I also personally think that you need a themostat in there for whole the system to work properly. You can easily fit a lower temp one that is a direct replacement for the existing one ( with zero modifications or extra bits ). I put a thread up on here years ago about it. And others have done other similar methods.

[edit: thread was here .... http://www.fullfatrr.com/forum/topic13318.html .... its quite old now, so you would need to go looking for newer sources of the part numbers ]

Reason I say that is that the stat itself is designed to balance the flow of coolant through both the engine block and the radiator because you want coolant to flow through the block to suck heat out of the block and flow through the radiator to lose that heat ... the stat ensures that flow is directed each way to do both.

In theory, without the stat, the bulk of the flow could always go to the radiator which reduces the flow through the block, and actually reduces the amount of heat taken away from the block. Also may explain that a potential poor flow is not purging the air as quickly as it should. V8 or else ...

Last edited by fisha on 26th Mar 2018 8:44am. Edited 1 time in total

Bled it like a mofo for an hour, think its a tiny leak in the head gasket. While idling there arw no bubbles but blip the throttle a few times and turn the bleeder screw all sort of bubbles come out. Did this also for a good 20 minutes but bubbles came back every time.

Went for a slow 15 min test drive and same result but not so much pressure that its spilling coolant but hissing for sure and top of radiator and bottom hose cold again. After bleeding, radiator and lower hose were hot before I went for the test drive, so even after a small slow drive a great amount of air is introduced into the system which causes the cooling system to air lock and get pressurised.

A sniffer test cant be found anywhere in the country.

Last edited by desertdude on 26th Mar 2018 9:06am. Edited 1 time in total

Fisha, Ive been running without a stat for over a year now with 0 issues. So dont think its a stat issue.

There are a number of products that claim to repair a leaking headgasket and some i have heard of actually working so although not an ideal solution it is certainly cheaper and easier than removing both heads.

This is one of them https://barsleaks.com/gaskets/symptoms-blown-head-gasket/

Do some research on the various products and you could remove the plugs as a free way of maybe confirming your leak and also look for white exhaust smoke but not sure if anti freeze is a thing in your climate but does also act as a corrosion inhibitor
Failing that then a compression test should tell you and a leak down test as already mentioned

Nah I rather not gum up the system, although I did use a radiator sealant long time a ago in my land cruiser and it lasted for years.

I dunno having done a through search of the forum, there are many threads with my exact same symptoms but none were a head gasket!

I did rebleed the system again and went for a small but slow drive. And again after a while I heard hissing frim the rad cap, but sounded more like it was trying to suck air in, but hoses were taunt and hot but not rock solid, maybe a bad rad cap? Could it be that simple?

Yep - always worth replacing 4.2 SC - sold , now bought back
4.4 AdBlu Tractor - Stolen

i have the 140 cap in mine and worth trying
You need to diagnose it properly really, take your plugs out and see if that tells you anything

I dun't think plugs will tell me anything, engine runs smooth and pulls like an ox. With the iCarsoft plugged in all cylinders are giving out readings like they should and there are no codes logged either, plus I dont have a spark plug or deep socket spanner!

And where i have moved a month back when all these troubles started, is literally in the middle of no where, plus I'm broke like a mofo, so all strikes against me

This is a similar engine


This is worth a read, especially last page

http://www.bimmerfest.com/forums/showthread.php?t=516669

Interesting! Might be worth a shot, only problem is ( and I have looked ) this isn't available locally which means an expensive when you add international shipping song and dance and a loooong gamble to see if it actually gets here.

But looks promising and a cheap fix. From videos I looked up on youtube looks like mercury mixed in with a lot of thick hair or straw. And instructions say to leave it in there even after it fixes your problem for "added protection" Dont know how xonfortable I would be with that though. With all that silvery sludge roaming around in my cooling system.

Update : Ive ordered a Bars Leak HG1 will take a couple of weeks to reach hear. I the meanwhile I was able to get a new rad cap but rated 200 or 2 bar. Quite a lot of coolant had been spurted out and it was late night so refilled and did a very basic bleed and put on the new cap a slow 15 drive around and the coolant wasnt spurting out nor tye cap hissing the system was super pressurized. The top hose had swelled to resemble a cobra at the radiator connection. So undid the screw a lot of airbubbles came out but I only let off enough pressure so the pipe could return to normal size. But still stiff to the touch.

Today midday went to check the hose still hard even after sitting overnight, with thr old cap. Hoses would be soft in the morning. Opened the cap and a lot of air escaped.

Question is if the HG was blown wouldn't the pressure leak back into the block and not hold overnight.

I'll do a proper bleed again later in the day and see if the hose again turns into a swollen anaconda. Im just scared of blowing a hose, then Im in real deep crap out here in the sticks!

Have asked a buddy in town to get me a 140 rad cap, but dunno when I'll be able to get it though.

Did you happen to figure out the problem? I'm having the same symptoms, water coming out of the cap once hot & the upper radiator hose getting rock hard.

Signs point to a head gasket but it runs to good! No water in the oil. Only a tiny drop of water out of the exhaust every once in a while

Did you ever get this resolved?
I too am in Dubai and have a similar problem. Performance is good, until the engine gets hot, then starts knocking due to not cooling the EOC....
Garage have done a pressure and gas test and told me its engine internal (head gaskets) some reason I dont believe then...

Any other ideas??

I'll chuck my 2p worth in

These systems do run hot and with a lot of pressure, the hoses always feel harder than most other engines...

The OP's to me sounds like a head gasket failure between the cylinder and a waterway, a very small leak, probably a split head gasket, as the temp rises it swells the head and opens the split which allows a minuscule amount of combustion gasses to get into the cooling system, when you switch off and it cools down the hole will close and not let the pressure escape. If you leave the cap off the miniscule amount of gasses will just escape out the cap...

The hoses are made from reinforced material and will take a lot of pressure but they should not stretch to twice their size as stated above.

If you do not have access to a garage with an emissions tester then you can buy kits online to test if you have HC's in your coolant...

To the other poster, a cylinder head gasket can fail between a cylinder and an oil way a cylinder and a waterway a cylinder and a waterway and an oilway and, but rare, a waterway to an oilway, you can also get a failure between any of them to the outside and you will have leaks...

Not having a thermostat will not effect or compound any of these failures.

Putting a higher pressure rad cap on will just overpressure the system and lead to a hose, or more likely, the header tank, to fail

You have to check with Land Rover which cap your engine needs with your vin, during the BMW 4.4 run they changed from the 140 to the 200 and back again, you need the correct one for your engine...

All the above presumes you have checked the cooling system and your radiator is not blocked, they do easily, you should do a flow test, check your coolant pipes have not collapsed, the ones to the gearbox cooler tend to, and your waterpump is in good order and working correctly.

Hope this helps... Pete

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