Recently I've been getting light headed while driving. I thought this was do to an exhaust leak, so I just recently had the whole exhaust redone, from the Y-Pipe back. Unfortunately I'm still getting the same feeling while driving. I'm not really sure where to turn next. The only things I can come up with are: There is an exhaust leak in the engine bay somewhere. Possibly the gasket is bad between the engine block and the manifold; the manifold and the Y-Pipe, or its something else. Possibly a radiator leak somewhere....maybe I'm breathing in the fumes from that? It started happening shortly after I had the local shop here replace the gas cap filler hose that runs from the gas cap to the fuel tank. The previous hose had gotten brittle and was falling apart. I don't smell gas in the cab so I don't think that's it. However I am having another shop take a close look at it. Any help would be greatly appreciated!

91 Ranger
4.0L Extended cab 5 speed

 

Open hood
Start engine

Have someone hold towel/rag over tail pipe
Engine should start to stumble as back pressure builds up, and you WILL hear any exhaust leaks in the engine bay, if there are any
Don't forget the EGR tube, which 1991 4.0l should NOT have unless its a Calif vehicle


Loosen gas cap, and drive vehicle that way for a few days, this will prevent EVAP system from sucking in gas fumes to engine bay area, you may get a check engine light(CEL), it will go away after a few days of driving with gas cap tight again

EVAP's charcoal canister is in engine bay, front, attached to radiator support, usually on drivers side, it has a hose that goes back to the gas tank, and a hose the goes to the upper intake manifold
It filters gas fumes

Not sure if coolant/water could cause your headaches, it doesn't contain any hydro-carbons like gasoline and exhaust does

Try driving without AC or Heat on, could be mold issue in the vents?

 

thank you sir!! I will try these things and report back what I find. thanks again.

 

Your welcome

Oh, and I forgot.....................................don't drive with a hangover.......................

 

also if it is carbon monoxide buy one for a house and have it in the cab with you. if it starts going off you know what the problem is.

 

RonD, me and a friend did try holding towels over the exhaust tips, however we didn't hear anything from the engine bay or anywhere else.

With regards to the gas cap, should I just take it off completely and drive around? Or just loosen it? I wonder if replacing the EVAP charcoal canister and the hoses its connected to would fix it. The hoses are old, could be a leak somewhere.
I haven't used the AC in years, I know it doesn't work.


I'm going to take up your suggestion Dngr Rngr. Just bought a carbon monoxide tester, should be in Thursday and we'll see what happens.

 

I've had the carbon monoxide tester in the truck and it has never gone off while driving. I've had it for about two months now. This is the one I bought in case you were curious.

I'm wondering if there are grommets/seals that have rotted out in the firewall. I plan on taking out the carpet this weekend to see what I see. Maybe there are holes in the floor board.