Guess its time for an overhead to be done on my C-16!!!

Like he said ^^ the green might be from the snake oil you added.

The first question would be has the oil level risen? If you have fuel or coolant going into the crankcase the oil level will rise.

Second question - has the coolant level gone down? And if so is it leaking externally anywhere? Overflow tube?

I wouldn't worry about it yet or get the bridges and Jakes done down there. Does CAT even make a service manual in Espanol?

Find a CAT shop with an oil lab or buy an SOS kit and mail it in.

I guess it couldn't hurt to have Speedy lube do a oil sample check for coolant if it will make you feel better but if it says bad then go to another shop for a second sample check if it will give you peace of mind.

You need to learn to do your own valve adjustment. It's easy and saves you good money. Buy a service manual.

 

As stated I wouldn't do an overhead if you do have problems all that will have to come off and be reset anyway. diesel dilution will usually start the cleaning process of internal parts that all the really dark oil sticks to and thus turn oil black really fast, coolant will have little green bubbles on stick after it sets overnite in the early stages before it really turns milky. My oil stays clean a long time and some have a funny tint to them, but I am not there looking at it and you are usually a guy doesn't get concerned over nothing I would definetly get a sample asap even a truck cheapo they will tell you if antifreeze or oil, It will make you feel better or worse lol. Good luck

 

I agree with everything said by Semi Crazy. As a former CAT mechanic, there are usually other signs that something is happening (increasing oil level, decreasing coolant level, milky, slick and thin, rough or greasy oil). An oil sample will tell all, and if done by a reputable business, will give you a great insight on whats going on inside your motor. Good businesses will also give a breakdown of what metals and materials are in the oil and where those come from(coolant, fuel, bearings, block metals, etc..)

I use Blackstone Labs for my samples on my personal truck. They will tell you all that I described and more, and they will keep a history of your samples for comparison, as long as you keep.up with your sample schedule.

And also, if you're even slightly mechanically inclined, I would do my own valve adjustments... They are fairly quick and easy to do in the driveway, and you'll save good money, along with knowing that the job was done 100% correct.

Oh, and I have always been hesitant to add anything into my oil. The oil that you're using should be the best that you can afford on a regular basis. If you're running a C-16, I would look into using a synthetic oil, possibly even a 5-W40. The synthetics can tolerate the heat of the newer emission engines a lot better than normal dino-based oils. And the 5-W40, will help with cold starts, as the oil is not as thick when its cold, but when its up to temp, it has the same viscosity as 15-W40.
But, back to my point...the additive and your oil may not be playing properly, or in other words, the additive package in the oil, may not be meshing well. The manufacturer of the oil has already included an additive package in the oil you're buying, and has gone to great lengths to ensure that they all work together for the betterment of your motor. Why throw money at another additive that may or may not play nicely with the one in the oil already?

 

my thoughts on Lucas, and other additives is they only thicken the oil, the only benefit I can see of this is if you are in need of a rebuild but don't have the money. they can buy you time. but short of your engine burning a gallon a day off oil, any other use is just throwing good money away.

 

Driver you said the truck is equipped with a gulf coast filter. Call jerry and have him send you an oil sample kit for $20. Take your sample and send it to him. Don't run the head do NOT have anything done with the motor. Explain your findings to jerry on the phone. When your truck is serviced (10k) all you do since you have a gulf coast filter is put the new filter elements in the gulf coast filter, add the makeup oil, and go another 10k and wait to hear from jerry if there's a problem. Since there's a bypass filter on the truck go through them not cat. Depending on when the filter was installed they can run in excess of 2 million without being torn apart. Oil is usually clean with bypass filters. Usually looks like new everything is cleaned up. Not saying things don't go wrong but jerry will tell you when something needs to he done to the truck or if you're okay with things.

I have not put the bypass filter on my truck yet I just service my truck every 10-12k and have a sample taken. My samples have all come back clean. The mystery green in your oil has me scratching my head coolant will turn it gray or a milky white color. Diesel is possible but I would think as others have stated that your oil level would rise given that issue. Your safest bet is to get a sample kit and send it off. Given the filter is hooked up your oil won't look much different after 1000 miles like it usually does. All you can do is take your sample don't go spending money until you know what is wrong with the truck. Running the head will throw everything off and you will be back to square one.

 

If you listen to people on here and do as they suggest let us know what was the problem (if any) after you find out what the green tint is. It could benefit someone else in the future. Hope it is nothing serious.

 

Good he should be able to give you the lowdown on your motor history as well if that filter has been on there for a while. Good luck bud keep us up to date.

 

The only time blowby should be looked at as a problem is when it becomes excessive or theres a large puddle after idling for a little while. Every engine breaths, and blowby is it breathing. The rings wont ever seal 100% off, due to them being clocked and rotating slightly. But, if you have excessive blowby, then that could signal other issues with the power packs, valve seals or other things..

Im not trying to tell you how to run your truck, just trying to give a different opinion...lol