What do I do if there is white smoke coming out my exhaust pipe, but it is not overheating? A 93 Audi 100S.?

Answer 1

Check for blown head gasket or bad valves. If it's not overheating yet, it will.

Answer 2

The Audi 2.8L engine in the early '90s is prone to head gasket leakage at about 175,000 miles. (Ours, in my wife's '93 100CS quattro, went out at 182k...) The symptoms are gradual coolant loss and, you guessed it, white smoke out the exhaust.

You have basically two options:

1 - Sell it, with the understanding that you're not going to get anything like the car you have now for five or six times the price you'll realize. (And... I know that FWD Audis are great -- I've owned two of them from various years -- but Audi's done such a great job promoting quattro that the FWD cars have an even lower resale value than the quattros.)

2 - Fix it, and have another 150,000 miles of trouble-free engine performance.

We went with route #2 after my wife came to the conclusion that there was nothing we could afford that she liked a tenth as much as her Audi. So we paid a couple thousand dollars to have a shop do both heads, valve jobs, water pump and timing belt.

Oh, water pump -- if you haven't seen a loss of coolant, you will soon: the warning light on the dash will flash (a red thermometer icon) when your coolant level drops in the recovery tank. If you think you're being a careful motorist and keep adding water, you will wear out the bearings in the water pump (not realizing that the coolant contains lubrication for the pump bearings), and then your car will overheat when the water pump seizes.

And some final notes from experience with these cars -- if you haven't already discovered this, your Audi requires special Audi-only stuff in three regular-maintenance items:

1 - Phosphate-free coolant. Prestone now makes one, so you don't have to use the special stuff purchased only at the Audi dealer -- just make sure it's phosphate-free. The phosphates in standard coolant (designed for iron blocks) will cause problems in the aluminum alloy that Audi uses.

2 - Power-steering fluid. The steering pump and rack used in your 100 (and ours) requires a special brand of fluid; the Audi dealer will have it (the part number begins with G002000, so "goo two thousand" is how I think of it and I can't remember the brand name...). Any really good import auto store will carry it as well, once you get the brand name from Audi. It's known as "green gold" in the Audi community; it runs about $11 a liter. But here's the thing: if you use regular domestic power-steering fluid, it will dissolve the seals in your rack and pump, and then you'll be pouring fluid in every week. If you keep your rack topped up with G002000, you may have to add a fourth of a liter every year or so on a '93. (We've had our 100CSQ since 1999 and I'm on my second can.)

3 - Oil filters. The 2.8L Audi V6 in your car (and ours) is cleverly designed to retain oil pressure in the hydraulic lifters when the engine shuts down, so that the car starts quickly and doesn't wear out the cams from having dry lifters (since they're up at the top of the engine). And in their typically clever German way, they achieved this by specifying an oil filter with an anti-drainback valve -- a spring-loaded flap that requires engine oil pressure, not simple gravity, in the return line. The genuine Audi (actually made by Mann) oil filters have this anti-drainback valve. Standard US-domestic oil filters of the same size often do not.

Other than that, these are wonderful cars, tremendously durable and enjoyable to drive. I've got, oh, a whole bunch of cars, and I love riding in my wife's 100CSQ, even though hers is always full of kid things -- music books, stuffed animals, Bionicles, craft projects, etc. It's a fantastic long-distance car, with great driving dynamics and comfort. Enjoy yours for many years!

Answer 3

normally blueish smoke is burning oil and white is burning anti freeze. if its only for a short time from when the engines cold it could be water vapor working its way out of the exhaust. but i would keep a very good eye on the coolant level

Answer 4

White...Always? or just when cold?
Always? Internal water leak somewhere. You should be low on antifreeze after a while.
Just cold? It's just condensation in the exhaust pipe.

Answer 5

hold your hand at exhaust pipe for a few seconds now taste the condensation if its sweet you got problems I know it sounds gross but dont be such a little ********

Answer 6

Might as well go ahead and Rebuild it, it is over 150,00 miles and or 500hrs. Rebuild it, Valves, Springs,Moisture,Seals,Lubrication, Rings, could be one of any moveing or non moveing part. But at that age, I would R&R it totall rebuild.

Answer 7

head gasket or cracked head