Puking Coolant & Don't Know Why?

[MatthewH]

Okay, I have done a lot of searching and haven't found an answer, so,

in the past couple of weeks, my M1009 has been loosing large amounts of coolant for some unknown reason. There is no visible leaks on the engine itself, none in the oil, and it dosen't smell like it is burning it. I have installed a new cap, new thermostat, new heater core and hoses all the way around.The radiator is a little dirty, but not plugged by any means. This is a recent problem, as i have been driving it since may.
But i have noticed that it is overfilling the exapansion tank to the point of overflowing, spilling coolant inside the front fender and out the side marker light, coating the side of my truck. When the truck cools down, the coolant in the tank returns to the radiator, but always loses more than it takes back in, causing me to add at least 1 gal everyday, and that dosen't even get close filling it.
I'm lost as to the problem, and tired of filling it, so it has been parked until i can fix it. Any help or thoughts would be greatly appreciated
Thanks

 

[southdave]

flush and rod the rad. and replace the heater core if need be is my first thought what the oil look like?

 

[MatthewH]

I just changed the oil a month ago, so its black. I also replaced the heater core a couple months ago. The rad is a little dirty, but had one in a different truck that was horribly corrodied, and never had this problem, so i guess it could be. The coolant system was flushed when i got the truck in march, and fresh coolant put in.

 

[southdave]

have checked the timing or the air filter?

 

[MatthewH]

No i haven't. Please explain the reasoning for the timing, as i'm new to the whole diesel thing, and not sure what timing has to do with my coolant issue.
Thanks

 

[DokWatson]

Run it to operating temperature with the radiator cap off, might have air in the system. Sounds like a cap issue though, it sounds like its not working. Should be holding around 16 PSI, might try a different one and see what happens.

 

[MatthewH]

Run it to operating temperature with the radiator cap off, might have air in the system. Sounds like a cap issue though, it sounds like its not working. Should be holding around 16 PSI, might try a different one and see what happens.

When the problem started, I replaced the cap, with no good results. Per a mechanic friend, i removed the rubber seal on the plunger part of the cap, so it would still seal the rad, but allow air/coolant to flow back and forth to the tank without leaks. That was 2 weeks ago. I have reprimed the system, getting the air out, only to get to work, finding the rad half empty. Its 8 miles to work, maybe 15 mins of run time.

 

[Ken_86gt]

Just as Watson mentioned, my first thought is still radiator cap. Once the engine is cold- fill the radiator to the top, start the engine and try to top it off some more. Coolant should not come out of the top of the radiator on a cold running engine. As the engine warms look for continuous bubles air at the radiator cap (still cap off). If bubbles present it could be a head gasket. As it warms the fluid should rise and start overflowing the radiator- now put the cap back on. Let the engine idle for 5 or 10 minutes, keep checking how firm the upper radiator hose is, and its temperature. It should get firm and then after a while it will get hot once the thermostat opens up. Once the engine is up to its operating temperature the top hose should be about rock hard and hot. At this point it is normal for a quart or two coolant to have overflowed into the recovery tank. If the hose never gets hard then it is a problem with the radiator cap keeping the pressure. If the hose does not get hot but then overflows it could be the thermostat. If there is any deviation reply and we can try to troubleshoot some more.

 

[Ken_86gt]

Per a mechanic friend, i removed the rubber seal on the plunger part of the cap, so it would still seal the rad, but allow air/coolant to flow back and forth to the tank without leaks.

Your mechanic friend is giving you bad advice. You need the cap with rubber seals the way it came from the manufacturer. Doing what you said will cause the same problems that you are having. Time to find a new mechanic.

 

[466Navastar]

if its puking coolant - must be getting pressure in the cooling system from either a bad head gasket - or maybe some cavitation holes in one of the cylinders -----since you just got the truck you have no idea if cooling system was properly treated to prevent cavitation damage.

got to a shop that has a cooling system pressure tester---pump up the pressure to 15-20# and see if it holds....if it doesnt and you dont see any external leaks - you have an internal leak ---with coolant in the oil or some coolant in the cylinder that has cavitation pits

if it bleeds down - might take multiple pump up cycles to get enough coolant to be visible.....might want to disconect the hot wire to the injection pump when you try starting - in case its hydrolocked.......so you dont bend a rod

if its leaking from a cavitated cylinder - a sleeve or a block replacement is the only fix...if its a head gasket you will see where it leaked - when you take it apart....

good luck

 

[466Navastar]

Cavitation in enginesEdit

Some bigger diesel engines suffer from cavitation due to high compression and undersized cylinder walls. The result is pit holes in the cylinder wall that let cooling fluid leak into the cylinder.
It is possible to prevent this from happening with chemical additives in the cooling fluid that form a protecting layer on the cylinder wall. This layer will be exposed from the same cavitation, but rebuilds itself.

 

[466Navastar]

dont click on any of the links from above post ------I just cut and pasted - dont know why the highlighted links appeared

 

[armytruckdriverddsso]

I had similar problem with my wife's truck. I replaced the thermostat and it stopped.

 

[ODdave]

Sounds like a head gasket or cavitation to me.

 

[oddshot]

if its puking coolant - must be getting pressure in the cooling system from either a bad head gasket - or maybe some cavitation holes in one of the cylinders -----since you just got the truck you have no idea if cooling system was properly treated to prevent cavitation damage.

got to a shop that has a cooling system pressure tester---pump up the pressure to 15-20# and see if it holds....if it doesnt and you dont see any external leaks - you have an internal leak ---with coolant in the oil or some coolant in the cylinder that has cavitation pits

if it bleeds down - might take multiple pump up cycles to get enough coolant to be visible.....might want to disconect the hot wire to the injection pump when you try starting - in case its hydrolocked.......so you dont bend a rod

if its leaking from a cavitated cylinder - a sleeve or a block replacement is the only fix...if its a head gasket you will see where it leaked - when you take it apart....

good luck

A big old +1. Word for word.

My first thought when I read the title of this thread ... was Head Gasket.

oddshot

 

[Bob H]

Kinda sounds like combustion pressure leaking into the coolant system.
If it transfers coolant to the overflow tank when it is still cold it is likely a head gasket.

 

[captw]

coolant

I must agree with OD Dave and Bob H...my M1008 had coolant being blown out of the overflow tank...the cause was the driver side head gasket leaking between cyl. and coolant jacket ...milled the head slightly to clean up the damage done by the coolant forced through the area in the gasket, and no problem over the past 20,000 miles

 

[AllenEM]

I locked up a engine in my M1009 with the same problem. Head gasket or cracked head the 6.2's are know for cracking heads (so I'm told).

 

[Barrman]

I didn't see it mentioned above. It it was, sorry I missed it.

Try to do a coolant system pressure test. Pump it up to 14 or so psi and then see if it stays. If it does then you are back to cap and thermostat. If it leaks down, then listen through the oil fill, oil dip stick, air intake, exhaust pipes and anything else you can think of for air leaking to figure out where.

If you find nothing, try turning the engine over by hand and listening as you turn.

 

[MatthewH]

Since I have replaced everything but the engine and rad, i was betting the engine, but I know new parts aren't always good when you get them.
I'm gonna pressure check the system, and go from there.

Thanks