chidrock

Last night I was cruising along on the Interstate in the middle lane with the back of a tractor trailer somewhat in line with my nose. All of a sudden I hear a huge popping noise as if a big rock had hit my car. I pull over and can't see any damage. I hop back in the car and everything seems fine. It's too dark where I'm going so I can't see anything. After reading about spark plugs ejecting I start it up this morning and try to listen under the hood for any unsual ticking. I hear a little bit of a fast ticking/rattle, but I don't know if that is just normal engine sounds and my mind is just playing with me because I am paranoid at this point and haven't slept well.

The performance seems okay, but the only odd thing is that there doesn't seem to be any engine braking going on - as in I was coasting without my foot on the gas and where I'd normally see my A/F Gauge pop up to 16.0 and hear the engine slow itself down & gurgling. Granted, I was being really gentle with it & keeping the RPMs low, but I am not sure what to do now.

The dealer says that they couldn't find anything wrong with it thrugh their diagnostics test and took it out for a test ride and it seemed fine, but they also aren't used to dealing with superchargers. I don't really have any performance shops in my area, so I was hoping that they could check it somehow and see if there is anything noticeable.

Anyways...would a blown sparkplug automatically trigger a check engine light? It seems to run okay, but the exhaust sounds a little different to me and like I said before it wasn't doing the gurgling thing in the short time I drove it since. Could this really just have been a truck tire blowout or something hitting my car from underneath?

Any thoughts would be greatly appreciated. I'm stuck on whether I want the dealer to do anything else.

mapitts

If you had blown out a spark plug, you would have known it. Every time you came up on a compression stroke for that cylinder, it would make a loud popping noise. It would really sound like a cheap air compressor running. Yes it would be throwing you a miss fire code as well. I think you have answered your own question. You ran over something in the road, or the tractor trailer had a blow out. I do not have much knowledge on supercharged gasoline engines to even attempt to guess about that. The one thing I do know is that if you had a problem with a broken belt or squealing bearings, you would have pickep up on that as well. On a different note, how do you like your MGW shifter?

chidrock

I figured a blown sparkplug would be something that I would notice. I was just worried because I wasn't sure if I had lost back pressure because of the way that the car wasn't slowing down itself. (then again that could also be because I didn't go near the 3000 RPM mark and was babying it)

My big concern was that I didn't want to let a fixable problem turn into a major repair where I might blow an engine.

When I first got the Whipple put on there was a problem with an O-Ring and a plug that didn't set off any codes, so I didn't know if this might be another of those cases. (it was shaking at a standstill though) I've never had a supercharged car and don't knw anyone who has, so I figured I'd bring this to the experts - you guys. I'm only 4,000 miles in on this one.

Most things I read about the sparkplugs blowing online was similar to mine - where they heard a loud pop like something hit the car and then a ticking sound. Not having the best of hearing, I wasn't sure if I was hearing a tick or normal motor sounds under the hood. Most had issues where it was obvious something was up, but some were more subtle. Like I said - I just didn't want to wind up cracking a piston or blowing the engine by ignoring it.

Thanks for your reply! I'm just looking forward to picking it up and going on another test ride.

edit: The MGW shifter is awesome! I haven't played around with the settings for it because I like how it is now. IMO it is definitely worth it. I feel like there is a lot less lag for switching between gears and best of all I haven't experienced the 3rd gear lockout since I got it. With the stock shifter it would keep me from shifting into third every once in a while and besides being very frustrating it was pretty embarassing...

mapitts

When I say loud, I mean loud! The faster the engine turns the more the popping increases. I have seen people driving around town with a blown out plug like everything is alright. Youtube it and see what you come up with. Thanks for the info on the shifter. Can't make up my mind between an MGW or a Steeda Tri-Ax.

chidrock

Well, got it back last night and took it out - everything seems fine. The car doesn't seem to gurgle as much or as loud as it used to when slowing down, but other than that it seems fine.

Yeah, I didn't know if blowing a sparkplug would be a one-time pop, or repeatedly.

Besides the ability to adjust the heck out of it, I like the MGW shifter because of their ***** that go with it. I have a chrome running pony one that really goes perfectly with the interior. (it's just like the steering wheel and the chrome ring around the logo matches perfectly with the chrome ring that goes around the shift boot; it's not gaudy or anything - it looks like it belongs)