Thread: 1998 buick century 3.1L problem--audio included

https://www.facebook.com/photo.php?v...06199521124750 I don't know why but my return/enter button is not working on this website so I can't make paragraphs. sorry. anyway, the video is the sound of the engine. it sounds bad. when you drive the car it has substantial loss of power. it feels kinda like when a tranny is bad. i only moved it in the driveway but the kid who was driving it--this suddenly occurred while he was driving normally (allegedly) and limped it home. its his moms car. two codes that I don't think are related but maybe.....P0440 (gas cap?) and P1676. two google searches on this one showed either evap system related like the 0440 code or pcm problem. this problem sounds internal engine to me. oil is half range on the dipstick. I thought when I got home maybe it could be the transmission because it kind of acts like that but it sounds like its coming from the block. I should have checked the fluid. lots of vibration. you can see it in the video--worse in person. shakes the car at idle and while moving. the sound seems to get a little better when putting it in gear. i'm curious because I will probably be the one fixing it and I want to learn some more stuff. if its not clear what the problem is what more can I look for next time I go back?

well, I guess i'll take a stab at it. I think it might be a push rod knocking. any thoughts?

sorry bout that. I don't know why. it shows up on my computer when I click the link. it was posted quickly on facebook because the computer wouldn't see the phone. I was talking to her and found out that she had some lube shop do the intake gaskets a month or two before the problem started--that was after I thought it was rod knock. coincidently, I just did the intake gaskets on my wife's 3.4 so I could see if they didn't put the rods back in place in the right order maybe that messed it up--or they didn't torque it down tight enough and it worked its way loose. its a lot louder and more violent than piston slap. major loss of power. I think I might try checking the icm. would that give me any misfire codes if the icm were bad? thanks Jevik!

Um that does not sound good. Sounds like rod knock.

Icm does not explain the rod knock thats happening there.... did I mention I heard rod knock? Because im pretty sure thats rod knock. Or at least a flex plate / other misc hard part failure.

i think its rod knock, too. now the question is why? and if there is more damage. i know i can get in there and change the rods--physically speaking. but is a rod the problem? what should i look for when i'm in there? is there a way to isolate which one or ones it is?

If it's rod knock, look for any score marks or chips on the bearings. That will hopefully narrow it down

I finally got to work on this car. took the intake manifold off and checked to make sure the bolts were tight on the rockers--at least on the front side. I didn't pull the back side yet cause have to take alternator off. ran out of time. could still see them though. the rods looked straight, no scratches or burs or anything. however, some of them had some wiggle in them. maybe half, actually. i'm thinking that isn't the way it should be. I can see how this would cause noise but would this explain loss of power? is there a way to verify which rods go in the right spots? some crappy shop changed her intake gaskets a little while before the problem started so i'm wondering if they put them in the wrong order as a possible explanation. sorry there are no paragraphs. for some reason on my laptop it won't let me make paragraphs.

Rod knock is connecting rods not push rods.

I don't know the correct terms but I was also wondering if one of the springs is bad or if the head where it pivots that connects the rod and the spring could be bad. from sight I cannot tell, though.

Originally Posted by slick2500

Rod knock is connecting rods not push rods.

oh. from the sound of that this may be a waste of time completely.

Yeah the 3x00 v6 was a pitiful excuse for an engine. Not really worth fixing if something breaks on them.

is this what I would be looking at: I would have to pull the rockers off. pull the heads off. then take the piston out the top. or do you have to pull the engine and be able to get at it underneath at the crank to take the connecting rod out? (or both) and I would be dealing with timing and stuff. or can that just be put back the way it was? I think I am understanding how engines work generally but the specifics of actually doing the work is where I've got a lot to learn. I'm guessing if one were to do that they would just essentially rebuild the whole thing? right? thanks!

not that I want to do it. I would like to be able to tell her what needs to be done, though. and have some more understanding for myself.

Best bet is try to find a low mileage 3100 out of a 94-99 car. I don't know if the 2000+ engine will work as the intake manifolds are different, I know you cant put the newer intake on the older engines as the rocker arms will hit the intake manifold and make the car sound like its knocking, but I think you should be able to get away with an old intake on a new engine though as the rockers won't hit. But like I said best bet is just find a new engine. 3100s are not worth rebuilding.

I think i'm going to tell her to just move on from the car. I told her from the start not to expect good things. I've changed a motor before but I don't think messing with buick century is even worth it. thanks for all your help Slick2500!