How/Why would the small, 5/16 hose get plugged? Can I just flush that section of the cooling system to see? No harm, right?

 

Before you take it to the shop, do the inline thermostat conversion and run the truck with the cap one turn loose. That will take care of any trapped air and should settle your temp swings down. Then you can get a solid baseline on where the coolant is going

 

Inline Tstat was in when I bought the truck. How would the system create a vacuum? Heat (in the cab) is also fluctuating. Sometimes toasty sometimes nothing - within the same trip.

 

Open the cap or take it off, warm up the engine until the thermostat is open, rev the engine to 2000 rpm and hold it there for 45 seconds. That will flush all the air out. If that does not resolve your issues remove the thermostat completely from inside the housing.

 

Just following up - ends up it’s a slipped cylinder sleeve. This allowed exhaust into the cooling system and a massive air pocket to roll around. Looks like I’ll be getting out of the Disco business. Thank you all for the help trying to figure this out.
Anyone interested in picking up a new project truck?😬
Or do y’all have any thoughts on what to ask if I was going to sell an 04 that needs this kind of work?

 

location?

 

Upstate SC

Anyone had any luck with the LS Swap?

 

There's a whole section of this forum on engine swaps, including the LS swap.

 

doesnt sound like hes gonna spend the money and the headache of any swaps let alone a ls swap which is from what i read is a total nightmare with finding engines kits eletrical unless you have your own shop and know the tools this is not a good financial option, was there not a couple guys on this forum that tried to create kits and was just too much involved. they gave up.

 

The LS kit is back in production. I think if you don't try to cut every corner or nickel and dime on sourcing parts for the swap it's not that complicated (in theory). Buying a block with the correct ECU and harness isn't that hard, might have to spend a little more but sure beats hunting it all down individually. Wiring isn't hard, it's tedious and time consuming. Plus seems like most in the swap thread didn't take the time to rebuild the LS before dropping it in, so all new gaskets and wear parts need to be factored into the cost imo. What's the point of all the work if you don't reseal/refresh a totally unknown motor.