01 Sport Track - Rough Idle

[Regaan]

My 2001 Ford Explorer Sport Track (4L V6) has a very rough idle on cold starts to the point I have to blip the throttle or it’ll stall and shut off.

It’s been happening since last winter, the truck starts and after 5ish minutes of blipping the throttle it’ll manage to keep itself running. Once it can idle on its own I’ve noticed the truck almost vibrate and shake intermittently as it sits with the engine running.

Recently the check engine light came on and I’d taken it to a garage who said it ran back to an O2 sensor, I had it changed and it didn’t fix any of the idling issues I’m having. A week later, the check engine light comes back on and it runs back to a 2nd O2 sensor, so I had them replace that too. However again, just today the CEL has come back on.

I’ve noticed the strong smell of gas when the truck first turns over and the exhaust seems to be leaking a small amount of liquid when stationary.

Any ideas on how I can fix the rough idle and stalling issues?

So far I’ve :
• Replaced 2 O2 sensors
• Replaced IAC Valve
• Replaced MAF sensor

 

[410Fortune]

What are the actual codes in memory

Parts store code readers do not always diagnose properly
Because it is an oxygen sensor code does not mean replace the 02 sensor often times the 02 sensor is doing its job telling you rich or lean

With hard starting and a long crank first place I would start is check the codes, give us the actual codes like p0171
Second check fuel pressure

Does your sohc engine make a rattling noise when it starts? Like marbles in a can?

How many miles on the 01?

 

[Regaan]

What are the actual codes in memory

Parts store code readers do not always diagnose properly
Because it is an oxygen sensor code does not mean replace the 02 sensor often times the 02 sensor is doing its job telling you rich or lean

With hard starting and a long crank first place I would start is check the codes, give us the actual codes like p0171
Second check fuel pressure

Does your sohc engine make a rattling noise when it starts? Like marbles in a can?

How many miles on the 01?

Took it to Autozone earlier to have the codes pulled and the 2 came back as p0171 & p0174. They told me it was a PCV valve issue and to replace it, however I don't believe the one they gave me will work after looking around on here. I had an 01 Job lot 1, the PCV valve goes into a T splitter, the piece they gave doesn't look like it'll go in...

The truck has around 120k Miles on it and from what I can hear over the loud ass fan, I don't believe there is any rattle.

Appreciate the help, its my grandmothers truck and the last place she'd taken it to just took every penny they could and never fixed a thing.

(Edit: Added image of PCV valve they told me to install)

 

[410Fortune]

Po171 and 174 are almost always intake plenum gaskets in the sohc 4.0’engine

Try doing a search you will see the intake o rings dry up and allow air to leak

It is a fairly straight forward job
And not terribly expensive

Pcv is not likely to fix your issue
I have replaced about 50 sets of intake o rings on sohc engines the 171 and 174 codes are dead give away

 

[BigDakota]

Took it to Autozone earlier to have the codes pulled and the 2 came back as p0171 & p0174. They told me it was a PCV valve issue and to replace it, however I don't believe the one they gave me will work after looking around on here. I had an 01 Job lot 1, the PCV valve goes into a T splitter, the piece they gave doesn't look like it'll go in...

The truck has around 120k Miles on it and from what I can hear over the loud ass fan, I don't believe there is any rattle.

Appreciate the help, its my grandmothers truck and the last place she'd taken it to just took every penny they could and never fixed a thing.

(Edit: Added image of PCV valve they told me to install)

Po171 and 174 are almost always intake plenum gaskets in the sohc 4.0’engine

Try doing a search you will see the intake o rings dry up and allow air to leak

It is a fairly straight forward job
And not terribly expensive

Pcv is not likely to fix your issue
I have replaced about 50 sets of intake o rings on sohc engines the 171 and 174 codes are dead give away

Same exact problems here too. I also did the carb spray check with no change in idle. I had engine marble sound too .. i also replaced the rear timing chain tensioner because thiscould be a rattle issue. Engine has about 140,000 i think. No major difference noticed. The first start a bad idle. Shut off the start again and idles at the normal roar. The exhaust area of the tailpipe shows gray So its not running a rich fuel mix

 

[Regaan]

Po171 and 174 are almost always intake plenum gaskets in the sohc 4.0’engine

Try doing a search you will see the intake o rings dry up and allow air to leak

It is a fairly straight forward job
And not terribly expensive

Pcv is not likely to fix your issue
I have replaced about 50 sets of intake o rings on sohc engines the 171 and 174 codes are dead give away

Replaced PCV as I already had the replacement and thought I might as well seeing as I could get at it with the intake manifold removed, but you were spot on about the upper / lower intake gaskets. Replaced both sets and it idles like it’s brand new, took around 4 hours from start to finish and cost $27. The garage quoted $550. Really appreciate the time and money you’ve saved me! Thank you

 

[410Fortune]

Now that is good news!

All modern engines have plastic intakes on metal manifolds, o rings are used to make the seal. The o rings dry up

 

[BigDakota]

Po171 and 174 are almost always intake plenum gaskets in the sohc 4.0’engine

Try doing a search you will see the intake o rings dry up and allow air to leak

It is a fairly straight forward job
And not terribly expensive

Pcv is not likely to fix your issue
I have replaced about 50 sets of intake o rings on sohc engines the 171 and 174 codes are dead give away

Replaced PCV as I already had the replacement and thought I might as well seeing as I could get at it with the intake manifold removed, but you were spot on about the upper / lower intake gaskets. Replaced both sets and it idles like it’s brand new, took around 4 hours from start to finish and cost $27. The garage quoted $550. Really appreciate the time and money you’ve saved me! Thank you

I am glad u fixed it !! I guess mine is next to do. My 01 sportrac has had all the same symptoms and parts done except the manifold..

 

[Regaan]

I am glad u fixed it !! I guess mine is next to do. My 01 sportrac has had all the same symptoms and parts done except the manifold..

I have 0 mechanical experience but after watching these videos it was super simple

 

[410Fortune]

Another YouTube mechanic is born!

I have been wrenching on these trucks for 25 years

YouTube is one of the best tools ever!!