matt_king95

The other night i did a very stupid thing, I let one of my buddies take my 1998 Trans Am out for a booze run. I was riding in the passenger seat and wasnt really worried about his driving when he popped the clutch in reverse. Now my computer has three new engine codes stored in it that are Mulitiple Cylinder Misfire, Knock Sensor 1 on left bank low voltage, and 02 Sensor heater. The engine knocks hardcore on both banks. Not only that but there is a wicked vibration in the shifter when u drive from a stop and it smells like a little bit of clutch is burning when u drive around in traffic. Also, the Service Engine Light flashes above 35 miles per hour. I took it to a very reputable shop today to see what he thinks is the problem and he thinks that my buddy might have blown out a transmission mount but doesnt know whats wrong with the motor yet. Any ideas or hints? By the way, I have learned my lesson and will no longer let ANYONE drive my baby anymore. Also, he is paying for all repairs to make my baby whole again.

Matt King

Boostaholic

iTrader: (4)

Need a little more info, he dumped the clutch in reverse from a stop at what RPM?

Did he over rev it?
Does the knock sound like its coming from a broken mount or something (I kind of doubt this) or is it the engine knocking?

The tranny mount is pretty easy to check, there is a cross member under the back with 1 bolt that screws up into the tranny, if he sheered that bolt off it could cause some hell, but I wouldn't think that a SES code would have been set because of that.

If your knock sounds like its engine internal, your buddy probably didn't do anything bad enough to cause it, he just pushed it over the edge (There was a pre-existing problem).

What kind of oil pressure are you getting at idle? Does your pressure go up with RPM? You should have 37-60 on a cold startup idling at 700-1100rpms.

matt_king95

he dumped it at around 3500 rpm. there is definatly a knock coming from the engine. it sounds like its coming from each of the back cyclinders (closest to the windshield) on both sides of the motor. im pretty sure it over reved because i dont think there is a rev limiter in reverse, i may be wrong but thats why im posting on here. so far im holding good oil pressure, at cold startup it stays around 40 to 45 psi and it does rise with my rpm's. at normal operating tempurature the oil psi is around 20 to 25. the engine codes are a PO327, a PO300, and a PO161. i had autozone check it because it was free. i know they dont have the best scanners but like i said, it was free. i havent checked the crossmember because i dont have access to a lift to put the car on. Thanks for the info. Ill keep posting with more info as i find out more.

Matt King

Boostaholic

iTrader: (4)

Depending on how car savvy you are you may not want to attempt any of this.

PO327 is knock sensor
PO300 is multiple misfires (flashing ses?)
And I'm not sure what PO161 is


The first thing I would do is the easy stuff, grab a 10mm and 8mm socket, ratchet, some extenders, pull your valve covers, then pull each rocker arm one at a time and pull the pushrod out, check to make sure they are all straight and none of your valvesprings are broke / dropped, when you put your rocker arms back on you will need a torque wrench, retorque them to 22lb/ft.

If that is all ok, I would pull all your spark plugs and make sure they are still intact.

After that its probably time to pull the oil pan which is quite a chore, it involves dropping the kmember, jacking or lifting up the motor, taking out about 12 bolts, then you can take off all your caps and check for spun bearings and metal filings / needle bearings in your oil pan.

Maybe someone else can give you some better ideas or simpler things to try, you might want to get a stethascope and listen closer to each cylinder to see if you can isolate the sound.

Boostaholic

iTrader: (4)

How loud is the knock? Is it like a hammer hitting metal knock or a ticking that is mostly audible with the hood up? Can you hear it while your in the car with the windows up?

Its kind of hard to guess whats wrong without knowing what the knock sounds like. Your oil pressure is too low, there is definantly a problem with that, the little valve in the oil pump could be getting stuck - mine did this right before it finally totally siezed up and my oil pressure permenantly went to 0 (Bye connecting rod #5!). Anyway, post up more info

matt_king95

the knock is pretty loud and you can difinatley hear it in the cockpit. when the windows are up, you can kind of feel it in the brake pedal. when the windows are down, there is definatly an audible knock from the motor. as far as pulling the valve covers off and checking the rocker arms, that might be more of a task than i can handle safely. Thanks for all the info

Matt King

Boostaholic

iTrader: (4)

Ok, a few other tips for pulling the valvecover - the drivers side WILL come off without disconnecting the fuel line, but if you need to pull the fuel line go get the little plastic "quick disconenct" tools, you will probably get a lighter blue one, thats the right one.

That tool is a little trickey to use, you shove it in the connecter then pull the big part of the connector off without the blue piece, lots of people make a mistake of trying to yank the blue piece out with the big part - which won't work.

I can't think of anything else that is hard with it, you can rent a torque wrench from your local auto parts store - don't use a cheap needle wrench, rent a good clicker one or borrow one from a mechanic friend.

Odds are you won't find anything wrong with your valvetrain with your oil pressure low, your probably going to have a blown bottom end on your hands, sorry to say.

matt_king95

well, i have awesome news for everyone. i took the t/a to the shop to have it fixed and in about an hour they came out and said it was fixed. i was like wtf. they said that the #7 and #8 cylinder had melted spark plug wires. he put new ones on and it runs back to normal. also, he said that bosch platnium plugs suck and he suggested using ac delco or ngk plugs from now on. is this true or is he blowing smoke to get mr to buy his stuff? thanks for everyones opinions.

Matt King

WS-Sick

I agree with him on the plugs. I believe the bosch are what comes from the factory. Glad you got everything fixed.

Boostaholic

iTrader: (4)

Glad to hear you got it resolved, the knocking must not have been loud as I thought.

Oh, and tell your buddy no more reverse clutch dumps until he gets his own FBODY.

Another_User

I did one of those in my first car, an 82 RX-7. I revved it higher than that though. Afterwards my car wouldn't idle. So I took it down the road doing about 80mph in second gear, and magically it ran and idled. I have no idea what I screwed up and how I fixed it. Some cars I have tried to do it in just stall out.