blue smoke at warm/cold idle
- Thread starter magnethead494
- Start date
Valve that goes in the hose from turbo to wastegate. Usually maxes out a stock LB7 turbo to around 32lbs.
http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=43
http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=43
That says increases pressure...I was asking about reducing it if there is a need for it. We don't know what all has been done to the truck. It is set up for heavy towing/hauling, but the blue smoke is concerning. It goesmaway just off idle.
Might be a good idea to ask if there's anyone with EFILive close to you that would be willing to scan the truck for you. I think they could also download the tune and check to see if it is stock or not. I still think there's larger injectors and poor tuning in it.
Anyway, good luck with the truck. They are addicting. Have fun.
Anyway, good luck with the truck. They are addicting. Have fun.
Would blue indicate being lean, if black is rich unburned fuel? It goes away just off idle, but I haven't watched the boost gauge or egt's, to see any correlation. We know its at the window of needing injectors (36,000 on current set), but I thought that would be white? I haven't checked oil level for diesel.
I'm going to say your injectors are out. Keep an eye on your oil level. If it starts to "rise" on its own, definitely injectors.
Search lb7 injectors on here. There is tons of info about checking to see if they are bad.
Search lb7 injectors on here. There is tons of info about checking to see if they are bad.
If diesel goes lean it shuts off. Diesels are un throttled and are controlled by how much fuel goes in, so there is no such thing as to lean. Blue smoke is either oil getting into the intake and burning, low compression, or poor spray pattern from your injectors. White smoke is unburnt fuel, and black is over fueled.
Interesting! So there's no real throttle body, the pedal controls the PWM on the injectors, and the turbo self supplies the air?
We use Lucas stuff exclusively for all our vehicles, is Lucas fuel injector cleaner fine, or should we use seafoam or something else?
How would one do a,compression check on a diesel? We have leakdown and compression equipment, but they use the spark plug hole.....
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i personally wouldn't use seafoam, stick with additives specific for a diesel.
you can do a compression test like a gasser just remove the glowplugs.
So our Lucas stuff is fine?
I didn't know diesels still had glow plugs. I thought they were a thing of the past.
What PSI is normal? I'll have to see where our gauge maxes out at. We aren't trusting our 20 year old leakdown gauge, but it shows our race motor as less than 5% with gasports so it might still be accurate.
So i guess there's 2 things that everybody is pointing at...
1. Clogged injector nozzles/bad fuel -> run injector cleaner = simple
2. Poor combustion -> low compression/oil getting in combustion chambers -> leaky intake/head gaskets or injector cups -> leakdown/compression test = detrimental
Since it clears up off idle, here's my thoughts...
1. combustion pressure is enough to over come oil pressure (leaky head gaskets or injector cups or piston rings)
2. boost pressure is enough to overcome oil pressure (leaky intake gaskets)
3. longer pulse for more fuel overcomes losses of clogged injector
Am I working in the right direction?
in order
#1 get your balance rates checked, simplest place to start. either with a V2, tech2, or edge CTS, or other similar touch screen monitors.
#2 as far as fuel additive goes it cannot have any alcahol content in the additive itself to be safe for diesels. check your product.
if yours is not compatible do a quick forum search and there is literally a bajillion threads about fuel additive so i will not even start that war.
#3 try this also http://www.duramaxdiesels.com/forum/showthread.php?t=36198&highlight=upper+injector+cleaner
its not for the tank but a procedure you do to clean out the injectors (check post #11 i think.
#4 after all the easy stuff is done and if everything checks out then move onto a compression check.
also do you have any smoke coming out of the crankcase breather on the front of the motor or out of the oil fill tube?
Dad is out driving the truck right now for a quick drive, so we will look at it when he gets back.
Looking at that log, all 8 injectors were done at 40,000, but 1,3,5 were left out at 91,xxx. So those three are considered suspect at this point.
Can somebody translate the middle entry of middle photo? "4-29 reprogrammed spoons(?) for 235/85/16"
Edit- dad thinks it says reprogrammed speedo.
Theres a gap from 11 to 13, but cover says to change fuel filter every 15,000 but last documented change is marked a question mark between 95,000 and 100,000. It has 126,000 now so it was either changed undocumented, or it's due 2 times over. Where is the filter located?
Looking at that log, all 8 injectors were done at 40,000, but 1,3,5 were left out at 91,xxx. So those three are considered suspect at this point.
Can somebody translate the middle entry of middle photo? "4-29 reprogrammed spoons(?) for 235/85/16"
Edit- dad thinks it says reprogrammed speedo.
Theres a gap from 11 to 13, but cover says to change fuel filter every 15,000 but last documented change is marked a question mark between 95,000 and 100,000. It has 126,000 now so it was either changed undocumented, or it's due 2 times over. Where is the filter located?
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Didn't you get it from a dealer? Why not take it back and have them hook the tech2 up? They can look at balance rates, rail pressures, and get somewhat of an idea of the health of the injectors. A compression test isn't that big of a deal as long as no glow plugs break off. You should have around 400psi compression pressure. You'll need the Duramax glow plug adapter. Harbor freight sells a pretty nice diesel compression tester kit for around $70 that has the Duramax fitting.
Fuel filter is on passenger side of engine by battery, they are a bit tricky to get a wrench on if to tight to loosen by hand. If it won't come off by hand I either pull the battery or wheel well.
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Fuel filter is on passenger side of engine by battery, they are a bit tricky to get a wrench on if to tight to loosen by hand. If it won't come off by hand I either pull the battery or wheel well.
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So the smoke seems to have gone away. We let it cool down, I ran all the RPO codes and went out and found the block heater cord (wrapped around the coolant overflow tank..smart!...except not where manual says it should be) and hunted down the trailer harness (found out it doesn't exist, have to buy it). Then fired it up, temp gauge was still bottomed out, and no smoke at idle or off idle. Ran it for 5 minutes or so, then shut it off.
May have just been bad fuel or something. We're still gonna throw some injector cleaner through it.
May have just been bad fuel or something. We're still gonna throw some injector cleaner through it.
I spoke too soon. It comes back only under certain circumstances. I couldn't get it to do it on camera of course. But off camera, I was coasting/engine braking down a hill. Then I went to back into a parking spot, and it started spewing blue smoke from when I put it in reverse, until I put it in park.
When coasting/engine tracking, it has a ch-ch-chg-ch-ch-chg-ch-ch-chg, like it has a minor miss. Which being fuel controlled, I can understand. It doesn't do it under power.
I'm wondering if the two are related. Oil pressure stays good, but I'm starting to wonder if a turbo seal has gone bad, and it's sucking oil through under coast/back load.
I have photos and videos coming.
When coasting/engine tracking, it has a ch-ch-chg-ch-ch-chg-ch-ch-chg, like it has a minor miss. Which being fuel controlled, I can understand. It doesn't do it under power.
I'm wondering if the two are related. Oil pressure stays good, but I'm starting to wonder if a turbo seal has gone bad, and it's sucking oil through under coast/back load.
I have photos and videos coming.