I own a Range Rover 4.0 GEMS 1999 with 160k miles on the clock.
I've owned the vehicle for about the past 10 years and it's been an honest and reliable motor for me over the past 100k mls.


It started overheating which I traced to a leaking inlet manifold gasket. I replaced the gasket and things were OK again.


2k miles ago, I replaced the thermostat basically through guilt as I'd never replaced it before. 2kmiles later, it started to overheat again spewing coolant out of the header (expansion) tank. Blown head gasket!


I pulled both heads (adios heat shields, they were so rusted, I had to cut them off) and reground the valves, re-cut the valve seats (negligible wear on guides - must be good valve geometry!) replaced with new stem oil seals gaskets etc. As I was 'In' there, I also replaced the water pump. I even treated it to a new hose set.


It still overheated.


Last week, I replaced the radiator as there may have been a problem with it's age and mileage, and I'll admit to also pouring a couple of bottles of Barrs rad seal into it during the collant leakage issues until I could get to it.


After installation, I let the motor idle for about 5 mins with the header tank cap off, blew out the small dia. hose from the top of the rad. to the header tank to clear but after about 5 miles, the temp gauge pegged and the light came on.


I pulled over and popped the hood. The heater blew fine, but it didn't throw out any heat from the vents. The coolant was boiling and again, spewing out of the overflow hose of the header tank.


What's going on here? I'm out of ideas.
Appreciate assistance
RogeR

 

you don't say if the heads were decked, i imagine so.

So you put the Barr's in before you replace the t-stat and radiator?

have you bleed the system properly? it does not sound it; if your not getting heat.

assuming you flushed the system good, before replacing the t-stat and radiator and have properly bleed the system; i would look at your new t-sat.

if not time to check for co2 in the coolant.