Strange "detonation" in my 401 today
iCEMAN
Senior Jeeper
Out wheeling some rocks and trails today with my local club. Stopped to do a repair on a guys driveshaft and when I restarted the jeep - BANG!!!
Smoke poured out from under the hood for about a minute and everything was quiet. Opened the hood slowly and discovered the 'smoke' was coming from my oil fill tube which was now missing the breather cap. Found the cap about 10' from the side of the Jeep. Upon further inspection, discovered that both valve covers had lifted on the inside (intake manifold side) about 1/4" and blown the rubber valve cover gasket out in chunks about 6-8" long.
Sat for about 10 minutes then said, what the hell, it is probably already blown, see if it turns over. Motor started on the first click of the key and idled perfectly. Drove it slowly to the parking lot and removed the valve covers. Pounded the bent edges back into place, installed a new set of gaskets and the truck ran perfectly the rest of the day wheeling (about 5 hours).
So my question to you motorheads is this:
What would cause a detonation in the valve covers hard enough to almost blow both covers off the jeep? Can't be something real serious or I would think the motor would not have run the rest of the day.
Smoke poured out from under the hood for about a minute and everything was quiet. Opened the hood slowly and discovered the 'smoke' was coming from my oil fill tube which was now missing the breather cap. Found the cap about 10' from the side of the Jeep. Upon further inspection, discovered that both valve covers had lifted on the inside (intake manifold side) about 1/4" and blown the rubber valve cover gasket out in chunks about 6-8" long.
Sat for about 10 minutes then said, what the hell, it is probably already blown, see if it turns over. Motor started on the first click of the key and idled perfectly. Drove it slowly to the parking lot and removed the valve covers. Pounded the bent edges back into place, installed a new set of gaskets and the truck ran perfectly the rest of the day wheeling (about 5 hours).
So my question to you motorheads is this:
What would cause a detonation in the valve covers hard enough to almost blow both covers off the jeep? Can't be something real serious or I would think the motor would not have run the rest of the day.