Mack V8 Coolant in Oil

[Fish 0]

I have a 1990 RW713 with a V8. I recently had some issues with it starting after setting for a month. I finally got it to start and after running for a few miles to warm it up I discovered a lot of blow by that looked like steam. I brought it home and pulled the dip stick and it was way over full and looked milky. I decided to make a few more trips to town and the more I ran it the better the oil looked and the coolant level is staying up after all that. I then took an oil sample and the results came back as antifreeze. I'm wondering if anyone has had this happen and where I should start looking? The confusing part to me is why it seemed to quit loosing coolant. Thanks for the help. 

[JoeH 237]

Not sure, but don't run it with antifreeze in the oil! Youll destroy the bearings in the engine. Not sure what the V8s used for an oil cooler, I'd suspect that or a head gasket. Do a compression check and see if you have a cylinder with low compression.

[JoeH 237]

Describe the hard starting. 

If it has a bad head gasket and coolant leaked into the cylinder you can break a crankshaft trying to start it. Water doesn't compress.  My dad broke one that way on our Case wheel loader years ago. 

If a piston is waterlogged it'll struggle to get passed compression stroke on that one cylinder, even if batteries are good.

[Rob 1,405]

Square cut "O" ring at the back of the water pump, oil cooler pack sealing rings, head gasket, all suspect. With the engine running is there bubbling in the radiator? If so, head gasket or head cracked. Not a bad idea to rebuild oil cooler unit regardless. 

[Fish 0]

The hard starting was due to loosing its prime. It cranked over easy but wasn't getting fuel.  To answer Robs question, I did look in the radiator for bubbles and there wasn't any. I sure am disappointed that this happened, I haven't even got to use the truck yet ant it broke down sitting in the driveway.  Any thoughts on why it quit loosing coolant? I realize it didn't fix itself but maybe thats a sign of what the problem is. 

[Fish 0]

Thanks Rob. That sounds like a good place to start. There Is guy here locally that I used to haul with that just might have a service manual. I better give him a call.   My old truck does sound good, it has dual exhaust with a set of Dynaflex chrome muffler stacks.  Brings back a lot of memories of riding with my dad in the one he drove. As far as parts go for things like that oil cooler, and head gaskets, where is a good place to buy them? Will any Mack dealer be able to get them for me? 

[Fish 0]

Hopefully exploring those two things i will find the problem and not have to go searching for a head gasket failure.  I agree with you about theses new trucks. I just sold a 2017 Western Star with a DD16 Detroit. It was a damn good truck and I really liked that engine.  For me Financially It didn't make sense to keep a newer truck more than 3 or 4 years. They seem to start costing you money and down time IMO. 

[Fish 0]

My goal is to put a dump box back on it. Just need the box , Ram, and cab controls. Its just going to take time and money. Those two things don't always go together.

[Rob 1,405]

How long of cylinder do you need. I have a good one from an R model the bed rusted away from. I think it was a 14' bed but the cylinder was in good condition:

[terry 351]

That tank and hoist looks like an older galion set up.    terry

[Fish 0]

I’m looking for a 14’ bed. I will keep that one in mind if I come across a bed. Thanks 

[Rob 1,405]

It was Galion or Heil but I can't remember for sure. The truck was a 1972 R-685 converted to a dump truck back in the late 1970's. I still have most of the carcass but it was really eaten away.

I'd have to stroke that cylinder before I'd let it go to ensure it's a good one. Worked the bed just fine but that's been about 10 years ago and it's been setting since. No real problem to build a jig to both allow extension and push it back down with my shop pump.

 

[terry 351]

I had an older Dm years ago with that tank and hoist, it was a Galion, ran it a lot of years with no problems.    terry

[Rob 1,405]

I had repacked the cylinder and installed a new pump the last four or five years this truck ran hauling asphalt. When it finally was put out of service by DOT it came to me for parts. I drove it home about 70 miles with "Momma" in chase and started robbing parts from the carcass as I've done for many years now.

What put it out of service was one of the rear brake drums finally broke apart from no material thickness left in the surface and they got caught running it that way. 

Edited March 8 by Rob

[JoeH 237]

7 hours ago, Rob said:

I had repacked the cylinder and installed a new pump the last four or five years this truck ran hauling asphalt. When it finally was put out of service by DOT it came to me for parts. I drove it home about 70 miles with "Momma" in chase and started robbing parts from the carcass as I've done for many years now.

What put it out of service was one of the rear brake drums finally broke apart from no material thickness left in the surface and they got caught running it that way. 

Wow. We replace our drums when they get 1/8" lip inside. We don't run a nice new fleet, but we maintain our trucks to be safe.

[Rob 1,405]

Opposite of what this now defunct operation did. Minority owned business, high school vocational program repairs, six inch splices in air lines, wire nuts in the electrical, worm drive clamps on air brake lines etc.....

[JoeH 237]

Nothing wrong with minority ownership, but if you're going to own trucks you have to keep them safe! If you can't afford to take trucking seriously then get out of the business before you kill someone! (The rhetorical "you", not you!)

[Fish 0]

On 3/7/2019 at 5:03 PM, Rob said:

Square cut "O" ring at the back of the water pump, oil cooler pack sealing rings, head gasket, all suspect. With the engine running is there bubbling in the radiator? If so, head gasket or head cracked. Not a bad idea to rebuild oil cooler unit regardless. 

I have an update on the V8 with coolant in the oil.  I pulled the pan yesterday  and pressurized the coolant system. After an hour or so I started noticing antifreeze leaking from the oil pump.  After removing the tube from the oil pump up to the block where it meets the oil cooler, there was a fast drip of antifreeze coming out of the oil cooler. I ordered O rings and gaskets to reseal  the oil cooler and the square cut o rings for the water pump.  Hopefully that will fix the problem. Thanks JoeH and Rob for the help. 

[fjh 518]

Very lucky on your part! Liner orings was on my mind Just be aware it is very important to keep your antifreeze in good standing in these as in most diesel engines ! You still could have a cooler tube failure be well advised to pressure test before putting the pan on! IF  you do not change the coolant please do so 
I would!  If your pulling the pump most parts guys forget to order the gasket for the bypass tube on the top and the the lower pump rad gasket adapter ! Just saying!

Edited March 15 by fjh

[Fish 0]

Yes I feel really lucky!  Left it pressurized all day and never saw any signs of coolant coming from the liners.  I will remind my parts guy to order those gaskets. Thanks

[Rob 1,405]

Yes, keep good maintenance on your coolant. One of my trucks ran neglected coolant and the liners perforated through. I could see light shine through when working a "snake light" in through the block while under the truck with the pan off. New liners are NLA and I had a set made at $175.00 each!!!! When you have that oil cooler pack off the truck for rebuild and after resealing it, block the oil path discharge opening and pressurize it to 75psi while it's under water to check the core integrity. That's just a suggestion but I hate doing something twice.

[Fish 0]

I found a oil cooler  core online for an E9 for $338. I’m assuming it’s aftermarket. I can get an OEM one out of Canada for $795.  Is it worth trying an aftermarket one if mine is no good?

[AZB755V8 425]

Not mentioned yet. While you have the oil pump off put a NEW pressure relieve spring in the pump. It is a $15 part that does fail over time. Just a good precaution. 

[Fish 0]

I will have to order one. I wondered what that spring was for. Thanks

[Fish 0]

Finally got all the parts to rebuild oil cooler including new core. Resealed the water pump. I got everything back together, pressure tested the cooler like suggested and no leaks. Put the cooler back on and filled the radiator. Pressure tested the coolant system and did not find any leaks. I put the pan back on, filled it with oil and test drove it.  I'm still getting moisture dripping  out of the blow by tube. The oil fill tube on the valve cover has a lot of moisture as well.  Could this be left over coolant from before or should I dig deeper? 

[fjh 518]

Did you pressure test with the pan off after the second time to check your work?

Yes the moisture can be trapped in the valley and  fuel pump and can take a while to cook off!

Edited March 29 by fjh