2008 LTD 4.6L Gas/fuel smell in cab when stopped

[pjw73nh]

This is a continuation of another, older, thread that tended to creep and was a bit stale. I thought I would start fresh. If you MUST see where it came from, have a look here:

http://www.explorerforum.com/forums/showthread.php?t=352880

My exhaust manifold issue has been fixed. I still have some gas fumes in the cab under the following conditions.

1. Heater/AC is on fresh (not recirc). It goes away on recirc.
2. When first starting the car and when coming to any stop I can smell the odor of almost raw fuel coming out the dash vents.
3. It goes away after I start moving again.
4. There are no visible leaks anywhere front to back (had it on a lift, followed the lines as best I could). No indication of a leak anywhere that I could see.
5. The smell is more predominant on the passenger side of the V8 in the engine compartment.
6. The car runs fine, has no DTC codes set and is in full I/M readiness.
7. I suspect a leaky injector seal/o-ring(s).

Unless anyone has some more ideas of what I might be smelling or dealing with, what is the best way to test for a leaky injector o-ring. Bubble stuff? I don't have access to a halogen detector.

What is involved in changing the o-rings? Easy? Difficult? In between?

Thanks for any insight.

P.../NH

 

[pjw73nh]

Checked the injectors with Mr bubbles. No leaks that I could find.

Next?

Thanks.

 

[waskly]

you are leaking fuel if you smell it inside. i would find the leak, and not drive it till i do, its a fire risk, waiting to happen. just needs a spark or static discharge to ignite it.

 

[Town]

A possibility is fuel vapour leak from EVAP system. There is an EVAP solenoid (Evap cannister purge valve) located on the firewall, probably the passenger side to control the flow of fuel vapour from the cannister to the intake. The valve has a line back to the EVAP cannister and another to the throttle body and there is an electrical connector. There may be a problem (leak of fuel vapour) with the line to the throttle body. A leak to the EVAP cannister would prevent a vacuum being drawn and lead to an EVAP DTC.

I don't know about the Explorer but there is often a drain from the HVAC air intake to the exterior (engine compartment usually on passenger side) to drain rain water accumulation. The drain should have a closing feature to prevent engine compartment fumes from entering the HVAC intake, but it could be stuck open or damaged.

The engine compartment should have a rubber seal between cowl and hood to stop underhood vapours from reaching the HVAC inlet openings in the cowl. Sometimes these seals are damaged.

Check the air inlet tube to the throttle body for cracks and leakage, and each attaching hose. Fuel vapour is moved about in the intake and throttle body by the reactions in an open and closed intake runner system. The PCV system is a possible source of fuel vapour due to the oil/fuel causing deterioration of the hoses. The V6 and V8 use different systems.

Good luck.

 

[pjw73nh]

Update (final).

You may recall I had a situation where there were combustion fumes of some kind entering my passenger compartment. Initially I thought it was due to the leaking exh manifold (2 broken bolts on Cyl #1) but I had that fixed and I STILL had the fumes. The car appeared to run ok. No skips or misses. Getting about 19.5 mpg on the highway, driving like an old man.

The weather and my schedule finally aligned today for me to change my plugs. I have been putting this off for months. My 4.6L has 75 k miles on it now.

I bought the Motorcraft PZH plugs on Amazon about 3 months ago. They were about $90 for all eight.

For the past few weeks I have run 3 cans of Techron through the fuel system

I got up early today to a stone cold vehicle, blew out the plug areas with compressed air and removed the coils and sprayed PBlaster in each spark plug well enough to cover the hex. I attempted to "crack" each one 1/10 of a turn with a 9/16 socket and torque wrench. It took about 50-60 ft lbs of torque to crack the hard ones. #5 & #6 felt like they broke. #8 was hard, but didn't let go suddenly like 5 & 6. #2 was hand tight. LITERALLY. (I found my fume leak). The rest were just very tight but I was able to crack them.

I let them sit with the PBlaster for about 6-7 hours while I went to work.

When I came home form work this afternoon, I started in on them. I left 5 & 6 for last.

I worked with a 3/8 breaker bar and 9/16 socket. I worked each one back and forth a little at a time, then gradually made bigger swings in each direction, eventually getting the plug out. When I got to #5 & #6, I was sure they were broken. Nope. Just needed patience and to go very slowly. All 8 plugs came out. None broken. I turned the engine over a few times to blow out any residual dirt and PBlaster.

Following the TSB recommendation, I looked for some nickel anti-seize. I went to 5 auto parts places. No one had any. I stopped by my local Ford dealer, and they had a 8 oz jar that was several years old. The parts guy said that all of techs share the same jar and it lasts forever. He didn't have any he could sell me, but he gave me a "dollop" of it to take home.

I coated the plugs per the TSB and installed them. Torqued to 25 ft-lbs.

I cleaned the coils and boots with some brake cleaner and rags, and I put some Permatex dielectric grease on the end of each boot before re-installing them.

When I started the engine, it blew out a lot blue and white smoke for 15-10 seconds or so (PBlaster I presume).

I took the car for a test ride. I could easily tell it was missing one cylinder. I stopped, checked all the injector and coil connectors (I had them off when changing the plugs) and could not isolate which was the bad cylinder. I think it may have been #5. I pulled them off one at a time to see which had the least affect on the engine. #5 was the least. I got back in the car, and it seemed to smooth out. I drove another 25 miles so far and it's running fine. There are no fumes in the passenger compartment, and I "think" it is running better, but I really can notice a difference.

Hope this helps someone. My pix are here:

https://picasaweb.google.com/pjw73nh/2008ExplorerSparkPlugChange?authuser=0&authkey=Gv1sRgCJuj3eXpm_ji5AE&feat=directlink

 

[pjw73nh]

UPDATE: A few hundred miles later, I changed out all the OEM coils for ACCEL coils. The car has run great for several thousand miles without a single misfire or code.

 

[Boomyal]

UPDATE: A few hundred miles later, I changed out all the OEM coils for ACCEL coils. The car has run great for several thousand miles without a single misfire or code.

Wow! That only took a year to post back!

 

[pjw73nh]

Sorry Boom (and the rest). I guess I got caught up in the joy of success of it all. And forgot to report back. Better late than never....