Ohh man. This has been a long struggle, but today I was finally able to start up the Rover after a HG+timing chain refresh. I pulled the spark plug cables and the fuel pump relay and tried to prime it for about 20 seconds. When cranking, it still didn't want to turn-over right away. I gave it a short rest and another few seconds it turned right over. After about 5 seconds the oil pressure light went out and it continued to run without oil pressure loss or any trouble codes.

I did see the temperature start rising and shut it off at 220F. Checking under the hood, it looks like I have a leaky hose at the top of the lower intake manifold where the hose runs to the throttle body heater. I think it was running down the valley pan gasket and off the back of the block. No one has any tricks to get to that without pulling the upper intake off do they? I'll get to it this evening.

I'm hoping that's the only coolant leak.

 

Great news bro! Anyway, try to disconnect that hose and tap it directly without going through the throttle body heater. I had mine removed permanently but you can try temporarily to resolve some issues. Cheers
Gerry

 

UIM will not need to come off to replace, but it's easier that way

 

I have bypassed the throttle body heater itself. I left the original hose, disconnected it from the TBH, stuck a bolt in the end and tightened it up. It's good and tight on that end. It's the point where it starts on the lower manifold which appears to be leaking.

How did you tap and plug it directly?

 

No, I don't think you can plug that thing up
https://www.mscdirect.com/browse/tnp...FVRYDQodmjUKHA
I got this barb fitting and shortened the hose and connected them both together instead of plugging a blot there.

 

Is this the part where its leaking? red arrow
Bypass with red circle

 

Yep I found coolant and heard a hissing noise right at this connection.



Is there any benefit to connecting the two hoses? Currently I have both ends plugged since one is coming off the coolant reservoir. I also think I should be able to remove the Upper Intake Manifold, tighten that bolt and pressure test the system with it still off?

 

Turns out it wasn't the TBH hose but the hard plenum(??) hose which goes into the lower intake manifold. It was spewing out when I pressurized the system. I didn't have a gasket or an O-ring for this connection. It's possible I lost it. What should be there?

 

O ring ERR7202 > O RING COOLANT ELBOW DISCOVERY II/P38A RANGE ROVER 99-02, RND353, ERR7202 - Rovers North - Classic Land Rover Parts

> Coolant Elbow At Intake O-Ring (BOSCH) (Genuine Part # ERR7202 ) - Land Rover gaskets and seals from Atlantic British

It's also a good idea to put a very thin bead of RTV (like Hylomar ) around the flange and 3 bolt holes. Keep the RTV OFF the O ring.

 

I think it may be fairly common that after replacing the headgaskets other weak spots in the cooling system are revealed. If the system hasn't been fully pressurized for a while because of the headgaskets other problems may have been masked.

In my case within a few days after replacing the headgaskest a throttle body heater leak was revealed, and then, driving home from work, the old-style upper radiator hose blew out the bleed screw port.

It's a lot of fun to see the temp gauge spike a few days after you finish the headgasket job. But I somehow happened to have a golf tee and some duct tape in the truck and I was able to plug the house well enough to limp home. Happily, almost 50,000 miles later all seems good with the cooling system.