74 XKE blowing white smoke.

[bpmofva]

Woke up my E this morning after a long winter and cranked it up to find non-stop white smoke pouring from the left exhaust pipe. Only has 44K miles and heads replaced last summer. Thoughts?

 

[jessebogan]

Auto or stick?? If auto most likely the modulator has given up the ghost and trans fluid is being sucked up the vacuum line and burned. Also check the brake fluid levels, as the same thing can happen with the booster. Good Luck.

 

[bpmofva]

That's really good Jessie. It is auto and the the brakes go straight to the floor. I didn't mention it because I didn't think they could be related. Can you now explain "modulator has given up the ghost" and "booster"? I really appreciate this.

 

[Deleted member 8987]

Brakes to the floor could be the booster bad, and brake fluid going through.

Now, there is a real problem.
In another marque, an article in the monthly magazine went into great detail about silicone brake fluid.
And power boosters.
IF you use silicone, and IF you power booster goes, you might have just bought an engine.

That got my curiosity, so I read on.

Seems silicone fluid (or so they claimed), when it went through the high-temperature combustion process, turns into silica, or sand.

So, if you have silicone fluid, and a bad booster, don't run it until it's fixed.

That may be hoo-ey, but I ain't gonna take any chances!

 

[Exotexs]

I'm not an expert on this type of problem but in my '65 S type, the same symptom happened whenever I turned the Heater Valve ON, lots of white smoke. through the exhaust.

Inspection revealed that coolant was being aspirated into the intake manifold through the vacuum line whenever the Heater Valve was OPENED to allow coolant flow into the Heater Core. (Heater Valve in these cars is Normally Closed).

Replaced the Heater Valve and problema no moe.

Ex

 

[jessebogan]

The trans modulator is pretty much a diaphragam that engine vacuum acts on, and as it is moved by the vacuum, it moves a valve inside the trans to change the shift points in response to engine load. If the diaphragm ruptures, trans fluid can be sucked out and burned, causing lots o smoke.

Same with the brake booster. If the seals in the cylinder leak, fluid can be drawn into the vacuum chamber, and from there into the engine.

I have a V12 2+2 here, and when I get it on a lift today, I will see if in fact it does have a vacuum modulator. I have a 75 XJ12 in here, and it has one, but for the life of me, I cannot keep straight which BW transes have them and which don't. I am fairly sure that the V12 cars ALL have them, but I will check later.

 

[DrEntropy]

Funny aside is you can tell from the odor at the tailpipe which fluid it is, once you've sniffed 'em both a couple times. Hard to explain "smell" with a keyboard, tho. :wink:

...but it sure 'sounds' like it's the brake M/C and booster from the posted info.

 

[Deleted member 8987]

Even without the sniff.....the statment that his brake pedal now goes to the floor might be a clue.....

 

[jessebogan]

Yeah Doc, it is true, but how on earth do you explain that to someone that might not have smelled it all? I envision a small altar, with a druid like person of some sort,with wizard pointy cap, taking small ladles of various fluids, and warming them over a brazier, and inhaling the "vapours", then running to the garage to "whiff" the exhaust smoke. This would be immediately followed by a visit from the folks with the neat tight fitting white coats.... Nor am I going to explain how things taste.

 

[Deleted member 8987]

Or, how sometimes one needs to walk through a cloud of exhaust and breath in lightly through the MOUTH......you can TASTE the difference......

 

[DrEntropy]

Meh... "What's it TASTE like?"

"umm... horse crap!"

"AH-HAH!!... BRAKE FLUID!!"


...not that I've ever tasted actual horse crap...

 

[Deleted member 8987]

You can tell all sorts of stuff.
I can spot ATF, Anti-Freeze is the easiest.

Once you've worked on them for 40 years, you'd be surprised.

Easier than ramming a hose.......oh, wait.

 

[DrEntropy]

mehheh.

sooo true, TOC!!! :laugh:

 

[WA1KWA]

Open a bottle of brake fluid, smell that.

Open a bottle of anti freeze, smell that.

Which one does your exhaust smell like?

Colin

 

[V6MGB]

One point with brake fluid and ATF is the volume of fluid needed to make huge amounts of white smoke is really small.

Pete.