[RobtRoma]

2002 Escape, V6...

My idle is very erratic and there is a noise coming from the intake that sounds like popcorn popping inside an insulated box. I thought it sounded like a misfire. The check engine light has not come on so it doesn't seem to be throwing any codes. I had a similar problem a few months back. When it happened that first time, I thought it was bad gas. I added some fuel additive and went to a different gas station and it went away after 2 tanks. This time, the problem started after I went to another new gas station. I ran off 2/3's of that tank and went back to my usual station and added the gas additive. It seems worse now. So...

I took it to a mechanic today. When they heard it, they said there was no way it was bad gas. They also ruled out misfiring because they said they would hear it from the exhaust and they said they heard nothing. Initially they were stumped. Then they found a kinked vacuum hose and changed it. They thought that would fix it but it didn't completely fix it. They said it sounded better after the change but something was still happening. BTW, they also checked all the manifold gaskets (spray and look for bubbles) but they didn't find anything. Their opinion was it might be a problem with the engine computer relearning how it should work after I had my battery changed. The asked me if the truck had been shifting funny lately and it has. They said this supported their theory. They think the combination of the kinked hose and the battery being replaced has fouled up the computer and it's searching for the right settings. They said the Ford engine computers are notoriously slow at learning and it could take up to 1000 miles for it to figure things out. They said I should wait a few weeks and drive it under varying conditions to see if there are any changes. I'm not so sure about this since I had a similar problem before the battery was changed...

On my drive to the office after the work was done, I'm hearing a very light odd noise from the HVAC vents in the truck that I had never heard before... I'm wondering if they made things worse...

I just wanted to know if anyone had any thoughts on this advice and what the real problem might be. These are the things I was discussing with the mechanics:

- mass air flow (MAP) sensor: They said maybe. They clean them when they do there fuel injector service.

- idle air control (IAC) valve: Again a maybe but they said cleaning them properly was next to impossible and they were very expensive.

- coil pack: He said that would create a misfire and a code so that could be ruled out.

- spark plugs: Same as the coil pack...

- manifold gaskets: They checked them and didn't find anything.

- clogged catalytic converter: He said it would throw a code if there was anything wrong with the cats. Besides that, he said you can hear when there are issues with the cats. :shrug:

I'm uploading some YouTube Videos. You can see the idle bouncing on one. On the other, you can actually hear the popping noise I'm talking about. I'll post them when they are live...

 

[RobtRoma]

Here are the videos. First one is the tach bouncing:

 

[LX302]

Hmm, popping noise and erratic idle, now a HVAC noise?
And a mechanic looked at it?

I'm gonna guess and say you might want to investigate a possible leaking head gasket or bad thermostat making the engine run hotter than normal. How's your oil look, milky? Getting bubbles building up in the coolant overflow tank of overfilled?
Might not be it, but buy looking at your post, the mechanic went over most of the issue that would cause this and I didn't see anthing about the coolant.
Good Luck.

 

[TopElimn8r]

It almost sounds like detonation or lean popping that is real muffled. Do you have any "tuners" etc on the vehicle? Are you using more oil lately? Oil will detonate long before gas will. If this is a higher mileage vehicle there is the possibility that the valve seals are leaking and causing this. When the vehicle is idling the vaccuum in the cylinders will draw oil past the valve seals and into the combustion chamber. If it gets bad enough when you shut the engine down the engine will continue to run horribly for a short time, commonly known as dieseling. This can also fool your O2 sensors giving the engine idle problems. I'm assuming that this only occurs at idle and under normal driving conditions you do not notice the problem.

I'm not saying that this is your problem for sure, I'm simply saying that this could be the problem. I've been burned before giving advice that is why i'm stating this. Example: "Person X" asks for advice on an issue. I replied this "may" fit the scenario. The person takes the vehicle to their local mechanic and says i want such and such changed. The change does not fix the problem and the mechanic will not refund their money because he did exactly what "Person X" asked him to do. "Person X" goes back on the forum saying i'm an idiot and don't know what i'm doing.

I have not examined the vehicle or diagnosed any problems. I'm simply trying to give you a question for your mechanic to answer.

I hope this helps. Good luck finding the problem. Hopefully it is as simple as a learning curve for the processor.

 

[RobtRoma]

Thanks for the replies guys.

I'm gonna guess and say you might want to investigate a possible leaking head gasket or bad thermostat making the engine run hotter than normal. How's your oil look, milky? Getting bubbles building up in the coolant overflow tank of overfilled?
Might not be it, but buy looking at your post, the mechanic went over most of the issue that would cause this and I didn't see anything about the coolant. Good Luck.

I don't think anyone looked at the coolant. I'll try to look at it after my next trip. The oil looked fine last week when I checked it.

It almost sounds like detonation or lean popping that is real muffled. Do you have any "tuners" etc on the vehicle? Are you using more oil lately? ….. I'm assuming that this only occurs at idle and under normal driving conditions you do not notice the problem.

My escape has only 72,300 miles in the O.D. No tuner items. It's stock. The engine has been using/loosing oil over the last year or so. I had the oil pan gasket changed over the summer because it was leaking. I thought that would stop the oil loss but either it didn't or the dealership I went to didn't re-fill the oil the way they should have (a real possibility). I had to put a quart and a half in the motor 3500 miles after the last oil change. I'm going to be watching that more closely now. It does only happen at idle… intermittently. There is no dieseling though. The engine shuts right off.

I'm not saying that this is your problem for sure, I'm simply saying that this could be the problem. I've been burned before giving advice that is why I'm stating this.

Excellent disclaimer eace: I get that. Sorry you've had issues in the past. I'm just looking for possibilities I can discuss with the mechanic. I had a similar problem a few months ago. It went away a week after I changed gas stations so I thought it was bad gas. The first time, the popping was much more muted. I hardly noticed it and I don't think I could have recorded it. I just went for a long ride and the bouncy idle was intermittent. It was really bad at 3 or 4 stops. It was noticeable at another 10 or so and non-existent at another 10 or so.

I hope this helps. Good luck finding the problem. Hopefully it is as simple as a learning curve for the processor.

Hopefully it is that simple. We'll see. Thanks again for the input eace:

 

[LEO_Escape]

wow. Well, something similar happened to me. I had pulled the DPFE off of the tubes but left the harness plugged in while I was replacing the brake booster. I had forgotten to put it back on and it sounded and acted almost exactly like that. I would hope the mechanics would have noticed something like that but you never know. It's easy to check. Worth a look anyway.

 

[RobtRoma]

Cool... I'll take a look. Was your issue intermittent also? Thanks for the input!

 

[TopElimn8r]

When you fix this, please post your solution.

I am curious.

 

[RobtRoma]

I hope I can get it fixed... :worry:

 

[LEO_Escape]

Cool... I'll take a look. Was your issue intermittent also? Thanks for the input!

It was for the short time it was off. I had the hood up I was leaning over the engine when it happened so I noticed it pretty quickly. That's why I'm doubtful that it is the problem but you just never know. Definitely keep us posted.

 

[Walkingchaos]

this is going to sound dumb but have you totaly taken your intake out and checked through all the tubes and all ? It almost sounds to me like something blocking the intake intermitently . . . .

 

[RobtRoma]

I haven't. I'm not very good when it comes to cars. I can take a computer apart and put it back together but I have a tendency to break things on my cars. :doh: Even if I was, it's freezing here :frozen: and I don't have a garage to work in. The mechanics I took it to gave it a pretty good going over but I didn't see exactly what they took apart and looked at. If things don't clear up, that will be one of the things I'll ask about... Thanks for the input

 

[Walkingchaos]

taking the intake out is just like stripping a computer tower Its one harness connector, two flip catches, and 2 hose clamps Run your motor for 15-20 min before if its cold so you dont break anything due to cold brittleness see if anything is stuck in there.

 

[RobtRoma]

It's supposed to warm up a little (40's) near the end of the week. If I can fine some time in the daylight I'll see if I can take a look. With my luck, one of the clamps will fall into the intake...

 

[TopElimn8r]

taking the intake out is just like stripping a computer tower Its one harness connector, two flip catches, and 2 hose clamps

What he is refering to as the "intake" is actually the airbox lid and the "zip tube". This is a common misconception due to the "tuner" market refering to "cold air intakes". The upper intake manifold is mounted on top of the engine on the V6. You are required to remove a dozen bolts or so to remove it. However, my opinion is i believe it would be very hard for something large enough to block your intake to get past the air filter. I have heard of cases where mice have gotten in the air box and eaten the air filter when vehicles have been stored for long periods. Maybe your engine swallowed a critter :taz:

 

[RobtRoma]

Maybe your engine swallowed a critter :taz:

LOL... I wouldn't be surprised... Thanks for the clarification

 

[Walkingchaos]

ya sorry about that, first part of the intake, you dont need to go as far as removing the intake manifold . . . not yet at least.

 

[LEO_Escape]

The more I think about it, it really seems like a failing/failed intake gasket. Even though they checked, it's possible they didn't reach the one that is causing the problem. Unfortunately, the only way to be sure is to replace both the upper and lower gaskets.

 

[RobtRoma]

I was planning on getting the upper(?) gasket changed along with the spark plugs. I might as well have them change the lowers as well... I just need to find the funds and the time...

 

[tonycastec]

Robert,
You are not alone ! I also have the "popcorn popping" noise with my '05 V6 with only 22,000 miles.It occurs at idle when the engine is fully warmed up. If you engage Drive while it has this popcorn popping idle problem ,it will move the vehicle forward in a jerky manner.
I recently has a TSB done at the Dealer for pinging. The same TSB also fixes a hot re-start issue (which I did not have). It ran great after the TSB. Then I added an XCal3 tune for towing. That brought the ping problem back.Torrie fixed that .Then this idle surge/popcorn thing started. So , I returned it to stock. It still does the popcorn thing in stock tune,when fully warmed up.Like your truck, mine has no check engine light or pending codes. The only other symptom that I sense(no proof) is that when driving up a steady grade on freeways, it seems to be low on power.That may be a mistaken impression caused by unfairly comparing it to my car which is supercharged.
I am hoping the computer will eventually re-learn because I don't want another Dealer 'experien$e'!
Let us know what happens to fix your problem.