I have a 2000 4WD LS Blazerw/98000miles. Crank shaft pulley is really LOUD...like bearing are getting ready to explode out of it. Also have ALOT of oil and sludge around the pulley and area of oil pan underneath the pulley. Am I correct in thinking that I need to replace my main front oil seal??...I.E. pulling the flywheel, damper, oil seal? Will this fix the oil leak and noisey pulley you think?? Seems to dramatically quiet down when I spray WD-40 up in there. Works only for 5-10 seconds though. Any suggestions would help. Thanks!!

 

I definately think replacing that seal would help. The noise could be the belt slipping due to oil getting on the pulley. But I don't see how WD-40 could quiet it down. Unless it's a coincidence. I think making sure the pulley is clean and maybe replacing the belt if it's contaminated with oil.

 

I don't think pulling the flywheel will do much for fixing a leaking front seal.

 

Let me back up a bit and give a quick history leading up to this. BTW I think I figured out the "loud noise" issue. My tensioner pulley was going bad....I procrastinated in fixing and it finally DISINAGRATED. Bearings and all. In fact, still picking up pieces out of the engine compartment. However, when this happened, I was running a gator-back drive belt and aside from shredding two tracks off, it stayed strong and only God knows how long it was rotating around with the absence of the tensioner pulley. Well, when I replaced the tensioner pulley....still had a lot of noisy racket. So I replaced the tensioner mechanism...still had the noise. Sounded like it was coming from the crankshaft area. Oh yea, the new belt I put on was a standard DAYCO. In between now and my original post, I read about how great the gator-back belts are. I decided to go out and spray the belt (DAYCO) to see if that made any difference. I sprayed both sides of the belt in a couple of different places and the sound disappeared. This tells me, I need to get a gator-back belt and that the DAYCO belt was the noisy culprit from the day I put it on. I'm glad I realized this before I plunged into pulling the front oil seal. I think I am going to check my oil pan bolts tomorrow since the oil really does seem to be leaking from all sides of the oil pan itself. Who knew a belt could cause such problems. I recommend that anyone chasing noisey pulleys around. trying the lubricating the belt trick especially if they have recently changed their drivebelt. Thank you guys for your suggestions!!

 

that belt spray is great. really makes it sticky. mine said it rejuvinates rubber so i sprayed all my bushings. havent had to replace 1 yet!