Sudden blue/white smoke on start-up

[mshu7]

Hey guys, yesterday I was starting up my truck (see sig) and I noticed a small cloud of blue/white smoke behind my vehicle. Since my truck has never done that before, I thought maybe it was from someone else's vehicle so I kind of brushed it off. A while later when I stopped somewhere for a few minutes and started back up again, I got a huge cloud of blue/white smoke behind me. I had my windows cracked so when I backed up, in got inside the truck and it smelled like something was obviously burning. It happened a third time later that day, but it was a smaller cloud of smoke. It also did it during my first start-up of the morning today.

I don't know what's going on at this point. As I said earlier, this truck has never smoked on start-up or any other time. I changed the oil a thousand miles ago. Checking the dipstick, it does look like it has burned some already though.

Any thoughts or ideas of what might be going on?

 

[lawman1909]

Head gasket going is probably the cause. Seems to be a trend with that particular model and engine.

 

[mshu7]

That's what I was thinking, unfortunately.

 

[supton]

How is the coolant level?

I think a mechanic can test for combustion gasses in the coolant.

Sorry...

 

[mshu7]

The coolant level is definitely low. I can still see it in the over-flow tank, but only an inch or two. It's about 4-5 inches from where it should be.

 

[bigt61]

Throw some of these in there before you spend any money. Should be available at NAPA. In the radiator, not the overflow tank.

 

[tudorart]

valve seals...did you change oil brand 1000 miles ago?

 

[mshu7]

I dropped down from M1 HM 5w30 at 7500 mile intervals to MS HM 5w30 planning to do 5000 mile intervals because I was noticing the oil level dropping over the last OCI.

 

[tudorart]

Well from HM to HM, leaves viscosity as the major difference factor. Not by much, but M1 is thicker than MS. You want more low shear viscosity with both a hot and a cold engine.

Maybe top off with 10W40 MS HM to bring it up a bit at both start up and operating temps.

 

[Rick in PA]

Sounds like a head gasket. I had similar symptoms years ago. Here's what my brother the mechanic did. Pressurized the cooling system with a hand-pump cooling system checker. Removed all the spark plugs (on this car you could look down the spark plug holes. Took a little light on a stalk that would fit through the spark plug holes. Stuck the light through the spark plug holes and looked in the cylinders. Sure enough, we could see coolant pooling in one of the cylinders - head gasket.

 

[mshu7]

Thanks for the insight Rick. I might give that a try. Weird thing is, I've probably done 5-6 start-ups since posting this thread and I've not seen a trace of smoke. Could the smoke just have been from some build-up or something that is now gone?

That said, with the oil consumption & lack of coolant in the over-flow tank, I'm guessing a faulty head gasket is where it's eventually leading. If it was the head gasket though, would that cause oil consumption, or would that be caused by something in the cylinders themselves?

Thanks again guys.

 

[Trav]

If you remove the radiator cap does it just circulate around or does it blow out like a geyser? Any oil in the coolant?

 

[mshu7]

Quick update. Has yet to smoke on start-up (or any time for that matter) since my last reply. Whatever it was, it's gone now. I'll continue to keep an eye on the coolant & oil.

 

[kwikrnu]

Before you start throwing away money, consider renting a pressure tester from autozone. Clip it on to the radiator cap and it should indicate whether your vehicle has a head gasket problem.

 

[mshu7]

Thanks kwikrnu, I'll keep that in mind.

 

[mshu7]

Hey guys, I'm digging up an old thread of mine because it recently happened again.

I was leaving work last week and when I started the engine, I got a huge plume of blue smoke. I was due to change the spark plugs, so I went ahead and replaced them over the weekend. The old ones don't look too good.

Just a reminder. This is my '04 Colorado 3.5 Inline 5-cylinder with 180k total miles. These plugs have around 90k miles on them (Denso's). The lone AC Delco was replaced a couple years ago when I had a coil pack go bad.







Thanks for your feedback!

 

[Trav]

The 5 Denso plugs are well worn, how does it run now?

 

[mshu7]

Sorry, that last picture got flipped around so the AC Delco plug is on the left.

 

[mshu7]

It runs great now. Idle is smoother and overall, it purr's now. It was definitely rougher before replacing the plugs.

I also replaced the spring inside the coil plug boot. Details here: http://www.355nation.net/forum/superspar...ering-info.html

 

[Trav]

I meant 4 plugs, anyway it wouldn't surprise me if the smoking stopped. Does it start faster now?