a violent shake and questiona for the wise

[67'maro]

Alright I was out on this road with my friend with my '67 Camaro and he got on it in his car so I stepped on it in mine. well i got through 1st gear shifted to second at 6500 rpms, by time it shifted it was at 7000 rpms (its an automatic and when at the drag strip our set redline is 7500 rpms and a rev limiter set at 8000rpms) everything fine, Got through second all was fine, Went into third, still everything fine. In third gear everything was good and I let off on the gas just under 6000 rpms. I am almost positive these rpm's are when i shifted gears. I am sure i didn't over rev the motor. Well, Once i let off the whole car had a short violent shake. I was very unsure of what had caused this. well the next time the car was started the fuel pressure was abnormally low, but i never checked it that day when i went out with my friend. The car leaks a little oil but nothing serious. Also had a very very small puddle of coolant when i Checked. So... My question is what caused this shake? did that affect my oil pressure? Or did the car slowly leaking oil affect my oil pressure? Could have over revving the motor have caused this and it did something to the bearings or what? Or were the bearings already going bad before I drove it (I take this car out once in a great while) I am very confused and i need help.

[RocKin1967]

Awsome!!! another 1st gen in here i got a 67 too. what motor is in the car? thats a high rpm to be shifting at i would never take my old 350 past 5500rpm. can u tell from where the shaking came from if it was from the motor or rear of the car? some more info would help and maybe doing and oil change and checking if their is any metal shavings in the oil might help to see if any bearing damage has happened and check for knocks and stuff like that.

[Joe 1320]

Difficult to diagnose. The shake could be anything from excessive play in u-joints, suspension bushings, transmission and engine mounts all the way to internal mechanical damage. As mentioned, check all the fluids for contamination. low fuel pressure? Are you running a mechanical pump? That is driven off the engine so if rpms are very low and erratic, there goes your fuel pressure. To me, I just don't like the sound of the whole thing. Leaking oil, puddle of coolant, shakes, low fuel pressure. I wouldn't feel confident taking that to redline. I would do leakdown and compression checks, cooling system pressure check and maybe even send an oil sample off for analysis. I have a hunch that there may be a leaking but not completely blown headgasket. The car may run great until high vacuum/high rpm like when you get off the throttle at high rpms and still in gear. That may draw fluid past the gasket and into the combustion chamber, giving you the roughness until the fluid clears out. hopefully it was an isolated incident and doesn't happen again. Heck, it could have even been a stuck carb float that caused it to momentarily bog and run pig rich. Hopefully this will give you some things to look in to.

[67'maro]

well it defitnately wasn't a rear end deal. about the rpm's . . . thats what it was made for. Its a 327 bored to a 331 with quite a bit of work done to it. It can run into the higher 11's at right under 4000 feet elevation. But we kinda have gotten out of racing the past year.. just no time
Thanks for the help i will keep informed

[67'maro]

Alright I looked at the oil pan today and was going to take out the plug that tells you when the oil pan is full with oil. Well i looked at it for a second and that was where the oil leak was coming from (the plug). I looked closer and the plug was so loose that I unscrewed it with my hand with no force. The oil pan was obviously full since it was leaking from there. So I took the plug out let it drain out some oil and put it back in and snugged it up. Considering that was basically a hole in the oil pan and it was venting air or what ever, could that lower oil pressure??? And can bad oil lower oil pressure also???