P38 Plenum Heater Tubing - ByPass/Blanking

[davidsonsm]

I've disconnected the coolant feed and return to the plenum chamber on my inlet manifold. So all I'm left with is the tubing that runs between the outlet from the engine and the expansion tank - pipe no. 9 in RAVE (called the bleed pipe). In other words the plenum has been by-passed.

Can the outlet from the engine be plugged/blanked off. The reason I ask, is the expansion tank that I've modified with a 32mm cap (for a level sensor), doesn't have the plenum bleed nipple on its underside (looks like the tank is off a diesel disco - PCF101420 - even though the scrappers had it marked up for a P38).

I reckon it'd be a safer option to install the diesel expansion tank as it would be one less tube that could leak and drain coolant. Can anybody confirm I'd be OK to plug off the "plenum coolant outlet" pipe from the engine? Also, what's the best long term secure method of doing this?

Thanks in advance for your musings and help.

[wayneg]

Is your car Thor or Gems? On Thor cars the Throttle body heater area is a common source of leaks so is often bypassed, not needed in hot climates anyway. Many I have seen have just removed the 2 hoses and joined them close to the throttle body. For me a much better way is to completely remove the 2 hoses and then just run a new rubber hose from the Expansion Tank to the block nipple behind the Alternator. The Alternator really needs to be removed to do this. I thought about doing away with the hose but there is quite a flow through it especially with the thermostat closed so thought better of it. Dont want the possibility of any new air pockets

[davidsonsm]

Sorry - should have said - mine is a GEMS. But I understand the plenum heater circuit with the connection to the expansion tank is similar.

I guess my question boils down to - can I blank off the tube that feeds out from the intake manifold? Given the modified expansion tank doesn't have the underside bleed outlet connection.

Push comes to shove, I'll have to modify a petrol expansion tank.

[benji]

I can't see why not to block it off. You've still got the bleed pipe from the radiator which is a higher bleed point.

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[davidsonsm]

Just to be crystal, I've already by-passed the "throttle" heater. The tubing now runs from the intake manifold coolant outlet, to the expansion tank.

This is the tube I'm enquiring about - can it be done away with.

[TheTree]

Mate

If that is the bleed pipe, then how are you going to get the air out of the system?

Maybe a pic so we can see exactly which one it is :D

Steve

[davidsonsm]

Hopefully you can see the attached diagram from RAVE. Its the pipe no. 9 that I'm considering removing. As mentioned, there is still the bleed pipe between the radiator and the expansion tank.

[TheTree]

Hi

I am not very up to speed on the GEMS setup, but looking at it and knowing it's called a bleed pipe, I would suspect it helps to get the air out of the upper part of the plenum

I guess you could remove it then monitor your temps carefully!

Steve