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MG MGF Technical - Can HGF be prevented ?
I was wondering if there were any recognised modifications that could be utilised to reduce the chance of HGF >?.
I am very happy with my 1999 VVC and I would like to stay that way.
you could use my prefered method which is to keep the block geographicaly three feet away from the head
although not without cost, the dealership wants his workshop space back :-(
Waiting for a MS special Head Gasket in the hope that I won't have a third HGF :-)
|I have just had the 5th year service on my 96 model and had the H/G changed for the uprated one with steel dowels and MS undercar alloy pipes in preperation for a HGF, hopefully this will stop me getting one oh and i also had all the rover spring clips changed for MS S/S screw up type....|
|The car is in for a service today and I think the uprated HG has got to be on the shopping list.....|
Either that or I go with Matt from Wexham's idea.
|and steel dowels for sure!|
|Talking to B&G yesterday (cleaned my K&N as part of 12K service - now v. zoomy!) and they seem to think that the uprated HG will solve most of the problem.|
The MS pipes are tempting too.
|Check out how much they charge for fitting the uprated gasket first. I think its not a cheap job!|
|B&G said that they charge £500 for replace the head gasket (when they did mine as part of the service last week)|
|Hawkish attention to detail on early cars is certainly an important way of ensuring that the head gasket does not fail. |
Pay particular attention to coolant temperatures and levels- because the older cars are more prone to problems that result in HGF:
Check coolant levels because:
1. Failure of the inlet manifold gasket: if yours still has the black gasket, then it is far far more prone to failure that the later green-coloured spec material.
2. Corrosion of the underbody coolant pipes
3. Corrosion and failure of the radiator (I've only heard of a couple of cases- unfortunately, one was on mine!)
4. Old age degradation of rubber pipe work and the rather cheap jubilee clamps that are used- Mike Satur's are much better in that they provide a much more equal loading force over the the circumference of the pipes.
5. Also ensure that the cooling system is properly bled following a coolant change- see Dieter's web for more info- also some pix of the location of the bleed nipples on http://www.mgf.4mg.com
Check coolant temperatures because:
1. If overheating, there is a problem!!!
2. The terminals on the ECU temperature sender can corrode or indeed, the sender fail. This leads to bad running, non-operation of the radiator fan and overheating in standing traffic. Not good for longevity of the head gasket!
If your car has suffered from a head gasket failure, ensure that the work is carried out by competent mechanics who know what they are doing, or you'll soon be returning to them with another failure!
Make sure that you have the following:
1. Latest spec OE head gasket (you might consider the Mike Satur head gasket)
2. Steel head locator dowels.
You might also consider the following (which may largely depend on the kind of driving you do):
1. Drill a single 2 mm hole in the thermostat ring to reduce thermal fluctuations resulting from the binary open/closing of the thermostat
2. Consider a thermostat with a lower opening temperature
3. Drastic one this, but include an auxillary thermostat at the radiator end of the cooling circuit as pioneered by Simon and Carl. See Dieter's web site for more details on this- but to be quite honest, is probably overkill for a road car- only consider if you do a lot of track driving.
|>You might also consider the following (which may largely depend on the kind of driving you do):|
Style of driving is of course another interesting one.
I think the engine is reliable also when going on almost long rides on i.e. motorways (high speed german for instance). Did so all the time in the last two years without any problem at my 1.8i.
Always let the engine cool down before parking and shutting down the ignition.
In the same careful manner you heat it up when starting from cold.
I did so after hot motorway rides when I found the oil temperature at 120° C near reaching the target. Left the motorway one exit earlier and cruised on country roads hoome in low revs (2500 to 3000) until the oil temperature got down to lets say app. 100° C.
Prevents in any way from to much temperature difference when no more coolant flow exists.
|Larger capacity radiator.|
If its the large temp diff ( from long cold routing to rad and back to hot engine ) when the thermo opens that is thought to cause the head to move then how can a bigger rad help ?
I don't think so, nor did MG obviously.
|i DONT THINK its the radiator size that is the problem - but the distance from the rad to the engine |
How about mounting the rad in the Boot aka Porsche style - it could flip up at 70mph :) be a cool mod :P
|Question was how to reduce the possibility of HGF, Ralph,I have to agree with you that MG didn't think.Rob covered most of the causes and things to watch for, Dieter mentioned the style of driving, of course ambient temperature is going to make a difference as well, so if you decide to take the MG on a thrash a larger capacity rad wil help,as it does on the Cup cars.Remember the VVC has about 20% more power but uses the same cooling system to dissipate the extra heat.|
|If you are a 'thrashing the car' type - for example like track and airfield days - would not an oil cooler help?|
my oil temperature, after warming up, is 125, and that's with low rev driving (always below 3000RPM). If I'm driving aggressively, which I do regularly, the temperature is 135-140. I have a 1.8I, Nov 1999 manufacter, 27,500 miles. Is this one of the faulty MY2000 oil sensors?
It has never worried me because engine oil breaks down at 160, and the oil temperature meter redlines at 150. The oil temperature never exceeds 145, even with a constant 6000 RPM's.
no, I don't think it's like the MY2000 failure.
Some other have such high oil gauge readings also. Tony from Utrecht i.e.
May be sensor tolerance or gauge tolerance related ? I don't know.
|OK, I'll continue not to worry about it then.|
>>>>>I did so after hot motorway rides when I found the oil temperature at 120° C near reaching the target. Left the motorway one exit earlier and cruised on country roads hoome in low revs (2500 to 3000) until the oil temperature got down to lets say app. 100° C.
Prevents in any way from to much temperature difference when no more coolant flow exists.<<<<<
This is excellent advice Dieter. Not only for MGFs but any car. The enormous latent heat built up in an engine straight off a sustained high speed motorway or track run can be harmful on immediate switch off. With no coolant circulation where does that excessive heat go?
This is particularly true of turbo engined cars!
Other side effects of an immediate very hot engine switch off include fuel vapourisation in the fuel lines leading to near impossible hot restart and severe coolant pressure build up. The latter can be sufficient to burst an old radiator hose or push one completely off if the securing clip has not been fully tightened (dealers!). I speak from direct experience on all counts.
I know that loads of MGF Enthusiasts almost look for 'true and clear' advise from anybody. This try currently almost Roger Parker, Dave, Rob Bell and Carl, Bruce, Spyros, Mike Satur and also me, if applicable. Apologise in advance if I forgot one of the semi-professionals, this BBS lives from all different input ;) without mega, though.
The MGF and lots of other light weight engines currently running are designs from the early 90th (IMO). I agree with you due to the hint on 'careful acting' with this technology. IMO newer design engine systems may be much better, but have other troubles due to redesigns in direction of lowest fuel consumption requirements.
My wish to all is. Please don't take everything I write, or what we discuss here to seriuous.
Opinions, only opinions and individual experiance. Some officila stuff too :))
Beeing sensitive on one hand is OK, but on first hand is fun, fun, fun.
Anyway, had a first curious look the other week to the total different engine system installation of a GM Ecotech 2.2 litre to the Vauxhall VX220. A former MGF owner who is also very interested in mechanics got one. If not known, the VX220 is a Lotus Chassis with different engine and panelwork.
The mate is the Matthias P., where I dimantled the MGF wreck two years ago.
Guys what a difference ! High tech design with latest technology. They installed a water-oil chiller just from the beginning. Temperature is so stable and obviously best controlled by electronics, valves and optinized cooling.
Not that I want a VX220, can't efford one though and it's still 'only a modified Lotus'!!! but interesting to see and copy something to my MGF at any time. :)
I keep in touch and hopefully can find out more later in summer.
- larger radiator ... may be, but I think the existing should do
- remote thermostat ... may be, but together with other mods
- oil-air cooler ... No, not my case
- oil-water cooler... may be, but quite expensive
- electric water pump... may be
All about a high tech temerature control system is what I'm after to meeting my requirements.
- Long motorway rides above 120 mph in summer
- a few track days
- short distance rides below 3 miles
PS almost curious getting older mechanical engineer, measurement and controls technology :)
|The oil-water cooler is the same solution that Simon Scutham arrived at for his racing Elise as well. This appears to work brilliantly, but you need a reliable and effective water cooling system. For this Simon pioneered the cooling system that is described on Dieter's web page.|
Which is a long way of answering Ted's point regarding track use and oil coolers- the answer is yes.
Oddly, MGR preferred the oil-air cooler solution- with the radiator mounted at the front... which is an odd solution when you come to think about it. It possess the same unstable thermal characteristics as the water radiator thanks to all that extra pipework. Oscillations aren't an issue- BECAUSE the 'cooler isn't thermostatically controlled. So a *BAD* idea for a road car- the oil will be OVER cooled... :o(
|I would have thought that an electric water pump to assist the engine pump would be a good idea. It could be wired with its own thermostat to continue pumping when the engine has been turned off. As noted in previous entries on this thread, the "heatsoak" that arrives when the engine is turned off after a long fast run is very large. I suppose there may be some thermosyphoning but maybe not so much??? Trouble is, its another item in the water circuit which can fail and/or leak, somewhat defeating the object!!|
|>>Oddly, MGR preferred the oil-air cooler solution- with the radiator mounted at the front... which is an odd solution when you come to think about it. <<|
I just love the idea of two pipes, full of oil going from the engine bay to the front of the car, with lots of cheap clips. luvverly, just lovely !
An oil/water cooler would be far better (and cheaper) - perhaps bringing the oil to temperature quicker but would also maintain it close to water temperature.
|Heat soak is obviously bad- but it is different to the kind of temperature oscillations that are thought to be the cause of HGF.|
In the case of the HGF, there is a thermal difference between the head and the engine block, that causes the head and the block to slide over one another as the head differentially expands and contracts as cold coolant from the rad is dumped into it as the thermostat opens.
In the case of heat soak after engine switch off, these thermal differentials would, I'd have thought, be much less.
So a bad idea, but not necessarily a HGF-triggering bad idea...
Steve- I completely agree. An oil-water cooler does seem to be a much better solution. But as I mentioned before, it would be a good idea to get the water cooling sorted out first before pumping more heat into that circuit...
|Oil-water cooler, working on a reasonably priced item for the F ;-) Dieter, |
|>>But as I mentioned before, it would be a good idea to get the water cooling sorted out first before pumping more heat into that circuit... <<|
Is there really that much more heat to remove ?
The engine's not producing any more heat just because the oil-water cooler is fitted. The only difference is that less heat will be convected from the sump (lower temperature). I think it's a matter of controlling the temperature more closely.
The other matter to consider is placement of oil filter with the oil-water cooler - is it more exposed ?
|>>Is there really that much more heat to remove ?|
The engine's not producing any more heat just because the oil-water cooler is fitted. The only difference is that less heat will be convected from the sump (lower temperature). <<
Coolant temp oscillates at around the thermostat opening temp- so let's say 80 degrees celcius. Oil temperatures can run up to 150 degrees celcius, depending on the driving conditions. That means that the oils is over 80% warmer than the coolant- so that is quite a bit of heat energy to dissappate. Okay, the thermodynamics of the system is a good deal more involved than that, but you see what I am getting at.
Is this going to cause problems? If the oil-water cooler is attached to the engine side of the cooling circuit, then yes, it may- with the additional heat being pumped into the engine cooling circuit, one would reasonably expect that the temperatures oscillations will be that much greater, peak to trough. (It'd be interesting to see the modelling on that).
Get the water coolant system sorted however, and this will not be an issue- as has been proven on Racing K-series engines. Carl's modification I think is particularly neat, see http://www.mgfcar.de/thermostat/Water_System_Mods.htm
>>I think it's a matter of controlling the temperature more closely.<<
Yes- exactly. The standard set-up has problems with ultimate control of the temperature, which broadly doesn't cause too much problem for a road car, but a hard driven motor with additional heat being transferred from the oil system- I really have doubts that this would work.
>>The other matter to consider is placement of oil filter with the oil-water cooler - is it more exposed ?<<
Simon Scutham mounted his on the front of the engine block, on the opposite side to the alternator. There's a picture on his web site (well, somewhere, I can't find it right now!). In this position, it is well protected within the confines of the engine bay, with the added advantages that the oil lines are kept to an absolute minimum.
|The OE MGR head gaskets (at least the older ones) of inferior construction. With age the sealing strip loses adhesion to the stainless steel base giving way to the infamous water jet spraying the exhaust manifold.|
Until a really good gasket becomes available (IMO it has to be of the spring steel type) HGFs will continue to occur.
|Vauxhall/Opel X20XEV engines as fitted to the VX220 (though I presume in the 2.2l guise - X22XEV?) aren't immune to HGF - they fail due to corrosion of the head gaskit!|
(from experience - anyone want a picture of the failed 2l head gaskit!!!)
There is obviously alot of clever people out there with abilities far above mine. However on the issue of whether MGR will accept any responsibility for this obviously flawed design, has there been any indication of whether they will or not? This may be in the form of modifying the car at a reduced rate or extending warranty cover on this specific problem.
Anybody tried or is it a dead loss.Or has anybody got a contact at MGR?
|MGR have fallen over backwards to help people that have had problems with their cars and certainly they have helped those that have had a head gasket failure just out side the warranty period - and here I am talking about the old one year warranty - however if the car is well out side this period then it is unlikely that MGR will help.|
BTW to say it is an 'obviously flawed design' is a little strong as there are many thousands of K series engines (probably hundreds of thousands) out there giving first rate service and where it is used in the *F* a lot of the problem seems to be down to poor service, especially after a coolant change.
My *F* is now six years old, used daily, is our only car and has never suffered from an HGF or any other major problem and the couple of small faults that there were were sorted promptly under warranty.
|Sorry Ted didnt mean to hurt the old feelings, but I did suffer a HGF and would not consider myself unduly harsh on the car.|
I can only hope that I have your luck and like many others I would like to keep the car for all its good points.
You have not hurt my feelings! Just pointing out a couple of facts.
If your car is fairly new or has a very low mileage and has a full service history then there is nothing to prevent you trying to get some sort of help from your official MGR dealer or direct from MGR - The Head Man there is John Towers (I think) so write to him in person - unless you try you don't know what you will get.
I did this with my BMW and wrote to 'Burnt Fishtrousers' direct in Munich and whilst I did not get a personal reply (I never expected one) I did have BMW GB on the phone to me within two days and sorted the problem within a week.
|I think if you contacted MGR you may get a reasonable response - even out of warranty - but you will have to argue well and put the pressure on - do not ever accept No as an answer - just move up the chain and be a pain in the ass to them- the higher you go the more likely you are to get a YES!|
Say for instance you had FSH from MGR dealer and had a HGF - You would then have an argument that the car failed due to design - and not poor maintainance - MGR may well respond by reducing or covering part of the bill = Always get on the phone and talk to the Manufacturer = your usually wasting your time talking to a dealer in this instance!
In saying that MGR is often the worst place to take your F for servicing as many dealers are awful - So try to find one of the good MGR dealers - ask on the board for your area!
I do believe there is a "hidden" policy that if you moan enough MGR will do a deal regardless of warranty
>Oil-water cooler, working on a reasonably priced item for the F ;-)
Nice one Mike, will find his market. But please make the mod easy (DIY) and think about daubts related to leaks between the water to oil side. Cheap adaption to the oil circuit with thermostat is required also.
>VX220 (though I presume in the 2.2l guise - X22XEV?) aren't immune to HGF - they fail due to corrosion of the head gaskit!
Haarrr, Haaar, ROFL !! thank you for this hint!! I'll forward ASAP to my friend.
.. now I know at last why the Opel/Vauxhall guys require such an impressive controlled and obviously stable working cooling system ;)))))
|As we all know the head gasket/joint is a construction necessity as well a safety device and until someone designs an engine that is constructed from one solid block the question of failed HG's is going to remain with us for the forseeable future. Good maintenance and checking the fluid levels on a weekly basis is essential to reliable motoring.|
|Henry Royce thought that rubber was not a 'proper engineering material'. Early Rolls Royce engines were built to such high production tolerances that they didn't actually USE a head gasket: just a metal against metal interface of the head and block.|
How times have changed ;o)
|I wonder if head gaskets, like brake linings, are a victim of the non-availability of asbestos due to its toxicity.|
Head gaskets used to be made of a copper/asbestos/copper sandwich and rarely failed.
When brake linings were made of asbestos, disks lasted almost the life of the car. But probably killed quite a few mechanics.
|AS long as they were all MGR mechanics :) |
You can buy Kevlar Headgaskets - supposed to be nearly impervious to heat/flex expansion etc etc
This thread was discussed between 28/02/2002 and 07/03/2002
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