Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => General Discussion => Topic started by: eldoguy on June 26, 2017, 12:57:22 PM

Title: White Smoke when driving my 57 Caddy
Post by: eldoguy on June 26, 2017, 12:57:22 PM
I'm new to the forum.  My son has posted before about my Caddy under salguod.  Why am I now getting white smoke from the exhaust?  Some say head gasket, others mention a modulating valve which could pump transmission fluid into vacuum system and into cylinders.  What is causing it?  The car was running fine until just recently.  92,000 miles on engine.
Title: Re: White Smoke when driving my 57 Caddy
Post by: J. Gomez on June 26, 2017, 01:50:12 PM
Quote from: eldoguy on June 26, 2017, 12:57:22 PM
I'm new to the forum.  My son has posted before about my Caddy under salguod.  Why am I now getting white smoke from the exhaust?  Some say head gasket, others mention a modulating valve which could pump transmission fluid into vacuum system and into cylinders.  What is causing it?  The car was running fine until just recently.  92,000 miles on engine.

FYI There is no "modulating valve" on the original Hydramatic transmission..!

I would first check the vacuum assist valve which is located on the right side main block just above the oil pan behind the starter.

This valve which extends vacuum from the vacuum pump (which is driven by the oil pump  :( ) up to the firewall vacuum manifold blocks oil to be suction when engine is running. The valve has a small spring with a small plate to block the path and it has a tendency to go bad or get blocked open allowing oil into the combustion.  :o

You can block the output and see if the smoke goes out, if not then other methods would need to be performed to find the issue.

Good luck…! 
Title: Re: White Smoke when driving my 57 Caddy
Post by: 55 CDV Fan 82 on June 26, 2017, 02:26:37 PM

Might be your pressure hose for the power steering.  Mine was dry rotten which created small leaks that dripped onto the exhaust manifold.  I fixed it with a reproduction for Caddy Repros and no more smoke!
Title: Re: White Smoke when driving my 57 Caddy
Post by: Jon S on June 26, 2017, 04:22:15 PM
White smoke from the exhaust is most likely antifreeze being sucked and burned through the engine. Most likely cause a blown head gasket. Usually accompanied with a sweet smell.
Title: Re: White Smoke when driving my 57 Caddy
Post by: Roger Zimmermann on June 27, 2017, 02:56:47 AM
It's probably not relevant right now as it's summer time: when cold, some white smoke is coming from the exhaust, it's just vapor...
When the valve behind the starter motor from my '56 de Ville went bad, the smoke at the exhaust was also white even if oil was burnt.
Title: Re: White Smoke when driving my 57 Caddy
Post by: cadman56 on June 28, 2017, 08:10:33 PM
Have a shop run a combustion gas test on the cooling system.
Another one is compression test.  I thing Jon S is right on.
Good luck.
Title: Re: White Smoke when driving my 57 Caddy
Post by: V63 on June 29, 2017, 12:10:40 AM
'White smoke' may not be enough information to provide specific remedy. My thought here is to suggest other possible smoke origins besides already mentioned:

1) stale  or contaminated fuel

2) fuel additives, improper dosage

3) fuel contaminated oil (defective fuel pump)

4) oil additives or elixirs

5) improper drainage of oil from cylinder heads to pan

6) valve stem guide wear or seals

7) oil level too high, incorrect/inaccurate dip stick

8) water in oil

9) too thin of oil viscosity

10) fouled plugs or incomplete combustion

11) excessive engine temperature

12) restricted exhaust

13) windshield washer pump introducing water into vaccum system

14) defective, worn, or broken piston rings

15) oil bath filter introducing oil (over filled) to intake.

And I'm sure there are a few others
Title: Re: White Smoke when driving my 57 Caddy
Post by: Duncan Fox on June 29, 2017, 01:15:37 AM
I have always associated WHITE smoke as brake fluid burning , check your m/cyl fluid levels ( have you had to top up?)
and then booster seals from the m/cyl to the manifold vac side of the booster
Title: Re: White Smoke when driving my 57 Caddy
Post by: V63 on June 29, 2017, 05:46:30 AM
Yes, brake fluid....that is a great suggestion!

I have heard that 1956 (I realize 1957 model here) was particularly bad for this, as all the brake fluid would be sucked out of the reservoir and complete brake loss was the result. Certainly check for brake fluid loss.