2004 Suzuki Grand Vitara hot oil smell

[Doug Sage]

I have a 2004 Suzuki Grand Vitara with four wheel drive, two speed transfer case and automatic transmission. I have towed it four wheels down for 35,000 miles. I religiously stop within 200 miles and run the motor in drive for 1 - 2 minutes as the owner's manual requests. I typically drive at 62 - 65 mph although the owner's manual says 55 mph. Anyway, everything has worked fine and I have an additional 75,000 miles on the vehicle. Now I have noticed a new problem. After towing it for about 300 miles (including making the required stop) I get a smell that seems to come from under the hood and oftentimes can be smelled at the hood to windshield joint. We can also smell it inside the car. It smells to me like hot tar. Possibly hot oil. I took it in to have it lubed and asked them to check under it for tar that could have been thrown up under the vehicle and they did not find anything except for some caked on mud here and there. After I drive the Grand Vitara for a few days, the smell gradually diminishes until it is gone. I checked the temperatures with a laser thermometer and found the wheels all about the same temperature and the transmission and both differentials essentially at ambient temperature. The transfer case was about 129° which surprised me. Later, I checked the transfer case temperature after dirving for a while and it was about 129°again. I don't know if this is high or not and since the tailpiece going into the back of the transfer case turns when being towed then maybe this is not an issue. So my question is what could be getting hot while the car is being towed? What could be causing the hot tar smell? Does anyone have any ideas? It is going to be hard to take it in to a mechanic when it has just been towed and is still making the smell so it will be hard for them to diagnose the problem.

[stuhly]

Most likely cause is road grime blowing up on the engine and exhaust from under the MH. When you start the car the hot exhaust parts are burning off the oil, tire residue and road oil deposited on them. I have had the same problem on a Liberty and a Tahoe. Ron

[Doug Sage]

What has me confused is that this smell is new but consistent in the last month. I have towed this car for several years now and not had the smell occur until recently.