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Blowing white/lightblue smoke when idleing... what could this mean?

2002 Freightliner Century S/T

detroit 12.7

1,032,000 miles

NO inframe done yet.

When we idle, truck blows blue smoke, then clears after about 5 mins. Once we get going, it blows blueish white smoke for about 1 min then clears. We do have a an oil leak but not sure if that would be causing this or not. There is NO oil splatter at top of exhaust or on the top corner or trailer.

Open to ideas &/or comments... I'm thinking I may need to "run the rack" aka head adjustment.

Update

ok guys here's what i found so far,checked air firlter clean no oil ,took off airintake hose from air cooler side found sticky oil "caked" on but none running,checked around exhaust maifold ,no oil leaks,check where it connects to turbo no visible oil around it....when i mention idle i mean for like 10 to 15 minutes at the most...last night we idled for 6hrs cause it was cold when we left out we blew smoke and some oil for about 10 miles before it cleared......so know that I have done that what are your ideas and also thank you all so much for your imput

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5 Replies

Blue Smoke is burning oil

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Like Ron said blue smoke is oil. Might be leaking injector cups. Whiite smoke might

be coolant or a sticky injector/s cutting out fuel (you'd definately hear/feel a sputter with a misfire).

Do an oil sample to see if you have fuel or coolant mixing in. I think it'll be your injectors or headgasket. Quit idling your truck, that's the worst thing for a high mileage motor. Get a gas generator from any Walmart or car parts store, like O'reilly, for $200 - $500 and a household window AC unit for under $200 - you're set and your engine will last longer.

Overhead will more than likely not help in this case. Are you adding coolant or oil more often when you idle? I bet you do at least one of them. Do you bump the RPMs up at idle or leave them low? I'd suggest a full dyno test or at least a compression and blow by test. If you do a full dyno and an oil sample you can zero in on the issue or exclude the most worrysome possibilities.

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bad injector, after it warms up it un sticks itself. or just built fuel in the starting process. most trucks with any amount of miles do this when they first start then clear themselves

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So my problem is had new head done new injectors and a liner and piston kit put in ran fine got 4 hrs down the road and a sputtering in my stacks soon as u give it fuel it goes away I’m not losing boost or power truck run normal we pulled top of ck everything and reset and adjusted everything on top end and ever repacked new injectors still no change and idea on what it could be

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I think this is an injector/injector cups issue. I have a 2000 century with a 12.7 detroit (1.3 million original miles)and am fighting something similar. If its possible, you need to do an oil sample with a good lab. My guess is were going to see high soot and high fuel dilution. If you go to letstruck.com then go to SHOP, then categories, then fluid analysis. That lets you [#|purchase] a 5pack of sample kits. I’m not sure how to just get one. Make sure you have a good amount of miles on the oil at least 10,000 would be ideal. Make sure the engine is warmed up first, then drain the oil and try to let the oil drain for 30 seconds or so then take the sample. Then we can take a look at the sample and go from there. If you have any questions just ask.

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