3.4 not sounding good, runs bad, knocking

[gerard]

well heres what i got. a 94 camaro, 3.4L 70k miles. just paid it off the day i got this problem...talk about luck.

car died at a light...restarted car, check gauges came on, no oil pressure at idle.... had to crank about 4x longer to get it started, seems harder to turn over. pulled over...checked oil level, it was fine. cranked for about 20 seconds till it started. had no oil pressure at idle still so i kept it above idle for the trip home.

the motor has a knocking noise to it on the right hand side of the motor when u accelerate in mid rpm range whether the motor is under load or not. car is about 1/3 as fast as it was.

i thought well maybe an egr valve caused the chamber to get hot, but i started it cold the next day and same thing. no power and knocking. could spark problems cause a knocking sound? however oil pressure is awesome when i restarted it.

my next guess well maybe a plugged converter? but would this cause a knocking sound? i guess if maybe it caused a leak or something near the manifold idk.


this summer though the car always seemed to have a real light hesitation under acceleration throughout the powerband. it always ran good for the first couple minutes till it warmed up though, then it seemed maybe 15 horse slower and then u could real faintly feel it stumbling just a hair while accelerating almost like what it would feel like when the a/c pump kicks in and out. very similiar to that feeling.
it also every now and then wouldnt rev totally to redline...it'd cut out about 1k sooner other times it'd redline no prob.


what do you all think is going on here?

[StudlyCamaro]

whenever its time for me to change my plugs i get a slight hessitation , but ive never let it go very long before i changed em, however that would be my first guess, how long has it been since they were changed

i wouldnt expect anything major, that motor is still a baby ive got almost double that many miles :D

[gerard]

it knocks like a champ though. since i bought this car over the last 3 yrs i havent even put 9k miles on it.

i changed the plugs early last summer. maybe 2k miles on them. wires 2 with hi performance 8mm silicon ones. o2 sensors were changed too.

[3.4 slow to go]

The cat on my Blazer died before I went overseas. It could barely go uphill, in fact I /m suprised it ran at all. Definately get it checked out. Also look for a leak where the y-pipe hooks up to the exhaust manifold.

[gerard]

ok i just started it up and ran it for about 5 min drive. it started right up...sounds fine at idle.... the longer u drive it the worse the knock gets and the lower the oil pressure reads... so the motor is def getting real hot. the knock is mainly at real light throttle... if i totally let off no knock...if i let off the gas but keep my foot lightly on the throttle it knocks bad...same if i give it maybe 1/4 throttle...but give it more gas...3/4 to full knock goes away.


so after 5 min drive, i come home and open the hood. the right side manifold is glowing red...and the left side is glowing around the 02 sensor.


a plugged cat?

[crasher]

yeah your cat is cloged up and needs to be replaced. if you look under your car after its been running for a while it will probably be glowing white hot also. You can probably feel the heat on the passenger side where it pops up by the seat and center console.

[93camaro_zzz]

Have you tried, to open the hood while its on and listen where the knock is coming from. A clogged cat can cause that sound, but you said, you ran your car, if only for a short time, on 0 psi of oil. You can take a length of hose, and place it around the engine, kinda as a stethiscope, and listen exactly where its coming from. Also, if you get bored one day, your exhaust unbolts right after the cat, and you can just take a look in there with a flashlight. Good luck.

P.S You have a very nice looking car. no crap man, your car looks extremely sweet. Later,

[gerard]

ya the zero psi thing scares me. i imagine the motor is gettin so hot that the oil is wicked thin at that temp and isnt flowing real good at all. the knocking seems to be coming from around the valve train area, starts on the right then the hotter it gets you hear it coming from the left side also.

....thanks for the comments on the car... it's cool to hear people like it. i should edit the pics, i have a new deck and amp in there and a false floor with fans and plexiglass i built over the amp.