30 replies to this topic

[97cooper]

Hi everyone the reason why Rover systems overheat is becuase they are pressuirized system and they have a hole in the black expansion tank lid/cap to let pressure escape at 15PSI, the cap is rated at 15PSI. Over time that hole colapses and meaning pressure cannot escape due the blocked hole this leads onto increasing pressure very quick and then onto overheating, So be careful it should be a regular replaced item only 2.00 for a new cap!!

Edited by 97cooper, 02 February 2013 - 11:20 PM.

[sledgehammer]

Hi everyone the reason why Rover systems overheat is because they are pressurised system , and they have a hole in the black expansion tank lid/cap to let pressure escape at 100 degress. Over time that hole colapses and meaning pressure cannot escape due the blocked hole this leads onto increasing pressure very quick and then onto overheating, So be careful it should be a regular replaced item only 2.00 for a new cap!!

I may be wrong - but slightly confusing ?

a cap that releases pressure when a temp is reached ?

normal expansion caps hold up to a given pressure , then vent when over that pressure -

they don't usually sense temperature

thermostat's sense temp -

rad / expansion tank caps maintain a given pressure

Edited by sledgehammer, 02 February 2013 - 06:45 PM.

[97cooper]

Hi everyone the reason why Rover systems overheat is because they are pressurised system , and they have a hole in the black expansion tank lid/cap to let pressure escape at 100 degress. Over time that hole colapses and meaning pressure cannot escape due the blocked hole this leads onto increasing pressure very quick and then onto overheating, So be careful it should be a regular replaced item only 2.00 for a new cap!!

I may be wrong - but slightly confusing ?

a cap that releases pressure when a temp is reached ?

normal expansion caps hold up to a given pressure , then vent when over that pressure -

they don't usually sense temperature

thermostat's sense temp -

rad / expansion tank caps maintain a given pressure

Hi there 100 degress is boling point when it is meant to release the pressure, it realses the pressure at boling point.

[dow62]

Thought they pressurized systems to raise the boiling point ?

[danie garry]

the pressure is caused by expansion and steam, you can get steam at almost any temperature so i'm guessing that the cap is pressure rated rather than temperature

[97cooper]

Thought they pressurized systems to raise the boiling point ?

Hi there, When the fluid in the cooling system heats up, it expands, causing the pressure to build up. The cap is the only place where this pressure can escape.

[97cooper]

the pressure is caused by expansion and steam, you can get steam at almost any temperature so i'm guessing that the cap is pressure rated rather than temperature

Yes sorry for the confusion on how I wrote it there all pressure rated at 15psi

Edited by 97cooper, 02 February 2013 - 07:15 PM.

[sledgehammer]

where did you see them for £2.00 - would be worth a link for the MPI lads

[Ethel]

Wasn't the Freelander the worst exponent of cooked K Series?

I think various causes are quite well known, might even have been a documentary. A.15lb cap should hold off boiling to over 120 degrees, but if any part of the water jacket gets that hot you get localised boiling & trouble. What is it about the UK that there were lots eager to put the boot in, but so few ready to sing the praises of Rover for what still is an excellent piece of engineering?

[Cooperman]

The Rover 214 & 25 were/are excellent cars. In their class, up to 1.4 litre saloon hatchback they drive and ride better than anything else that size. Build quality was great. In fact they were over-engineered. The K-series could develop a HG problem, but so long as metal locating studs were fitted, the head skimmed and a top quality late-type gasket fitted then reliability is good.

[yanto]

A new cap cost me £5.45? There is something in the cap when you turn it over though, could be a thermostat?

[TopGearRules]

There was a theory that after the MG Rover take over (2000), the K series engines were being made of lower grade aluminium, thus not having great rigidity. Add the small amount of cooling capacity, a small leak can lead to overheating in no time!! Otherwise, great engines nonetheless!!

Edited by TopGearRules, 02 February 2013 - 09:45 PM.

[97cooper]

where did you see them for £2.00 - would be worth a link for the MPI lads

HI mate on ebay.

[Ethel]

The genius with the K was the pressed steel "ladder frames" to keep them together without stressing the alloy castings. Maybe it was a tad too ambitious in the innovation. Minimising the coolant volume gives a quicker warm up & better economy, but there's little margin if things go wrong with plastic manifolding & minimalistic gasket design - accountancy engineering to blame?

[jaydee]

Lots of misinformation here, this thread makes me feel like DILLIGAF....
No coolant wont boil at 100° and all modern cars have a 15-16 rad cap. It is there to hold the system pressurized which means an higher boiling point.