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MG MGF Technical - Its reputation preceeds it.....???

Re HGF, now I found this product online on a US site. Now I am not really that concerned about whether the product works or not (Does it??) I was more interested in the vehicle used to illustrate the page. Now it's not very clear but I know what it looks like to me.

http://www.rxauto.com/

Cheers

Sally
Sally

The description of it working is highly dubious.

Consider the 'standard' F HGF, a failure of the rubber seal over the alternator:

Seal fails, car continues to run, loosing a slight amount of water.
loss of water fails to be noticed.
car finally runs out of water (the water only flows because the whole system is full, the pump doesn't have enough pressure to lift the water, just recirculate)
the water is now not moving,
if there are air pockets they are in the head.
the head overheats around the exhaust ports (natural hotspot)

At this point this product claims to coat the waterways around the exhaust ports in some goo, but the failure is some 5" away by the alternator, the engine continues to overheat untill the whole head is baking hot, but the alternator hole is still below the waterline and far from a heat source.
The bores are now getting visiously hot, the product coats the bores with goo, but the overheating is starting to wreck the rest of the engine, the last of the rubber seals have now failed and the water is mixing with the oil. this product gets pumped around the oil circuit coming into contact with the other side of the bores and the bearings - this side of the bores are perfectly smooth and perfectly sized - any additional material here is _BAD NEWS_, simmiler the bearings....


etc etc.

After a while it might get so hot it plugs the head gasket over the alternator, but by then you have reduced the size of all the waterways and all the oilways, potentially wrecking all the bearing surfaces in the engine, and if it hasn't fixed the problem then the inside of the engine is covered in forign material, unevenly layed that will have to be removed by the garage.


I wouldn't use it in my engine.
Will Munns

Don't worry Sally, :)

That's definitely not an MG used for the illustration.

More like a Honda NSX or mk1 rx7 in my opinion.
(Hope this puts your mind at ease!)
Kris

Id guess an rx7 given the site name.

I didn't think rx7's had truuble with HGF, just rotor tips
Will Munns

Wow it fixes warped heads....they are clever them yanks!
R Baker

Hehehe, wouldn't touch the stuff with a barge pole either myself, should have too-good-to-be-true plastered all over it.

Now for my next Q! Of those of us who have experienced HGF how long did the respective garages take to 'fix' it, ours went in yesterday & Horners expect us to have it back on Thursday. Now personally I think that's pretty good (quick) & may have a lot to do with the way the gasket went. No spectacular steam clouds / loss of oil, more coolant ingress into the oil. But the AA P & L seem to think that it only takes 24 hours (hmmm are they working in the assumption that along with the pubs garages have gone for round the clock opening?) & are now refusing to pay for more than one days' car hire because they think that the garage are dragging their heels

Believe me they will be getting one of my 'famous' letters, but I was just interested to know your experiences.

Cheers

Sally
Sally

My car was in for 4 working days when it had a HGF - a 'minor' one with no actual engine damage - they still had to check the head wasn't damaged which wasn't something the garage could do 'on site' so I think they had to take it to a specialist for crack-testing and skimming. 24 hours would be pushing it unless you had a garage with all the facilities to hand and exclusive use of a couple of mechanics.
Al

most (all?) garages will not have the head skimming capability on site and will farm this off to a machine shop - I doubt that any machine shop can turn round heads much faster than 1/2 day.
Will Munns

1 day (or part thereof) to strip and diagnose, 1 for the machine shop work, and 1 (or part) to re-assemble would be pretty good going. In our case there was an extra day 'cos the mechanic threw a sickie on Monday with the job half-done.
David Smith


Of course, thats "elapsed time" rather than man-hours. I assume the machione shop charge for 'head skimming' rather than '0.3 hours skimming head' and I would expect a garage to take about 3 hours to dissasseble (including head strip), 3 hours to reassemble, and probebly an hour or two for propper flushing and refilling of the system (oil and water, dependant on contamination).
So by my reconning 8 hours, possibly two people, 16 hours


All times plucked out of the air based on my (ameatur mechanic) Head gasket change 2 years ago, which I did in two consecutive nights after work.
Will Munns

Metalic block seal clogs radiators terribly. They you REALLY get overheating along with its full consequences. Tried it on a TR7 once and the resulting meltdown put the engine out of its misery.
Glenn Mallory

The gasket change is an 8 hour job for a garage who is used to doing it and has the right kit. My daughters ran into 2 days as the head needed skimming and we had the cam belt done at the same time. Total cost £430. The gasket seems to be fine but its making strange noises, rattling from the exhaust and a whisling on overun that seems to come from the induction system.
Paul Hollingworth

This thread was discussed between 29/11/2005 and 03/12/2005

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