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White Light Smoke From Exhaust


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Hello everyone, I have a 1996 Cadillac Seville SLS and I started noticing light white smoke coming from thee exhaust, every time I hit the gas. No engine lights and hopefully it's not serious. I was in the drive thru line @ the local Mcdonald's, and I kept tapping the gas to see if the smoke would vanish, but it didn't. There was a guy with a certified automotive tech shirt on and about to enter the fast food giant and I stopped him and asked him what could be the problem when light white smoke is coming from thee exhaust? He said that I needed to change my intake manifold gaskets. Said that I was loosing antifreeze through the exhaust. So I purchased the gaskets, but I wanted to see if he was just pulling a fast one on me, because I wasn't trying to take my car to the well known car dealership in town. Some say it could be a pcv valve that need changing. Any thoughts? Thanks!!!

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He was describing a lessor case scenario (it could also be a head gasket; not good). Sometimes it can even be loose intake bolts. Cadillac Jim should/might be along shortly (one of our Cadillac guru's), he should be able to shed (better) light on you condition.

Chuck

'17 XT5, '04 Bravada........but still lusting for that '69 Z-28

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The intake manifold doesn't carry water on the Northstar. The mechanic is thinking about most other cars that indeed do carry a water line across the intake manifold, either as a crossover or to help with cold starting and warm-up, or both. Old antifreeze and aluminum intake manifolds or heads leads to this kind of leak. It's happened twice in my wife's car which has the GM corporate 3.4 liter V6 circa 1996-2005, which was known for this problem.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Thanks everyone for replying. The engine warm or cold is perfect, it's not running ruff at all. I decided to take my chances and purchase the $2.99 pcv valve this morning. My pcv valve still had a rattle in it, but I replaced it. Also I bought some Honeywell Oil Treatment to go into the crankcase. I ran the car for several miles and haven't noticed any smoke. So hopefully that did the trick.

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These northstars have a dry intake. Therefore not coolant goes through the intake.

You either have a light oil burning problem or a coolant consumption issue.

If the rings have been sticking for awhile it may have built up in the cats and exhaust.

If it plumes white smoke then it is usually coolant. Does the engine use any coolant?

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Surprisingly it doesn't consume much coolant rockfangd!

But it does consume coolant which may point to headgaskets.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Actually the best thing to do is to go over your coolant system for leaks.

The most common cause of coolant loss is a leaking radiator cap, or the wrong type radiator cap.

Next, of course, is leaks at the hose clamps. In addition to the big radiator hoses, you have the heater hoses, the crossover from the water pump back to the overflow tank, and the plumbing from the overflow tank to a tee in the heater hose return line. The heater hoses have two rubber hoses on the left side to metal hoses that go between the engine and the firewall, and two rubber hoses that go from them to the heater core. The return line has the aforementioned tee that sends back water from the overflow tank.

The next think to look at is cracks in the radiator tanks. Usually, when the engine is hot, you can see tiny amounts of steam coming from leaking radiator tanks.

There is a remote possibility that there is a leak in a radiator tube, or the main body of the radiator.

You can have your cooling system pressure tested to locate any leaks. Also, if there is a head gasket leak, a pressure test will find that too unless it is in the very early stages (leaks only when hot and the engine is under load) but if the exhaust white plume is from coolant, a pressure test will find it.

The quickest way to tell whether you have a head gasket problem is to smell the exhaust. If it smells like coolant, you have a head gasket leak. The definitive test is to have the coolant tested for combustion products. If that is negative, you can rule out head leakage.

Note that a little white smoke when the car is cold is normal. Once the car warms up the exhaust should have no color.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I can relate to this issue. 05 deville would smoke when I started it up and as it sit at idle. What codes are you getting? I replaced 02 sensors, and to find out my 02 sensor fuse was blown. Haven't had a problem since.

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Hey IceCold, there's no codes what so ever that's coming up. The only warning that's coming up is the "Service Ride". I purchase some Arnott rear shocks and the electronic wiring system came off on the left rear side. I purchased the shocks only 3 months ago and I called Arnott and had my repair guy to talk to them and they said that they can't honor the 1 year warranty, because they don't know the reason why it fell out. Well, the repair guy told them that it just could have been defective. So I will not be ordering from them again! So that's thee only problem that I'm having, with warning lights.

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