My wife and I have an '82 240 Dl and have begun to experience pretty severe CO (carbon monoxide) poisoning symptoms while driving the car (e.g., difficulty breathing, light-headedness, headaches, etc). There is a pretty distinctive exhaust smell during the onset of the symptoms, which are the most extreme in hot weather, particularly when driving up hills or accelerating from stop signs. The problem is not ambient traffic fumes, because we have experienced these symptoms w/o traffic. We took the car to a smog/muffler shop, and they noticed a small leak between the exhaust pipe and the entrance to the muffler (not the muffler to the tail pipe) but claimed that such a leak would not likely contribute to CO entering the car. They noticed that the seals around the trunk were poor but doubted that could be a problem. They tested for CO and hydrocarbons in the car, but I'm not sure that the test replicated driving conditions, since the car was up on a lift during the test. Has anyone had exhaust problems like this with a 240? Any thoughts/suggestions?

Best,
Paul McBride

I have a similar problem with my '81 240 wagon. It only happens when the front window or windows are open. I have a couple of rust spots at the bottom of the rear quarter panels, and may have a slight leak just aft of the muffler in front of the axle. I don't know if the fumes are coming in through the rust holes or are being sucked in past the tailgate gasket.

I haven't driven it enough to experience poisoning symptoms, just enough to smell the fumes and be annoyed by them. If all the windows are open I don't notice the smell.

Having the windows closed also eliminates the problem, since it has positive ventilation.

I have this exact same problem on my '74 Jeep Wagoneer with the windows down. Eliminating exhaust leaks and sealing the body with new tailgate rubber and plastic filler for the rust holes should eliminate the problem. Good luck with it!

I'd also check very carefully for a leak where the exhaust manifold meets the engine. If there is a leak here exhaust will easily make its way into the cabin via the cowl vents and fender wells. My advice is to start searching for exhaust leaks - you've likely got one somewhere near the front of the car that's gone undetected.

I kinda doubt that the muffler leak would lead to that much CO getting in the car, but it's certainly possible, especially on a wagon that may have poor sealing at the rear end of the car.
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85 245 DL - 91 Mazda MX6 Turbo

If the "distinctive smell" is gasoline, your problem may be fuel fumes from the trunk. I had this problem. There are a couple of possible sources:

1. Fuel filler neck where it enters the trunk. The neck goes down into the tank and is secured by a clamp. It enters the trunk through a hole secured by a big rubber seal.

2. Just inside the rear quarter panel, the filler neck has a nipple for a rubber vent tube that leads to a steel tube and I assume eventually to the vapor recovery canister. If the rubber tube comes of you can get gasoline vapor in the trunk.

3. Fuel door seal where the filler neck passes through the quarter panel. If this seal is bad, a leaky fuel cap could conceivably allow vapor into the trunk.

4. Fuel spillage drain. The fuel door seal has a catch basin and hose that drains overflow through the trunk to a hole in the bottom passenger side spare well (normally hidden by that d***ed fiberboard cover that always warps).

An exhaust leak large enough to cause CO sickness will normally be loud enough to hear. Leaks after the muffler or resonator may be quiet, but exhaust fumes can make it into the car only if there are holes in the floorpan, so richink's suggestion is a very good one. Another possibility may be the openings in the firewall. I've never smelled exhaust fumes through the firewall, but two of our 244s have had water leaks that I fixed with silicone sealant.

Another, even longer shot, is a coolant leak. The ethylene glycol in antifreeze makes some people queasy. Your heater core or heater control valve may be leaking. Check for damp carpet in the floorboards.

Good luck.



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'88 244GL, '89 244GL, '90 244DL, '91 244, '92 244

Eliminate any leaks in the exhaust system under the car. Start the car and with the engine running, feel along the length of the exhaust with your hand for any puffs.

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1980 245 Canadian B21A with SU carb and M46 trans

Haven't seen the problem but would be very careful - sounds like an extremely dangerous condition!!!

What are the floorboards like - I know my 87 740 has developed large air leaks in the front wheel wells from rust holes and if there were any exhaust gases in that area they would be pushed right into the cabin.

I know parting with an 82 240 would be traumatic and seems like a real waste of at least half of it's useful life - not much could get me to willingly part with my 250K 87 model either - but I'd send it to the junkyard in a heartbeat if I had the least suspicion of unexplained/uncorrectable exhaust/CO getting into the cabin. If you do keep driving it make sure your Life insurance premiums are paid up! JMHO!!

Jim

Hello,

I'd be looking under your car to see where the hole in the floor is. It would have to be a pretty big one to let that kind of CO into the car.

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Happy Bricking!!! - Richard - '87 245 DL , '82 242 GLT - Half a million km between them!!!