What is that STENCH?

[deadmeat]

I have a new problem and it is costing me sleep at night. I recently drove my 79 spider on a two hour trip up the interstate. I got into some stop and go traffic along the way, and by the time I reached my destination there was a noticeably strong, pungent odor coming form the middle to the back of the car (possibly elsewhere but that is where I could trace it). On my return trip. I got into some construction traffic. It was a hot day, first gear and lots of back and forth between the brake, clutch and gas. I noticed the smell again. By the time I got home, I parked at the end of my driveway. I was pretty sure the car was going to burst into flames, the smell was just so overpowering. Everytime I stopped at a traffic light, it was cause me to choke a little. Now, there was no visible smoke I could see. I had no change in performance that I could ascertain. At home, the smell very clearly filled the trunk and the well for the top more than it did the engine compartment.

I know I have an oil leak (apparently around my oil pan or possible the front crank seal). I haven't determined if the transmission (manual) is leaking too, but there is wet "oil" on the front of the drive shaft, too. It is possible that it blew back there from the engine oil leak, i suppose. Also, my catalytic converter pops and pings after every drive. My brakes rattle a good bit and there is a rythmic, metallic squeak that I heard when rolling forward very slowly in the construction traffic (both the rattle and squeak are coming from the front driver's side).

So, with all that information, what is my most likely culprit? The smell has a "rotten egg" quality, but not like the normal bad cat smell I've experienced on other cars. It's far more pungent and noxious. I wondered if I had just never smelled a cat that bad before, but just don't know. Any ideas?

Thanks,

[kustom]

I've had something similar with a truck that was overcharging the battery. Cooked batteries smell terrible! I would check your voltage across the battery terminals while the car is running.

[deadmeat]

If that were the issue, what would cause that . . . a bad alternator? As a side note, when I first start my car in the am, my radio shuts down when I accelerate. Once it's run for a few minutes, it is comes back up and is fine. It's an aftermarket stereo, and I've suspected that it is a voltage issue that is triggering an automatic shutdown to protect itself.

[Raze]

check to see if your diff is leaking, if it leaks out the front and gets on the drive shaft it'll be flung every which way, when you put gear oil on exhaust, it's one of the most unbearable smells. If you've ever changed burned up or seriously old trans oil it's the same deal...

[Kent124]

If that were the issue, what would cause that . . . a bad alternator?

Voltage regulator on the back of the alternator could do that.

[deadmeat]

The diff has oil on it but it appears to have travelled back from the area of the trans. Could a seal on the back of the trans be leaking? That might fit with the oil pattern on the underside of the car.

[baltobernie]

If you're running rich, the cat can stink something fierce.

[Raze]

The diff has oil on it but it appears to have travelled back from the area of the trans. Could a seal on the back of the trans be leaking? That might fit with the oil pattern on the underside of the car.

output shaft seal, trans gear oil smells just as bad as diff gear oil if not worse, and if your driveshaft is wet, check for spots on your exhaust where it's getting flung onto...

[KidDingo]

I reckon it's your catalytic converter. Hydrogen sulphide (rotten egg smell) is almost inevitably your catalytic converter.

I think I'd take it to an exhaust centre and have them check it. Shouldn't cost you anything. At least you might be able to rule it if isn't the cat.

[DougC]

I had the exact same symptoms on my '79. That sucker stinks WAY more than a bad cat. It's an overcooked battery. Be sure you don't touch it until it cools down, that sucker can blow! I replaced the voltage regulator (you can do the whole alternator, or just the voltage regulator) and the battery and it was cured! It's a pretty easy job.

[deadmeat]

As I mentioned, my radio shuts down occassionally (usually after first start of the day) and I've suspected it's an over-voltage triggering some sort of auto-protect mode in the radio. I have a Magnetti Marelli alternator (its the original) and it doesn't appear to have an external voltage regulator on it. Any experience with replacing the regulator on this type of alternator or do you know where to get the part. I have the shop manual, but it's at home and I'm at work.

[azruss]

Not all the familiar with a 79, but the earlier models had the regulator on the drivers side inner fender. these have a set of semi-adjustable points inside that can push your charge voltage up enough to fry your battery.
Also may want to look under the seat or in the engine compartment and make sure some giant rat hasnt crawled into your car to take its final breath.

[deadmeat]

Thanks. I'll look. The car is super clean save for some oil leaking around the pan, so I can tell there are no rodents. I'll find that voltage regulator if it's there. Now if I could find a marelli replacement online somewhere, I'd be all set.

[DougC]

Not all the familiar with a 79, but the earlier models had the regulator on the drivers side inner fender. these have a set of semi-adjustable points inside that can push your charge voltage up enough to fry your battery.
Also may want to look under the seat or in the engine compartment and make sure some giant rat hasnt crawled into your car to take its final breath.

On my '79 it's a little plastic thing on the back of the alternator. I got mine at Auto Zone. They also have it at O'Brien's, but my store had to order it. The alternator isn't too expensive if I remember, so you might want to consider replacing the whole thing.

[majicwrench]

Before you go changing regulator check the voltage!!! No use changing good parts on a whim. Voltage at battery should be less than 15 volts, engine running at speed, leave the accessories off.
Keith