rear main seal, now bad knock, HELP

[aalugo2000]

ok guys,
i just had my rear main seal replaced. NOW when they replaced it they had to drain my oil and put more in. i usually use mobil 1, but the shop didnt have it so they used the cheap valvoline oil.

about 6-7 hours and alot of driving later i notice my engine is knocking, pretty loud, i could hear it in the cabin. at first i thought it was just that cheap oil so i put some motor honey in to try and do a quick fix... didnt work. so i plan on changing the oil completely the next day.

on my way home i notice the knock is getting a little louder. and when i had to accelerate 0-60, the car would knock loudly under load, and wouldnt really accellerate over 2500 rpm's. it didnt really jerk or anything, just struggled to accelerate.

the next day i change back to mobil 1 (10w30), didnt change a thing. about 10 mins after the oil change i notice something leaking. coming from passenger side, around area where header meets y-pipe, couldnt tell exactly. but when i checked again when i got home, no more leak. and i experimented with the knock, its kinda quiet at idle, loud for a second at startup, and really loud when i hold about 2000-2500 rpms. when trying to gauge where the sound is coming from, i found its loudest under the car, not all that loud up top around the valve covers.

the car is really hesitant under load, almost like a misfire-but not quite, no ses light yet either. so if anyone can help me id appreciate it, im kinda scared, i already searched under engine knock and didnt find much.

[Dojo2000]

Not sure what it could be, but maybe I could give you somewhere to start. When they replace your rear main seal they unbolt the driveshaft from the tranny, drop the tranny, and then take off your flywheel. Maybe they messed up somewhere along the way.

Are you sure its more of a knock then a tick? Valves tend to tick, but when you have an exhaust leak it also makes a ticking sound. The exhaust pipe running from your driver-side exhaust manifold to the y-pipe runs right under the flywheel/oil pan. Maybe they damaged it in some way removing/installing the tranny. I believe a clogged cat can cause hesitation under load also.

Wish I could be of more helpful.

[camaro_speedemon]

Sounds like they screwed something up. I would take it back and tell them what happened. They should fix it if they screwed it up.

[aalugo2000]

yeah,
i think they did screw it up, only thing is i have to wait till monday [img]graemlins/thumbsdown.gif[/img]

but yeah, its more of a knock than a tick, and i dont have a cat anymore so its not that.

[1998silverbird]

Sounds like rod knock.. You said you were leaking oil.. Maybe they didnt tourqe down a bolt all the way on the pan and the oil leaked out and when you were cruising the oil pump was pumping all the oil around the motor but since some oil leaked out there was no oil at the crank fro a second or so and bam you spun some bearings.. thats what happened to me.. I was 1 qt low, didnt know it, and got on it one night from second gear till 5th and when I got out of it at 100 or so All I heard was knocking.. what happened was the oil pumped pumped out all the oil from the bottem of the pan to the top of the motor like its suppose to do but I was 1 qt low so I didnt have the oil at the crank for that second and it spun 2 rod bearings.. Very mad.. car wouldnt accelerate over 70 mph and 3000rpms after that.. Does it sound like a ticking at idle and wjen you rev it up sounds like there is a rock or something banging around inside?? I thought I sucked up a rock in the intake but I didnt..

[aalugo2000]

yeah actually its kinda like that, ive gotten into a litte more detail in adv. tech... thread is titled i may have broken a rod... i think, so if u can, check out that post, and maybe u can help me [img]graemlins/thumbsup.gif[/img]