Check Engine Light

I recently had my check engine light come on and would like to locate the issue and get it back off.

What I've done so far is that I've taken it to AutoZone to read the codes. They told me that the codes are saying misfire on cylinders 1-6. I tried to do a little research on what would cause this and almost all of the info I've found so far points to the DISA valve.

I've removed mine and do not see any issues at all with it. It's not broken and is functioning fine with no play in it. I cleaned it anyhow and put it back but the light is still on.

What else might cause a misfire on all 6 cylinders? The car idles a little rough but not bad at all. I do notice that it is slightly a little more rough than before the light came on.

Ah, the forum crystal ball clinic is open. There are many variables to the code number and possible causes. Bravo for NOT changing 1 and 6 spark plugs as some would do. The code can be a result of a lean condition from a torn intake boot not visible to the eye. Feel, poke and carefully examine both rubber intake boots. A small rip can suck air making for weak mixture hitting the cylinders - misfire. Another favorite is a failing coil. Two at the same time would be unusual but who knows? Guys typically trade them around. As we have individual coils, swap #2 with #1 and #5 with #6. See if the mis-fire moves to #2 and #5 for example. If the symptom moves, replace the affected coil(s). While your in there toss in a fresh set of plugs if you don't know their replacement history. This rarely pays-off but eliminates coils and plugs.

Now it gets tricky. Deeper diagnostic tools or pro assistance may be required. Auto store OBDII code readers are fairly cheap. You can snag one with the error reset feature in the $45-$60 range. Don't worry about built-in code look-up data, we have the Internet for that. Having the reader in hand while troubleshooting is invaluable. Keeping your friends and neighbors from borrowing it is another matter. They never bring it back!!

If your comment is that there's a misfire in cylinders 1 through 6, then there's likely a tear in your intake boot that's letting unmetered air into the system.

If your comment is misfire in cylinders 1 and 6, then there's likely an issue with the coils...but still check the intake boot for tears. And clean your MAF sensor. And your idle control valve.

Providing that you can feel the misfire, does the issue go away when you're off idle?

Originally Posted by White_Knuckles

Ah, the forum crystal ball clinic is open. There are many variables to the code number and possible causes. Bravo for NOT changing 1 and 6 spark plugs as some would do. The code can be a result of a lean condition from a torn intake boot not visible to the eye. Feel, poke and carefully examine both rubber intake boots. A small rip can suck air making for weak mixture hitting the cylinders - misfire.

The rubber intake boots may be an issue, for sure.

As far as the coils go, I would think that it would almost be an impossibility for coils 1 all the way through 6 to go bad at the same time. I really don't think it's the coils but then again, I'm not sure.

One thing that I do notice is that when the car is cold, it idles a little rougher than when it's warm and if I don't allow it to warm up for a while and immediately start driving, it will sputter. It's even stalled once or twice since this started. When it stalled, it was because I didn't let it warm up.

Does this still sound like an intake boot to you?

By the way, thank you, for helping me.

Originally Posted by White_Knuckles

Auto store OBDII code readers are fairly cheap. You can snag one with the error reset feature in the $45-$60 range. Don't worry about built-in code look-up data, we have the Internet for that.

This is great to know and I will certainly pick one of these up tomorrow.

Originally Posted by SamDoe1

If your comment is that there's a misfire in cylinders 1 through 6, then there's likely a tear in your intake boot that's letting unmetered air into the system.

If your comment is misfire in cylinders 1 and 6, then there's likely an issue with the coils...but still check the intake boot for tears. And clean your MAF sensor. And your idle control valve.

Providing that you can feel the misfire, does the issue go away when you're off idle?

Hi Sam. Thanks for the reply. Actually, what they told me at AutoZone was that all the cylinders were misfiring. It's weird and I think as you and WhiteKnuckles have suggested, I will check the intake boots for any damage. This will probably be an easy fix if this is in fact the problem. I'll post back here tomorrow with my findings.

Thanks, Sam.

pcv/oil seperator for sure, replace the lower intake boot and disa o-ring (you can get them cheap on ebay) while you're in there. and if you notice your expansion tank has an original production date.. toss a new one in too- lol

Originally Posted by redbull 325is

pcv/oil seperator for sure, replace the lower intake boot and disa o-ring (you can get them cheap on ebay) while you're in there. and if you notice your expansion tank has an original production date.. toss a new one in too- lol

Hi Redbull, I'm not familiar with the pcv/oil separator. I looked it up and came up with like 4 or 5 different hoses on ebay.

Is the pcv/oil separator a collection of 4 or 5 hoses or just a single hose? Can you tell me if I should be singling out one particular hose?

Originally Posted by tomjohnson

Hi Redbull, I'm not familiar with the pcv/oil separator. I looked it up and came up with like 4 or 5 different hoses on ebay.

Is the pcv/oil separator a collection of 4 or 5 hoses or just a single hose? Can you tell me if I should be singling out one particular hose?

It's a collection of a bunch of hoses as well as the actual CCV (crank case vent valve) itself. The CCV is the same as a PCV and oil separator, just different names for the same thing.

Originally Posted by SamDoe1

It's a collection of a bunch of hoses as well as the actual CCV (crank case vent valve) itself. The CCV is the same as a PCV and oil separator, just different names for the same thing.

Thanks Sam. How hard is this repair? I don't have a lot of tools right now so would I need anything special to do this?

Search the subject there is a lot of info out there.

Originally Posted by tomjohnson

As far as the coils go, I would think that it would almost be an impossibility for coils 1 all the way through 6 to go bad at the same time...

Sorry, I read it as cylinders 1 and 6 not 1 through 6.

The CCV fail as suggested may be sucking oil and snuffing your plugs to create the missing. You should notice a burning oil smell, blue exhaust clouds and other symptoms. Maybe inspect the plug condition for oil deposits?

Originally Posted by White_Knuckles

Sorry, I read it as cylinders 1 and 6 not 1 through 6.

The CCV fail as suggested may be sucking oil and snuffing your plugs to create the missing. You should notice a burning oil smell, blue exhaust clouds and other symptoms. Maybe inspect the plug condition for oil deposits?

it's an e46 with over 100k it needs an pcv, only diag needed - lol. even if you aren't throwing a CEL your fuel trims are way off if you are still running the og pcv.

Originally Posted by tomjohnson

Thanks Sam. How hard is this repair? I don't have a lot of tools right now so would I need anything special to do this?

It's not easy. You won't need special tools but a good set is definitely a must have.

I have a way of checking for vac leaks that has worked for me on 2 of my 325's, I take out the air filter box and MAF sensor,
Where the maf sensor attaches to that 3" rubber hose I stand to the side bend over and put my mouth to the 3" hose get a seal around my face and blow, you should be able to pressurize the system and listen for any leaks. if all is good you should be able to build up a pressure and hear no air leaks, I have found 2 bad vac lines to the fuel filter pressure regulator, torn intake boot, and cracked line to the valve cover.
You can hear the hissing right away if you have a problem, it helps if you have someone look and listen as you blow in and hold a slight pressure, It looks and sounds funny but it has worked great for me. no need for smoke testing.

Originally Posted by White_Knuckles

You should notice a burning oil smell, blue exhaust clouds and other symptoms. Maybe inspect the plug condition for oil deposits?

I haven't noticed any smoke at all. I suppose I should probably change the plugs as well.

Originally Posted by redbull 325is

it's an e46 with over 100k it needs an pcv, only diag needed - lol. even if you aren't throwing a CEL your fuel trims are way off if you are still running the og pcv.

Redbull, is there a way to test my PCV valve or should I replace it? The car has 140k on it and I'm not sure if it was ever replaced.

Originally Posted by jonnie325xi

I have a way of checking for vac leaks that has worked for me on 2 of my 325's, I take out the air filter box and MAF sensor,
Where the maf sensor attaches to that 3" rubber hose I stand to the side bend over and put my mouth to the 3" hose get a seal around my face and blow, you should be able to pressurize the system and listen for any leaks. if all is good you should be able to build up a pressure and hear no air leaks, I have found 2 bad vac lines to the fuel filter pressure regulator, torn intake boot, and cracked line to the valve cover.
You can hear the hissing right away if you have a problem, it helps if you have someone look and listen as you blow in and hold a slight pressure, It looks and sounds funny but it has worked great for me. no need for smoke testing.

This is really strange because I do not have a MAF because there is no "box", only a chrome pipe with a v shaped filter on the end of it. My car is a 2002 and I'm not sure if this is factory installed or an aftermarket thing. Does anyone know where the MAF is located in my case?

I'll take a pic and post it tomorrow when I can get into the garage.

You have an aftermarket intake... I'd honestly suggest that you swap the OEM one back in. You should be able to find the airbox for pretty cheap on either ebay or the classifieds on this forum (check the part out section).

Your car has to have a MAF, it won't run without it (well it will, but a SES light would trigger). It should be right behind the filter, it's the thing with a wire running to it.

Everyone, I took the car in for an alignment today and they were able to read the codes. Here is everything they show:

P0300
P1344
P1346
P1350
P1085
P1083
P0171 (B1)
P0174 (B2)

Can anyone make sense of these codes?

Originally Posted by tomjohnson

P0300 - Random/Multiple Cylinder Misfire Detected
P1344 - Misfire During Start Cylinder 2
P1346 - Misfire During Start Cylinder 3
P1350 - Misfire During Start Cylinder 5
P1085 - Fuel Control Mixture Lean (Bank 2 Sensor 1)
P1083 - Fuel Control Mixture Lean (Bank 1 Sensor 1)
P0171 (B1) - System Too Lean (Bank 1)
P0174 (B2) - System Too Lean (Bank 2)

See above.

Your car is running lean. You either have a leak in your intake manifold, intake runner, bad MAF, have low fuel pressure, or insufficient fuel flow.

How old is your fuel pump and filter?