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Headache troubles

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wkilleffer

wkilleffer

Jedi Knight
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Ever since high school, I have been subject to crippling migranes from time to time. It seems to run in the family. My current jobs allows me to work with an old school chum who has the same problem. Friday, he asked me to give him a ride to pick up his car at a repair shop. Since the MG is my daily ride, that's what we took. Today, he told me that I might want to track my headaches based upon when I drove the MG, as he had one after I delivered him to the repair shop.

Now, just over a year ago, I had some exhaust work done when the pipe between the header and the pipe with the muffler rotted. It was in bad shape and noisy. It wasn't that way forever, as it built up and my first indication that something might be wrong was that the car's interior smelled gassier. My clothes smelled kind of like that after a ride.

As far as I can tell, the new pipe is holding up and the remainder of the pipe is in acceptable condition. There's nothing in the exhaust piping under the hood to give me cause for concern. However, I now am wondering if there might be some sort of combustion by-product getting into the cab through the firewall somehow. There used to be some kind of cover over the area where the wiring came into the dash, but with the work I've been trying to do, that's now an open hole. The car's been desmogged, but the charcoal system is still in place. There's a gadget that looks like it takes those gasses from the canister to a tube into the intake manifold that's non-functional and not hooked up to anything.

Is there another source whereby blowby gasses could be making their way into the cab? Any suggestions would be appreciated.

Thank you,
 
The only ways I can think of that combustion gases would be entering the car would be a leak at the exhaust manifold flange (common) or a blown head gasket causing the combustion gases to mingle with the coolant. Check the fit and sealing of your manifold to eliminate the first as an issue.


With the latter issue, the gases would really only enter in quantity if you had the heater turned on. The contaminated coolant would circulate into the heater core and possibly blow the gases into the cab. It could potentially happen without the heat on, but that's not terribly likely. It's also not likely that you're going to be driving around with a blown head gasket and not know it.

If you think that the missing grommet that the wiring went through could be a potential cause, by all means replace it and eliminate that as a source. Do get a handle on this issue soon though; the biggest problem with an exhaust leak for a human is the carbon monoxide. That would cause a hefty headache, and could even kill if breathed in enough quantity.

As a side note, check out your floorboards and make sure there aren't any pinholes in them. If there are, and you have an exhaust leak somewhere in the neighboring area, then the gases are likely getting in your car that way.

Hope this helps!
 
Thanks for your reply, Josh.

Do you know if a carbon monoxide detector like the ones that can be found at hardware stores would be useful in detecting an under-hood exhaust leak? I'd like to rule that out if possible. The engine was rebuilt and all the gaskets were replaced about five years ago, but it's only been driven more than 2 or 3000 miles per year in the last two years when I started driving it two or three days a week, and the last four months when I started driving it every day. I'll check the rest of the exhaust under the car as well. Might be a good excuse to get a Monza system.

Thank you,
 
You might check one of those out for mounting inside the car, just so you can see if there's any level of it building up inside the car.

As for mounting it under the hood, you would have to lift the hood to check it, and a great deal of the gas would escape to atmosphere before you could check the reading. Plus, fresh air circulates all around the engine bay while the car's moving, so that would also distort readings.

The best place for one of those would be inside the car, IMHO.

If you determine that you may indeed have an exhaust leak, good places to check are the flanges (manifold, pipe, muffler) for gasket/O-ring deterioration, cracks, loose fittings, et cetera.

If you find something, you might try this: "Honey, it's a matter of my health that I buy a Monza for my MGB! No, I could die from CO poisoning; my existing exhaust is leaking! That's why...ok, I'll call Moss right now then.."
 
I would more likely suspect a coolant leak in the heater core than an undetected exhaust leak...that could be a source of headaches too.

Also check your tailpipe for obstructions or being too short and allowing the exhaust gasses to draft back into the car.

Is it really that tight that there is not an adequate flow of fresh air, or is it a GT??? LOL

Bruce
 
[ QUOTE ]
I would more likely suspect a coolant leak in the heater core than an undetected exhaust leak...that could be a source of headaches too.

Also check your tailpipe for obstructions or being too short and allowing the exhaust gasses to draft back into the car.

Is it really that tight that there is not an adequate flow of fresh air, or is it a GT??? LOL

Bruce

[/ QUOTE ]

Well, I've not seen any evidence that the heater core's leaking, but am willing to entertain the idea. Is a small leak a pretty obvious thing?

As far as the exhaust goes, it's a stock system that exits near the left rear of the car. As I have said, I don't think there's a leak, but will inspect it more closely this weekend.

The car's a roadster, and the top is down about 95% of the time.

Thank you,
 
When the car is cold, start it, stuff a rag in the tailpipe, and have someone hold it there with their foot. While they do that, get under the car and listen and feel for exhaust leaks (it's obviously easier to feel for them with the exhaust cold!). With the addition backpressure from the rag, a leak should be obvious.

If you've got a heater core leak, you should be smelling a sweetish smell.

Do you drink a lot of coffee on some days but not others? You could be having caffeine withdrawal....
 
Hi there,

Is it a gasoline smell or exhaust?

When the top of my fuel tank rotted, I got a horribly strong gas smell in my trunk and cockpit,...to the point where I'd get a headache,..and I don't suffer from migraines.

A new tank was the end of that /ubbthreads/images/graemlins/smile.gif
 
With that grommet out, exhaust gassses exiting the rear of the exhaust CAN make their way backwords under the car and into the cockpit. How's the exhaust pipe where it meets up with the muffler? Mine is a little loose there, and leaks enough for me to smell it when driving slow or idling.
 
Look in your trunk - right side - & check the hoses going to & from your vapor separator...if they're bad or cracked or broken, you'll get that raw gas smell...
 
Also - how is your driver seat attached to the floor? Are you using all original hardware?
 
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