okay my '87 lg4 camaro was *lightly* knocking/tapping, and with low oil pressure, so i was going to drop the oil pan, change the oil pump, and put 15w40 oil in it, see if that fixed it. but before i drove to my grandmas (grandpa had built a pit and engine hoist there) i changed the spark plugs, radiator hoses, tstat, and tstat housing, had it up on stands for aobut a week cause i don't have alot of spare time. anyways i get it of the stands, and fire it up, and know its majorly knocking, sounds like a piston hitting, my dad (not a mechanic, but hes had his fare share of experiance) said my timing chain might have sliped. anything i could have done to cause this by doing what i listed above? ideas?...on a side note i used bosch platnium2s (seems like i read somthing negative about them here, might've even said there was problem with them)

 

Was it low on oil?


Sounds like time for a rebuild or new engine.

 

Did you start the car while it was on the stands? If you did the oil was not being picked up by the main bearings or rod bearings on cylinder one or two.

 

no, I took it off the stands before starting it, full oil, forgot to mention when i get the car it was lightly knocking(and low oil pressure), i changed the oil and it ran fine for about 300 miles(fine pressure as well), then the pressure went down and it started knocking (lightly) again, and the oil level never dropped, no oil leaks that i could find either, changed the oil again when i had it on the stands, and now when i started it it had good oil pressure, and the light knocking(/tapping), was replaced by loud knocking that sounds (and may be lol) a piston hitting. i really don't think its connected to oil, but the only other changes i made where tstat(and housing) and spark plugs, now when it was running fine, the carb was having choke problems, is there any way my carb could cause this?

 

You just bought the car recently?
If you take off the oil cap and look in the valve covers, can you see a lot of crap built up on the rockers and head? How many miles are on the car? What did the plugs look like when you pulled them(very white, brown, greasy black)?
Does the sound happen at idle if you are standing by the car, or can you only hear it when you are driving(accelerating). Does the knocking get faster as you increase throttle, or does it stay about the same speed?
How much pressure did the oil drop by?

 

yes, i bought the car a few hundred miles ago. it has about 101k on it. the plugs weren't very bad, aka they looked like any other plugs that needed changing from being used, they were black, slight deposits on them, (very slight). yeah, it happens at idle, it sounded very very bad so i didn't run it real long, or drive it anywhere, backed it out of the garage (a whole 12 feet i think lol), my car idles fast so my reverse was lower rpm, and i'm not sure if it was any quieter, but definatly slower. the oil pressure was actually fine when this happened, but what it had been doing was when i got the car OP was about 10, any rpm. changed the oil and filter (MAJORLY needed filter change) OP went to about 20psi idle, and 60psi by 3.5krpms, and the light knock went away, now i had a overheat problem i had to fix with a new Tstat (no, i never let it go red, after i saw it the first day(max of a moment or two) after about 200-300 miles the OP got as bad as the first time during a 2 mile drive home. light knocking came back. then i put it on stands and did all that other stuff, and was going to change oil pump, and oil pan(slightly caved in)

 

Sounds pretty bad in my opinion. I'd start looking at rebuilding or finding another motor. 10 or 20 psi is very low. Your bearings have probably been starved and are going to be bad. What exactly is knocking, I don't know. You can try replacing the pump, but you will most likely have some other underlying problems even if you can get the oil pressure to come back up.

 

On a V8 camaro your oil pressure is in spec with 15Psi @2k rpms so if it is less at idle that is okey...

sythetic or the real oil?
what grade oil are you running?
where do you live? how cold is it there?

 

real oil
castrol 10w-40
Paris, Texas (on tha north border :P)
well the past month or two has been abnormally cold, 30-45, week or so less than that, and now its up to 54

 

okay well after the car overheated did you change the oil?
did you ever replace the caved in oil pan that could be causing this low oil preassure problem? when you do replace the oil pan check the pickup and make sure there is no damage

you might try going to 10w-50 and see how that affects noise...

 

okay well after the car overheated did you change the oil?
did you ever replace the caved in oil pan that could be causing this low oil preassure problem? when you do replace the oil pan check the pickup and make sure there is no damage

you might try going to 10w-50 and see how that affects noise...

yes, i changed after overheat

I was about to drive 10 miles to an engine hoist so i could change the pan and pump, but the noise got really bad instead of being only light.

and right now, after a fresh oil change pressure is fine, and the noise is BAD

 

If the engine knocks, it is smoked.

You can change the oil pump every day, and twice on Sundays, and it will not fix the knock or even change it.

You can put oil as thick as candle wax in the crankcase, and it will not restore the missing mteal that has been lost from the bearings and crankshaft.

If the engine is knocking, the only solution is to replace the failed/worn/destroyed parts; and clean ALL metal shavings out of the inside of the engine to prevent immediate destruction of the new parts.

 

i was not saying that this engine isnt smoked... just trying to tell if he was talking about a real knock or his rockers need adjusting