91 bonneville vin "c" engine noise

[Le91Bonnie]

Ok, so im at the drive through last night, and i hear what sounds like a combination of an exhaust leak, lifter rattle and spark knock. it does it whether its in gear or not. i pulled it up on the ramps last night and it sounds like its coming from the oilpan area. i dont have clue as to what it could be. the car has 125 k on it, and i just changed the oil on it saturday. i dont know if the timing chain has ever been replaced or not. i will try to post a vid from my cell tonight. thanks in advance.

[RJolly87]

Does it sound like either of these?

1.

2.

[Le91Bonnie]

Yes, kinda, here are some vids i took tonight
. i think its that AC pulley, but i can also hear what sounds like a slight lifter rattle toward the bottom of the engine. Can that pulley be tightened? Or just replaced?

[Jrs3800]

Check the rubber in the balancer...

And never use a Fram oil filter on a 3800...

[Le91Bonnie]

Rubber????? I know about the Fram, sorry, i didnt read about it until it was too late.

[willwren]

The harmonic balancer (crank pulley) has a rubber face. If it cracks and separates, it'll make a helluva clatter. Pull on the belts and see if that pulley moves at all.

[Le91Bonnie]

Ok, i checked the rubber on the Crank pulley, its fine. I pulled the belt off and started it and let it run for about 8 seconds to see if i could hear that noise. It still sounds like lifters but from the bottom/ back of the engine. I did notice though, as i decided to check ALL the pulleys while i had the belt off, the A/C pulley bearings are shot. So, i took the alternator, coil assembly, and lower Rad hose off, and for the life of me cant figure out how to get that top left bolt out of that D*MN thing. I found an A/C bypass pulley at autozone for $40, any other suggestions on the noise? Also, how the hell do I get the coolant out w/o injuring myself with it? And is there a shorter belt i can use rather than the bypass pulley or will it rub? Thanks!!

[RJolly87]

I think the motor has to be unbolted from that mount, and jacked up a bit, but I may be wrong. Also, any reputable A/C shop would be able to safely evacuate the refrigerant <coolant is anti-freeze BTW> using a vacuum pump.

EDIT: And as for the noise, I think the motor will have to be dissected to determine the cause, unless you drive it until the cause makes itself known.

[Le91Bonnie]

Thank you for all of your help, I will try to get this tackled this week. Updates later.

[Le91Bonnie]

Ok, I got the compressor off finally, and a by-pass pulley put on. Now the belt is out of line on the water pump because of the by-pass pulley, it pulls the belt toward the engine side of the water pump pulley. So, Even though i already bought the darn by-pass, do you all know what length of belt i would need to by-pass that altogether and sort of "skip over" the by-pass pulley where the ac compressor was or will it rub? I read on another post that it was a 73" belt but that was for a different year bonnie and it was supercharged. Thanks

[Jrs3800]

actually I believe that a 73" is what I used on a 91 to bypass the compressor...

[Le91Bonnie]

Thank you VERY much, im going to pick one up now.

[Le91Bonnie]

Thanks again, that fixed it!!!I think I need to change the HB next, but well see. Thank again guys i really appreciate it.