I`ll try to explain what is happening and would like to know if anyone else is having the same problem. I have 7756 miles on my truck and have put coolant in it 3 times when the level gets about 3/4 in. below the cold level when the engine is cold. No apparent leak anywhere and none in the oil that I can tell. Have changed oil at 5500 and didn`t notice ony coolant in it, BUT, there is a small oil leak at the connection where the turbo tube comes out of the cooler. I am told that this oil comes from the PCV vent system and circulates thru the cooler and back into the engine. When I put the boost gage connection on the turbo line I noticed a film of oil in the tube, but this leak seems to me to be more than it should be since it is getting oil on the frame and fender liner and when I get under it and see a drop formed on the tube connection it`s kind of brownish yellow in color. The truck runs great, it`s a real " Rip Snorter " compaired to the LB7 I had and gets about the same milage which I can`t complain about. I took it to the dealer awhile back and was told the oil leak at that location was normal and to watch the coolant level a while longer. Anyone have any ideas ????

.... I took it to the dealer a while back and was told the oil leak at that location was normal and to watch the coolant level a while longer. Anyone have any ideas ????

NO oil leak is "normal" :eek:


I would ask the dealer to pressure check the cooling system and run a compression check on the engine. A leaking head gasket could cause the engine to suck coolant.

A defective/leaking EGR valve could also cause coolant to be sucked into the engine and eventually burned or blown out the tail pipe. DexCool is orange, so I would suspect it may turn "brownish yellow in color" when combined with dirty engine oil.

I would NOT accept the truck back until they find and fix any oil leaks and determine why you're losing coolant and fix it. If they give you any hassle, ask to see the GM rep. If that doesn't work, call the GM Customer Service Hot Line and tell them you are not satisfied.

You may need to go to a different dealer!

Good Luck!

Keep us posted on our outcome. :)

NO oil leak is "normal" :eek:


I would ask the dealer to pressure check the cooling system and run a compression check on the engine. A leaking head gasket could cause the engine to suck coolant.

A defective/leaking EGR valve could also cause coolant to be sucked into the engine and eventually burned or blown out the tail pipe. DexCool is orange, so I would suspect it may turn "brownish yellow in color" when combined with dirty engine oil.

I would NOT accept the truck back until they find and fix any oil leaks and determine why you're losing coolant and fix it. If they give you any hassle, ask to see the GM rep. If that doesn't work, call the GM Customer Service Hot Line and tell them you are not satisfied.

You may need to go to a different dealer!

Good Luck!

Keep us posted on our outcome. :)


Question How will a defective egr valve casue coolant to get sucked into the engine? The only way that i think this could happen is if you had a problem with the egr cooler.


Oil seepage from turbo charge air cooler hoses, or charge air cooler hose.

Due to the closed PCV system on the 6.6 LLY engine it is normal to have oil residue in the air charge cooler hoses and pipes.
The oil will migrate to the lower areas of the air charge cooler system and may cause customer concerns of oil seepage.As far as where your coolant is going good luck.

Just got back from the dealer, and the tech said blocking the EGR could cause a coolant loss, but didn`t say where the coolant would go. Also he said that the moisture in the turbo line was from humidity in the air that wasn`t being burned off because the EGR was blocked and the oil was from the PCV fumes and was not getting hot enough because the EGR was blocked and was puddling at the lowest point and oozing out from turbo pressure. I`m lost now. Is the EGR and the PCV system connected ? I told him that the coolant loss was 5 to 10 times more before I blocked the EGR. He didn`t have an answer for this but did say that the moisture leaking out with the oil was not coolant. It`s the same old story you sometimes get, if they can`t dazzle you with brilliance, they try to baffle you with bullsh*#t.
Should I take out the EGR block and see what happens. I remember it was leaking oil at the same place before it was blocked and had the same coloration.

I still say he is FOS!!

NO EXTERNAL LEAK IS "NORMAL"!!!

Blocking the EGR does NOT have anything to do with causing oil leaks or coolant leaks. However, I believe that a leak in the EGR cooler could cause coolant to be sucked into the engine.

If you do decide to pursue this with the factory rep or another dealer and want avoid any hassles, you should at the very least, remove the EGR blocker and contact Fingers to see what you can do to temporarily deactivate the FingerStick, just in case they probe your truck with a Tech 2. You don't want to give them any excuse to void your warranty when your mod has nothing to do with creating the problem.

I would NOT accept ANY leaks from a new truck!

I would NOT accept ANY leaks from a new truck!


NUFF said...I totally agree with ya. Its a brand new truck for crying out loud!!! C'on!!!:eek:

Anyone know of a quick way to contact Fingers. I`m taking a 600 mile trip this weekend and would like to take out the block and disable the stick if I can without taking it all the way out.

Your right I wouldnt want a leak on my new truck either and if it has a coolant issue then i would want it fixed, but you are not going to be able to fix the oil seepage at the intercooler pipes.

bruins499, Thanks for the info. From what I`ve been told about the leak, I`ve about come to the same opinion. Tell me something, is the EGR cooler the silver tube on the upper right side of the engine and has the EGR flange at the fire wall end where the blocker plate is installed. How do you check for a coolant leak in it and does it in anyway tie into the PCV ?

Do you appear to have any oil in the plastic coolant resevoir?

A slow leak can be a botch to detect. Theres only 3 places for the coolant to go so if theres no visual leak it would have to be going in the oil or out the exhaust. While monitoring the expansion tank level per the dealer it wouldn't hurt to get an oil analysis to confirm the absence of coolant since a little is hard to see visually. As far as coolant getting in the aftercooler hoses I can't think of anything but a leaking EGR cooler. Have you noticed a coolant smell coming out of the exhaust when the engine is in the warming up stage?

No, there is no indication of oil in the coolant resevoir.
I did wipe a drop of oil off the leak at the intercooler tube joint and it was gray color which to me means water, but I can`t figure out how it would get into the intercooler line.
I tried to take the egr block out this afternoon but couldn`t get the outside nut off so I`ll wait til I get back from this weekend trip. I still can`t figure out how the tech thinks the egr has anything to do with water in the intercooler tubes.

a bear,

I`m still not clear on how a leaking egr cooler could let water into the intercooler tubes. Where does the exhaust gas go when it leaves the egr valve. If it was leaking wouldn`t the water go into the engine and not the intercooler tubes ?
I haven`t noticed any odor in the exhaust except diesel.

I am not hi-jacking the thread but my transmission leaks and the dealer said that was normal and would stop with time. BS.

a bear,

I`m still not clear on how a leaking egr cooler could let water into the intercooler tubes. Where does the exhaust gas go when it leaves the egr valve. If it was leaking wouldn`t the water go into the engine and not the intercooler tubes ?
I haven`t noticed any odor in the exhaust except diesel.

The exhaust gas leaving the egr valve goes to the suction side of the turbo then to the intercooler. With the blocker plate still installed the coolant flow through the EGR cooler can be bypassed while monitoring the coolant level but you may not want to go that far since the truck is still under warranty. It would be a good check though.

a bear,

That being the case, I can see how a leak in the egr cooler would let water into the turbo tubes. Does that explain why it`s not losing as much coolant since the egr was blocked ? Thanks again.

Assuming your leak is the coolant side of the EGR cooler I can't see how blocking the gas side would make a difference.
Just thinking beyond the EGR cooler I wonder if the gray drops from the intercooler tube might be oil with air beat into it. Is it possible to catch enough to allow it to separate in a small container or post a pic. For the time being and since it's a small leak I would at least catch an oil sample for analysis. Then you would have the coolant to oil segment eliminated. FWIW I don't think the leak is fast enough to cause increased wear to the engine while troubleshooting the problem even if it's getting in the oil so in that respect you're lucky. Hopefully the EGR cooler is the culprit.

Thanks again. Gotta go for the weekend but will watch it and report back when we get back.

Good luck finding the problem and have a good weekend, a good dealer here is the key, I ended up driving 200 miles to find a good one. Makes all the difference.

You are always going to get some oil vapors into the intake side due to the closed crankase ventilation system. But I can tell you that my 2006 LBZ is 12 months old and I have over 13,800 miles with ZERO leaks anywhere.

I still think that if coolant is being lost and excess fluids are accumulating in the inake passages, I would look for a leak around the EGR cooler.

a bear's suggestion of getting and engine oil analysis is a good one. Blackstone Labs (http://www.blackstone-labs.com/free_test_kit.html) will run an oil analysis for $20. You may want to call them at 260.744.2380. They are very knowlegeable and very helpful. They will even send you the oil sample kit and you don't have to pay until you send in the oil sample. If any coolant shows up in the oil, this would be excellent ammunition to force the dealer off his A$$ and fix the truck! --If the oil analysis shows that there is a problem, you might even be able to get GM to reimburse you for the oil analysis.

You can contact Fingers via PM.

Keep us posted on your progress.

Good Luck!!
- Ray

I pulled my blocker plate out the other day and it was covered in oil on the EGR side. Any Ideas????

I pulled my blocker plate out the other day and it was covered in oil on the EGR side. Any Ideas????

Probably just a little oil from the crank case vent. Nothing to be concerned with....

Got back yesterday from a 4 day trip, about 700 miles round trip, and the coolant leak seems to have cured itself but the oil leak is still there and getting a little worse. When I park the truck for an hour or so there will be 6 or 7 drops of oil from the first tube connection coming out of the intercooler. Does this sound normal and if so . why doesn`t it go on into the engine. There is still a very noticeable amount on the frame and fender liner also. I read on some thread where someone had the same problem and the dearler said the turbo was leaking oil and should be replaced. Anyone know what happened in that case. I`m thinking about removing the egr blocker plate and finger then running it for awhile before taking it back to the dealer. Don`t want to give them any excuse to tell me it`s my fault.