How much start up smoke is too much start up smoke?

[WERA976]

When the truck's cold, I get a pretty noticeable puff of blue smoke on start up. It lasts longer the colder the air temperature is, but goes away in the first 30-45 seconds of run time.

If this were a gas engine, Id say I have a leaky valve guide/seal. Does that happen on 6.0L engines, too?

On a separate note [or maybe related note, I don't know], what is the condition that causes long crank times on warm engines? I find that when the coolant temperature's north of 180*, it takes longer to start than when the coolant temperatures at or under say, 160 or 155.

Thanks.

[dannyboy950]

1. Blue smoke conditions are the same for a gasser or a diesel. Valve stem seals; collapsed rings; excessive crankcase pressure with the addition of leaking turbo seals for the diesel.

2. Unless your ambient temps are really low your coolant temps are below normal. the thermostat doesn't open unitl 190/195 deg. Extreme cold will take you longer to get there but you should still reach 190/195 for proper engine operation.

3. The most common cause of hot no starts is HPOil system leaks. Colder oil is thicker and can mask a small leak, as oil warms it gets thinner and can leak out of a smaller crack so to speak.
The most common failure point in a 05 up is the STC fitting and o-ring failures on all models.

[WERA976]

Originally Posted by dannyboy950

2. Unless your ambient temps are really low your coolant temps are below normal. the thermostat doesn't open unitl 190/195 deg. Extreme cold will take you longer to get there but you should still reach 190/195 for proper engine operation.

I'm referring to the ECT at the time I re-start the engine; those are not my operating temps while going down the road.

For instance, as I arrive at my destination in the wintertime the ECT will be around 186-190, and the EOT will be around 193-196 or so. I'll shut the engine off, go inside and do what I'm doing, and return to the truck (it'll still be warm). When I re-start the warm engine, it'll take longer than it should to crank. Once it does light off, the gauges will read that the ECT is somewhere around 180 or just under, and the EOT will be right around that same number (depending on how long it has sat in the parking lot since I shut it off.

Yes, once it's run for a few minutes, the ECT and EOT rise again, but at the time I'm turning the key, those are the first temps I read on my Edge Insight.

I haven't noticed any unusual oil consumption at regular oil changes. I use Mobil 1 diesel synthetic changed every 5,000 miles; it drains about 14 1/2 - 15 quarts, and I refill with 15. Hmm...