Coolant in Oil

[BenDeez]

I know this topic has been spoken about, I've read through it. I have a '91 M1038 6.2 and still very new to me.

I drained the coolant and was very surprised at how little came out, a little over a gallon. As I was draining the oil the other day the first few seconds was pure green coolant, then the oil that came out had that green swirl-line mixed with it. It was a lot of coolant.

1.) Before I go tearing apart the heads, is their any easy/simple places to look to eliminate contamination?

2.) IF this is head gaskets or worse do I upgrade to the 6.5T at that time? I understand the cost difference but it seems as though replacing the head gaskets is a **** of a project. I'm looking to avoid opening up the heads, having to figure out where the coolant is coming from and then find more issues that require addressing. Or maybe this just seems more overwhelming than it is

Long term plan was to get the 6.5 at some point anyways, certainly not this soon though.

Anyone out there who has done the engine switch and done an in truck overhaul? Thanks,

 

[ken]

I was just in you shoes. I ended up replacing the 6.2 with a GEP6.5. The passenger side head blew the gasket and cracked the head on mine. Pulling the passenger side head in the truck was not easy. You could do a compression check and maybe yours blew the head gasket or head on the drivers side. That could make your repair much easier.

 

[Action]

Did you check the oil dipstick before draining it?
Maybe someone just put coolant in the oil fill. That has happened before.

 

[tage]

Did you check the oil dipstick before draining it?
Maybe someone just put coolant in the oil fill. That has happened before.

the things privates do....

 

[BenDeez]

I did check the dipstick first, it showed a very milky, chocolate milkshake looking oil. I was hoping it may have been something so simple. Do you suggest a drain everything, fill it up properly and run it for a while and see if I have the same situation before pulling everything?

Ken, Did you start the process with the intention of just replacing the gaskets? That is what I would like to avoid. A few other questions- Did you buy the 6.5, if so where? New, remanufactured? The TM says it's an 11.5hr job, how long did it take you? What are the big components that need to be changed when upgrading to the 6.5? Do you have the 242 or 218?

Any advice that you wish you had prior to doing so would be helpful and help me to figure out which direction I should go. Thanks,

 

[doghead]

Do a coolant system pressure test.

15 minutes, and you will not get dirty or spend money doing it.

Start there.

 

[ken]

Ben,
It first I just wanted to repair the engine in it. Because the mileage was so low. As I got more into it I changed my mind and decided to swap. I have a spare good 6.2 from a CUCV that I planned on installing. But I came across a GEP6.5 and purchased it instead. I still have the 3 speed TH400 and NP 218 Tcase. I kept them only because of cost. The places I drive it are back streets and off road. I almost never break 40 MPH. So I could not justify the cost of swapping to a 4 Speed.
Yes the TM said 11.5 hours. It took me closer to 50. But that's because I'm older and have a broken back/back problems from a motor cycle wreck. So I 20 year old private could swap one much faster. I also was in no hurry.
I purchased the proper metal engine sling from the evil auction site to do it. I had to modify my shop crane to be long enough the get it out. Along with removing the front bumper.

 

[BenDeez]

Thanks Ken, I'm going to do the coolant pressure check as soon as I get some time. Might be a couple weeks, will update

 

[NV555]

I had coolant in the upper end. I did end up putting a hole in the block after 400 miles.

 

[Action]

I had coolant in the upper end. I did end up putting a hole in the block after 400 miles. View attachment 718104View attachment 718105View attachment 718106

You are only supposed to put up to 15 psi for the pressure test!

 

[BenDeez]

Outcome: Finally got some time to do the pressure test, but never got around to it. I pulled the oil pan and saw one piston was scored on the outside. Push rod was bent and twisted. Seeing this I don't know what failed since I never removed the head covers but I'd guess it was the gasket. It makes the decision must easier, I'll now be getting a 6.5 with the 4L80 and putting it in. (well, I won't be, but someone will be).

 

[98G]

Push rod or connecting rod?

Thanks for the follow up by the way.

 

[Nomadic]

I had coolant in the upper end. I did end up putting a hole in the block after 400 miles. View attachment 718104View attachment 718105View attachment 718106

That isn't going to buff out.

 

[porkysplace]

That isn't going to buff out.

Just needs a little J-B Weld.

 

[tage]

Only can use the jb weld if he has the missing chunk.
Just remove that rod and run it until she really dies

 

[BenDeez]

Correction: Connecting Rod.