[415dispatcher]

2005 Ford Escape 6Cyl, 47,000 miles

Hello all:

The best way I can describe it is a gulping air sound around the intake. it's a deep kind of "woomp woomp" sound. It only happens when the engine is at an idle and ONLY after the engine comes up to operating temperature.

Error codes: Cylinder 4 Misfire Detected & Misfire at Startup first 1000 revolutions

Whats been done so far: Checked vacuum hoses for leaks, replaced all spark plugs (and 6 new upper intake gaskets), replaced coil pack for cylinder #4.

The problem returned immediately with the same error codes. What now? I've been all over the internet looking for the someone with the same problem. I am seeing tons of posts about cyl 4 misfires and rough idling. It seems my situation is unique with the "woomp woomp" sound and it only occurring after vehicle reaches operating temperature and only during idle. The idle seems rough no matter what the engine temp is.

I have a list of things to try but i'd like to prioritize it in the interest of saving money. The list was compiled after much internet research (escapes with similair problem):
-New Fuel Filter
-New #4 Fuel Injector
-Cleaning/Replacing IAC
-Cleaning/Replacing MAF sensor

Any Ideas? I appreciate any help, thanks!

 

[SUVord]

2005 Ford Escape 6Cyl, 47,000 miles

Hello all:

The best way I can describe it is a gulping air sound around the intake. it's a deep kind of "woomp woomp" sound. It only happens when the engine is at an idle and ONLY after the engine comes up to operating temperature.

Error codes: Cylinder 4 Misfire Detected & Misfire at Startup first 1000 revolutions

Whats been done so far: Checked vacuum hoses for leaks, replaced all spark plugs (and 6 new upper intake gaskets), replaced coil pack for cylinder #4.

The problem returned immediately with the same error codes. What now? I've been all over the internet looking for the someone with the same problem. I am seeing tons of posts about cyl 4 misfires and rough idling. It seems my situation is unique with the "woomp woomp" sound and it only occurring after vehicle reaches operating temperature and only during idle. The idle seems rough no matter what the engine temp is.

I have a list of things to try but i'd like to prioritize it in the interest of saving money. The list was compiled after much internet research (escapes with similair problem):
-New Fuel Filter
-New #4 Fuel Injector
-Cleaning/Replacing IAC
-Cleaning/Replacing MAF sensor

Any Ideas? I appreciate any help, thanks!

When you say engine at idle is the transmission at N or at D, or you have checked both positions and the "woomp-woomp" stays the same?
1/Fuel and air filters should be changed if they are overdue.
2/Leave the injector for last.
3/Unplug the IAC while the engine is idling at neutral.If the IAC is functioning, then by unplugging it the engine should stall.Cleaning it never hurts, but careful with those tiny gaskets or get some new ones.
4/Cleaning the whole intake and the MAF is a good practice.
Regardless of all the above, a vacuum leak somewhere is still my concern.With the engine idling at Neutral, step hard on the brake for quite a few seconds and see if slowly but gradually the brake pedal hits the floor.It may take more than 5 seconds for this to happen if you have a vacuum leak.
A different check for the crankcase ventilation.While idling take the oil dipstick off and see if there is a change in the idling.
Please keep us informed with your progress.

 

[415dispatcher]

When you say engine at idle is the transmission at N or at D, or you have checked both positions and the "woomp-woomp" stays the same?

Yes...it does it in P, N and D. Once i increase the rpms above 1000 it goes away.

Thank you very much for the reply! I will try everything you listed started with testing the IAC. I just saw another post on this board from a guy who had a "muted popcorn popping" sound. He has a video of the sound and it's exactly the same as mine! Unfortunately he hasn't found a solution yet.

Should I try cleaning the intake with Seafoam? I bought a bottle and read the directions and now i'm afraid i'll screw it up. I can't figure out where to insert the tube!

 

[SUVord]

In the "popcorn" thread you probably noticed the IAC valve was mentioned as well as the DPFE.
After lots of thousands of miles and depending on the quality of the gasoline, the DPFE goes crazy and at low revs it keeps slightly open the EGR valve.With that happenning the IAC gets the wrong signal and thinks that the car is moving, etc.End result is that more fuel than needed is going to the combustion chamber but not enough air and that gulping for air produces this unique sound.That also explains why many of us have noticed a considerable fuel economy when these issues have been fixed.
As for the intake cleaning I have never used seafoam.I know that many in here have used it and are pretty satisfied with it.It simply is not available where I live.
I clean the intake by taking it out and using anything for cleaning it with my favorite method being diesel fuel and a good soap cleaning on top of that.Blow dry it and put it back.

 

[RobtRoma]

I'm the original "popcorn" guy. For me it's a very intermittent problem. It only seems to happen in the winter. It stopped last April (2010) but came back last week. I had my IAC replaced about a month ago, because it failed, but apparently that didn't help.

The guys at the shop I took it too last winter swore up and down that the sound was coming from the manifold. They said if it was coming from the cylinder, there would be noise coming from the exhaust. They said they heard nothing from the exhaust. I thought I head something very faint but it was hard to tell. Basically they said it was a hose with a hole or kink or a bad manifold gasket. They sprayed a solution on just about everything looking for bubble but didn't see anything. They ended up replacing a kinked hose but that didn't help.

I'm going to have a major tune up done soon (spark plugs, C.O.P.'s changed on the back cylinder bank, manifold gaskets changed and get all the sensors checked out. I wish the problem would throw a code but it hasn't. Other than this little issue, my Escape is in great shape. I'd love to get it fixed...

 

[415dispatcher]

In the "popcorn" thread you probably noticed the IAC valve was mentioned as well as the DPFE.
After lots of thousands of miles and depending on the quality of the gasoline, the DPFE goes crazy and at low revs it keeps slightly open the EGR valve.With that happenning the IAC gets the wrong signal and thinks that the car is moving, etc.End result is that more fuel than needed is going to the combustion chamber but not enough air and that gulping for air produces this unique sound.That also explains why many of us have noticed a considerable fuel economy when these issues have been fixed.
As for the intake cleaning I have never used seafoam.I know that many in here have used it and are pretty satisfied with it.It simply is not available where I live.
I clean the intake by taking it out and using anything for cleaning it with my favorite method being diesel fuel and a good soap cleaning on top of that.Blow dry it and put it back.

Oh that's interesting...i've ignored all the other info about the DPFE because i read somewhere that it only causes problems above 40mph or so. So would you recommend i order a new one and try that before any of the other stuff??

 

[415dispatcher]

The guys at the shop I took it too last winter swore up and down that the sound was coming from the manifold. They said if it was coming from the cylinder, there would be noise coming from the exhaust. They said they heard nothing from the exhaust. I thought I head something very faint but it was hard to tell.

I think i can hear noises from the exhaust too. Very faint though. Interesting that although our problems sound very similar...mine throws the code and yours doesn't. As i'm sure you have...i've scoured the internet looking for other people with the same "poprcorn" sound and didn't find any other people but us!

 

[415dispatcher]

oh and by the way..when i left to go to work tonight...turned the key and it turned over a few more times than usual before it started up.

 

[SUVord]

oh and by the way..when i left to go to work tonight...turned the key and it turned over a few more times than usual before it started up.

That symptom may be coincidental to moisture and cold temperatures depending where you live.
A weak battery which is old may also cause this belated start-up.
As for your intake glitches you seem to have different issues to deal with from Robtroma.
An automotive stethoscope would help to distinguish where the strange sound comes from.It saves a lot of hassle and aggravation together with money.

 

[neubauer6]

Did you ever solve this problem? Mine is doing the same exact thing?

 

[JCZ]

That is my issue exactly. The noise is just like that. I do not have a check engine light on, but still hear it. The code is cylinder 4 misfire too. Any luck in finding a solution???