I don't drive this car often. I primarily use it for towing a 6000 lb trailer during the "good" season. I drive it once a week during the off season to keep the rust off and the "blood running".

NOW its got some kind of gas fume issue. No DTC's set. Windows up, fan on low, Nothing on startup. Nothing when driving. I smell it slightly when at a stop light and then it fades away. I smell it strongly when backing up to park. Almost as if it has something to do with fuel sloshing around in the tank. There is no visible fuel on the ground. But it doesn't take a large amount of fuel to make a BIG smell. Fuel cap is tight. I am averaging 19-20 mpg. (I drive like an old man).

Where do I start?

Thanks.

 

Check the vent tube where it connects to the tank. I had to replace the rubber tube on my wifes sport trac a few years back. Had similar problems, and once in a while I would get a vapor leak code to. New hose and clamps and it was good ever since. It never leaked fuel and gas milage was still around the same, it was just when the pressure built up and the fumes had escaped.

 

I got under the car and had a good look. I can see no sign of any fuel leak. Nothing on the filler pipe or inlet either. I think it is exhaust related.


Update: It does appear to be related to cabin intake air. I put the heat/AC in recirc and the smell subsides in a about 5 minutes. It is worse when the car first starts (runs rich until it's up to temp).

Could this be related to my missing/snapped #1 exhaust manifold bolt? It makes the tick tick tick on startup and then as the engine heats up, the noise goes away completely in about 90 seconds. But even after driving for an hour (non-recirc mode) I still get a faint gas fume smell.

I am putting a CO detector in tomorrow and going to see how bad it is.

Another question. When the car first starts up (after the AC has been on and I stopped for a few minutes to run in to a store), I get a foul smell from the vents. It goes away after a short while. Smells like mouse urine. Clogged drain? Mildew? I found out there's no cabin air filter. :-(

Thanks.

P.../NH

 

pjw, check around the top end of the engine for wet spots caused by fuel. Locate the fuel injectors and see if there is any wetness around each one. You can do this without the engine running, at first. Also find the fuel supply line that comes up to the engine from the frame area and see if any connection or line is wet with the engine off. If you don't see anything wet in either of these two areas with the engine off, then start it up and check them again. You'll need a flash light to see these places real well even in the daytime. Let us know how it goes. Also, do you have the 4 liter V6 or the V8 engine?

 

Thanks for the reply and I am sorry for the omission. The vehicle is a 2008 LTD 4.6L 67k miles.

OK I put a CO detector in for a week or so. I drove the vehicle with recirc on and recirc off. Detector read 0 the whole time. Even when I smelled fumes in the car. I am starting to think they're "rich exhaust" fumes. I tested the CO detector by putting near the tailpipe and it pegged it at 999 ppm.

I took a good look for fuel leaks both at day and at night with engine on and engine off. No wet spots or leaks. Fuel system appears to be tight.

Also, re the foul smell on AC startup. I did some research and found that there is no cabin air filter on these. I stumbled on a picture here in the forum of the evaporator drain hose/duct, but it was not clear enough for me to understand.

Does anyone have a good picture or description of where to look under the car for this hose (or the rear one as well. I have rear AC). I took a look and I can't locate it. I also poured over the shop manual for it too. They mention it a few times in the climate control section, but they don't show it on any diagram.

I stopped by a custom exhaust place yesterday on a whim. Actually, he came highly recommended to me. I just happened to be driving by and had some time to kill.

I asked the folks there for an estimate on replacing the bolt. I told him I was hesitant to do it myself because of drilling in the close proximity to the water jacket. He said "NEVER" drill them out. If you see someone taking a drill to your heads, run the other direction (he wouldn't tell me how he gets them out). He only said he does not jeopardize the head.

He said he has done hundreds of these, he knows it's a common issue. I asked him if it will break again, and he said unlikely. He did say the way to be sure is to put a "flex pipe" on each side. I am not sure about this. I would think if it was flexing issue, it wouldn't be JUST the #1 cylinder top bolt ?

He quoted me $300 on the low side and $400 on the high side for the bolt, and if I wanted the flex pipes, $200 more for the pair.

I am still toying with the idea of taking it to the dealer and asking them if it's covered under the 8/80 fed emissions warranty. The list posted above is pretty comprehensive and it doesn't specifically list the manifold bolts. Where the manifold IS covered, are the bolts "assumed"?

It will probably cost me $100 diag fee at the dealer. Maybe I'm just better off taking it to the exhaust guy, pay the fee and be done with it?

Thoughts? Comments? Suggs?

Thanks.

P.../NH

 

My 2006 4.6 Explorer was in and out of the Ford dealer for weeks as they tried one thing after another. In the end, they replaced the DS exhaust manifold gasket which cut down on exhaust smell in cab substantially. They showed me the carbon leak on the gasket.

After I complained the smell was still there to a lesser extent, they replaced the DS manifold and gasket b/c the manifold was so rusty. Once again, the gasket showed it was leaking in two spots with exhaust black. BTW, one bolt was broken. No more smell.

 

I did some research on the AC smell. From what I found, the evaporators can get gunked up with microbes etc and this is what causes the smell. There is a treatment that I found online. AT-211 Clean 'N Coat. I found a video for it. Google it. Looked like it might be a decent solution. Does not require any disassembly. I decided to blow the evaporator drains out first and see how that works.

If you do decide to check, clean or blow out the drains, here are a couple of pics that may help. Once you get under the car, it will make sense can be clear. The front one is kind of hidden, the rear one is in plain sight. I didn't know if mine were blocked or not.

https://picasaweb.google.com/1039561...eat=directlink

Good luck.

p.../NH

 

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. Odor would go away when on recirc. 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 Friday for me to change my plugs. I have been putting this off for months. My 4.6 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 last Friday, blew out the plug are 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 hand tight. (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 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, based on the sound they made in the morning. 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.

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 80 miles so far and it's running fine. There are no fumes in the passenger compartment, and it is definitely running better. Not night and day better, but better.

Hope this helps someone. My pix are here:

https://picasaweb.google.com/pjw73nh...eat=directlink