Ford escape rough idle

bigaudiofanatic

Hello all, I just bought a 2002 Escape from a friend of mine. It has 136,000 miles on her and is a V6. As I never drove it prior to buying it I do not know if this problem could be somewhat related to me cleaning the engine. I took delivery of the vehicle Sunday and quickly got to work gunking the engine down a few times when it cooled, and cleaned the engine more with cleaner. While it was still slightly warm (engine) I fired it up to let the moisture burn off, it ran just fine.

Fast forward to this morning when I just went out to fire it up for a few minutes. It is running rough, the RPM's drop and go up slightly around 850, when i tap the gas it stutters as well as very delayed. I called a ford dealer, they highly recommend I change the spark plugs first because they bet that's the problem. What other things should I check for this problem?

This is my first ford ever so please help me out. Thank you.

rpf65

Changing the spark plugs is a good start, I would also change all the belts while your in there. I would also suggest that you get the injectors cleaned, and fuel filter replaced. If it still idles rough, it will have to be driven with a pressure guage attached, to see if the pressure drops off. May have a pressure regulator going bad or a fuel pump going bad. My bet is dirty injectors/filter though.

I would recomend the plugs, belts, injector clean,and fuel filter to any used car purchase, unless the previous owner has the maintenance records. Fuel system should be done around 30k miles or so.

jeremymarcinko

If you got any oil in the mass air flow sensor when cleaning it, will cause a rough idol. Easy to fix(assuming its not damaged) unplug the leads and hose it with sensors starting fluid. Let it dry and hook it up. You may have to reset the obd2 also.

heartystatue

If it was running good before you cleaned the engine my bet is its in the spark plug wires where they connect to the coil packs or opposite end of the spark plug. Check where they hook up to the coil pack. Unhook each one and spray some WD40 on them and reconnect. You can also put the car in a very dark garage and start the engine with the hood up look and listen for any arcing across the plug wires. My bet is you will find where the moisture has puddled. Good luck!

F1nut

Yeah, you've got a moisture problem. New plug wires would be a good place to start.

Inspector 24

Coil on plug system, no wires, more rare to have moisture cause a problem.

One or several things can cause a rough idle. Check engine light on? Start with that if so. There may also be pending codes that may point to a problem. Spark/ignition/misfire codes? Coils, plugs, mechanical/electrical problems. Fuel Trim/MAF/O2 sensor codes? Could be MAF, vacuum leaks, post maf air leaks, even plugged/dirty injectors.

The most common thing I've dealt with is the PCV hoses. There's a half dozen or so rubber connections that love to deteriorate in the presence of oil vapor, heat, and time. Got a loud hissing sound? May be the culprit.

Here's what they look like. Half are easy to access and replace. The rest not so much.

At any rate a professional diagnosis may save you time and money of throwing parts at it in hopes of fixing it.

jbooker82

Unplug the conections from the coils, and take them out of the motor. You can let them air dry or spray a little wd40 in the connections to help remove water. The problem didn't appear until you washed the motor so that is most likely the problem. With a 136K miles on it is probably a good idea to change the plugs any way.

If you try to clean the Mass Air Flow Sensor do it with the proper cleaner. CRC makes a MAF Sensor cleaner. Make sure not to plug it in and fire it up until it is completely dry other wise you run the risk of burning it up.

F1nut

Coil on plug system, no wires

No wires, eh? I stand corrected.

tonyb

Plugs and wires....but first do a close inspection around the engine. In the cleaning process you may have knocked a wire loose from a sensor or knocked off a vacuum hose somewhere, that's if it has any.

bigaudiofanatic

So I replaced 3 spark plugs today, I started it up and it ran just fine RPM's stayed around 1K. Than I decided to take it around the block. Randomly it would run right but it was running rough most of it. I did get a flashing check engine light and than it became solid. I will be replacing the other 3 tomorrow. I confirmed that the COP's that I pulled were ok, one had been replaced. I can only hope that it is the spark plugs because it was running fine when it was dropped off.

Inspector, now that you mention it there has been a hiss however I thought it was part of the A/C. I will check it out tomorrow more.

Inspector 24

I did this job on a Mazda 6 today. Same symptoms. Found the rubber PCV elbow on the upper rear of the intake manifold had failed creating a massive vacuum leak. Also the intake boot between the MAF and the throttle body was torn which will also cause CEL's.

While working on it the customer opted to do some maintenance and replace the spark plugs. The rear plugs require removal of the upper intake in case you hadn't noticed yet. Do-able with basic tools. Plan on replacing the upper intake gaskets. There are six individual rubber rings it uses to seal. IIRC they're less than $20 from Napa/other parts store. OE Motorcraft plugs from the dealer are cheapest, $5-6ea vs Napa $11-13each for OE equivalent NGK's. YMMV.

Good luck.

bigaudiofanatic

Inspector 24 wrote: »

I did this job on a Mazda 6 today. Same symptoms. Found the rubber PCV elbow on the upper rear of the intake manifold had failed creating a massive vacuum leak. Also the intake boot between the MAF and the throttle body was torn which will also cause CEL's.

While working on it the customer opted to do some maintenance and replace the spark plugs. The rear plugs require removal of the upper intake in case you hadn't noticed yet. Do-able with basic tools. Plan on replacing the upper intake gaskets. There are six individual rubber rings it uses to seal. IIRC they're less than $20 from Napa/other parts store. OE Motorcraft plugs from the dealer are cheapest, $5-6ea vs Napa $11-13each for OE equivalent NGK's. YMMV.

Good luck.

Thank you! I will try my best to look over the tubes for cracks. I heard spraying them all down with carb cleaner helps somehow? I will pickup the gaskets tomorrow. If I can not find it I am sure the ford dealer will find it when they do a check over on thursday or friday.

Systems

Its a Ford!
Nuff said!

First thing, go to O'Reilly and have them hook up the code reader for free to see what codes you get.
Knowing its a Ford, they may not even come out of the store to check it.

Seriously they will tell you if it is a OS, or Map sensor or what ever.
If you have some error codes, they will find it.

If it is not that, then you have some minor "upgrades" that need to be done (cleaned fuel injectors, plugs ect), and I would recommend bypassing your fuses with .01 Clarity caps.:cheesygrin:

Face

pepster wrote: »

and I would recommend bypassing your fuses with .01 Clarity caps.:cheesygrin:

Don't you mean coils? :cheesygrin:

Inspector 24

bigaudiofanatic wrote: »

Thank you! I will try my best to look over the tubes for cracks. I heard spraying them all down with carb cleaner helps somehow? I will pickup the gaskets tomorrow. If I can not find it I am sure the ford dealer will find it when they do a check over on thursday or friday.

Carb cleaner rarely works on newer cars. They adjust to changes too quickly to air/fuel changes for the idle to fluctuate enough to be heard. You have to be monitoring air/fuel ratios and more specifically fuel trim percentages while spraying to determine if you have a leak. I've diagnosed several Ford intake manifold leaks this way...mostly 4.0 SOHC Explorers.

Diagnosing CEL's is not so straight forward either. For example, a lean code, IE a P0171 is set when the O2 sensor detects a lean condition. This usually indicates the O2 is actually working properly, and there may be a vacuum leak or a Mass Air Flow sensor failing. There are tests to diagnose each of these. Take caution in ****-U-ME-ing that a code related to a sensor is that sensor failing. It may be working perfectly and thus the ECU is able to tell you there is a problem with the electrical circuit or the system it is monitoring.

New cars are rarely as simple as symptom A requires fix C. More like diagnose the problem, or spend time/money applying fixes C-Z until the problem goes away.

Systems

Face wrote: »

Don't you mean coils? :cheesygrin:

I would do both, with MR's!:cheesygrin:

Systems

Diagnosing CEL's is not so straight forward either. For example, a lean code, IE a P0171 is set when the O2 sensor detects a lean condition.

That may be a little misleading, it is not that difficult to diagnose an O2 sensor.
Not to mention you can test it in multiple/redundant tests.

bobsauto49

Inspector 24 wrote: »

Carb cleaner rarely works on newer cars. They adjust to changes too quickly to air/fuel changes for the idle to fluctuate enough to be heard. You have to be monitoring air/fuel ratios and more specifically fuel trim percentages while spraying to determine if you have a leak. I've diagnosed several Ford intake manifold leaks this way...mostly 4.0 SOHC Explorers.

Diagnosing CEL's is not so straight forward either. For example, a lean code, IE a P0171 is set when the O2 sensor detects a lean condition. This usually indicates the O2 is actually working properly, and there may be a vacuum leak or a Mass Air Flow sensor failing. There are tests to diagnose each of these. Take caution in ****-U-ME-ing that a code related to a sensor is that sensor failing. It may be working perfectly and thus the ECU is able to tell you there is a problem with the electrical circuit or the system it is monitoring.

New cars are rarely as simple as symptom A requires fix C. More like diagnose the problem, or spend time/money applying fixes C-Z until the problem goes away.

+1 on everything he just said! Concrete advice! I do it for a living.

Systems

Really?
But there is trouble/false readings with an O2 sensor?
Not straight forward eh?

Any good driveability mechanic can show the you way.:cheesygrin:

Having done my share for that company myself (service management), my thoughts are (putting it nicely), it is not a problem, easily diagnosed, with no question.

False readings?
Really?

bobsauto49

Most P0171,and 174 codes,"lean" to a weak fuel Pump! Go figure:loneranger:

bobsauto49

pepster wrote: »

Really?
But there is trouble/false readings with an O2 sensor?
Not straight forward eh?

Any good driveability mechanic can show the you way.:cheesygrin:

Having done my share for that company myself (service management), my thoughts are (putting it nicely), it is not a problem, easily diagnosed, with no question.

False readings?
Really?

How long has it been since you were a "service tech"? Your postings reminds me a lot of my DIY customers.

Systems

bobsauto49 wrote: »

Most P0171,and 174 codes,"lean" to a weak fuel Pump! Go figure:loneranger:

Since the conversation has gone from simply diagnosing a OS sensor to fuel pump, I'll give you the benefit of the doubt, but have to wonder, how you would come to that conclusion with the mentioned tests/test equipment in a Ford Dealership, that can very easily diagnose.
.
My thoughts are, if a computer/digital integrated component is not measurable with any degree of accuracy (O2 sensor for an example), with a multitude of different tests available, what would lead me to believe your diagnosis of a "fuel pump" is correct????:redface:

Inspector 24

pepster wrote: »

That may be a little misleading, it is not that difficult to diagnose an O2 sensor.
Not to mention you can test it in multiple/redundant tests.

I'm speaking to the do-it-yourslefer, It's difficult if you don't have the knowledge or the tools to do it with. A proficient technician with the tools can do it quickly.

pepster wrote: »

Really?


False readings?
Really?

Where did false readings some in?

bobsauto49 wrote: »

Most P0171,and 174 codes,"lean" to a weak fuel Pump! Go figure:loneranger:

Ha! Very punny!

I've had quite different experiences with 171/174. Lately most of them have been due to either vacuum leaks or even more commonly MAF's that aren't reading all the air coming in. Usually easy enough to diagnose with calc load values, fuel trims, and MAF voltage. Usually...I've had a few Nissan's that initially looked ok, but upon replacement it was obvious the readings were just enough out of spec to cause a drivability problem but not far enough out to trigger a CEL. Seems all our fuel pumps come in on a tow truck.

Which cars have you found fuel pumps causing lean conditions?

Inspector 24

pepster wrote: »

Since the conversation has gone from simply diagnosing a OS sensor to fuel pump, I'll give you the benefit of the doubt, but have to wonder, how you would come to that conclusion with all mentioned above.
My thoughts are, if a computer/digital integral component integrate is not measurable with any degree, what would lead me to believe your diagnosis of a "fuel pump"????:redface:

Fuel pump is a possibility. Low fuel pressure/volume creates a lean condition as fast as a vacuum leak/malfunctioning air flow sensor.

bobsauto49

Inspector 24 wrote: »

Which cars have you found fuel pumps causing lean conditions?

I should have been more specific! I deal with a heavy GM crowd,and when the Fords come in,you're correct! Mostly vaccum leaks(pcv,or dpfe hoses)

bobsauto49

pepster wrote: »

Since the conversation has gone from simply diagnosing a OS sensor to fuel pump, I'll give you the benefit of the doubt, but have to wonder, how you would come to that conclusion with mentioned tests/test equipment in a Ford Dealership?.
My thoughts are, if a computer/digital integral component is not measurable with any degree, with a multitude of different tests, what would lead me to believe your diagnosis of a "fuel pump" is correct????:redface:

What would lead You to believe,that if a vehicle had a P0171(o2sensor,lean code upstream) it would make You,in a service garage,with years of expierence,believe the O2 sensor was reading wrong? OE O2 sensors usually fail because of the heating element,not false readings. YMMV

bobsauto49

Chances are,if a O2 sensor is reading "lean",or "rich",its doing its job,and something else is causing it! JMHO!

Systems

bobsauto49 wrote: »

How long has it been since you were a "service tech"? Your postings reminds me a lot of my DIY customers.

A long time............But I have no problem troubleshooting an electrical circuit and after all, isn't that where you start?
Then the "other tests" come into play after that.
Basic stuff really.

Google is your friend!

bobsauto49

I don't charge my customers/job. If I know of a common problem that lets me skip the 1 1/2 hrs diagnostics,then I fix it,and charge them accordingly! If i'm wrong,then they don't get charged for parts,or labor,for what I tried. But I only practice this,if i'm confident in what i'm doing!
This way of business has kept my family going,and customers returning for 29 years,and I'm proud of that fact.
Everybody has opinions. Carry on

Systems

Diagnosing CEL's is not so straight forward either. For example, a lean code, IE a P0171 is set when the O2 sensor detects a lean condition.

bobsauto49 wrote: »

What would lead You to believe,that if a vehicle had a P0171(o2sensor,lean code upstream) it would make You,in a service garage,with years of expierence,believe the O2 sensor was reading wrong? OE O2 sensors usually fail because of the heating element,not false readings. YMMV

Um?

Then you said:

+1 on everything he just said! Concrete advice! I do it for a living.

But I don't have a clue how these things work.............:cheesygrin:.
I am however looking forward to learning from you two.

OE O2 sensors usually fail because of the heating element,not false readings.

Not sure why they fail, but pretty sure even I can tell if it has failed, maybe just me?:eek:
Either they work or they don't?
Evidently, there is a VAST grey area as to why they don't?:eek:

Systems

Trouble shoot a 600 volt vintage tube amp sometime!
1.7 million resistors and caps!
And a HELLUVA lot deadlier if you make a mistake!

Yeah..... 14v/O2 sensor........Pffffffft!:eek:

Either you can tell if the sensor is bad or not, no need in dragging in other components, you should be able to trouble shoot to know the difference.

I'm out, and will leave it to ya!