1996 SC Riviera Misfire #6 Cylinder

Please, what order should I be looking for to solve this. Had it scanned at AutoZone.

It is only the #6 cylinder. The plugs/wires are original with 100k on them. The #6 wire is in good shape and tightly on both ends. Also, there is a tiny knock sound but I can't be sure it is related to the misfire. The Traction Control light is intermittently turning on and off. Usually goes back off after I'm moving.

I'm short on cash until January so I just wanna make sure I'm ok and not hurting the car and get it back to no Service Engine light.

Thanks

First check is to ensure the #6 wire isn't touching the O2 wiring or didn't get burned. It's right over the exhaust and that is going to take a toll on it. 100K is a nice long life for that wire considering where it's located.

Check the coil post for any corrosion. Clean and add dielectric grease if it's dirty.

Overall though..I'd think it's probably wire or plug

Ok thanks for the tips. I'm really worried it is going to turn out to be a major internal problem but it runs so good, and has run so well, it has to be something like that.

The coil looks in great shape, definitely no corrosion.

I think the "small knock" I'm hearing is actually the water pump or maybe the tensioner making a sound.

Any idea how long a code should take to go out of the system?

I just replaced the wires - think it feels smoother, but the light is still on.

you can unplug the battery (30 min?) which will reset it or wait until it cycles so many times and it will eventually turn off, provided it doesnt detect any more misfires. did you pull the plug to take a look at it?

AZ should be able to clear the code as well, so you can see if you fixed the problem or not.

The 'small knock' you hear could just be the SC coupler rattling. They can be a little noisy.

You can't really hear knock (detonation) with your ears. It's taken down by the knock sensor long before it becomes audible.

I'd inspect the wires about the misfire. If you can, watch the engine running in total darkness. You'll see blue glows if the wires are arcing anywhere.

"You can't really hear knock (detonation) with your ears. It's taken down by the knock sensor long before it becomes audible."

Depending on why it's occurring, knock can be audible, even 2-3º KR. I've heard it before when using less than ideal fuel, usually in a higher gear (low RPMs) with a large load (climbing a hill) is when you'll hear it.

But Derek is right, you shouldn't hear it if your car is running well, but even if you do, it's not generally related to a misfire.

I don't think this is engine knock. It is at idle. I'm pretty sure it is the tensioner or maybe the water pump bearing. I don't think the sound is related to the P0306 "Cylinder 6" misfire.

I put new wires in, but not plugs as that would have taken a bit more time.

The SES light didn't go out.

So, I'm gonna do the battery tomorrow, and pull the belt off and spin the tensioner and water pump and try to see which one it is making the noise.

be sure also to take off the supercharger belt and spin it too, just to check for looseness - call it preventive maintenance, it'll only take a couple minutes.

Albertj

The SES won't turn off for something like 30 or 50 start cycles I think, even if the problem is resolved. You need to have the code cleared and then see if it comes back.

-Derek

deekster_caddy wrote:

The SES won't turn off for something like 30 or 50 start cycles I think, even if the problem is resolved. You need to have the code cleared and then see if it comes back.

-Derek

Derek are you sure that the misfire is one of those codes? Some codes are 3 good start cycles, some immediate and others .. 50 billion start cycles.

And if these are NGK plugs.. check the end piece that the wire connects to for looseness.

I am fairly sure about the misfire being one that clears after 50. Not 100% of course, but at any rate still better to have all the codes cleared and see what is going on anew...

Well, the wires didn't do it. I just got the Delco Iridium 41-101 I think is the number. They'll go in tomorrow.

Then, I guess on to the fuel injector.

I'm assuming its not a MAF because it is specifically 6 cyl that is missing. I imagine it wouldn't hurt to check this?

How do you know it's still missing? Is it a dead miss?

Last time I had this type problem it was the coil.

Albertj

OK - I changed the plug wires and went and had the codes checked and it still showed a miss on 6.

However, today, the SES light went out for an hour before coming back on at an idle.

The Traction Control light is coming on at a stop and going off once under way too. I think this has to do with the miss happening at idle.

The SES light came back on, after idling, for awhile.

Also, today, the headlights started doing a weird fade to dim and then back to bright ever 10 to 20 seconds. All the dash lights did it and the interior lights too, even when the engine wasn't running.

I think it is separate from the SES light thing.

As for "feeling" the miss... the engine is still very smooth. It appears to be missing at idle - the idle is fluctuating from about 700 to 800RPM... used to be rock solid I believe.

Take an ohm meter and go across the posts for #3 and #6 what reading are you getting?

across the posts on the coil pack? And while the engine is running or not?

not!

ha, I could've guessed!

I'm not super good with these, but how does 5.4 ohms sound?

My Traction Control light is coming on and I found in the book that it is being caused by a Misfire on Cylinder #6. When a misfire occurs, the computer can turn off traction control.

So, it isn't just a sensor that can cause it to malfunction. I'm going to have the misfire fixed tomorrow hopefully, the traction control is fixed too.

is it bc one of your spark plugs isnt working? or wht could cause that? however my dad thinks its one of the sensors gone bad from the brake dust, but ill have my car scaned bc i never knew that could cause it.

I've never heard of a misfire condition that would turn the TC light on. Even if it "could" happen, doesn't mean that's the cause for certain.

Sometimes the sensor is just dirty and needs cleaned with electronic parts cleaner. Try this before replacing the unit. And get those codes cleared so you know if you've fixed the problem. Good luck.

yah i def have to try that instead of taking it to a shop, getting ripped and paying big bucks for a couple of sensors

The book says that a misfire condition can trigger the traction light because traction control and the firing of the cylinders is somehow connected. It can't work with a misfire condition.

I'll try to find the page it is on.