Cyl. 1 & 3, worn plugs

[Nasty Dream]

I had NGK BPR6ES in my car for I guess 30K miles and they've been fine. Not too long ago, I noticed it wasn't idling perfect.

Today I finally got around to changing them.

Cylinders 1 and 3 had almost no wear, they had a normal firing end. Cylinders 2 and 4 had rounded copper centers (excessive wear).

This has me worried.

Is this abnormal? Why is the wear seriously different through the cylinders?


EDIT: I got the cylinder numbers backwards. 1 = 4...

 

[twayne9mm]

Are there any differences in the "colors" of the plugs, and do you have any knock or noise from preignition? The color and texture of any material on the spark plug will tell you if it is running a proper fuel mixture. Ignition "knock" can destroy a plug in one cylinder and not in another. Go to one of the spark plug company websites, Autolite, Champion, etc and they should have pictures of what a proper working spark plug should look like

 

[Nasty Dream]

That's what I'm saying. I did a lot of research. They are all perfect. Everything was right. The perfect plugs, the perfect operating conditions.

It's just that 2 of them are worn. The other 2 are fine, and could go on working for a long time if I left them.

That has me concerned but I don't know enough to know what that could mean. More compression in 2 of the cylinders? More electrical current getting to those plugs? I have no idea.

I just figured they would wear fairly evenly. There's a big difference in the amount of wear.

Thanks

I mean, if nobody knows what it means, then maybe it means nothing. It's just chance. They just happened to erode faster.

I was reading something like - if 2 adjacent (which they weren't) plugs were worn and the others are fine, it means you may need a head gasket. If it was something else, it may indicate worn piston rings. Something else, it may mean exhaust valves are worn.

But it was none of those things, I think. WHEW

Shit. If you read enough on the internet, you'll be convinced you have everything and you'll be dead in a week.

 

[DSM1G90]

Standard copper core plugs, like the BPR6ES plugs, should be changed every 10 to 15k miles. At 30k miles, they definitely need to be replaced. The electrode has all but rounded corners and the spark goes pretty flat, weak and can snuff out - why you're noticing issues with 1 and 4 since that one coil is firing both at the same time - just one is firing during exhaust while the one is doing the compression ignition.

Set gap at .028 for turbos.

For a wild ride, use BPR6EY plugs - they have the groove in the electrode to produce a more rounder spark - which will produce a little bit more kick.

When you do the change and run them in for a month or two, and you still have yukky issues with nos. 1 and 4, the coil could have some issues in itself, or the power transistor could be acting up.

DSM

 

[bastarddsm]

Its because of the waisted spark system we use. 1 and 3 fire opposite polarity from 2 and 4.

 

[tonyspyder]

When my head went bad(intake and exhaust valve seats leaking) my spark plug did change color. Number 3 spark plug look different from 1,2, and 4. We did a leak down test and the head was bad. Do a compression test just to be sure.

 

[Nasty Dream]

Standard copper core plugs, like the BPR6ES plugs, should be changed every 10 to 15k miles. At 30k miles, they definitely need to be replaced. The electrode has all but rounded corners and the spark goes pretty flat, weak and can snuff out - why you're noticing issues with 1 and 4 since that one coil is firing both at the same time - just one is firing during exhaust while the one is doing the compression ignition.

Set gap at .028 for turbos.

For a wild ride, use BPR6EY plugs - they have the groove in the electrode to produce a more rounder spark - which will produce a little bit more kick.

When you do the change and run them in for a month or two, and you still have yukky issues with nos. 1 and 4, the coil could have some issues in itself, or the power transistor could be acting up.

DSM

I meant that I numbered them backwards - I started from the wrong side when I counted. So it would have been 2 and 4, not 1 and 3. Sorry for all the confusion.

Thanks guys!

Standard copper core plugs, like the BPR6ES plugs, should be changed every 10 to 15k miles. At 30k miles, they definitely need to be replaced.

Yeah, I knew it needed to be done, I can tell by the idle.

I remember my Stepdad saying he's got over 300,000 miles on his truck with the original spark plugs. But he might have forgotten, he takes it to the shop for repairs.

Its because of the waisted spark system we use. 1 and 3 fire opposite polarity from 2 and 4.

Intriguing. Anyone have more information?

 

[jackblack65]

Coil resistance seems likely .
Either the coil itself or wires, check and compare the ohms on all 4 paths for any phase shift.

 

[bastarddsm]

Coil resistance seems likely .
Either the coil itself or wires, check and compare the ohms on all 4 paths for any phase shift.

Err, come again? Last I checked a straight resistance, won't cause phase shift. Now if the wires had differen't inductances, then there could be a shift.

Really tho, its because 1 and 3 fire electrode to ground, and 2 and 4 fire ground to electrode.

 

[DSM1G90]

he's got over 300,000 miles on his truck with the original spark plugs

..bet they were welded to the head by that time ... prob was platinum tipped plugs in that truck....and we don't use platinum plugs.

Lot of Honda (and maybe other makes) motorcycles, esp the 4cyl types also used the wasted spark system - just to make the ignition system simple..and to eliminate the distributor.

DSM

 

[jackblack65]

Err, come again? Last I checked a straight resistance, won't cause phase shift. Now if the wires had differen't inductances, then there could be a shift.

Really tho, its because 1 and 3 fire electrode to ground, and 2 and 4 fire ground to electrode.

Obviously if there are differences in resistance in ANY path there is some breakdown weather it be in the coil windings OR the wires or even the plugs themselves.

Different resistance WILL cause shift resulting in different wear characteristics.
Weather the circuit is grounded forward or backward makes no difference.

The resistance is obviously less on those 2 plugs.
All plugs are affected by the wasted spark system not just 2.
DSM1G90 pegged it right the first time (coil)
most likely culprit. IMO

 

[Calan]

check and compare the ohms on all 4 paths for any phase shift.

How will a static resistance measurement tell you anything about the phase of an alternating current traveling through an ignition wire?

 

[jackblack65]

How will a static resistance measurement tell you anything about the phase of an alternating current traveling through an ignition wire?

The plugs are telling you
How you think a short will have NO effect on phase is a better question.
.

 

[Calan]

How you think a short will have NO effect is a better question.

What does a short have to do with anything?

You said:

check and compare the ohms on all 4 paths for any phase shift.

Different resistance WILL cause shift

And I'm asking... how is a resistance check going to show a phase shift?

 

[jackblack65]

Oh I see what you are getting at.
The test shows nothing of the phase of course,you will need an oscilloscope to see the actual wave form.
But that is after you rule out a simple short.
What I am saying is the throughput of the phase is affected by resistance.
Are you saying It Does not?

What does a short have to do with anything?

 

[Nasty Dream]

Thanks guys. So you all mostly agree that it is probably the "wasted spark system"?

And there isn't anything I can do about it unless I switch to an MSD system of some sort?

I think I'll just replace the plugs more frequently.

 

[Calan]

Thanks guys. So you all mostly agree that it is probably the "wasted spark system"?

And there isn't anything I can do about it unless I switch to an MSD system of some sort?

Using a CDI box won't change anything; the ECU is still designed to use a WS ignition, and there is nothing wrong with it anyway.

I think I'll just replace the plugs more frequently.

Good idea.

 

[Nasty Dream]

So I've finally had a chance to get it up to temp and drive it around a bit today with the new spark plugs.

The idle is still imperfect, there's been no change from before. It's fine, I guess, you might even call it normal or good. But the check engine light again came on at idle, just as before.

Figure it's because of the mods I've done and the lack of tuning for them. It didn't used to have this issue though, even with the same mods. Very rarely the CEL would come on (like once or twice a year), and I would reset it thinking it was just confused by the mods.

I'll continue to look into other things that could be causing it. I don't have the money to get ECMlink at this time, but that's my next planned upgrade.

The CEL OBDII says it's the O2 sensor detecting something wrong. So it's running rich or lean, right? I mean, can it detect anything else?

I don't drive the car hard, so I think it will be alright. I don't put a lot of miles on it either. It's not my DD right now.

 

[jackblack65]

Thanks guys. So you all mostly agree that it is probably the "wasted spark system"?

And there isn't anything I can do about it unless I switch to an MSD system of some sort?

I think I'll just replace the plugs more frequently.

Well some of us expect a lot more than 30k from a set of plugs.
Calan seems to have all the answers being some kind of DSM psycic able to diagnose
your problems without ever even back tracing the faults so if he says its a duck then ducksauce it is.

 

[Calan]

Well some of us expect a lot more than 30k from a set of plugs.

On a high-performance turbocharged engine, when new plugs cost about $9-$12 a set?

Yeah ok... right.

Calan seems to have all the answers being some kind of DSM psycic able to diagnose
your problems without ever even back tracing the faults so if he says its a duck then ducksauce it is.

There's a crapload of stuff I don't know about these cars; but I don't go spreading BS like silent shaft deletes cause crankwalk and its ok to run your plugs more than 30K miles.

But since good advice and sound logic seem to bother you... you guys figure your problems out on your own.

Good luck.

 

[jackblack65]

I just knew it was another premadonna with her feathers ruffled by my opinion in another thread come to stalk me, I'm sooo glad you admitted it princess!
Now that The BS artists have left the stage maybe we can do some actual work on your problem
For starters you are running the wrong plugs, I would suggest the
NGK BPR7ES .30 gap., if it wont put you out then change the wires and coil as well.
Check the plugs every 15k and you should get 50k out of them
P.S.
I will expect you to take actual pictures of the plugs when you come back.
twayne9mm gave you dam good advice so follow up on it!

 

['97boostinGST]

I just knew it was another premadonna with her feathers ruffled by my opinion in another thread come to stalk me, I'm sooo glad you admitted it princess!
Now that The BS artists have left the stage maybe we can do some actual work on your problem
For starters you are running the wrong plugs, I would suggest the
NGK BPR7ES .30 gap., if it wont put you out then change the wires and coil as well.
Check the plugs every 15k and you should get 50k out of them.

50k out of spark plugs?? WTF
BPR7ES is a step colder plug, I just saw the OP's mods and it doesn't tell weather he is running "moderate" boost (15-20psi) or more, but those plugs will probably bring more problems IF he doesn't have the setup for it.

OP: Have you done a compression test to see how your compression is?

 

[Calan]

I just knew it was another premadonna with her feathers ruffled by my opinion in another thread come to stalk me, I'm sooo glad you admitted it princess

Yeah right; that's what is going on. I'm sure everyone believes you too.

Keep posting bad advice and trying to cause problems.

 

[jackblack65]

50k out of spark plugs?? WTF
BPR7ES is a step colder plug, I just saw the OP's mods and it doesn't tell weather he is running "moderate" boost (15-20psi) or more, but those plugs will probably bring more problems IF he doesn't have the setup for it.

OP: Have you done a compression test to see how your compression is?

I find it unlikely he is using a manual boost controller for no reason

 

[DSM1G90]

50k out of spark plugs??

Unless he's playing with Platinum, or some other odd type of plug-like "Pulstars" .. YEECH!.

I hate to see standard plugs that have 50k on them....