loud knock noise after rear crank seal replacement

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

cjheath1

TYF Newbie
Joined
Aug 2, 2024
Posts
11
Reaction score
9
2015 gmc yukon danile 6.2 6 spd trans 4x4, ok here we go, friend had alight drip under truck shop said rear main, so she brought it to me and looked at it and yes rear seal and also possible by intake area, so removed trans and rear cover, cleaned and installed new seal and rubber o-ring type seal, silconed up and reinstalled, told her yes afm seal leaking also, she said no to thea ( oil pan upper and lower ok) put new oil cooler gasket on it and reassembled, add 8qts oil 0/20, new gm oil filter, start up and a knocking noise from motor( loud) turn off check oil ok recheck for any thing hitting ok, start up and oil pressure 40 that 30 than 25, light rev 45, check codes none. drive and noise got quiet, parked it let sit, later recheck and noise back. this time found after test drivep0131,p0171,p0324,p0300,u0101,u0401. checked no miss fire data, not sure what to do,? not the first time doing rear seal, just finished cad esclade last week same thing(reseal oilpan,cooler gasket gm filter) so I never seen this before so if any one seen or heard anything like this please let me know.
 

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
4,599
Reaction score
5,860
2015 is the newer LT engine I believe. you're in the older ls section. having never worked on a LT. i can only guess. but I've seen torque converter bolts left loose that sound like a knocking, and or pinched wiring harness between engine and bell housing. that caused codes, but I don't know about knocking.
 
OP
OP
C

cjheath1

TYF Newbie
Joined
Aug 2, 2024
Posts
11
Reaction score
9
2015 gmc yukon danile 6.2 6 spd trans 4x4, ok here we go, friend had alight drip under truck shop said rear main, so she brought it to me and looked at it and yes rear seal and also possible by intake area, so removed trans and rear cover, cleaned and installed new seal and rubber o-ring type seal, silconed up and reinstalled, told her yes afm seal leaking also, she said no to thea ( oil pan upper and lower ok) put new oil cooler gasket on it and reassembled, add 8qts oil 0/20, new gm oil filter, start up and a knocking noise from motor( loud) turn off check oil ok recheck for any thing hitting ok, start up and oil pressure 40 that 30 than 25, light rev 45, check codes none. drive and noise got quiet, parked it let sit, later recheck and noise back. this time found after test drivep0131,p0171,p0324,p0300,u0101,u0401. checked no miss fire data, not sure what to do,? not the first time doing rear seal, just finished cad esclade last week same thing(reseal oilpan,cooler gasket gm filter) so I never seen this before so if any one seen or heard anything like this please let me know. just a quick thuoght, could the new gm filter be bad? worked for gm 30 = years dont remeber hearing this before , also 153,000 miles and she wants to trade in but wants to get best price no bad engine price lol.
 
Last edited:

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
4,599
Reaction score
5,860
sorry about I'm tired and pissed, how do I repost in corrct thread?


usually a mod comes along and moves it for you. I don't know a time frame thou. might be faster if you just make a fresh thread.


good luck with it.
 

wjburken

Elite Member
Supporting Member
Joined
Dec 26, 2017
Posts
10,311
Reaction score
29,524
Location
Eastern Iowa
My first rule of troubleshooting is look at the work that was done right before a problem started. As mentioned, check your torque converter bolts.
Even seasoned mechanics miss things so just recheck everything you just touched.

I would also check all harness connections to make sure something didn’t come unplugged or get pinched/damaged.

It would be strange, not impossible, but strange, for a lifter to go bad right after you did all the work you did with no prior signs of trouble.

Other than the knocking sound, does the vehicle run smooth or does it have a lot of vibration?
 

wjburken

Elite Member
Supporting Member
Joined
Dec 26, 2017
Posts
10,311
Reaction score
29,524
Location
Eastern Iowa
1737129706422.png
 
OP
OP
C

cjheath1

TYF Newbie
Joined
Aug 2, 2024
Posts
11
Reaction score
9
sorry about that posting in wrong place but sh@t happens, anyway yes converter tight, no wires at this time( she needed it back) and I told her NOT TO DRIVE IT, only thing I can think of is oil filter, never seen gm 1 bad, but possible first time for everything, just thinking would loose vlom bolts make this happen?, was reading and found possible they work loose? will get back on it tomorow . thanks
 

07Burb

GM fan for life
Staff member
Moderator Supporting Member Administrator
Joined
Jan 3, 2011
Posts
50,911
Reaction score
19,230
sorry about that posting in wrong place but sh@t happens, anyway……
No worries. Its a common misstep and not a big deal. When it happens, just let us know and we can move the thread to the right location :waytogo:
 
OP
OP
C

cjheath1

TYF Newbie
Joined
Aug 2, 2024
Posts
11
Reaction score
9
New update, checked new oil filter and it was wrong, marked pf63, but inside was wrong, so quick check installed old filter and 85% noise gone, check codes p0300 only, lightly raised rpm 2000 rpm and pop noise and knock gone but light missfires #2,3,8 only, check plugs looks good but p0300 only ,don't know what's going on.
 

hagar

Full Access Member
Joined
Nov 13, 2010
Posts
280
Reaction score
318
New update, checked new oil filter and it was wrong, marked pf63, but inside was wrong, so quick check installed old filter and 85% noise gone, check codes p0300 only, lightly raised rpm 2000 rpm and pop noise and knock gone but light missfires #2,3,8 only, check plugs looks good but p0300 only ,don't know what's going on.
If the wrong oil filter caused oil delivery issues like it sounds, you might have scuffed the cam and or lifters. I have seen cam lobes on the LT engine barely have damage you can feel with your finger, yet be enough to throw misfires.
 

Forum statistics

Threads
137,667
Posts
1,989,034
Members
102,674
Latest member
15TahoeSSV
Back
Top