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MG MGF Technical - Another Coolant Loss Thread!!!

OK people, here's my problem. A few months ago my 2001 1.8 MGF started overheating in the traffic driving home from work. A quick check of the coolant level revealed an empty tank, which I put down to it running low while the car was garaged for 6 months, was able to top up and get the car home without too much trouble.

At the time the car was still under warranty so I booked it in and was told that it was only a faulty coolant cap which was replaced.

A couple of weeks ago I noticed the temperature gauge creeping up again and sure enough when I checked the coolant level it had dropped quite drastically (about 1.5 inches below the seam). I've been monitoring it and topping it up as necessary but having trawled through the archives on this BBS today I must admit that I'm getting a bit worried now, with all the talk of HGF associated with coolant loss.

And especially as I topped the coolant up on Saturday and this morning it was completely empty again!

I can't see any visible patches of coolant where I park, yet it seems to be going somewhere - any ideas anyone?!?

Also I don't know if this is relevant but at the same time the car was booked in for coolant leaks, it also had the tappits replaced because they were noisy. Well that noise had also returned within a couple of weeks but interestingly disappeared the other day when I filled the car up with an antifreeze mix instead of just water. Someone suggested this could all be related to a problem with the water pump but not being the slightest bit technical I haven't a clue.

Any ideas???
Cheers,
Nick
Nick Lehane

Nick

I am no expert on the K series engine BUT I can not see that the tappits should be quietened by putting anti freeze into the coolant system - you did put it into the coolant system didn't you? :-)

Ted
Ted Newman


Yes Ted, I may not be technical but I'm not that bad!!!

:o)

I think the point I was trying to make (although I'm sure you'll all agree I did waffle a bit!) was that maybe the ticking noise was to do with something in the cooling system rather than the tappits. After all, surely a new set of tappits shouldn't go within 2 or 3 weeks of being replaced?!? (Although I must admit the car went into the garage 3 times before the technician heard the intermittent sound and I think they just replaced them to get rid of me!)
Nick Lehane

Over heating in traffic could be a problem with the radiator fan not coming on in stationary traffic - usually caused by either failure of the radiator fan fuse or the MEMS water temperature sensor. More info here: http://www.mgf.ultimatemg.com/group2/common_problems/hgf_pages/related_problems_overheating.htm

Tappet noise is not very likely to be connected directly to the over heating problem. Replacement just involves removal of the cam cover and cam ladder: the engine remains in the car and nothing else is disturbed. Tappet noise is associated with a low oil level: what's the level in yours - and what oil are you using?

One thing worries me here: the coolant expansion tank has emptied on a number of occasions. Has the coolant system been bled since then? If not, you run the risk of air locks and future, expensive, problems.
Rob Bell

Hi Rob,

Thanks for the reply. I don't think I'm really getting my question across properly though so I'll bullet point them to try and clarify what I'm asking :o)

1) I'm pretty sure the fan is coming on OK mainly because I've heard it and also because the overheat in traffic has happened once in 6 months even though I use the car daily and sit in traffic regularly especially during term time!

2) Let's ignore tappets and call it a 'ticking noise which increases with revs' :o) I don't think the tappet noise is related to the coolant problem, but maybe it wasn't tappet noise in the first place. I wondered if a faulty water pump could make a similar sound? Is there a reason why topping up the coolant to the correct level would make the ticking noise go and not return?

3) No the coolant system hasn't been bled, am I running risks by keep topping it up? (My local MGF dealer couldn't find a leak but it's definitely going somewhere!)

I'm due a 24,000 mile service soon, can anyone recall if any of these things will be covered by it?

Thanks again for your comments so far Ted and Rob!

Nick
Nick Lehane

>> 1) I'm pretty sure the fan is coming on OK mainly because I've heard it and also because the overheat in traffic has happened once in 6 months even though I use the car daily and sit in traffic regularly especially during term time! <<

Nick, the front radiator fan is inaudible from the cockpit. It is more likely that you can hear the engine bay fan coming on (it's located on the driver's side, behind the engine air intake.

The fact that it doesn't always over heat in traffic doesn't necessilarly mean that the fan is running okay - as Will points out in the other coolant thread, the temperature gauge is useless: by the time the needle starts to move, the coolant is already extremely hot...

Check out the fan operation as indicated on that link above.

>> 2) Let's ignore tappets and call it a 'ticking noise which increases with revs' :o) I don't think the tappet noise is related to the coolant problem, but maybe it wasn't tappet noise in the first place. I wondered if a faulty water pump could make a similar sound? Is there a reason why topping up the coolant to the correct level would make the ticking noise go and not return? <<

Water pumps tend not to make a ticking sound - so I am not sure what this could be without hearing it first hand... I can't think of anything that would make a ticking noise that would be sensitive to coolant level?

>> 3) No the coolant system hasn't been bled, am I running risks by keep topping it up? (My local MGF dealer couldn't find a leak but it's definitely going somewhere!) <<

No problem with topping up - but if the expansion tank is completely empty when you do so, you have to assume that air has entered the cooling system. Air can cause airlocks - and can, over time, lead to head gasket failure. Bleeding the system is fairly easy - as Dave has written here: http://www.mgf.ultimatemg.com/group2/common_problems/hgf_pages/coolant_bleed_procedure.htm
Rob Bell

Hi Nick - as I've put on other threads we had same on 2001 'F' - ground to halt in cloud of steam & no coolant in tank. Was pressure tested by MG, found pressure cap was faulty, despite it being previously replaced at March service. They said that they had previously had 'a few faulty ones...' hmmm. Our ZR also has had a new cap at 2nd annual service recently....big hmmm! Check that it is under pressure when hot (with care!!) Apparently coolant escapes from under faulty caps & they don't hold pressure (MG can pressure test just the cap)

Very interested in your 'ticking noise' as we have the same - comes & goes, not too noticable at the moment, but has been bad recently - let me know if you find what's causing it - Cheers Dave
D Smithson

Thanks once again for your messages guys.

Rob - thanks for the quick lesson in the difference between an engine fan and a radiator fan, as you've probably guessed you're dealing with zero knowledge here :o)

Dave - I too had a faulty pressure cap which was replaced, maybe it's worth getting a supply of these as a primary fix when losing coolant!!! As for the ticking noise I really am at a loss. All I know is that it has been with me every morning without fail until 2 days ago when I topped up the coolant tank with a 50/50 mixture of water and antifreeze. I'm not saying that is what fixed it but I am relatively happy not to have people turning around to see the noisy jalopy coming down the road when I drive along!!!

I checked the coolant again this morning and once more it has dropped by an inch since yesterday. I think I will just book it in for a service, and get them to bleed the coolant system at the same time. Will keep you posted...

Cheers,
Nick


Nick Lehane

This thread was discussed between 15/11/2004 and 16/11/2004

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