What is this Pipe? PICS

Hi does anybody know what this is? (the big pipe which comes out of the top of the rad and over the top of the alternator) ....



only after a drive does this pipe pressurize. i know this because today i had the car on tick-over for about 30 mins and the pipe was hot but not pressurized!

what isit? is this normal?

Paul

main water pipe into block....

paulham said:

Hi does anybody know what this is? (the big pipe which comes out of the top of the rad and over the top of the alternator) ....

only after a drive does this pipe pressurize. i know this because today i had the car on tick-over for about 30 mins and the pipe was hot but not pressurized!

what isit? is this normal?

Paul

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That is the top hose. What you describe is quite normal. Only when engine is at full working temp will there be any pressure in it.

it should be firm but not hard, if its easy (very easy to squeeze) then check water level.

take the small pipe off the rad briefly, and water should come out.

If you don't know what that pipe is, you should not be doing any repairs on your car, if it is hot and you disconnect it, you risk severe burns!!!!!!!!!!!!!!!!

overlandrover said:

If you don't know what that pipe is, you should not be doing any repairs on your car, if it is hot and you disconnect it, you risk severe burns!!!!!!!!!!!!!!!!

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he'll be fine, or at least he'll learn how to take the little pipe off briefly!!!

overlandrover said:

If you don't know what that pipe is, you should not be doing any repairs on your car, if it is hot and you disconnect it, you risk severe burns!!!!!!!!!!!!!!!!

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Good point,well made.

i was just asking if the pipe should be pressurized or not, no need to try and insult me on a forum.

i am not a mechanic, but have done repairs on all my cars including a full engine replacement on one! so yes, i do already know how to take a little pipe off!

but anyway... thanks wammers for your help!!

paulham said:

i was just asking if the pipe should be pressurized or not, no need to try and insult me on a forum.

i am not a mechanic, but have done repairs on all my cars including a full engine replacement on one! so yes, i do already know how to take a little pipe off!

but anyway... thanks wammers for your help!!

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ark at her, touchy arent weeeeee!!!!!

paulham said:

i was just asking if the pipe should be pressurized or not, no need to try and insult me on a forum.

i am not a mechanic, but have done repairs on all my cars including a full engine replacement on one! so yes, i do already know how to take a little pipe off!

but anyway... thanks wammers for your help!!

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I find it amazing that someone can claim to have done a full engine transplant and not be able to recognise even the most basic of parts (top hose).

Did the said car ever run again?

Dorset VogueSE said:

I find it amazing that someone can claim to have done a full engine transplant and not be able to recognise even the most basic of parts (top hose).

Did the said car ever run again?

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He fitted an oak engine................
























































It wooden work.:doh:

Dorset VogueSE said:

I find it amazing that someone can claim to have done a full engine transplant and not be able to recognise even the most basic of parts (top hose).

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agreed, but i wouldn't say " you should not be doing any repairs on your car"...hows he sposed to learn!

now i've only had my p38 since June and already done:
discs, pads, calipers, shocks all round
water pump
coolant expansion tank
thermostat
and put a new long engine in!

before this car the most I'd ever done was change a windscreen wiper.

luckily i've had nothing but help from this forum but some of you guys can be a bunch of cocksuckers at times

skirabb said:

agreed, but i wouldn't say " you should not be doing any repairs on your car"...hows he sposed to learn!

now i've only had my p38 since June and already done:
discs, pads, calipers, shocks all round
water pump
coolant expansion tank
thermostat
and put a new long engine in!

before this car the most I'd ever done was change a windscreen wiper.

luckily i've had nothing but help from this forum but some of you guys can be a bunch of cocksuckers at times

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Yes some of the comments can be a little terse from time to time. But some of the questions can be an amusement to some i must admit. It always amuses me in a movie when the car breaks down and someone lifts the bonnet and after a short look over the engine announces that the carb has failed. Hope the fitting of the waterpump,thermostat,expansion tank were done after the engine change and were not the cause of it.

i have worked out today that that top pipe should be pressurized the whole time the engine is hot, but before it was de-pressurizing quite quickly.

i asked the original question because my coolant kept boiling and shooting out of the expansion tank overflow pipe, i just wanted to know what was normal for the p38's.

then i had the problem of the pulley snapping off from the water pump, loosing power to the alt, steering pump and water-pump!
i got the car recovered and fitted a new water-pump, then fitted a new thermostat (i thought this may of been the reason to the car overflowing the coolant) but it still happened.

i noticed that expansion tank cap was old and worn, and was the same as on my dads car, so i swapped them over. i haven't had the problem of the car loosing the coolant from the expansion bottle overflow since.

hopefully my problem is resolved. the top hose is now pressurized when the car is hot and everything seems well.

Is dad's car losing coolant now? If so then hopefully it was the cap, if not you may only be putting off the inevitable because your 'new' cap is able to hold on a bit longer. Keep an eye on things.

hippolover said:

Is dad's car losing coolant now? If so then hopefully it was the cap, if not you may only be putting off the inevitable because your 'new' cap is able to hold on a bit longer. Keep an eye on things.

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Yes...wot he said. Wonder if it ever ran again as it was a old thred

Yes, its 10 months later, Dads car is working fine, and the Range Rover is outside and it hasn't happened again!

i did some research about this the other day. The cap has 2 parallel rubber seals which create an airtight seal when the cap is secured tightly, which allows the system to pressurize.
if you go for a drive in your range rover(5 mins up the motor way) pullover and slowly undo the cap, you will see that water will get pushed out of the overflow pipe due to the cap not being sealed and the pressure in the cooling system. Do the cap back up and the water will stop flowing.

The reason for this cap is to ensure the coolant is under-pressure when hot, because when coolant is put under pressure it raises the boiling temperature!
There pressure relief valve under the cap and this can fail open so the coolant system will not pressurize. The result of this is the coolant will boil at a much lower temperature then it would if pressurized, and boil over.

i have noticed the problem a few times on the mg-rover forums (mg-rovers & Range Pover P38's share the same cap)

Bloody nora, its almost as if 2 different people using the same name. A very concise and full explaination of the header tank and pressurised cooling system lol.

Well done, an insight for me as well as some others I'm sure, I didn't know that pressurised water had a higher boiling point (but I did know about the pressure relief system in the cap).

One question though. Is your RR a 99> model?
I'm wondering why your radiator hose and oil filler neck are on the opposite side to mine.
(PS, I've never seen under the bonnet of a THOR engined P38!!!!)

Hamster97 said:

Bloody nora, its almost as if 2 different people using the same name. A very concise and full explaination of the header tank and pressurised cooling system lol.

Well done, an insight for me as well as some others I'm sure, I didn't know that pressurised water had a higher boiling point (but I did know about the pressure relief system in the cap).

One question though. Is your RR a 99> model?
I'm wondering why your radiator hose and oil filler neck are on the opposite side to mine.
(PS, I've never seen under the bonnet of a THOR engined P38!!!!)

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Well you bloody should have, 2 degrees F for each pound of pressure. It's been said often enough on here. That is why you have a pressure cap to stop the coolant boiling. And also for all those who keep coming on saying when my engines hot the top hose is pressurised. Well it's bloody supposed to be. So there. Rant over.

yes, firm but not too hard!!!