MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Suspected HGF :(

Continued from thred:

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&mode=thread&access=&subject=69&source=T&thread=2003042810114217344

I have just had my mate who is a machanic have a look and he recons it reeks of HGF there is water in the exhaust and when you rev it, it splutters as the revs go down :(

There is no gunge on the dip stick tho

He recomends I put all the original leads/plugs back in and get it done by a decent MGF centre on the warrenty, sounds good to me :)

He said apart from that the engine is immaculate :)

Looks like I will be without my car this bank holiday :''(

What does everyone recon?

Thanks for all your help guys

James
J Price

James...take a look at the oil filler cap to check for "mayonnaise"...if it's there..
:-(
If not you may be lucky!
Blue Max

The cap looks fine apart from a bit of oil it looks brand new :( I forgot to mention the white smoke/steam from the exhaust :(

I think if it is HGF it is only a small crack.

There is some strange liquid on the edge of the engine it is too thin to be oil it looks like dirty water (see pictures)

I have posted some pictures:

http://homepage.ntlworld.com/jamespriceuk/index.html

Feedback welcome :)


Cheers

James
J Price

James,

Changing the plugs and leads shouldn't invalidate the warranty. Does look like HGF IMHO. Probably safer to get it trailered wherever you want to take it, as if it lets go and overheats, could be expensive.

You've caught it at the point before most people do (i.e. before you're engine is cooked). With the new metal dowels, should be good as new. Replacing HG isn't much more of a strip-down when doing the 5Y service, so again that's actually fortunate.

Good luck.
Leigh

Find someone with a pressure tester.

Attach it to the expansion bottle and pump the pressure up.

If it IS a HGF, it'll loose pressure pretty quickly - and like as not it'll be obvious where it is going as you can do it with the engine cold.

If the pressure drops rapidly with no obvious leak, then disconnect the LT of the coils and turn the engine over. Then remove the plugs and check they're not wet: if they are, its leaking into a cylinder.

Most likely HGF place is to the outside world, over the alternator.

Neil.
Neil

>If the pressure drops rapidly with no obvious leak,
>then disconnect the LT of the coils and turn the engine
>over.
Eeek, don't do this! if you have to test it like this then instead remove the plugs before you turn the engine over, water will jump from one of the pots.

And now the alternatives:
It might be the inlet manifold gasket, HGFs tend to be between the outside world and the water, or the water and the oil. When HGFs occur between combustion and water then the pressure tends to be so high that exaust is pushed into the coolant and the coolant is pushed out of the coolant cap.
The inlet manifold gasket failure would lead to water being sucked in from the manifold which is at less than atmospheric pressure, and not give you this 'boiling'

It might be a cracked cylinder head - nasty, and quite difficult to spot

It might be a previous HGF which was badly repaired and the head was warped (so make sure they check the trueness of the head and get a skim if required)

I can't see any of the pictures though

Good luck
Will
Will Munns

First things, first.

Water in the exhaust... well, H2O is a by product of combustion. If there were an HGF any water would be turned into steam.

Secondly, has the coolant level dropped at all. If the level is normal, somewhere between 1/3 and 1/2 full then no HGF. The trick is to monitor the coolant level to see if it does drop.

If it is a HGF in the inner part of the gasket then there WILL be mayo in the coolant tank and on the dip stick. If however it is an external failure then you will probably have a small jet of coolant coming from cylinder No 4 on the passenger bulkhead side. You may also want to remove the engine inspection cover and remove the plugs to see if any of the pistons appear shiny when you shine a torch down, this will indicate that water is gettting in somewhere.

If still worried then get the system pressure tested as mentioned above and get a garage to put a hydrocarbon sniffer into the coolant tank.

I've been unable to look at your pics so it's difficult to comment further. I hope that it's not a HGF. Just be thorough with your inspection.

tim woolcott

Just spoken to the garrage I got it from (a SAAB garage) and they are going to take it in and check it over. I told them that if any work needs doing I would like it to go to at least a dealership if not a specialist. I think to be honest they will just book it streght in to a dealership for testing (as thats what happend last time). So watch this space :)
J Price

None of those pics indicate HGF :-)
Tech

Certainly the last 2-3 piccies seem to show a slight oil leakage past (what used to be called) a rocker cover gasket.

Get some of the leak on end of finger and sniff/taste - is it oil or antifreeze/water mix?
JohnP

>rocker cover gasket.
I think it's now called a cam cover gasket.
I think you are looking in the wrong place, the cam cover is the black bit with rover on it, the head is the bit which has the exaust and inlet manifold bolted to it, and the block it the bit below that, the the sump is the tray bolted to the bottom. the Head gasket is between the head and the block.
Will Munns

Yep, looks like a straightfoward camshaft oil seal/cam cover gasket leak to me, nothing more.
Tech

Be careful with pressure testing, if you have a leak then water is getting into the cylinders, if too much gets in then you will get what is called hydrolic lock, this is where too much liquid gets into the engine.
Given that in a petrol engine you are looking at a compression ratio of 1:10, that is the gas is squashed to ten times smaller than it started, if a small amount of liquid gets into the engine then it cannot be compressed, then you get over pressure and a end up destroying all sorts of expensive things. (hence my advice to remove the plugs before turning the engine over)
Note: this is applicable to both HGF and IMGF
Will Munns

Good point Wills :-)
Tech

Tech is that a big job? and would that cause the white smoke/steam? and spluttering?

JohnP i felt the liquid and it want that greesy just felt like water :(

James
J Price

>and would that cause the white smoke/steam?
>and spluttering?
Nope, it would cause neither of these, a lot of engines seep oil

>JohnP i felt the liquid and it want that greesy just >felt like water :(
there are oter ways water can get at an engine, for instance rain, there is no way that water can get from a HG or IMG to the cam cover. in the same way there is no way the water from outside can get into the engine from the outside of the block.

You haven't mentioned your water level at all - how is it?
Will Munns

Hi James,

no need to panic - there is nothing in what you've described so far that would indicate a HGF. I think that Tim summed it up rather well...

>> and would that cause the white smoke/steam? <<

Condensation - frequently builds up after short journeys, and is nothing to worry about. Be more concerned if there is smoke/steam after a 30+ mile run...

>>and spluttering?<<

I think that this is more than likely to be an ignition fault.

You've changed the leads and plugs James - next thing to do is the rotor arm and distributor cap.

Have you checked the spark plugs?
Rob Bell

Cam Cover Gasket replacement is fairly easy.....whereas camshaft oil seals are a b1tch to do!
Tech

Rob

The condensation and stuttering thing only just started recently. It is also not just a starting problem it has started to cut out even after 14mins of use. I did also change the spark plugs when I changed the leads.

Will

From what I can remember the water level has gone down slightly but not much. Also the oil doesnt seem to have gone down either.

P.s Just spoken to the garage and they are willing to fix it and have a look at getting the 60K service done or at the very least doing the bits that should of been done (cam belts etc). I am just trying to get a curtsey car out of them :) apparently they don’t have any but I am allowed one as part of the warranty so I may just hire one and charge it to them ;)



J Price

Will

<<I think you are looking in the wrong place, the cam cover is the black bit with rover on it, the head is the bit which has the exaust and inlet manifold bolted to it, and the block it the bit below that, the the sump is the tray bolted to the bottom. the Head gasket is between the head and the block. >>

Surely the cam cover is the nice alloy bit with TWIN CAM written (stamped/moulded - choose a word) on it? I do agree that it would possibly say ROVER were it not an MG.

The oil mist around the TWIN CAM cover bolts and along the base of the TWIN CAM cover does look oily in the piccies.

Your brief roadmap to the layout of the engine is superb but ... where does the crankshaft fit into your sceme of things :-)

<<I can't see any of the pictures though>> have they turned up yet?

Is it nearly time to go home for the weekend? This is the first 5 day week I've done in 8 weeks and it's getting to me.
JohnP

>Surely the cam cover is the nice alloy bit with TWIN
>CAM written (stamped/moulded - choose a word) on it?
Ah yes, in those pictures!

>I do agree that it would possibly say ROVER were it not
>an MG.
I think you'll find that just out of shot (over the exaust cam shaft) it says ROVER, you can get nice shiny polished alu cam covers which get around this problem though!

Will

Will Munns

The car is going in to the garage at lunch time so they can take a look. I dont think they will want to do the work so I am going to try and get in to a decent MG garage.

It was heart breaking on Saturday with it being such a nice day :(

I will keep you posted.
J Price

I have just spoken to the garrage and they think it is a the starter coil (whatever that is) They are waiting on the part and I may even get it back today :) I am still worried about that dampness on the engine, what do you guys think?
J Price

The saga continues :( I got the car back last night (and was over the moon) and she was fine until this morning where she started doing exactly the same things :( So I just waved her off the the garrage AGAIN :(
J Price

This thread was discussed between 01/05/2003 and 08/05/2003

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now