not start although the security system was activated and controls were active. The local GM dealer could not find the problem, nor could a couple of local, good-reputation mechanics who tried. Needless to say, a car that runs great but won’t always start, is not worth having.

I searched the internet including Corvette Forum of course, for days and found lots of similar experiences from other owners, but not one solution that came even close to making sense for my situation. At least I wasn’t alone with the problem, but that didn’t help a bit as far as solving the problem.

I finally went to a shop that works only on ‘super cars’, which kept my ‘Vette for several weeks, as they were determined to solve the ghost electrical problems and asked that I let them work until they found the solution, which I did.

They immediately replaced the 1-yr-old battery although it tested okay. They checked all the sensors and everything they thought could possibly cause the ‘no start’ problems but day after day the symptoms continued intermittently. Sometimes it would start, sometimes not, and the gurus eventually discovered another oddity. The battery was sometimes fully charged and sometimes almost fully depleted! They had already sent the alternator out for rebuilding, but their vendor said it was perfect and did not need rebuilding so they sent it back as is.

To make a long story (and long time in the shop, being started--when it would start, driven and worked on intermittently every day) the head guru finally found the culprit. The evildoer was the set screw for the harmonic balancer! It appeared to be tight, but somehow the pulley assembly had moved toward the block just enough to cause the alternator to not always send a charge back to the electrical system. According to the head guru, a few more times running this way might have caused the need for a new crankshaft. Yikes! Needless to say, many of the exterior engine components had to be removed to complete the installation of a new harmonic balancer. All of this after many hours of time to diagnose each day.

Cutting to the chase, the results: The car runs perfectly again and (so far) always starts.

I have no idea how many people have a similar problem, but from my reading it appears to be quite a few. I can only hope someone saves the 4 grand and the inconvenience I spent to find the solution to this issue, should the cause be the same. At least it's something to check out.

(A new balancer runs about $500 for the average car installed, maybe add a hundred for "Corvette Complexity & Mystique." ) Or DIY.for $100-$250.

Good luck & happy driving,

Dan

3684rickc

Will somebody please tell me that this is a JOKE!

Vette_DD

If you're so sure it's a joke, why did you respond to it?

RaptorD

Hi rickc,

If it makes youhappy, by all means, consider it a joke. However, it wasn't funny at all to me.

Dan

449er

Wow! This is a new one on me, glad that you got it fixed!

cmonkey713

Great info for everyone, thanks for posting your fix.

73DBG

Not sure I even wanna know how much all the labor time cost you😳 glad it’s fixed though, sounds like you had a real unique situation probably unavoidable to have cut down the diagnostics cost it being so odd.

Vette_DD

That's what this forum is for.

TraceZ

Harmonic balancers are notorious for failing. I'm puzzled as to how that could impact the alternator the way you describe. From that standpoint either the belt is turning the alternator or it is not. If the belt fell off you would of definitely noticed that as you would of also lost power steering and coolant flow.

ErikR

I've got to agree..... there's too much questionable stuff in the original post... pulley alignment issues will make the belts squeak (mine did before HB replacement), but if the alternator's turning it's charging... There's no way a pulley alignment issue keeps the alternator from working..... not buying it

Now if the balancer failed and the engine is running but the out pulley portion of the balancer is not turning...... But then like TraceZ says, you'd have other issues...


The air conditioning, water pump, alternator, and power steering would all quit working...

Judgebull

What is the “set screw for the harmonic balancer”?

baxsom

My thoughts as well. A set screw presses into the threads of another screw to hold it. Mine doesn’t have one. I’m thinking op was fed a line to justify an expensive repair

SMaster

Maybe talking about the main center bolt was loose and the damper was spinning on the crank, causing it not to charge??? Just my guess from the information given because I don't know of any set screw on the damper.

Steve

Josephu

If that balancer hub was spinning on the snout of the crank........the crank is toast. If they are just relying on the bolt to keep the balancer on the crank.......get ready for another bill.

3684rickc

Enough said!

carsnpars

Set screw? Balancer moved back? Towards the block?