[f18guy]

So my wife's 2004 E popped a CEL last night. I went and had the codes read at Autozone today and got the P-0300, P-0301, P-0302, P-0304 code.

My first thought was electrical stemming from the coils. But then it occured to me that the likelihood of 3 coild going bad at the same time was very low. Looking around on the forums here I read a few posts from people that had similar codes and the problem stemmed from the valves.

So I removed the spark plugs and checked the compression on the cyliders.
The results were as follows:
Cylinder 1: 175
Cylinder 2: 190
Cylinder 3: 190
Cylinder 4: 190

So obviously #1 is a little low, but still within 10%. What was much more concerning however was the condition of the spark plug from #1

If you look at the attachment, the plugs are in order from left to right, 1-4.

The electrode has ash all over it and there is oil residue on the threads.

I am adjusting the valves tomorrow hoping that will correct the difference in the compression. But the question is will it correct what is fouling the plug?
Hopefully the valves in cylinder 1 is so far off that it isn't seating properly.

If not, anyone want to wager a guess of whether it is a burned valve seat or blown rings?

 

[Dom.five]

The random misfire shown in the codes will not be fixed with a valve adjustment on one cylinder !!

This can be big trouble in the Electronics, or as simple as Bad Gas !!

My money is on bad gas!


Dom

 

[f18guy]

What would account for the fouled plug from the #1 cylinder?

 

[Dom.five]

What would account for the fouled plug from the #1 cylinder?

Several things can be the cause of plugs being Fouled. One of those things is Misfiring, that will cause that symptom, a misfire !!
Unburned Fuel can and will make a plug look like that. It looks like you may have water in the fuel.

Fix that first! Then see if there are other issues.


Dom

 

[ApriliaGuy]

yup....I'm guessing bad gas too.

Try a bottle of "dry gas" or a good fuel treatment, run out as much as you can before refilling 1/2 way at a place you trust. Add another bottle of fuel treatment just in case. Run that way down below 1/4 before filling again.


good luck.

 

[LMntGuy1982]

How old are the plugs?? Could it have been that so much carbon built up that it wasn't fully firing and fuel built up and fouled it out?

 

[Dom.five]

How old are the plugs?? Could it have been that so much carbon built up that it wasn't fully firing and fuel built up and fouled it out?

Look at his first post! It's throwing codes like Crazy !!! That has bad fuel written all over it.


Dom

 

[LMntGuy1982]

http://www.honda-tech.com/showthread.php?t=978933

Good point but I'm just looking at the plugs and they look like mine after 6 years when I replaced them. The porcelain is toast. Just wondering if swapping the plugs will have them fire better. If another plug fouls out then u know something else is wrong. $5 is a cheap fix.

 

[Jackson49]

#1 Spark Plug

Why would bad fuel only cause the #1 spark plug to misfire? Would it not cause all the plugs to misfire? I realize that #1 is the first in the firing order but water in the fuel would be distributed to all cylinders. Removing the water from the fuel is a good first step but there seems to be a little more going on here. Just sayin'

 

[ApriliaGuy]

Why would bad fuel only cause the #1 spark plug to misfire? Would it not cause all the plugs to misfire?

The codes show a multi cylinder misfire.....not just #1.


P0300- Random Misfire detected
P0301- Misfire detected on cylinder 1
P0302- Misfire detected on cylinder 2
P0303- Misfire detected on cylinder 3
P0304- Misfire detected on cylinder 4

 

[Dom.five]

Why would bad fuel only cause the #1 spark plug to misfire? Would it not cause all the plugs to misfire? I realize that #1 is the first in the firing order but water in the fuel would be distributed to all cylinders. Removing the water from the fuel is a good first step but there seems to be a little more going on here. Just sayin'

That may be true! The first thing to do is solve the issue that's causing the misfire. It sounds like fuel, It may be something other than the fuel. but not likely.

If a single plug fowls so badly, that it misfires for several revolutions and the others don't, the plugs will look like what he is showing us.

The water in the fuel will not necessarily be distributed equally to all cylinders, all the time. For example, you may only pick it up on a left hand turn. Then it may take several miles to reach the injector stream. You may have only picked up enough to reach one injector this time. then several seconds after that another drop gets into the mix. Some may be alcohol rich fuel that precipitated out of the gas, some may be all water.

If as you suggest, " there seems to be a little more going on here " I think more of the plugs would look like #1. It is not all that unusual for one cylinder to have lower compression numbers than the others. That is especially true if the cylinder is misfiring. The unburned fuel will wash the lube oil off the rings, degrading the seal in that cylinder. That will always produce a lower compression number.

A good start would be to follow ApriliaGuy's directions. It beats draining the tank, by removing it. Then replace the plugs, and keep an Eye on it for a tank or so. Then pull the plugs, take a look, and do another compression test. That will remove all doubt/speculation, and prove the trouble definitively.

Dom

 

[f18guy]

That may be true! The first thing to do is solve the issue that's causing the misfire. It sounds like fuel, It may be something other than the fuel. but not likely.

If a single plug fowls so badly, that it misfires for several revolutions and the others don't, the plugs will look like what he is showing us.

The water in the fuel will not necessarily be distributed equally to all cylinders, all the time. For example, you may only pick it up on a left hand turn. Then it may take several miles to reach the injector stream. You may have only picked up enough to reach one injector this time. then several seconds after that another drop gets into the mix. Some may be alcohol rich fuel that precipitated out of the gas, some may be all water.

If as you suggest, " there seems to be a little more going on here " I think more of the plugs would look like #1. It is not all that unusual for one cylinder to have lower compression numbers than the others. That is especially true if the cylinder is misfiring. The unburned fuel will wash the lube oil off the rings, degrading the seal in that cylinder. That will always produce a lower compression number.

A good start would be to follow ApriliaGuy's directions. It beats draining the tank, by removing it. Then replace the plugs, and keep an Eye on it for a tank or so. Then pull the plugs, take a look, and do another compression test. That will remove all doubt/speculation, and prove the trouble definitively.

Dom

For a follow up, The plugs have been replaced, valves adjusted, and fuel treatment has been added to the tank. I reset the codes and am giving a few thousand or so miles to pull the plugs to inspect them.

With any luck the CEL won't pop between now and then.

Cheers

 

[ApriliaGuy]

was it running rough/badly before you did the valves, plugs, & fuel treatment?

Is it running any better now?

how many miles on the old plugs?

 

[f18guy]

was it running rough/badly before you did the valves, plugs, & fuel treatment?

Is it running any better now?

how many miles on the old plugs?

Wasn't running poorly before maintenance, but was idling high.

As far as how it's running now, it may be a placebo effect but I think, as does my wife, it's running much better now. After doing the idle learn procedure it idles smoother and accelerates better.

I have to assume it was still running the original plugs as we recently bought the E used from a private party. The E has 85k on it.

 

[ApriliaGuy]

As far as how it's running now, it may be a placebo effect but I think, as does my wife, it's running much better now. After doing the idle learn procedure it idles smoother and accelerates better.

Cool. The nice thing is it was about due for a valve check and new plugs anyway. ;-)
(I like checking valves every 60k or so, and 100k out of the factory plugs)

Were the valves far off from spec? Just #1 or the other cylinders too?

 

[f18guy]

Cool. The nice thing is it was about due for a valve check and new plugs anyway. ;-)
(I like checking valves every 60k or so, and 100k out of the factory plugs)

Were the valves far off from spec? Just #1 or the other cylinders too?

All the cylinders required a little adjustment. The exhaust sides were further out than the intake side on all cylinders. None of the valves were loose, they were all too tight/not enough gap.

 

[ApriliaGuy]

None of the valves were loose, they were all too tight/not enough gap.

This is why I like to check the adjustment early...waiting 'til 100k can cause problems, and it is well after most warrenties have expired besides!

 

[Jackson49]

That may be true! The first thing to do is solve the issue that's causing the misfire. It sounds like fuel, It may be something other than the fuel. but not likely.

If a single plug fowls so badly, that it misfires for several revolutions and the others don't, the plugs will look like what he is showing us.

The water in the fuel will not necessarily be distributed equally to all cylinders, all the time. For example, you may only pick it up on a left hand turn. Then it may take several miles to reach the injector stream. You may have only picked up enough to reach one injector this time. then several seconds after that another drop gets into the mix. Some may be alcohol rich fuel that precipitated out of the gas, some may be all water.

If as you suggest, " there seems to be a little more going on here " I think more of the plugs would look like #1. It is not all that unusual for one cylinder to have lower compression numbers than the others. That is especially true if the cylinder is misfiring. The unburned fuel will wash the lube oil off the rings, degrading the seal in that cylinder. That will always produce a lower compression number.

A good start would be to follow ApriliaGuy's directions. It beats draining the tank, by removing it. Then replace the plugs, and keep an Eye on it for a tank or so. Then pull the plugs, take a look, and do another compression test. That will remove all doubt/speculation, and prove the trouble definitively.

Dom

Dom,

Thanks for showing me the way. I did not have code information available to me when I weighed in. If I had that info. available at the time my comment would have read a little differently.

 

[f18guy]

This is why I like to check the adjustment early...waiting 'til 100k can cause problems, and it is well after most warrenties have expired besides!

Just to satisfy my curiosity, what are some of the issues that can occur as a result of improperly adjusted valves, in particular, when they are too tight?

 

[slimerdogs]

The other issue that would cause a multible misfire code would be low fuel pressure. As for what would happen if the valves were too tight it would cause leaking by the valve and at the least low compression but more then likely you would get a burnt valve and if it was the intake you would hear a popping through the intake. If the valves were too loose and I have seen this on VWs it can beat the seat into the head.