Sunday strange situation pals, need some advise from you all.

Since a couple of weeks I’ve noticed a clear reduction on the mpg my truck does, and today I started up the truck and noticed that when idling, the truck shacked more than usual. Also I noticed a gas smell through the exhaust, not smoke just gas smell. Note that the check engine light never came on!
The first thing that came to mind was to clean the IAC valve, which I did.
Assembled everything and went for a test drive. When idling the truck still shackes and the gas smell is still present. When I hit the gas the engine response is normal, the issue is while idling only.

I don’t want to start changing parts randomly, so, any ideas where can the problem be?

To sum up;
- no check engine light
- gas smell through the exhaust
- shakes only when idle
- normal engine reaction when pressing the gas pedal
- bad mpg

Also good to mention;
- oil change (castrol magnatec full synthetic 5W-30 1 month ago
- new Motorcraft FL400S oil filter
- brand new K&N air filter

Any ideas will be welcome!!!!
Thanks a lot and have a great weekend

__________________
Paysandú, Uruguay
1996 Reg. Cab Ford Ranger, V6 3.0L, 5 speed manual trans.

THAT AWESOME MOMENT WHEN YOU REALIZE YOU CAN TAKE ALL THE PEOPLE THAT BOUGHT A JUSTIN BIEBER ALBUM, MULTIPLY IT BY 6 AND STILL DON`T GET TO REACH THE SELLINGS OF PINK FLOYD`S "DARK SIDE OF THE MOON"

UPDATE:

Went for a longer test drive on the HW.
Not sure if has something to do, but I noticed the temp gauge never reached the normal operating temperature. The needle on the dash raised half way the C and the normal operating temperature, just below the thermometer icon.

Im going to test if its the sender unit or the temp sensor

__________________
Paysandú, Uruguay
1996 Reg. Cab Ford Ranger, V6 3.0L, 5 speed manual trans.

THAT AWESOME MOMENT WHEN YOU REALIZE YOU CAN TAKE ALL THE PEOPLE THAT BOUGHT A JUSTIN BIEBER ALBUM, MULTIPLY IT BY 6 AND STILL DON`T GET TO REACH THE SELLINGS OF PINK FLOYD`S "DARK SIDE OF THE MOON"

MONDAY UPDATE:

With the engione on, I can hear air, which means VACUUM LEAK.

I dont know exactly where its comming from, but deffinetely I can hear vacuum scaping from some where.

Any idea how to troubleshoot a vacuum leak????

Can a simple leak causes all the sympthoms mentioned above???

__________________
Paysandú, Uruguay
1996 Reg. Cab Ford Ranger, V6 3.0L, 5 speed manual trans.

THAT AWESOME MOMENT WHEN YOU REALIZE YOU CAN TAKE ALL THE PEOPLE THAT BOUGHT A JUSTIN BIEBER ALBUM, MULTIPLY IT BY 6 AND STILL DON`T GET TO REACH THE SELLINGS OF PINK FLOYD`S "DARK SIDE OF THE MOON"

Get a can of brake clean or carb cleaner and spray around the intake while the engine is running. If the engine rpm increases or changes you found your leak. Do this while the engine is cold.Check for broken vacuum hoses too.

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barneycat11 2006 FX4

Thanks a lor for the answer man.
I think I found the vacuum leak using the method you suggest.
I sprayed throttle body cleaner and I think the vacuum leak is on the IAC gasket.
Question is, can a simple IAC gasket leak can cause all the sympthoms mentioned above?

__________________
Paysandú, Uruguay
1996 Reg. Cab Ford Ranger, V6 3.0L, 5 speed manual trans.

THAT AWESOME MOMENT WHEN YOU REALIZE YOU CAN TAKE ALL THE PEOPLE THAT BOUGHT A JUSTIN BIEBER ALBUM, MULTIPLY IT BY 6 AND STILL DON`T GET TO REACH THE SELLINGS OF PINK FLOYD`S "DARK SIDE OF THE MOON"