Coolant Leak?

[ak46champ]

Hello All,

My 2000 6.5 developed a coolant leak some where in the back of the engine on the right side. I took the starter off and lowered the bell housing cover to get a closer look. As near as I can see, there is no residue of coolant between the head and the block. I have felt around and looked for discoloration. It seems to be coming from where the tranny and the engine mate. I cant see for sure, but the coolant leak seems to be coming from in there. I have looked all over with a mirror but cant see anything. A bore scope is the only way to see in there as far as I can tell. This is the only location that it shows up at. After driving for 40 min, there is a cup of 1/4 " to 1/2" of clean coolant, no other colors and the oil is black, no indication of internal leaking. This happens every trip. Once the engine sits for a while, it stops, no more leaking. It is not a constant leak either. I hate to pull the engine if I don't have too. Not to mention thats where it will get expensive. Has any one else had this problem. Any advise would be greatly appreciated.

Thank you!

[DmaxMaverick]

Probably the heater core connector at the firewall dripping down. Wrap it with a cloth and it will get soaked if that's it.

[ak46champ]

Looked at that too. It isn't that. The only place that it seems to be coming out of is the bell housing and starter.
Thanks though!

[DmaxMaverick]

Freeze plug or cracked block. That's all that's left back there....

[Plowboy81]

I had that problem once and it was leaking right at the water crossover pipe where it bolts at the heads. It was running down the valley around the injector pump and coming out the back at the same place. Also could be the quick disconnect. What I would do is go to autozone and rent one of those coolant pressure testers for 70 bucks and pump it up to 16lbs and look for the leak.

[ak46champ]

Thanks I will try that next!

[Robyn]

I agree with Plowboy.
There is a small hole in the back of the valley right at the bottom edge that allows any liquids that might get into that area to drain out.
A leaking fuel filter or IP will also drain out through the bell housing.\

Getting agood look into the valley can be tough without removing the fuel filter but you should be able to see enough to get a hint.

There are block off plates on the heads right behind the intake.
These are sort of oval in shape and are held on with two bolts. These are the countparts to the ports where the crossover is bolted on up front.

The coolant pipe that feeds the heater from the RH front of the crossover could be an issue.
It has a welded on clip about midway down the engine that bolts the pipe to the intake.
If this cracks it can drain coolant into the valley area.

Here are the options

Head to block, soft plugs, crossover at the front, blockoff plates at the rear. Heater transfer line. Water crossover (Tstat housing)
The 2000 will have a dual stat housing and it could be leaking slightly at the bottom edge and the coolant will drop straight to the valley floor from there.

There are no softplugs or any other access points in the back of the engine that can leak.

If its not the head to block joining and the coolant is coming out the bottom then it has to be one of these other spots.

Look it over well and Im sure it will jump out at you.

Good luck

Robyn

[ak46champ]

Thanks for the help, it turns out that is was the gasket on the right thermostat and the plastic quick disconnect going to the heater core. Had to do a little digging. Much cheaper.

[Plowboy81]

Thats good to hear. They are a very common thing to go bad on these trucks. That pressure tester works wonders.