L.T.

I have a 2006 cummins and I have noticed a few drops of oil on the garage floor. They seem to be under the front of the engine. I haven't seen a leak. Is this normal for the diesel? Thanks for the help.

Louie

Jmac

I would crawl under your truck if you can and check your crankcase breather hose. If you can see no other leakage it might be coming from there. I think it's considered normal but maybe someone else with more knowledge will chime in.

If you don't know the crank case breather hose comes off the drivers side of the motor just under the black plastic valve cover. Follow the hose down and give it a check.

Jamie

lucey

Could this be the infamous lift pump leak ? Can that happen on the 06 ?

djbikeman

I had that happen on my 06. It ended up being a plug leaking on the accessory cover on the front of the motor. It was replaced under warranty.

If you are getting oil coming down the front and dripping near the crank sensor, that is probably what it is. If you look from the top, you can see the plug on the front right side of the accessory cover. You should be able to see if the leak is coming from there. The plug is about 2" in diameter.

If you push the fan belt away fron the motor, you can see the plug clearly from the top. Or get under it and follow the oil up the cover and see if that's where it's coming from.

My dealer wanted to replace my CP3 right away. It was not a diesel fuel leak, it was an oil leak.

Here is a pic of where my leak was coming from.

Jonesey

That would be the infamous CP3 injection pump leak. It is on the left front of the engine, Crawl under the truck and look at the bottom of the pump. If it is leaking, you will see fuel on the wiring below the pump. I have never seen a drip hit the driveway on mine from the crankcase breather tube which is on the same side of the engine, but farther towards the rear.

Lrdchaos

You don't own a 6.0 so no it's not supposed to leak oil anywhere. Get it fixed while it's under warranty.

L.T.

I looked under the truck and I think it is the CP3 injection pump like Jonesey said. There are also a few drops on the ground under the breather tube. I will take it to the shop next week. I guess it is ok to drive it the way it is until I can take it in. Thanks again.

Louie

djbikeman

Is it leaking oil or diesel fuel?

If it's oil, it's not the CP3. if it's diesel fuel it is. That plug I told you about is right above the CP3, so it will still look like it is coming from it.

WSA308

I read in someones sig that the Cummins doesn't leak oil, it sweats horsepower...

L.T.

Well I looked again and it is oil and I believe it is the cover you talked about above the CP3. Thanks again.

ftltmp

The front side of that pump has oil in it, and the back side is fuel, so it could very well could be oil.

djbikeman

Many people have had fuel leaks from the CP3 (including myself with my last CTD), but I have yet to read about anyone leaking oil from it. I wasn't aware that the CP3 was oil fed/lubricated in any way. I was under the impression that it was lubricated by the diesel fuel it is pressurizing. Please correct me if I am wrong as I am learning a lot from this forum.

From my own experience with an oil leak on a 2006 CTD, I am guessing it is this accessory plug that is leaking. I had that plug replaced and resealed and it has been fine since.

ftltmp

I did not know either until I had talked to our cummins mech the other day, I guess it would make sense if it is gear driven that it would have to have a way to lubricate it.Just my .02

rich2500

only the cp3 drive gear gets oil on it,the oil does not enter the pump at all.the plug that is being shown as leaking is the plug to accsess the cp3 gear to remove it,just take a 3/8 ratchet and snug it up a little.

djbikeman

L.T.

Well hopefully that's all there is to it.

Thanks Rich for the tech info. I had mine at the dealer when Superduty helped me figure this one out and they had to replace it. From what they told me, they couldn't bill DC if they just tightened it and sent me home. Whether that is true or not, I don't know.