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MG MGF Technical - gunge on dipstick !!

I have just checked the oil level on my 97 vvc and can see some yellow/brown gunge indicating that water is mixing with the oil somewhere. There are no other obvious signs of problems with the car.

I am now bracing myself for some major expense - can anyone suggest what the problem is/likely cost ?

Bad luck Miles
It looks like a other HGF (head gasket). Its going to be expensive. There are two routes you can go>

1. Get someone with some abitly to swap the gasket for you. This is the cheap option, however it will go again in no time (do this if you get shut the car)

2. Get the job done by a good dealership, they will have to skim the head to ensure its flat and its going to cost......anything up to 1000 ish.

If you love the car than i can understand you wanting to keep it. If you relie on the car than to be honest you would be better off with a differant brand.

MR2 MX5 etc.
Regards Mega.

Ignore Mega.

Has the car been stood stationary for a long period, and when was the oil last changed? Is there any sign of problems in the water?

It's possible it's a head-gasket failure. But it's also possible, if the car hasn't had much use recently or is just used for short journeys, that condensation has emulsified on the dipstick.

I'd get it checked out by a decent garage if you're not sure.
Darren Ainsworth

It's amazing how Mega has picked this all up so quickly!!
However, i suspect in this case it's another fake post simply put on here as fuel for Mega's hatred of all things MG Rover.
Anyone else see where i'm coming from on this? Surely he can't be that bad at spelling, if he tried, no doubt he would come across as being remotely normal.

MMMM.... (M)iles (Lancs)
(M)ega (L)iverpool

I might be wrong but...
Gareth Kidman


Unfortunately my problem does really exist.

Darren, the car is used daily, usually on a 20 mile round trip. The oil was last changed 28th june for its last service with the main dealer, so I am fearing the worst.



I left a little disclaimer at the bottom, didn't i :)

Personally i would change the oil and filter yourself, but the give the car a good run beforehand.
A 20 mile (Ok so 10 miles each way) round trip might not be enough time for the oil to get up to temperature, especially this time of year.
Have you checked under the filler cap? Any signs of water mixing with oil there? Even if there is, it might be related to the cold weather and not a HGF.

If after changing the oil (Some type are better than others for this mayo syndrome) you find it's getting worse, then i would investigate further and take it to a specialist.

Gareth Kidman

Thanks for your comments

I have had a look down the filler cap and there are signs of orange coloured residue coating the bottom but not much. The coolant looks okay in the
expansion tank.

The oil used by MG rover was semi-synthetic. Incidently, since the last service my daily mileage 10 miles each way approx does now involve a fair
amount of stationary traffic queues and usually no motorway work which could be a factor - or am I clutching at straws ?!?


When i worked at a Rover garage they used Castrol GTX Magnatec, could still be the case now. I've found that normal Castrol GTX (thicker grade and mineral-based) was actaully quite prone to the mayonaisse effect on one of our MG Maestro's, which was reduced when oil was switched to Duckhams Hypergrade.

Depending on how many miles your car has done, i'd go for a fully synthetic oil. Comma do a pretty good range and it's been excellent in my Maestro Turbo, burning very little despite the age and viscosity (5w 40). Other makes to consider are Valvoline and Penrite. Mobil One used to be a good choice but it's a very light weight oil (Ow 40/30) and could make the engine louder, although could help reduce fuel consumption. The same goes for a 5w 40, i wouldn't go any lower than this grade on any engine.
The fact that you do virtually no motorway work means the engine really isn't working that hard enough to get that oil up to working temperature.
At this stage i would say you have nothing to worry about, but do keep an eye on the water level, and if the coolent hasn't been changed for a while, now might be a good time to do so, but make sure the system is drained/flushed/refilled correctly as this has been known to aggravate the problems of HGF.

Gareth Kidman


The water that has emulisfied with the oil has to come from somewhere. Two alternatives exist:

#1. From the atmosphere (condensation due to short periods of running/not got the chance to evaporate)

#2. From the cooling system (head gasket failure between the cooling jacket and crankcase. Coolant level in expansion tank level has dropped and keeps on doing so.)

If the coolant level has not dropped, alternative #2 is eliminated.
Jon Fredheim

Would suggest to check the oil filler cap from below on the cam cover as well.

To echo Jon, what about the coolant level ?
Dieter Koennecke

But it doesn,t look good!

I don't think the coolant level in the expansion tank has changed but I will monitor it daily to be sure.


Mega shut up.
Gareth Kidman

Ddraig, should we have some fun with em ?
.. you know what I think, do you ?
Dieter Koennecke

Hi , The day after i picked my mgf up a month ago i looked at the dipstick and noticed a rusty gunge at the top, i wiped it off and ran the car for a few days (long runs as i suspect the car had been parked and not run for a long time and if it had it was only for short runs). I've not had the problem again , the dealer said they would do an engine flush if i had the problem again but nothing so far.


This may well be nothing to worry about - so don't panic just yet. I've experienced similar with mayonaise like gunk on the dip stick, again my car was being used mainly for short journeys. The gunk soon seemed to clear up with a longer run (or two) and no further related problems have resulted since. At the time I also went to the lengths of removing the engine access cover and checking for mayonaise gunk on the 'proper' oil filler cap (cam cover cap as Dieter refers to above). This was totally clean of any such gunk as was the coolant cap/expansion tank of any contamination. HTH. :)

Home of the new MGF FAQ, MG Dealer Guide and F'ers Gallery. :)
Paul Lathwell

Or your about to lose your head gasket and about 1000. Like i said it doesn't look good!


this is 4U
Dieter Koennecke

How much money spent on the MGF this week Matey?

Hi - - [02/Dec/2001:19:49:51 +0100]

Dieter Koennecke

I was always told any engine needs 20 minutes warm up minimum
10 miles isnt far so i would suspect that it is lack of full warm up rather than HGF

As above - if the coolant isnt dropping - you have no worries!

Just to complete the lookup - - [02/Dec/2001:19:53:25 +0100]

Paul Lathwell, mate you use Mozilla 4.75, do you ?
Dieter Koennecke

The only sure way to detect a hgf is to take it to the dealer who will pressure test the coolant system.
Do it now. If you have a leak what ever is leaking could give completely and then you will have a "mega" repair bill.
If the head gasket needs replacing get the timing belts changed at the same time.

Mega is talking out of his ar*e.
A head gasket repair should cost more like 500.
Jon Baker


Sorry not with you? =-s
Paul Lathwell

Pressure check is a good idea. I really suspect this is condensation from short runs and low temperatures, but you can't be too careful.

Darren Ainsworth

Mega is very wrong. Even if it is the head gasket thats gone, you can't just swap the gasket - you need a head check.

If there's no coolant loss its not likely to be that though.

Hi Dieter, just tried your link :o)

Dot, the link was the same as a couple of weeks ago 'for Joanasy' I removed the *rse background already.... IP lookup, see above :)
(Had emails also with Paul, he got me now) *g*
Dieter Koennecke

Well guys, I called in to the dealer yesterday who had a good look at the dipstick and coolant expansion tank. The coolant level hasn't changed at all and there are no signs of any contamination.

Based on this he concluded the same as your comments above - that there is no reason for concern. I will keep my eye on it - but it looks like Christmas is now back on !

One thing he couldn't tell me was what the optimum oil temperature for the engine is (on the gauge) when fully warmed up, if there is one ?


Any above 90C is normal. Temperature raises in relation to engine rev average.

I.e. if you go 60mph constant under current ambient temperatures it will be app. 100C ??

But different values should better be written by VVC owners. Me is only an MPI which runs a bit colder.

BTW. wondering still about your spotting of gunge the other weeek. What is your style of driving.
I think on average of revs. Do you run the engine very low or almost in the range of maximum torque ? (4.500 revs for a VVC, IMO)


Dieter Koennecke


Your comments on oil temperature are interesting since mine doesn't rise above about 75C at the moment on my normal journey to work.

The engine isn't worked hard at all on this daily run with an average speed of about 40mph if I'm lucky, which just sees it into 5th gear - and the revs are kept low due to traffic etc.

Its only when I'm not doing this journey I get to have more fun with it.


Hi Miles - If your not getting the temp up over 90 then the engine isnt getting up to temperature - so the mechanic is right - no reason to be concerned about gunge - its a normal occurance in thiese conditions - however i would suggest more frequent oil changes or a good long run as and when you can to disperse the water/condensation in the engine!

Agree with Tony,
but the only 75 average makes me curious about other thoughts ?

Nobody else with a VVC out there ?
Dieter Koennecke

D, my VVC runs at around 90 most of the time. Journeys arouond London and 'normal' Motorway driving that is (for me, keeping the revs around 3K-4K).

But isn't there some doubt as to the accuracy of th oil temp guage?

Ed Clarke

My VVC runs at about 120. Takes about half hour running to get their and never goes hotter.
T Green

I have taken it for a good run today and the oil temp rose to about 90C. The car is always great fun to drive especially on the duel carriageways, when roundabouts are involved. I'm now satisfied that all is okay.



Oil temp on my 2000VVC is about 120 C. I had a problem with very high temperatures >150 C at 80 mph. This was rectified by MGR who fitted an additional resistor, 15 ohm, in the sensor lead. I don't think the readings of this gauge are very accurate if this is a normal mod. Just use it as a guide.
Stuart Elliot

The 'mod' to the oil temperature gauge was something that had to be done to a batch MY2000 cars all the previous cars there was no problem and the gauge is fairly stable.

Ted Newman

You know everyone elise who is "UNlucky" not to own a "F" Just get in, start up, and go. Its a trip tip work, not a bloody grand prix car.

seen this before, yes it could be HGF but could still be condensation due to low milage. If you watch the temp guage in the oil you will see that it doesn't move off 0 until you have done 8-10 miles. Provided your coolant level is ok take it on a long run and see what the oil looks like afterwards. My gran did this to her car all the time (emulsified the oil) and used to ask me t0 fix it for her. 200 miles on the motorway did the job just great, the car ran better,smoother, more resposive, more power the works (Ok it was a bright pink Hilman Avenger and she was a hairdresser (seriously) but the principle still applies)If it is just poor use the high temp for an extended period will 'boil' off any water in the oil and things should go back to normal. If it is HGF I dont see why it should cost 1000, as it is not much extra work to skim the head once it is off the car

This thread was discussed between 02/12/2001 and 10/12/2001

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