Range rover p38 4.6L 2002 bosch engine

I recently did up the engine in our p38 4.6L petrol 2002, got head cylinder heads redone, valves ground, timing chain, new gaskets (cylinder head, Valley gasket, water pump, sump etc) , new pipes, radiator and thermostat, finished the work yesterday and bled the air out by taking off small pipe to expansion tank but there's not a great flow. But once the engine is running for 5 -7 minutes it starts bubbling the coolant out the expansion tank it is fairly hot but the heater needle on dash hasn't passed the middle. Have I missed something or plumbed it wrong or is it just because I was running it without the cap on to try and make sure it was not air locked as it only held about 9L of coolant? Thanks

Getting all the air out can be a pain in the ***. Parking it uphill and holding the revs at 2000 rpm with the cap off can help.

Couldn't say if you have plumbed it in wrong from here or blocked a passage with sealant but I doubt it as the pipes only fit one way.

The coolant will boil at a lower temperature with the cap removed.

Thanks, so maybe I am worrying to much, Would it be normal if cap is off for it to buble out after a wait of ticking over? Should I refit the cap and let it run a while so long as the tempurature hand stays in the middle, maybe take it for a short drive?

Personally I leave the cap off while bleeding. Sqeezing the coolant pipes helps too.

How do you know if all air out of the system?

Tom T said:

Thanks, so maybe I am worrying to much, Would it be normal if cap is off for it to buble out after a wait of ticking over? Should I refit the cap and let it run a while so long as the tempurature hand stays in the middle, maybe take it for a short drive?

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Personally, if you think you have got all the air out, I would put the cap on, take it for a drive and see if it gets up to temperature.

Here's some guys bleeding a Thor 4.0 in a Disco. I notice the disco has a bleed screw/vent in the top hose, but my P38 doesn't.

Datatek said:

Personally, if you think you have got all the air out, I would put the cap on, take it for a drive and see if it gets up to temperature.

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Thank you very much for your advice I will do that and hopefully all is good. Much appreciated

DanClarke said:

Here's some guys bleeding a Thor 4.0 in a Disco. I notice the disco has a bleed screw/vent in the top hose, but my P38 doesn't.

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Thank you

Pretty much what the other guys had have said, plenty of squeezing of the top hose while off can help a great deal, Even if you can just lift corner of the car with the expansion bottle with a jack or something helps to make sure the bottle is at the highest point which air naturally wants to travel to.

In regards to only getting 9 litres you will probably find something like the heater matrix given the fact the pipes basically go up hill from it will hold a bunch of water not to mention other places.

I replaced the thermostat on mine the other day and managed to get in 9.9L and mine has the LPG stuff on top that bound to add extra volume.

Thank you very much, did what you all recommended, got another 0.5 L of coolant in and as far looks to be running ok when warmed up. Much appreciated.

Tom T said:

Thank you very much, did what you all recommended, got another 0.5 L of coolant in and as far looks to be running ok when warmed up. Much appreciated.

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Excellent news, keep an eye on it for the next week or so, you might find there is still a bit of air in there that will slowly come up to the surface so require a bit of additional top up. At this point though I would say you’ve got the bulk of it out if not all though.