Am I in trouble here?

[kcobean]

My car feels like it's been hesitating lately, losing power under heavy acceleration. The VA/MD club had our annual Dyno Day today, and on the way up to the shop after a quick run through 3rd gear (up to about 100 I guess) and then breaking for the off ramp, I looked down to find my check engine light flashing. It flashed for a few seconds and then went off.

We put the car on the dyno and it made a whopping 348 WHP. We witnessed a massive drop in power around 3100-3200 RPM, but the A/F ratio looks normal. We reset the computer by pulling the connectors for a few minutes before the 2nd run, but it didn't help.

So in the name of troubleshooting, I pulled the plugs out tonight. Here's what I found:

The entire odd(drivers) bank looked fine. Center electrode on all were still flat and sharp edged, outer electrodes were clean and metallic/white in color and the insulators were in tact and not too discolored.

For the Even (Passenger) bank:

Pulled 2: Looks fine, as described above.
Pulled 4: Looks fine, as described above.
Pulled 6: Looks fine, as described above.
Pulled 8: Looks fine, as described above.
Pulled 10: COVERED in oil, and I mean sloppy wet.

Now the question is, what is that a symptom of? This is where I'm over my head.

 

[NZGTS]

it can be a few things on.

1/ broken rings.
2/ dropped valve.(would have made lots of bad noises though)
3/ holed piston.



you can buy a cheap compression tester and take a reading of all your cylinders. If there is no compression on that cylinder then one of the three above might have happened.
you should not run the car anymore until you get this sorted.

 

[plumcrazy]

first thing id do is swap in a new plg in #10 and drive it to see if any change.

then id do a quick compression check

what mods do you have, im assuming simple bolt ons ?

 

[kcobean]

first thing id do is swap in a new plg in #10 and drive it to see if any change.

then id do a quick compression check

what mods do you have, im assuming simple bolt ons ?

Only the Corsa exhaust and Random Tech cats, otherwise the car is pretty much stock.

 

[plumcrazy]

thought so, now id quick go and change that #10 plug and take a test drive. and see if any change

 

[kcobean]

thought so, now id quick go and change that #10 plug and take a test drive. and see if any change

Will do. Should be able to get that done later today.

 

[KNG SNKE]

it can be a few things on.

1/ broken rings.
2/ dropped valve.(would have made lots of bad noises though)
3/ holed piston.



you can buy a cheap compression tester and take a reading of all your cylinders. If there is no compression on that cylinder then one of the three above might have happened.
you should not run the car anymore until you get this sorted.

I agree with this guy. If you know there is a problem and you found an oil soaked plug, definitely do a compression test before driving. Why risk actually damaging the motor by driving on it again.

 

[kcobean]

I've been driving the car for awhile like this, since I wasn't really sure if it was just my imagination or not. The CEL and the dyno proves there is a problem. One more drive isn't going to hurt anything.

 

[V10SpeedLuvr]

Obviously 348WHP is way off, but had you dynoed it before their were problems? aka do you know how much power you've lost?

 

[EllowViper]

Connect your ODB-II scanner up and see if you have any P0XXX misfire codes . If the CEL flashed off/on but did not stay on, there are probably some "pending"codes stored that may indicate something of interest. P0300 is a random/multiple cylinder misfire and P0310 is the #10 misfire detected. Hopefully, you may just have a bag plug wire or something of this nature that potentially fouled the plug. I would think if it was a cronic mechanical condition, the CEL would stay on... if the condition is something the ODB-II monitors. The CEL flashed for some reason, just curious as to what that was.

 

[plumcrazy]

one more ride around the block at this point aint gonna make a difference.

 

[agentf1]

Sorry to hear this. Hopefully it is just a fouled plug and you will be back on the road soon.

 

[KNG SNKE]

I've been driving the car for awhile like this, since I wasn't really sure if it was just my imagination or not. The CEL and the dyno proves there is a problem. One more drive isn't going to hurt anything.

im a better safe then sorry kinda guy

 

[AviP]

1. OBDII code check. Looks like you are getting an intermittent code.
2. Replace #10 spark plug.
3. Compression test. I just had mine tested as a mule at Tator's tech session. It's very enlightening.

And do not rev it over 2000rpm during testing. Since you have been driving it like this for a while, one cylinder has been dead weight for a while. That means an unbalanced engine and could lead to more wear on other cylinders. YMMV.

 

[ViperJohn]

Obviously 348WHP is way off, but had you dynoed it before their were problems? aka do you know how much power you've lost?

I'll answer this as I was there. We compared last years pulls to this years and the curves were exactly the same under 3100-3200 RPM. After his point, there was a dramatic drop off in power the rest of the way up the powerband.

I suspected a bad valve, or perhaps the car was in a "safe" mode, although I was expecting to see an check engine light.

I hope it's something simple. (cheap)

 

[Tom F&L GoR]

If the power under 3100 was same, perhaps also a soft spring that floats above that speed.

 

[PatentLaw]

Ok, I will chime in here. You have an oil soaked plug. You need to clean the wire, put in a new plug and see what is happening. Yes, on the safe side, you can do a compression test. It won't hurt. But, you have answered your own question by the information you put down. The power loss is at a higher rpm, not at low levels. If you had a compression loss, you would have felt it down low as well.

Oil soaked plugs and wires can really screw up the firing of the piston. It happens all the time when the individual does not install the plug correctly, or in some engines, a gasket is blown (such as a cam cover gasket). Replace the plug, install with proper torque. Clean any oil anywhere near the connection. Do the simple things first.

 

[kcobean]

I plugged the OBD-II scanner in, and as predicted: P0310. I cleared the code, put 10 brand new plugs in, properly gapped to .035 and put the factory wires back on just to test. It's after 12AM here, so I'll fire it up in the morning and see what happens.

Thanks for the input so far guys.

 

[Warfang]

I plugged the OBD-II scanner in, and as predicted: P0310. I cleared the code, put 10 brand new plugs in, properly gapped to .035 and put the factory wires back on just to test. It's after 12AM here, so I'll fire it up in the morning and see what happens.

Thanks for the input so far guys.

Wait until morning? What? You must like your neighbors or something.

I know they curse me as I pull in at 3am, setting off every car alarm as I pass.

 

[kcobean]

Wait until morning? What? You must like your neighbors or something.

I know they curse me as I pull in at 3am, setting off every car alarm as I pass.

LOL..yeah, I don't want to make enemies of people who live so close by.

 

[plumcrazy]

well, its morning ?

 

[Madduc]

After the run today with the new plugs my guess is it will be fine, but you may also consider some new wires. Like AB's wires.

 

[dave6666]

We put the car on the dyno and it made a whopping 348 WHP. We witnessed a massive drop in power around 3100-3200 RPM, but the A/F ratio looks normal. We reset the computer by pulling the connectors for a few minutes before the 2nd run, but it didn't help.

Did somebody slip you a Corvette motor?!?

 

[kcobean]

Ok, she's got fresh plugs and I pulled Ab's wires off the car and put my Mopar wires back on. I cleared the P0310, fired it up and took it out....
.
.
.
SHE'S BACK!!!!!!

Man does it feel good to have all the power back. I kept the scanner plugged in to the OBD port and continuously scanned for pending codes, but I could tell from the power and the smoothness of the acceleration (where before the car seemed to have a weird vibration and hesitation to it under heavy acceleration) that the problem is gone.

Now the question here is, what would cause oil fouling on a plug like that?

Thanks so much for all your help guys. I feel like I have been dodging bullets with this car between the blown fuse that took down ignition system (while giving a ride to a co-worker), to the 2 (yes 2) crank damper separations (both of which happened close enough to home for me to limp the car back to the garage), to the coolant leak (which I'm still trying to trace), to this....This car has been a great adventure to say the least.

 

[V10SpeedLuvr]

Any plans to re-dyno it? Since it seems to be working fine, you should be back in the normal dyno #'s for a yellow Viper...right around 350RWHP. Glad you found your missing 2RWHP

 

[EllowViper]

Oh CHAD...that really HURTS...!!!...but you have probbly heard that before..LOL

 

[ViperJohn]

Oh CHAD...that really HURTS...!!!...but you have probbly heard that before..LOL

Damn!

 

[KepRght]

time to go forged!!!!

 

[agentf1]

Glad to hear you got your problem straightened out. Did you check the wires? Could just have been a bad ignition wire causing the plug to foul.

 

[KenH]

I would pull the #10 plug again and make sure that it isn't starting to get loaded back up with oil even though it seems to be running OK. If you have a cylinder or head problem, new plugs may make the symptom go away for a while, but will eventually fail again in the same fashion once the plug fouls out.

If it still looks good after some run-time, then I would assume you had a bad plug wire or it wasn't connected to the plug well on #10.