Yesterday I was driving home from school, so i get in the freeway and i was going about 60mph in 5th gear..... so i step on the gas to speed up, then i heard a very loud boom, it sounded like a firecraker... it was very loud, it sounded like a gun shot.... so take my foot off the gas and keep on driving... a few minutes later i tried speeding up again (to about 4000 rpm) and i heard it again, but not as loud.... nothing seemed to happen to the engine... i made it home.. after i opened the hood i noticed that my #1, and #2 sparkplug wires were barely connected to the sparkplugs... so i pushed them in.. it seems that the wires dont get a grip of the spark plugs, if i lift the wires they come off right away.... could this have been the problem?? or what can it be?? This has never happened before.... please help... now im scared of reving the car past 4000 rpm....
thanks

 

you was loosing spark momentarily on those cylinders, gas was kaing in into the ehaustt and what you heard was a good old fashioned backfire. Will damage your muffler if it happens enough.

 

agreed.

change your plugs and wires and you should be good.

 

I will replace them this weekend... but is does it sound that loud?? it was like a gun shot.. haha... it scared me for a minute.. haha
thanks

 

yeah, it definitely does sound that loud, essentially there was an explosion in your exhaust manifold.

on a side note, some rally cars use this technique (allowing fuel to combust in the exhaust manifold) to keep the turbo spinning even when the engine is loosing rpms (like going through a turn).

 

plus I gurantee you it isn't doing anything good to the cat. It could damage that also. including blow out your muffler.

 

its happened to my 90 hatch.. it was that and the fact that the spark plug wire boots used to pop up fast(like shoot out hole) and hit engine hood causing a loud bang at the same time as the backfire sometimes.

by any chance where do you live?? did you have the AC compressor on?? or heater on?? thats when mine used to do it.

 

I once had a small crack in my windshield then when I moved from AZ to UT (in the winter) I took the car out and put the heat on. The crack expanded to the entire length of the windshield all at once and when it did that it made a POP that fired a gun in my car... Scared the shizzle out of me.

My suggestion... change plug wires.