Losing Coolant

[6.5 Detroit Diesel]

Something I have been watching for the last little while, and it is starting to concern me. The truck is using coolant up, not a lot, but enough that I have noticed. I'm hoping a bad head gasket, but..? Any ideas?

[Robyn]

Very well may be a head gasket going away.
I would tear it apart and look at the gaskets before you get a catastrophic failure.
The gaskets generally go away between the end cylinders and the water passage.
It could be a cracked head too.
Are you seeing excess pressure in the cooling system and blow over from the coolant tank.
In short the only really good way to figure it out is to tear it apart.
You can pull the water crossover off and fill the head up and then start it and watch for bubbles.
The side having the bubbles is the culprit.
Unfortunately if one gasket is gone the other is soon to follow.
If you decide to replace the gaskets you must buy new head bolts too as they are a one time use TTY bolt (Torque to yield)

Poor design I know but thats life. Many engine have them now.

Hope this helps

Robyn

[Chris611]

How much coolant is it losing? I take it there is not puddle under the truck? I had a leak at the heater core hose quick connect that comes off the thermostat housing. It would leak slowly, but never left a puddle. I've also had the block heater start leaking. I was leaking from around the terminals IIRC. Is there any coolant around the overflow hose? Just some ideas. Hopefully it's something small instead of the head gasket.

Chris

[sailun]

Can you smell A/F under the hood ? My Dad's Expedition just had a pinhole leak in a hose near the firewall, you could smell it, but it would never puddle or drip.

[6.5 Detroit Diesel]

I'm going to take a look and see if maybe there is any loss happening in the heater lines. Engine rebuild is four months away so I really don't want to start it early. If it was a cracked head, then I would start right away.:(

[a5150nut]

Did yo check arround the thremostat housing where it attaches to the block? Mine loosened up on the stud where the right battery ground attaches. Wasn't real noticable but could smell it from time to time.

[bcbigfoot]

Water pump, heater core, thermastate housing, hose connnections, frost plugs anyone can slowly weep anifreeze onto hot engine components and evaporate without you noticing, after a while there usally becomes a green crusty tell tale sign of were the antifreeze is evaprating. Check that first, if not a pre-emptive head gasket, head bolts and check the heads might be in order.