Earlier today i timed my car....immediately afterwards i got in my car and started it up. I gave it a small rev to about 2500 rpm and heard a loud POP come from under the hood. I had my friend start the car and the noise persisted coming from what sounded like the number 1 cylinder. It made the sound every time the engine fired on that cylinder. I disconnected the power to the distributor and had my friend crank it over for a second, and all i heard was a light whoosh of air coming from that general area. my friend said he thought he saw some white smoke coming from that area while i ran it for a few seconds, but i dont want to run it again to find out. I was thinking that it might be a blown head gasket, but my friend had that happen to his car and he didnt have a noise like that. The gasket that was on there was just a regular fel-pro head gasket, and i wasnt sure if it was gonna be able to hold the compression of the motor(about 10.7:1). i was just wondering if these symptoms were consistent with a blown head gasket, and what other possibilities could it be. Thanks
HELP! i blew something in my motor
- Thread starter KJNY
- Start date
Maryland Stang
Active Member
Michael Yount
Mustang Master
Head gaskets can "blow" in a variety of areas. Depending on where they stop sealing, the symptoms can be different. If they blow between two cylinders, the symptoms will be a bad miss (2 out of 8 won't be firing) and blowing mixture back into the intake manifold - which throws mixture off for the other cylinders, and makes for a potentially explosive situation. If it blows around a water passage, then coolant can leak into or fill the cylinder; also allows that cylinder to lose pressure - may cause misfire, may not; also may allow the cylinder to pressurize the cooling system. If it blows around an oil return passage - you can get pressurized crankcase, oil in coolant, coolant in oil. There are lots of possibilities - so a bad hg doesn't just have one set of symptoms. But I'd go back to the original procedure - setting the timing PROPERLY shouldn't have caused any issues. Are you certain you timed it properly? We don't know anything about your car other than the compression ratio, it has at least 1 cylinder, and the fact that it will rev to at least 2500 rpm. 
V-8? 5.0L? aluminum heads or cast iron? efi or carb? Did you have the spout out? With that compression, unless the curve is altered via springs weights or chip, you probably don't want to run more than 12 or 14 initial - what did you set it at? Are you certain your balancer/timing marks/pointer are accurate?
V-8? 5.0L? aluminum heads or cast iron? efi or carb? Did you have the spout out? With that compression, unless the curve is altered via springs weights or chip, you probably don't want to run more than 12 or 14 initial - what did you set it at? Are you certain your balancer/timing marks/pointer are accurate?It is an efi 302 that i had timed to 14*. They are the stock cast heads. As for the marks on the balancer, they're def. correct. my friend had originally marked it at 4* by accident, but i double checked that before i ever started it. I double checked the spark plug to make sure it was put in correctly and it was, so its def. not that. It basically comes down to me running a compression check, and then eventually pulling the head off to figure it out. But hey, the good news is that a friend of mine just got offered a great deal on a port and polish job for our heads.
