To start off with, i had a 95 lt 4.3 4x4 blazer until monday morning at 9:38 am. when it got totaled by a 2009 f-150 in delaware. so now i am looking at replacing it with another blazer. (won't find the same deal i got from the last one, but still looking)

i found one here locally (va beach) 96 4 door, 4.3 4x4, outside is super clean, inside is manageable only drawback is a knocking noise in the engine. when i went and looked at it today, has a rather loud knock, but not quite a knock, more like if you put playing cards on your drive shaft so they hit something everytime they went around. Here is the kicker, when in park and neutral, noise stays consistent with engine rpm. but when put into gear and revved up noise is gone, (or at least unnoticable). it makes me think the noise is not engine related but tranny related.

any ideas as to what could make the noise? i am wondering if the torque converter is going bad or the transmission pump is going out.
didn't check all the fluids or drive it today, just looked at it and listened to the engine noise (was listed in ad).

is there a way to fully verify if the noise is engine or tranny?

thanks,
sorry for the long post.

 

Keep looking-better Blazers out there-took me 9 months to find a replacement for my last Jimmy,so all the parts would fit. Be patient-They ARE out there! HINT! Look in impound lots-Thats where I found my current unit! 20K in one year! And less than $2500 invested...love these cars!

 

I am pretty patient. the only problem is. i don't have anything else to drive while i wait. this one is only 700, which would suffice for my DD if it is fixable and have time to wait for another after that, but have to have something to drive. sooon.

 

bump for more looks

 

I used to have a Honda Passport (Izusu Rodeo) that had a knock. I knew it was in the motor, but could never pin-point exactly where (rod, timing, cam, etc), until the day I stuck a stethoscope all over the motor, when I got to the oil pan it was VERY obvious where the noise was coming from.
It's very easy to miss-diagnose motor/transmission noises just 'by ear', even the old 'screwdriver trick' isn't completely accurate. Using a stethoscope isolates both ears to listening to what is coming from the scopes probe, thereby pin-pointing without surrounding noise distraction.

Sara Lou

 

There is nothing in a transmission that is rotating in park or neutral except for the rotor and vanes of the oil pump. Either that or the torque converter.

I would not rule out torque converter though.

I also though of the catalytic converter. If you reach under and give that some taps with your fist, does it make any noise?

I also am wondering how you rev the engine while in gear if you were not able to drive it?

 

Pass on it. There are tons of more problem-free Blazers out there for sale, so it's not worth dealing with a vehicle that is making ugly noises when it runs. Save yourself the headache and repair expenses.

I don't know how far you're willing to drive to get one, but there are always a lot of Blazers for sale here in the central-NY area (Syracuse/Rome/Utica). I have seen perfectly good Blazers (4X4) with less than 130k miles on them (and little to no visible rust) advertised for $2500 or less. 1995-97 models can be easily found for under $2000. We're saturated with these vehicles in this area.

 

Mail bearings can make a dull knock at low throttle and the seem to go away with a little throttle as the crank shaft deforms slightly with pressure.

My sister bought a 99 caddy with a dull knock. She drove it several years with no difference.

Keep good Havoline oil in it and a good Wix filter.