Can you hear an engine misfire through the air filter?

**JayTA98** · 09-15-2014, 05:06 PM

Hello guys. I have a general engine question. This is from my ford F150. the truck is old and has 162k on it. The engine is the 5.4L. I replaced the spark plugs 6k ago. I cleaned the TB, MAF and air filter. The truck came with KN filter on it. Last week I noticed the engine was missing hard. I made it home and i had codes for #3. I swapped coils and the code did not followed. It ended up been the ignition coil connector dirty because I cleaned it with some electrical cleaner and it worked again. I did noticed this noise the same day I had the misfire issue and now I can hear it all the time. It sounds like a popping noise or maybe the engine is still missing? I don't have any codes stored or SES light.

I haven't changed the coils on this truck. I have read that they are probably too old and need to be replaced. I'm wondering about the noise since I never heard it before.

Has anyone heard this noise before on their car or truck? Thanks guys. Sorry i'm posting about my truck but nobody seems to give me an answer on the F150 forums.

http://vid811.photobucket.com/albums...ps1fe64dc3.mp4

**pajeff02** · 09-15-2014, 05:23 PM

That is very odd sounding... not sure what it is.

**JayTA98** · 09-15-2014, 05:27 PM

Originally Posted by pajeff02

That is very odd sounding... not sure what it is.

I know right? I'm just getting concerned that is going to be an issue. I just got this truck and I want fix a few more things but don't want to do more until I find out if it is serious or not. If it is I might just sell the truck.

**JayTA98** · 09-15-2014, 05:32 PM

I might have to take it to ford to get a diagnostic done... its not going to be cheap but if they can at least tell me what is the issue I can then fix it. I do feel a slight miss on the idle but very light. I have checked for vacuum leaks.

**pajeff02** · 09-16-2014, 02:23 AM

The sound is emanating from the air cleaner? Any chance the EGR is sticking open and feeding exhaust to the intake at idle?

***SMWS6TA*** · 09-16-2014, 06:04 AM

that's a new one on me....

**JayTA98** · 09-16-2014, 06:55 AM

Yes the sound is heard from the air filter. Hmm. You think the egr could cause that? I tried showing it to a friend today and is not doing the noise ... I do know when im drivng around I do feel like the truck exhaust is slightly missing or gurgling. I checked for exhaust leaks and nothing on the exhaust system

**JayTA98** · 09-16-2014, 06:58 AM

What it gets me is that is not a constant noise. When it does it is intermittent. So if the egr was leaking why is not making the noise constant?

**0rion** · 09-16-2014, 01:33 PM

what happens if you hold the idle up some? I've never heard that noise before. It doesn't really sound like a misfire to me though and the engine doesn't sound like it has a misfire. It almost sounds like some kind of resonance from something bumping that intake tube or something? Take the filter off and see if you get a different or better sound.

**JayTA98** · 09-16-2014, 04:01 PM

I do have a slight miss at idle and every time it misses the sound is present. It is very slight miss. I will check the air filter assembly and take the filter off. Im not a big fan of kn anyway but I have to find the stock air box.

**JayTA98** · 09-19-2014, 06:37 AM

well the noise is not happening anymore, so I don't know what is going on. I do noticed is hesitating under acceleration. It almost sounds like the exhaust is leaking or a have a bad fuel pump. I checked the fuel pressure and it is within specs. I might have to go to the stealership for a diagnostics...

**0rion** · 09-19-2014, 03:04 PM

spray some carb cleaner around your intake and TB.....maybe you didn't get something tight???? Perhaps that noise was the idle air cycling or something? Just throwing out some guess' here and an air metering problem would cause hesitation off idle. EGR might be another thing to check.....maybe the valve has some carbon build up? Like I say.....just guessing.

**JayTA98** · 09-19-2014, 03:41 PM

Thanks I appreciate it. I will check the egr and spray some carb cleaner around the intake.

Everyone at the f150 forum keeps telling me is the coils that need replacement.

**pajeff02** · 09-19-2014, 05:06 PM

I had coils go bad on the Stratus my daughter drives. Granted, it was a 4 cylinder, but when each one went bad you definitely knew something was amiss. It didn't get weak or start to miss, it just plain quit each time.

**35th-ANV-SS** · 09-20-2014, 10:17 AM

Sounds like there was a little chipmunk in your engine with a drum set.

**JayTA98** · 09-20-2014, 04:31 PM

Originally Posted by 35th-ANV-SS

Sounds like there was a little chipmunk in your engine with a drum set.

well... I did move to the country side so it could be a possibilty. lol. I guess the chipmunk got tired of living in there as I don't hear it anymore.

I pulled out the TB and plenum today to reinspect the gasket and check the pcv elbow on the back. I also pulled all passenger side plugs out to re check the gap and condition. I did noticed there was some rust stains close to the bottom of the plug but there is no water. No cracks on the plugs. These plugs are motorcrafts and I installed them 3k ago, so they are new. I can see a lot of gunk in the area were the plugs go in. I always vacuum the holes before I pull the plugs out to avoid debris entering the cylinder. I also check the resistance in all the ignition coils to compare and see if I have one that is out of spec. So far I have one that is off.

I pulled the IAC valve and EGR valve. Both were cleaned with TB cleaner and there was no build up. I couldn't finish the other side today as it got dark. I will do the other side tomorrow and finish up.

I called ford and they charge $100 for specific diagnostics. I might just do that so they can use live scan or order the coils or just keep driving it until I actually get a ses light.

**JayTA98** · 09-20-2014, 04:35 PM

im starting to learn that ford's OBD system is not as sensitive as GM as far as telling me when there is even a slight problem. From what I read it only throws codes when the part stopped working. I might have to invest in some live scan software myself. I do have an OBD 2 reader with some live data but not mode 6

**pajeff02** · 09-21-2014, 06:00 PM

Sorry, I don't speak Ford - Mode 6?

Sounds like you are on the right track though.

**35th-ANV-SS** · 09-21-2014, 06:13 PM

OBDII is separated into 9 different modes. Each mode is a different category.

Mode 1 - Real time data
Mode 2 - Freeze frame
Mode 3 - Stored DTC's
Mode 4 - Clear/reset DTC's and emissions related diagnostic information.
Mode 5 - O2 monitoring tests
Mode 6 - Test results for continuously and non-continuously monitored systems, supported. Mode 7 - Pending DTC's
Mode 8 - Request control of on-board-system, test or component (bidirectional controls).
Mode 9 - Request VIN and other data.