1970 camaro... Any ideas?????

08-03-2009, 02:35 PM
whenever i start the car up and let it idle i hear a knocking noise. i dont have any idea as to what it is... but i dont think its good. but, this only happens when the car is idling, never when i give it just a little gas. does anybody have any ideas at all???

08-03-2009, 03:28 PM
Check for worn fuel pump lever asm. with stethoscope or lenth of rubber hose. If you have no knock under load but have it when letting off gas, It could be a wrist pin. Check oil pressure with mechanical guage to see if bearings are wiped out

08-03-2009, 04:46 PM
Call me what you want, but I don't know where Or how to check the wrist pin. Can you tell me? Thanks

08-03-2009, 05:10 PM
The wrist pin is the pin that connects the piston to the connecting rod which connects to the crankshaft. Often they are hard to detect when they are bad, however running the car down the road, while accelerating you would hear a wrap (knock) sound similar to a rod bearing failure, but letting off the gas and hearing the noise slightly disappear would indicate a worn piston/wrist pin.
I would start with the other suggestions first to elimininate the easy stuff. Let us know what you find.
And last but not least, there will be no name calling from me. Everyones concerns are valuable no matter how big or small. Just keep the information flowing and we will try to help out.

08-03-2009, 09:00 PM
thank you for your help and for all your time.
but can you tell me where and how to check the fuel pump and what to look for?

08-04-2009, 05:01 AM
Looking at the engine from the front of the car, the fuel pump is located left side, front of engine, below the cylinder head, above the oil pan. It should be made of aluminum.
Running the engine, place a piece of rubber hose on the fuel pump and listen with your ear to isolate the noise. If the sound you're hearing is more pronounced with the hose then I would suspect the fuel pump being worn.

08-04-2009, 05:35 PM
ok. well i checked the fuel pump and the knocking noise was not more pronounced. so im pretty sure the fuel pump is good. and the knocking noise only occurs when idling. but its not consistent. itll happen, then nothing for a few seconds, then it will come again, sometimes in little "one two threes". so since it only occurs when idling, the wrist pin isnt the problem then

08-04-2009, 06:59 PM
An oil pressure test is in order if you dont have a gauge on the dash. Is the transmission an automatic? Often the torque convertor bolts or cracked flex plate could cause strange noises. See if you can isolate the noise with your listening device so that we can better diagnos this. I hate to throw you all over the car without knowing where the noise is comming from. listen for noises comming from valve covers, pcv valve, timming chain cover etc. A diagnostics stethoscope is very inexpensive at your local auto parts store and can be very helpful.

08-04-2009, 07:03 PM
well, we just dropped off the car for a day to get a transmission leak fixed so ill have to get back to you on those later tomorow. its an automatic too. also, when idling, the oil pressure runs between 0-20. im pretty sure that normal pressure is around 40-60, but i dont know if that number applies to an idling car. but it does shoot up to that range once i give it some gas. and no problem, if i can diagnose this thing by my self, it'll all be worth it.

08-09-2009, 10:15 PM
ok this is where we stand. we checked the torque converter bolts and their fine. now, when im in park and idling, oil pressure is 15psi. when im in drive, its at 10psi. once i start giving it some gas, it varies between 10 and 30psi. and from what ive been told, that is really low. we've checked the oil and its full. i havent gotten an oil change yet. but i will soon. i dont know exactly what oil is in the car right now because we just got it back from a body shop and it sat there for about a year. but, if the oil change (and a filter change) with higher grade oil doesnt solve this low pressure problem, ive been told that ill need a new engine. so, i dont know if that has to do with the knocking noise or not (because we only hear it when the car is cold and idling) but right now im a little worried about the oil pressure being so low.

Add your comment to this topic!