Harmonic balancer question

EDWINSIXX

MEMBER
1998 FORD TAURUS
6 CYL
FWD
AUTOMATIC
200,000 MILES

My car has been having a bit of trouble starting. I have noticed that I am able to move by hand the belt, everything spins very smoothly, but if I recall correctly the harmonic balancer/cranckshaft shouldn't do that. Is this correct? I also have noticed that there is a lot of oil around it, looks like its leaking oil from the engine. The other day I tried to start the car and noticed that the alternator was spinning but not everything else, so I quickly turned of the engine and have left it alone for the time being. Any suggestions or ideas of what the problem can be will help. I tested the alternator at an auto parts store and its still good, also it has a new water pump, about 11 months old.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Something doesn't sound right but I'm having a hard time visualizing what's happening. The harmonic balancer is actually two pieces, a center hub bolted to the crankshaft, and an outer ring glued to the hub. On your engine the drive pulley is bolted on; it's not part of the outer ring. If just the pulley came loose, it would fall off but not cause an oil leak. Since you do have oil leaking, it suggests the center bolt has worked loose and the balancer has walked out and is not engaged with the crankshaft. That will expose a seal and let oil leak out rather quickly.

The fix might be as simple as pushing the balancer back on and tightening the bolt, but this happened to my minivan a few years ago and the hub got all chewed up. Cost me five bucks for a used one from the salvage yard. No damage occurred to the crankshaft snout. If you do try to push it back on, there is a keyway that has to slide through a groove in the center of the hub so you'll have to rotate it until they line up. There's also a chance the key fell out but they're usually in there pretty tight.

A lot of manufacturers are having trouble with their harmonic balancers. Auto parts stores have fat catalogs showing nothing but replacements. There are three different units for the Taurus. One is plastic and looks like there's no way it could possibly hold up to the stresses of running a belt, but that one doesn't go into the oil seal.