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MG MGF Technical - hgf or just condensation?

Hello MG'ers!
I recently got hold of a 97 F and have a question.
the car was sat for about 2 months before i got it and there is some real smeg on the dip stick now i have been driving it for a while but no muck in the water.
i replaced the pipes under the car and the hose for the head coolant as it was on its way out.
I am not loosing any coolant.
what do you suggest? replace oil and see how i go, or take it to a garrage?

ta!

Sorry I may have dropped these ,,.,...,.,..,.,.,.,.,.
Dan Hrkalovic

Hi Dan,

The absence of oil in the coolant seems reassuring. If the car has been idle for a couple of months it would be worth using an oil flush to help shift any dried-on deposits, and then change the oil & filter.
Mike Hankin

Does the car come up to temp properly - showing heat in the water after about a mile from cold and showing middle and not moving off middle after about 2 miles.

If the engine does not get to temp then the thermostat is faulty and the oil will continue to collect water vapor from the blowby and never spit it out via the breether.

How long are your journeys for the oil to clean up it needs to get propper hot, it won't do this on a 3 mile crawl to work, but a 20 mile blat up the motorway might
Will Munns

Dan,

I have a little mayo on the top of my dipstick. First noticed it exactly one year ago (MOT time). It stayed all winter even after 100mile trips, went in the summer and is back now. I have (almost) stopped worrying about it. Did a block compression test in spring, i get no consistant water loss so I reckon all is ok. Just changed the oil, all fine. I shouldnt worry unduly.

One thing - I do have K&N pipes from under the car which I know supply the engine bay with cool air (because I put a thermometer probe on my K&N in the summer). I wonder if these are sufficient to keep the dipstick area from heating enough to drive off the emulsion.

Oh, and I have just ordered my B&G coolant level sensor kit!

Pete
P Davey

Thanks you lot!

1.Posted 03 January 2007 at 18:02:25 UK time
Will Munns, Cambs
Does the car come up to temp properly -heats up fine and stays constant.... sometimes it will shoot up abount 3 more notches but then go straight back to mid way.

How long are your journeys. 9 miles in the morning and 9 at night. I will take it out for a real poke after i have swaped the oil / filters.

2. "it would be worth using an oil flush " an advice on this?

3. The car is killing my legs :( I am 6' 7" and its a bit of a squeeze. never mind! it fun to drive and it makes me smile :)

thanks a lot people!
Dan Hrkalovic

>sometimes it will shoot up abount 3 more notches but then go straight back to mid way.

This is bad news, when this happens does the heater go colder or hotter, and how long does it show hot?

This could be a sign of an airlock, faulty fan or a sticky thermostat.

It is possible that the airlock might be caused by a combustion leak into the water (on type of HGF), which may cause slight water loss without oil contamination, and this can be tested by using a hydrocarbon sniffer in the expansion tank (every MOT garage has one of these to do emissions testing).


if the gauge 'flicks' up and down with no decernable wait then the wire might be rubbing and causing an intermittent short somewhere.
Will Munns

Hmmm. cracked head?

the heaters go cold it lasts about 10 to 15 secconds.
#

I will check the fan. how do i check the thermo? or would it be best to just swap it out?
Dan Hrkalovic

if the heater goes cold it is an airlock, get the cooling system sniffed immediately as it might be impending HGF. If that comes up clean then come back and we'll tell you how to drain the air out.
Will Munns

Ta. I have bled the rad and the Heater matrix but cant get to the pipe in the engine bay. will have a poke on sat (will get it sniffed tommorow)
Dan Hrkalovic

Will, if combustion gasses where in the coolant I would expect it to pressurise the coolant an leave some evidence of the pressure cap blowing. Such as green water around the engine bay.

Am I being too simplistic. Do you get an early warning stage that does not leave evidence of coolant release.

Just wondering because my wife's W reg R200 looses a little coolant and I have assumed it is from the coolant system hose joints etc as the temperature guage behaves and there is no evidence of the cap blowing. We do get some white deposits around some of the hose joints.

Sorry it is not F/TF but this seems to be good source of K info.

With the R200 and my K turbo ZT160+ I am alwats impressed with how quickly they reach normal temperature. Ideal for my wife's short journeys.
David Witham

It depends on the amount of gas escaping.

If the car is losing coolant then it could be from several places:

into the oil, boiling off and ending up in the exhaust
- milky oil, exhaust billows more steam for longer than other cars (taek care, in this weather most cars will be showing some steam)

into combustion
-probebly whould see some effects on the gauge, often what appears to be boil-over

evaporation
-a faulty coolant cap might also cause Dans problems

Leaking water pump
-The newer water pumps even have aslot to evaporate coolant that has leaked, check around the timing belt

Leaking head gasket to outside world
- usually some green stuff on the top of the alternator, or on the front(in a 200) of the engine [exhaust side]

Leaking inlet manifold gasket
-either dropping coolant into cylinder 1 (lots of steam) or down the rear (in a 200) of the engine

Or a leaking pipe, or a leaking radiator, or a leaking heater matrix.

You can get UV dye to put in th coolant, when the coolant dissappears the dye stays behind leaving telltale tracks.

Will Munns

me Again. thanks for you help. at the moment the expantion tank is like a jacusi when i take the cap off whilst running. is this normal?
dAn hrkalovic

This thread was discussed between 03/01/2007 and 25/01/2007

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