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Hi there,

I have whitish, grayish smoke comimg out of my left ( driver's side) tailpipe on accelaration only, not while cruising.When cold the tailpipe also spurts out water droplets.The right tailpipe does not smoke and is dry.
The engine is a 374 in a Packard 400.

First guess would be a head gasket.

Some drops of condensation and a little "white" smoke (steam) could be normal during cold starts, especially in humid conditions. And the exhaust manifold heat riser could direct it to one exhaust until the engine warms. But as suggested above, it could be a head gasket or worse, the key question is whether you are consuming coolant? And check for evidence of combustion byproducts in the radiator.

There is some coolant consumption, nothing dramatic and the coolant is crystal clear.
Does a compression test help?
Some suggested it could be the valve seals.
Thanks sofar!

Quote:

White "smoke" on acceleration... coming out of left tailpipe only..."spurting water when cold"... nothing likewise happening out of the right-hand tailpipe? This all sounds like a left bank head gasket going or gone bad. Summer is the season for blown head gaskets. If your engine has a weak one, this is most likely time when it will reveal itself.

White-grayish "smoke" out of the exhaust is usually a sign of burning coolant. Even more likely if this is happening under acceleration. And while some cars may have slight condensation emanating out of the tailpipe when cold, the volume of liquid can really be substantial if a head gasket is going bad.

A compression test won't necessarily reveal a lot. But there are testing devices you can hook into your cooling system to determine if exhaust is leaking into it. The coolant won't usually change colors and may appear perfectly normal.

And, you may want to monitor your oil dipstick and watch for a milky yellowish color that often occurs when the gasket is really bad.

1. Standard compression test

2. Cylinder leak-down test

3. Cooling system leakdown test. A hand pressure pump is installed on the radiator cap and pumped up to indicated pressure on the gauge. If there is leakage into a cylinder, it can be heard with the spark plugs removed.

4. As mentioned, the coolant can be tested for the presence of combustion gases.

jack vines

This may be off base but when the hydrovac on my Cadillac failed, it sucked brake fluid into the engine and the only sign was white smoke from the left tail,pipe.
I recall someone suggesting the same when the BTV fails.
With these old cars with single master cylinders, it might be worth while to check the level,of the fluid in the master cylinder. My brakes worked fine until the pedal went to the floor...fortunately at low speed in a parking lot.
Just a thought.....and a simple check.

Hi,

Many thanks for your replies and suggestions sofar.
I will do the necessary tests.

Rodney

Several years ago when starting my '65 Cadillac, a bad head gasket demonstrated to me that water does not compress. Proof: A bent connecting rod. I shudder to think what would have happened if it had failed at 70 mph.

Hi there,

Today I did some tests on the engine. A vacuumtest and testing the coolant for combustion gases.
The vacuumtest was steady at 18 on idle dropping to almost 0 on acceleration and climbing to 20 and settling again at 16-18 on deceleration.
The coolant test was negative at first but after the engine warmed up some more I repeated it and the testliquid turned lightgreen from blue.
Also I watched the tailpipes closely having another person accelerate and maintaining a high RPM. There was smoke at first but that disappeared at the higher RPM but instead I noticed the left tailpipe squirting quite some water.
That leaves me to conclude from your remarks that I have a coolant leak ( though coolant and oil are clear).
I will try to find someone who has the hardware to do a leakdown test and I could do a compression test myself but I think there is enough proof to take down the heads and look for a gasket leak ( or worse).Any other opinions or suggestions?

Would it be safe to drive the car no more than a couple of 100 miles in this condition?