Rough ilde and rev fluctuation

[WillieWapper]

Howzit guys. I am new to the forum and thank goodness I found it. I was about to light a match and watch it burn.

I have a terrible idle that developed after driving through a storm on a dirt road. On cold start she stalls if I don't keep the revs up. A warm engine is better, but the revs are bouncing quite a bit.

Dealer and other workshops checked her out and could not find any error codes which I find really really strange. I have been trying a few suggestions I found on this forum but would greatly appreciate any advice. My best guess is that it might be a vacuum leak or some sort of electronic fault that originated in the mud bath.

Here are some videos of the idling:

She revs up fine and there's sometimes a slight jerk, but otherwise goes fine on the freeway.

Any and all help will be appreciated!

 

[LionsTooth]

Anyone check the air filter?

 

[scotman]

Air filter element and the little square foam breather element that is located below the "dirty side" of that air filter! Also might be a sticky Idle air control valve. The IAC valve can get gummed up to a point where it wont open fully but it's functional enough to not set a MIL.
If the IAC is sticky, the throttle body might not be far from the same condition.
Ford offers this spray cleaner product # PM2 that is not predominantly alcohol. It's rather oily and is great to let it soak inside of the IAC for overnight. If that doesn't fix a clogged up IAC valve, It's done for!

 

[Handy Andy]

When you ride on bumpy roads, the harness that communicates to the front knock sensors EVAP and that Catalyst

Check for dents!

Many times, the lines to the back EVAP box and fuel system are whacked - might want to double check the condition and if you find "road rash" as in skid marks from where gravel road or bumps hit it, INVESTIGATE - this may mean a failed exhaust system or cracked or crushed pipe or O2 sensor - I only see ABS light on, so it tells me something in the muffler might be causing all of this.

Doesn't always set a code right away, so the rough idle may be from the system trying to find a new idle setting.

But if the tailpipe got submerged - there may be a mud plug or rocks hindering the flow - when it's at the idle it stalls means there may be a crack in the exhaust or intake system - when you idle up it takes off means the idle circuit and that EVAP system which is part of the idle circuit may have been damaged - or plugged with mud.

The "jerk" usually tells me it's not expecting any changes - but it may have debris entry into the transmission housing.

Don't take it back to those dealers - you need someone to be more thorough to go over it.

That ABS light tells me there's more.... don't like that "Brap" at idle down - that's something loose or in a pipe somewhere.

 

[WillieWapper]

Anyone check the air filter?

The air filter is basically new. I checked it and seems fine.

 

[WillieWapper]

Air filter element and the little square foam breather element that is located below the "dirty side" of that air filter! Also might be a sticky Idle air control valve. The IAC valve can get gummed up to a point where it wont open fully but it's functional enough to not set a MIL.
If the IAC is sticky, the throttle body might not be far from the same condition.
Ford offers this spray cleaner product # PM2 that is not predominantly alcohol. It's rather oily and is great to let it soak inside of the IAC for overnight. If that doesn't fix a clogged up IAC valve, It's done for! View attachment 6658 View attachment 6659

Thanks for the idea. I don't think my model has an IAC, because it is drive by wire. But will take a look at the dirty side of the filter for any debris.

 

[WillieWapper]

Thanks for all the replies so far. I have not gotten around to check all the suggestions, however, I did notice that the amount of fuel in the tank did not make a real difference in idle quality which is presumed to indicate vacuum I believe.

The other thing I noticed is that the car idles better with the AC running. The AC has always picked up the revs slightly so it kind of makes sense that it would be idling better with it on.

I investigated the MAP sensor and it looked like it was covered in oil, not sure if this is normal. Maybe worth it to replace?

The search continues over the weekend! I have a service booking for Monday if I cant find the fault over the weekend.

 

[Handy Andy]

The thing being in mud has me concerned that the O2 sensor might have been "contaminated" with dirt and mud, at least one of them - for if the waterline - if it was above the wheels, then the line in the sand was crossed and the O2 sensors will need service - the dirt on them affects their ability to adjust fuel trim.

The other concern is the amount of mud pulled into the exhaust from the rev up and slam down - that vacuum moments of unwind in the revs is able to pull that mud further up the pipe to a point where it can even reach the catalyst - so you know.

This Idle thing may be more of a blockage issue - which you'll have to undo the bolts and flush out the system with CLEAN water and hope like hell the O2s' are still working.

In recent events, we've seen quite a few "recoveries" of flooded vehicles, one main one is the issue of the exhaust system and the damage that standing water or mud can do - the above is just a scratching of the surface that are of the details that have to be fixed to get it running right.

 

[WillieWapper]

The thing being in mud has me concerned that the O2 sensor might have been "contaminated" with dirt and mud, at least one of them - for if the waterline - if it was above the wheels, then the line in the sand was crossed and the O2 sensors will need service - the dirt on them affects their ability to adjust fuel trim.

The other concern is the amount of mud pulled into the exhaust from the rev up and slam down - that vacuum moments of unwind in the revs is able to pull that mud further up the pipe to a point where it can even reach the catalyst - so you know.

This Idle thing may be more of a blockage issue - which you'll have to undo the bolts and flush out the system with CLEAN water and hope like hell the O2s' are still working.

In recent events, we've seen quite a few "recoveries" of flooded vehicles, one main one is the issue of the exhaust system and the damage that standing water or mud can do - the above is just a scratching of the surface that are of the details that have to be fixed to get it running right.

Thanx Handy Andy for the great advice so far! I will get to work today and check everything you mentioned!

 

[WillieWapper]

After a weekend of fiddling and pondering and swearing, I decided to take the car to another dealership for an assessment.

Within 30 minutes they phoned me back saying that the problem is valve timing!? Could this be? How would valve timing happen so suddenly?

 

[Handy Andy]

How deep was the car buried in mud?

Valve timing might just be a "relearn" issue of pulling the battery cable and now it's past "whatever" that happened to it, try another "reset - Relearn" procedure for those 10 minutes of Idle and just let it re-learn.

Then if it still, does it - then there may have been an overrev moment where the timing BELT jumped - then you have a timing issue, and the valves aren't working like they should.

But if I can share an experience with you - this might help you stay focused (ahemn) and prepared for other things that may have occurred that although are serious, might be fixable by you doing the work.

A long time ago I owned a Chevy Sprint 3-cylinder car - about the time GM started going Metro / GEO line - so this was a 87' sprint a TINY car meant really for two passengers and a baby, until it's (Baby) about 7 years old and then you went back to the dealership and bought the 4th cylinder and the extended compartment for that kid to sit.

The thing was carbureted - and used a tiny muffler - it was N/A so no-turbo and got about 50+ MPG on a consistent basis.

So with the above in mind - <1.0L of air pump in the winter and below 0F stretch for about a week, leaving it parked outside...

IF the thing didn't warm up hot enough to melt the moisture inside the exhaust pipe, it can form an ice plug and then you're in a world of hurt because you may wind up stranded with a car that won't run because it needs to thaw out it's iced up muffler - and in the winters we've had in the MI IN IL area - if you're stranded - you're stranded...dangerous if you're not prepared.

Had to use a hammer, vice grips and a long handled screwdriver to pound out that plug.

But once that was all cleared out and the car given a chance for it to drain the moisture collected in the pipe and muffler - all was fine - but when you're in the middle of traffic and this happens - you're going to find grey hairs on your head sooner than later - if you haven't pulled out all the rest of them in frustration.

The car acted similar, surged and had a heck of a time idling - this was a manual - which added a level of quirkiness to the operation of such events on icy roads.

In light of your experience, I have my own to relate - to me this sounds like you may have "jumped time" and it just may need some elbow grease and some hours of your time to locate the belt in reference aspect to TDC of Cylinder 1 and if needed reposition the belt on the right teeth of which ever side the belt jumped on - one or two teeth isn't much but remember a stuck car you can easily overrev the motor trying to get it out in a panic.

A plugged Catalytic is still possible - because of the mud getting up that far into the pipe - in my experience - it was simple ice - but you had to give it time to "rinse out" the old ice and any carbon sludge left in the pipe from the experience - but idling helps to get the system to dry out and then highway miles on premium fuel might be all that's needed to "blow out" the catalysts plug and restore operation.

 

[WillieWapper]

Well. The dealership got back to me and said it was indeed timing and that after they trued the timing to TDC all was well. I asked them what could have caused this ito mechanical failure? Worn out tensioner belt or pulleys? Nope, all of those seem okay, so nothing else was done except for correcting the timing.

I am completely stumped and think the best for me would be to get rid of it while still running

 

[Handy Andy]

So it was a timing issue, and to "correct it" means more of a programming problem?

In "specific" cases of where the engines been overrevved - there will be flags set - but to simply correct without disclosing the whole process to the customer?

This is more of a @scotman related issue of resetting TDC.

​

Would not say throw the Baby out with the Bathwater just yet, but if you keep putting the car thru conditions like this thread described before...well, you Might want to look at 4WD, ATV's or Pickup trucks to get to work, or for your commute.

It is my hope that if the condition were to occur again in less extreme environments - someone's been had...

​

 

[scotman]

Timing doesn't jump for no reason. My guess is that the car was in fairly deep mud and some of it migrated behind the timing cover. Or, at some point very soon after the mud bath the engine was revved
And the correct timing was "lost".
I honestly don't know how this engine could be over revved. Maybe a more likely way to get a tired timing belt/ tensioner to jump a cog would be forced downshifts from fifth or sixth gear to third at a high speed. It goes against all logic to do that because it feeds all that inertia back through the valvetrain.
Forced downshifts are not wise if you care about how long your engine lasts. I a friend of mine who was a very aggressive driver, broke an exhaust valve spring on the manual transmission mid nineties Escort he used as a daily driver. Only time I ever saw a valve spring fail on a 1.9 Escort!
Would have been helpful to know that the car was sunk in mud early on. "Driving through a storm" gives an entirely different impression than "driven into mud".

 

[WillieWapper]

Well, from what I hear from you guys, it sounds like the motor had to be under a lot of strain in order to het the belt to jump. It really was not an 4x4 off-roading session, but rather a compacted gravel road washed with a lot of water.

Proud image I took moments before the problems occurred:


There were times that the muddy water completely washed over the car as we drove through water pockets but I would not say it was that bad.

That said, I have sent an email to the national customer service team to investigate the case as the service manager could not provide me with an explanation other than:

1. The timing was wrong on the installation done 60 000km ago
2. The timing went out by some unexplainable phenomenon

My best guess is that something is failing and its only a matter of time before it all goes pear shaped if I cant identify the root cause.

 

[scotman]

"Completely washed over" is basically "temporarily submerged". I can't make any recommendation's. Water and electricity are not good companions.

 

[Handy Andy]

On top of the fact that vibration of the gravel kind - makes any sort of electronic system have potential jumble from loose or even a moment of jumped time can be from the LOSS of data caused by vibration and the noise in the electrical sensing units for a brief unit of time - so I can see where the noise from the rough road, then masked a timing issue, then because of the lost timing information - the PCM has a I Don't Know Where TDC is moment.

Shame - many other carmakers always force the motor to turn over and locate TDC every start moment - so for FORD to lose timing and has to "relearn and retrim" speaks volumes about the VVT effort and where it thinks timing should be.

I have not experienced this in my own vehicle, but it does raise questions about driving issues in others I do use on a daily basis.

 

[WillieWapper]

I just wanted to thank everyone for the help on this thread. I really appreciate it!

Since the timing was adjusted the car seems to be running just fine. Based on this experience I will be much more hesitant to drive in bad weather conditions and be a little more cautious when it comes to off-roading with ford XD