Coolant Level

ewancc · 24th November 2015, 22:07

Last couple of nights when checking coolant level it was very,very low.Almost nothing in the expansion tank.then,when I loosen the cap, it comes back up to near normal level.The car hadn't been driven for 2 or 3 hours.Is this likely to be the expansion tank cap or something else? Any ideas?

T-Cut · 24th November 2015, 22:25

Are you saying something is very different from normal? It may be something or nothing. If there's an airlock, then releasing the pressure cap may cause the coolant level to rise as air is exhausted. I'd suggest you do a simple methodical test. Start with the cold coolant at Max with no trapped air. Do a top up and bleed following the procedure for your engine. This is available around the forum (search) or read it in the Haynes manual. Drive the car normally (up to 70 mph) for 10 miles minimum. Park up and leave it overnight. Next day when it's stone cold, unscrew the cap carefully and listen for any pressure release. Observe the coolant level and any change in level. Report back here.

TC

ewancc · 24th November 2015, 22:31

Ok.I'll give it a go over the weekend and report back!

crown · 1st December 2015, 02:04

Quote:

Originally Posted by ewancc

Ok.I'll give it a go over the weekend and report back!

Any news on this?

ewancc · 13th December 2015, 21:30

Hi crown.
Well last week my top hose blew a hole in it and I can't be sure but I would maybe guess that this could have been caused by pressure within the coolant system! Anyway, this weekend I fitted a new top hose including blowing on the "jiggle" valve to ensure that it wasn't stuck, refilling as per the haynes manual using the bleed screw near the air filter and finally fitting a new expansion cap, being an OEM one from Rimmer Bros.Interesting this cap was completely black and different to all the other caps I've had in so much that the end of the middle bit wasn't a yellow/orange colour.
So far everything seems okay overnight without loss of coolant and with no pressure coming from expansion tank when I removed the cao this morning.
Fingers crossed here on in!
Thanks to T Cut for the advice.

crown · 14th December 2015, 07:11

Fingers crossed indeed. ☺

Mark

T-Cut · 14th December 2015, 10:46

Quote:

Originally Posted by ewancc

- - - OEM one from Rimmer Bros. Interesting this cap was completely black and different to all the other caps I've had in so much that the end of the middle bit wasn't a yellow/orange colour.

The relevant thing is it should have '140' moulded on the cap. It usually appears on the coloured insert as well, but the colour isn't important.

TC

ewancc · 14th December 2015, 11:40

It has indeed "140" on the top of the cap and on the inside!

24th November 2015, 22:07	#1
ewancc Newbie Rover 75 Tourer Join Date: Aug 2009 Location: Bingham Posts: 29 Thanks: 7 Thanked 1 Time in 1 Post	Coolant Level Last couple of nights when checking coolant level it was very,very low.Almost nothing in the expansion tank.then,when I loosen the cap, it comes back up to near normal level.The car hadn't been driven for 2 or 3 hours.Is this likely to be the expansion tank cap or something else? Any ideas?

14th December 2015, 07:11	#6
crown Gets stuck in mg zt saloon Join Date: Jun 2013 Location: Norwich Posts: 868 Thanks: 463 Thanked 142 Times in 106 Posts	Fingers crossed indeed. ☺ Mark __________________ [SIGPIC][/SIGPIC]mods so far; auto boot lift mod, stainless steel back box, jvc double din head unit, vibe speakers, black oak dash, plenum mod, refurbished hairpins, retro fit illuminated sun visors k & n air filter,aero wipers.retro fit electric rear blind. roewe front bumper with mg grill badge.new turbo vac pipes.

24th November 2015, 22:25	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Are you saying something is very different from normal? It may be something or nothing. If there's an airlock, then releasing the pressure cap may cause the coolant level to rise as air is exhausted. I'd suggest you do a simple methodical test. Start with the cold coolant at Max with no trapped air. Do a top up and bleed following the procedure for your engine. This is available around the forum (search) or read it in the Haynes manual. Drive the car normally (up to 70 mph) for 10 miles minimum. Park up and leave it overnight. Next day when it's stone cold, unscrew the cap carefully and listen for any pressure release. Observe the coolant level and any change in level. Report back here. TC

24th November 2015, 22:31	#3
ewancc Newbie Rover 75 Tourer Join Date: Aug 2009 Location: Bingham Posts: 29 Thanks: 7 Thanked 1 Time in 1 Post	Ok.I'll give it a go over the weekend and report back!

13th December 2015, 21:30	#5
ewancc Newbie Rover 75 Tourer Join Date: Aug 2009 Location: Bingham Posts: 29 Thanks: 7 Thanked 1 Time in 1 Post	Hi crown. Well last week my top hose blew a hole in it and I can't be sure but I would maybe guess that this could have been caused by pressure within the coolant system! Anyway, this weekend I fitted a new top hose including blowing on the "jiggle" valve to ensure that it wasn't stuck, refilling as per the haynes manual using the bleed screw near the air filter and finally fitting a new expansion cap, being an OEM one from Rimmer Bros.Interesting this cap was completely black and different to all the other caps I've had in so much that the end of the middle bit wasn't a yellow/orange colour. So far everything seems okay overnight without loss of coolant and with no pressure coming from expansion tank when I removed the cao this morning. Fingers crossed here on in! Thanks to T Cut for the advice.

14th December 2015, 11:40	#8
ewancc Newbie Rover 75 Tourer Join Date: Aug 2009 Location: Bingham Posts: 29 Thanks: 7 Thanked 1 Time in 1 Post	It has indeed "140" on the top of the cap and on the inside!