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MG MGF Technical - Coolant level

'F' has been at the garage for last 2 days, having major service and cambelts replaced. During inpection - found both rear brake discs and pads to be heavily worn (me = Leadfoot), radiator on its last legs and some damaged done to suspension arm (believe I caused this damage when I spun off the roundabout and mounted the grassy bank lol!) - all work done and repairs made to the tune of £900 ouch.

Everything seems fine, took it for a test drive earlier. I was kind of worried when I dropped the car off on Tuesday and the mechanic asked ME how he was going to get the engine out! Then admitted he hadn't worked on a 'F' before....but said he liked a challenge! He's worked on my cars for 5 years and has always done an excellent job, and so far everything seems fine.

I have a question though about the coolant. I had a look round when I got it back today and noticed he has filled the coolant to well over the mark of the seam - the level is now halfway between the seam and the filler cap. Is that a dire problem, or should I just leave it?

Any advice appreciated,

cheers
Fiona :-D

P reg VVC
Fiona

Not too much of a problem - although the correct level is at the seam of the tank. I guess you could always syphon off the excess?
Rob Bell

Just open the radiator bleed screw until the level drops to half way then tighten up, 2 person job if you want to avoid running back and forth.
Chris Catchpole

Syphon off is more secure IMO. Any access to the crap front bleed plastic will shorten it's live.

However, if you leave it overfilled as it is, you risk the live cycle of the coolant expansion cap. It hates hot the coolant bath.
Dieter K.

I think I'll have a go at syphoning a bit off. I wonder if a turkey baster will do the job?

I am being serious with that comment by the way ;-D
Or does anyone have any better ideas?

Fiona

Fiona
I shouldn't worry. The coolant obviously expands when it gets hot. There will be a pressure release device on the filler cap (usually a simple spring and seat) which opens at at pre-set value. All that will happen if the level is too high is that there will be a small escape of coolant when the pressure is released. It will then find it's own level.
If you use the turkey baster, I should make sure that you wash it thoroughly before next Christmas! :o)
G P Bailey

G P Bailey,

my suggestion, try yourself and see what will happen ;)

Done that in last year. The cap _was_ damaged after boil over due to overfilled coolant.
I keep immidiately on the advise to keep the max. level and never overfill.

Anyway, may be the *internals* of this poor cheap plastic part are of interest.
http://www.mgfcar.de/expansion_tank/index.html

Cheers
Dieter
Dieter K.

Fiona,

When did you check the coolant? Was the car hot or cold. If cold then is is likely that the coolant system has a little too much in it and xhould be removed (turkey baster is a good idea!) If the car was hot and the coolant level returns to the correct level when cold then I would suggest that you replace the coolant cap.

The cap is designed to let off pressure above 14psi. If the cap blows off early then the pressure in the system will be less and consequently the coolant will boil more quickly (think pressure cooker, higher pressure=higher cooking temperature ie boiling).

A cap is only £3.50 from a dealer and is a simple thing to change I would be inclined to do this once a year regardless.

Tim
tim woolcott

I checked it after the 5 min drive back from the garage, so I would hardly say it was hot...although I will check again at the weekend when cold.

I will follow Dieter's advice and get it back down to the seam level.

Now got to go and buy a turkey baster LOL

Fiona :-O
Fiona

Fiona
I totally disagree with some of your other respondents. The filler cap will see the same temperature whether or not the system is too full. However, if for peace of mind you wish to get the coolant level correct (you may find that it is by now, depending on if you have done any 'hard' driving), you could always use an old tea towel (or such) to dip in and wring out until the level is correct. I wouldn't want your dinner guests complaining that the turkey tastes of anti-freeze!!!
Geoff
G P Bailey

This is taken from the archive of the "Lotuslife" bulletin board and was written by Nick Adams (chief engineer of some sort at Lotus):

"[...] the pressure cap will simply vent the air to maintain the correct system pressure. If the tank is overfilled to the point where all of the air is vented and the system is completely filled with water then two things happen, firstly and most obviously you run the risk of venting water into the engine bay, which makes a mess and a smell. Secondly, you have removed the majority of "spring" from the cooling system, because water is much harder to compress than air. This has no immediate effect, but in the long term the very rapid fluctuations in system pressure that result could cause problems with components such as the water pump seal."

Another "component" which springs to mind is the head gasket...

Per
Per

<< However, if for peace of mind you wish to get the coolant level correct (you may find that it is by now, depending on if you have done any 'hard' driving), you could always use an old tea towel (or such) to dip in and wring out until the level is correct>>

Thanks for that Geoff. Errr does 3hrs driving on the motorway at speed and passing 130mph count as "hard driving" [not saying that I did or anything was just wondering in a hypothetical situation ;-O ]

Fiona :-P
Fiona

This thread was discussed between 25/02/2004 and 01/03/2004

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