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A Boom to start my day

So I have a 1999 Cavalier…I drove it yesterday without issues but when I got up this morning to go to work, I turned the key to start it and it seemed as if there was a boom from the engine. The engine didn’t start, but when I tried the key again, it started right up. I drove 35 miles to work, including some highway miles at 70 mph. What would that have been? Is it a sign of things to come?

You might inspect / open up the air-cleaner box and see if all is well…Sounds like it might be a back-fire into the air-cleaner…A malfunctioning fuel tank vent system can fill the air-box with gasoline fumes…

In the future, when you attempt to start your car and you hear something go “BOOM” under the hood, you might want to open the hood and check things right then and there instead of just driving on…

You can stop by the local parts store and have th ECU checked for stored codes and post them here (most parts stores do it for free).

If there are none, thank the Gods and drive happily on.

I’ll have to check everything before I drive home. Two most recent things I have done…I changed the air filter last weekend. Yesterday, I was trying to change the fuel filter, but I couldn’t get the thing to release so I just quit trying. But, last night, I drove the car several hours after I was messing with the fuel filter. I had even checked to make sure that the fuel filter was still in place and was not leaking or anything.

I will have the car for inspection soon so I can have him check the codes. My check engine light is always on though because the catalytic converter is shot and it always triggers a stored code. Sort of a downside because I never know if a new code is stored, but I’m not going to fix the catalytic converter on a 1999 Cavalier with 210,000 miles. Same applies to my lack of Air Conditioning because of a failed evaporator.

Ah, the plot thickens.

It is entirely possible that you have a problem such as an erratic plug or malfunctioning injector that’s allowing raw fuel to enter your exhaust system and you don;t know it because you’ve effectively rendered your CEL light inoperative by allowing the light to stay lit. You also might be backfiring due to a bad valve. A valve that doesn;t close fully because it’s sticking or burned can allow the combustion to go places it should not.

I’m betting you have a bad valve.

Download the ECU anyway. It stores codes even if the light is already on.

By the way, were you trying to change the fuel filter? Was there an operating problem?

Yes, I was trying to change the fuel filter. When I got the car back in 2001, it had some problems with the injectors and it turned out the previous owner had never change the fuel filter. It was so clogged up my mechanic had a hard time blowing through it. So since then, I’ve tried to keep the filter changed on a regular basis. The problem is I never changed it myself. I’ve always let the mechanic do it but when I tried once, I couldn’t get the thing off. So I thought I’d try again and still couldn’t do it. I couldn’t get the right grip on the thing though because I can’t lift it off the ground (no jack stands). I have to slide under it.

A set of ramps may be the best investment a DIY’r can make. I think they;re safer than jackstands.

Define “regular basis.” Fuel filters don’t need to be changed as often as oil filters. How often are you doing this?

Thanks for the tip. I’ve been thinking about jackstands for a while now, but the ramps would actually be a better idea. Then I wouldn’t need to fool with a jack. My dad had some of those at one point, but I hadn’t thought of them. Here’s a good question though. I have only ever seen someone put the front end on ramps. Can you back onto them too to get a the back end?

Another thing…I was thinking in terms of being able to do common tasks, such as rotating tires, brake pads, etc. You can’t really do that with ramps.

@Shadowfax - I got the car with 80,000 miles on it. I’ve changed fuel filter every 30,000-50,000 miles, so with 210,000 miles, I’ve had it changed about 4 times now, I think. And for a few dollars, that’s not a bad price to pay to make sure I’m getting the performance I should without worrying about gunking up the injectors again.

Yup, you can back onto them. I do it whenever I need to get under the back end for any reason. Acually, the only time I’ve had to get under the back end of my current car was to change the sway bar…to a stiffer one.

I think it just backfired and I don’t think I’d worry much about it unless it happens more often. Maybe a little fuel leaked in from the injectors.

Personally, folks will argue, but I would never get under a car on jack stands. Don’t care if the car has been pushed and pulled to make sure they are solid. I personally won’t get under them. Chinese steel and welders and all. They can say anything they want on the package but coming from China doesn’t make it so. If they sell bad electronics, inferior bolts, parts, etc. to the Air Force, they sure don’t care about you.

I have reinforced ramps and will usually also place a couple jack stands under it in case the ramp would give way. I’ve backed on them as long as you watch what you are doing. I also have drilled strategic holes in the garage floor to stabilize the ramps so they don’t slide when you drive up on them. Makes life a lot easier to work underneath with some room.

Maybe I’ll just do that. Get ramps for use when getting under the car to change oil, etc, but get some jack stands to use when fixing brakes or anything else that involves me not getting under it.

Thanks for the help…And by the way, I didn’t see anything odd when I looked at the car yesterday and it hasn’t made that sound again, so I hope this was an isolated incident.

It probably was. Random “events” do sometimes happen. Everything has a root cause, but sometimes that combination of variables that caused the “event” never repeat.

I tip my hat to Bing’s safety consciousness. I prefer the plastic ramps to the metal ramps. The way plastic ramps are molded, there are the sides plus molded-in ribs that create a direct compression path from the tire’s surface to the ground. They’re in essence solid material all the way down. The material they’re made of would take many tons of pressure to compress, and the total weight of the wheel is typically about 700-800 pounds.

Re: the jack stands, don’t buy the WallyWorld cheapos. Get some good ones rated at at least 2 tons from a parts store. It’s cheap insurance.

Sincere best.