1999 Jeep Grand Cherokee Laredo Gas Smell Issue and possible Transmission issue?

jeep
grand-cherokee

#1

When I fill my tank with gas I get a very strong odor of gas throughout the vehicle, what do I need to check to fix this?

Also this one is weird, but everytime I make left turns ONLY, my Jeep does a down shift but stays in Neutral longer than it should but then kicks into gear by me taking my foot off the gas pedal and reapplying . Any ideas what this could be? I have made sure that my Transmission levels were fine but I am baffled what the problem is?


#2

The gas vapor smell means there’s likely a problem with the evaporative emissions control system. Have a mechanic check it out. If you top off your gas tank, it’s possible some gas has gotten into the charcoal canister that catches the gas vapors from the gas tank. In that case the canister may have to be replaced. Or maybe a purge solenoid valve is stuck open. If the gas smell doesn’t ever go away, it’s possible a mouse has chewed through one of the vapor recovery hoses. If no one can find the source of the vapor, have the gas tank smoke tested.


#3

In addition to evap system issues you may have a filler neck issue. Someone just has to inspect it.

The turning and downshifting/neutraling out is odd. All I can think of is that the vehicle probably has a pressure switch on the power steering. The pressure switch reports to the computer so that it can ramp up the RPMs enough to take the extra load put on by the power steering pump. Normally the adjustment is not noticable, but perhaps you have either a steering rack or pressure switch issue that is calling for a bigger jolt. The transmission is computer controlled, so it will change gears in response to sudden load increases. Try to pay attention to whether turning left is associated with a bit of an engine surge - you might sit still in the driveway and turn right then left to see if there’s any difference. I’m reaching here, but it’s all I can really think of, though you might take a look all around the wheels and front axles - perhaps - for a wiring harness hanging loose and getting disturbed. Also a reach.


#4

Fuel smell: Evap system or fuel filler. In my case when I had the same issue with my '99 Dakota, it was the filler neck. It had rusted through in a couple of spots. It was a $60, 15 minute fix in the driveway. The “Check Engine” light was on and I got an evaporative emissions leak code.

Transmission issue: It could be as simple as low fluid level. Check it as per the procedure in the owner’s manual. Be sure to use the recommended fluid if it’s low.


#5

It’s weird indeed that the transmission only acts up on left turns, but that symptom could be a transmission problem, possibly requiring a rebuild but maybe just replacing a solenoid or making some adjustment. I’d probably start by giving the transmission a proper service if such is due. After that, you’d need to take it to a transmission specialist for an opinion.

The gas odor problem is probably something simple. Picture how it works. Most modern day gas tank systems are sealed, but they have to allow air in otherwise the tank would collapse as the gas was used up. The top of the tank is filled with air and gas vapors. When you fill the tank, it drives the air and gas vapors upward. They are supposed to go into a tube and be directed to the charcoal canister. Then the canister is supposed to occasionally vent into the intake manifold, usually controlled by a purge valve. Something must be wrong w/all that. Check for DTC’s before making any assumptions. Hopefully the vehicle’s ECM already knows what the problem is. If pressed for a guess I’d say it was the purge valve is on the fritz.


#6

Depending on the transmission you have the fluid may need to be checked with the engine running and trans in neutral, not park. Checking in park will give an artificially high reading. Or perhaps the seal between the filter and the valve body in the transmission is bad.