I was wondering how I could tell if this was coolant being burned off.
I get white smoke when I start it up, but its not too thick and it disappates pretty quick.
Its not blue smoke so I know its not oil.
I was just wondering if it was coolant as I always check my coolant level and it hasn't gone down at all since about 4 months ago.
I'm just trying to put my mind to ease or find out the bad news now before I get suprised by something

 

As the weather gets cooler, you'll notice more condensation coming out of the exhaust when the car starts up. It's normal as long as it not coolant being burned.

If you get out and get behind the car, coolant being burned will have a different smell.. Not a typical exhaust smell (some people say a sweet smell but I've never considered burning coolant *sweet smelling*).

 

just smell it, it's prolly fuel.

 

its probally nothing to worry about, most fd's have this, especially if your running a striaght thru type of exhaust/ cb, mp, dp

 

The weather is actually getting a bit warmer here, thats why I had the concern. Thought this would clear up once it got warmer but its pretty much the same.

Yeah, I know people say that coolant burning would sme
ll 'sweet' but I just don't notice it in the smoke that I'm getting. I wasn't sure exactly what they ment by 'sweet' so just wanted to know if there were other ways to tell.

I thought fuel would be a darker, greyer smoke...

My car is boooone stock for now... except for a boost gauge.

 

I know this might sound gross but, have you tasted it? Check the tip of your exhaust. Dab it with your finger and taste it (But don't swallow!!). Hee hee. Anyway, if it tastes sweet--

-HeX

 

Two words: Uh Oh.

Pull off the filler cap above the water pump when it's stone cold - start the car. Fill it with distilled water to the brim. Let it idle for 10 to 15 minutes as
the coolant gets hot. Wrap a small towell(s) as
needed around the filler neck to absorb any overflow - don't let the towell get caught in the belts. If you have "champagne" bubbles percolating up after
the coolant is warm your O rings are toast.

If the leak is MINOR, it can be repaired with Copper Block Weld. If you have BIG bubbles, an engine rebuild is the ONLY option. Sorry.

Good luck!

 

Found this on Ciriani's excellent page.-just as ron said with a little more detail. Does anybody know what temp the Tstat opens (I'm assuming that's why Ron said to let the coolant warm up)?

http://www.scuderiaciriani.com/rx7/o-ring_failure.html
Date: Wed, 16 Feb 2000 22:02:30 -0500
From: "David Lane" (dlane@peabody.jhu.edu)

COMBUSTION GASSES IN THE COOLANT
When the engine is running, combustion pressures far exceed pressure in the cooling system, so combustion gasses work their way into the coolant.

If damage to O-ring is slight, you will get what looks like a slow, frustrating coolant leak somewhere. Every so often, your Low Coolant light will come on, but you won't be able to see evidence of an external leak. You may notice that for some reason you have more coolant in the overflow bottle than normal. If this occurs, first check your radiator cap for a tight seal. Then check your overflow tube for a split. Either situation can result in coolant coming to the overflow tank in the usual way, but air being sucked back into the radiator due to the air gap (either at the cap or in the hose). If the problem persists suspect an O-ring problem.

If the O-ring has a larger break,, you will have a significant amount of combustion gasses trying to displace the coolant in the system. This will tend to push coolant out of the radiator, into the overflow tank, and possibly right out of the top. With the engine running (thermostat open) you will see a steady stream of bubbles coming from the submerged end of the overflow line. The resulting hydrocarbons can be detected by a smog sniffer.

With a really large break, combustion gasses will not be able to work their way out of the cooling system fast enough, and the system will tend to blow coolant out of the path of least resistance--usually the overflow bottle.

 

Guys, if the smoke/vapor dissipates quick, it's not coolant being burned it's just condensation in the exhaust.

Trust me. When coolant is being burned, it will look like a smoke grenade is sitting behind your car. I've been there.

 

I agree it's easy to tell from the tailpipe in extreme cases, but when the damage is slight, and the temps are low it's harder to determine the cause based on tailpipe smoke alone.

 

When my coolant seals went, my car only smoked slightly at startup. It got progressivly worse quickly.

 

How can i tell it's condensation or burning coolant???
how does coolant smell by thw way??

 

Ok, I'll give it a shot: like burned cotton candy.

Do the test I described. It is the most simple and reliable way to define your problem, and it does not cost ANYTHING.

 

as u say...
burning coolant must smell good~
lol

 

when my car starts, white smoke comes out for 1~2mins. it does dissipate fairly qucikly, and it smells like gas/fuel. And the gas stimulates my eyes.
So it that coolant or not?

 

and I get some white smoke at start-up for a minute or two, but clears up completely. Seems perfectly normal during this time of year in the midwest? Methinks condensation in the 3-inch exhaust plumbing...

 

My motor failed that way after 102,543 miles of hard use. The first sign was coolant overflowing out of the overflow reservoir. A pressure test won't tell you anything, as mine passed a leak-down test, as well as a coolant pressure check. The coolant buzzer going off intermittenly, and needing to refill the water pump fillerneck with new coolant are other symptoms of a failed o-ring gasket.

 

After the "start the car" step, every other step should be performed while the engine is running, correct?

 

i've read post like this several times... but lately my car has been doing the same thing, white smokes coming out for 1-2minutes... not only that, but when i press hard, i can c white smokes coming out as well...

but when i checked, i can only smell fuel and exhaust fumes... is this normal?

 

is the filler cap the white coolant bottle behind the passager's side head light??

 

one more question~
if coolant leaks to the combustion chamber,
shouldn't the coolant being burnt all the time when the engine is running??
so should the white smoke (burning coolant) keeps shooting out of the exhasut, but not just the first 2 mins after start up???

 

No, it's the one with the yellow sticker on it that's closer to the engine.



Here's a copy and paste from this link:
http://www.scuderiaciriani.com/rx7/o-ring_failure.html

When the car is running, there is high pressure in the combustion chambers, so gases migrate into the coolant and displace liquid. This can force coolant out of the overflow bottle. Symptoms are a full overflow bottle, and a mysterious loss of coolant. If you can see it on a late 2-gen (I don't have one), you will see a stream of bubbles exiting from the bottom of the tube that goes into the overflow bottle when the engine is idling warm with the thermostat open.

When the car is shut down, the combustion pressure drops to zero, but the coolant pressure stays up for awhile, pushing coolant into the combustion chambers. If you start the car before the coolant has a chance to evaporate, you will see white smoke which smells like antifreeze coming from the exhaust. In bad cases, a stop for fuel will result in a veritable fog of white smoke, and missing from one of the rotors until the coolant gets out of there.