I have many memories as a kid of my grandads many cars, he had them all, Allegros, Ladas, Cortinas but never sunk as low as a Marina but he did have a nice old A40 which was slightly before my time.
I remember at least twice these cars (one Lada, one Allegro) overheating with steam pouring out of the bonnet, both times he fitted a new thermostat and all was well. On a modern car if this happens surely the headgasket will crack?
Is it something to with the change of cylinder head material from iron? I also remember my dads car [Lada] had a cracked radiator and he managed drive 12 miles to the specialist mechanic we used at the time which must have been over heating. When my first bought my dads current Fiesta on the first day it overheated again with steam coming out of the bonnet needle in red and fan spinning at stupid speeds. New thermostat and 22,000 miles later no signs of any head gasket failure, his engine is the Ford Endura which is an iron kent block.
So why do head gasket failures seem so common now? Is that people are just driving their cars with the needle in the red without realising the water pump has failed or something?
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Headgaskets, even on K-series engines, tend not to fail before 60k miles, usually much more.
Not many Allaggros got that far.
If you look on youtube, you'll find various videos of cars being abused to death - there's a Civic in there being run for 2 DAYS without any coolant before it succumbed.
Edited by Lygonos on 05/11/2009 at 00:23
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Indeed but all the examples above the car actually over heated quite badly. The head gaskets were fine.
So why do head gaskets often fail after a simple over heat? is it because drivers keep driving them in the red?
Come to think of it my grandad always kept a spare A series because no matter what car he had he knew it would be needed one day, my uncle fitted it though.
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Modern cooling systems run at a higher pressure than back in t'day.
A 'simple overheat' is usually the end result of major abuse/lack of maintenance, or is the result of a HGF rather than the cause.
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Modern cooling systems run at a higher pressure than back in t'day.
There's not *that* much difference - perhaps a few PSI - the compression ratio is rather higher these days, perhaps that's an issue. That said, it seems to me that there're fewer failures now, not more.
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So why do head gaskets often fail after a simple over heat?
Do they? I'll have to take your word for it. In 50 odd years I've never had a car overheat or had a head gasket fail.
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>>>>If you look on youtube, you'll find various videos of cars being abused to death - there's a Civic in there being run for 2 DAYS without any coolant before it succumbed.
I know it's daft at a very fundamental level, but at an equally profound one I find it terrible that someone can deliberately run an engine into the ground. People say it's only a collection of moving parts, but I think it's dreadful. It reminds me of the TV programme presented I think by Quentin Willson in which a perfectly good estate car being driven to destruction by an incompetent driver.
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I think i get Rattles point
I have never had a HGF and have taken cars to well over 160k + (1983 reg and 1993 in this particular example) so that was a good innings for them, in a car i own to me thats the very last thing to i expect to go
one of them did over heat albiet briefly but there was no HGF
but its becoming more common to hear of stories of HGF eg Rover k series, so the questions are are Head gaskets these days simply not up to the job, are they made out of cheaper materials or is it that they cant cope due to high pressure water systems
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I think a lot of it is poor design and that design not being updated or improved.
My son had a L200 pickup- worked hard but never abused and always serviced in time.
Head gasket failed at about 100k miles, significant engine damage. He had pulled over to the side as soon as he could. It was TOOOO expensive to fix so sold for parts and he bought another L200 newer model. Same thing happened after 1 yr and 20k( total mileage about 80k) . SO sold as was and bought a FORD RANGER- so far so good.
It is sloopy engineering maybe mixed with a lack of maintenance.
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I find it terrible that someone can deliberately run an engine into the ground
I couldn't agree more, I can't understand how someone can find pleasure in deliberately damaging something... I'm glad it's not just me.
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Head gasket failure isn't necessarily the fault of the gasket. It could be caused by distortion of the mating faces of the cylinder head or engine block, incorrect bolt torque, incorrect bolt tightening sequence, and last but by no means least the inappropriate use of a so-called "sealant". A sealant should never be used on any gasket unless specified by the car manufacturer.
Edited by L'escargot on 05/11/2009 at 09:17
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How about it's because we used to have to take the head off and give it a de-coke every now and then, replacing the head gasket in the process.
Hence head gaskets still last just as long.
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Could it be the cars which do suffer HGF tend to be the ones with smaller coolant capacities which lead to faster engine warm up so the cycles between hot and cold are more severe ?
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Rattle
In the "old" days it was common place to have the heads off a car to do other stuff. Decokes, valve grinding, pistpon rings, rebores, etc etc. when that happened a new gasket was fitted. A thick old thing it was too. Probably aided by many tubs of goo of varying colours laughingly called "head gasket sealant"
This happened so often (every 50k miles in some cases) that there was no chance for gasket failure.
These days, you never lift the head off an engine unless something catastrophic happens
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In the days of all iron engines there was little differential movement between the head and the block - temperatures were similar (coolant being pumped through both) and coefficients of expansion the same.
The need for much higher engine efficiencies has dictated the use of aluminium for cylinder heads. The far higher thermal conductivity of this material has enabled cooling to be effective at high combustion chamber temperatures and generally much higher values of heat release found in modern engines.
The downside, of course is that aluminium expands more than iron - such that despite the cylinder head being bolted to the block, some movement occurs as the engine heats and cools. A good gasket design will accomodate this - for a while, but thermal cycling will eventually cause fatigue and failure of the gasket.
Thanks to modern lubricants and bearing materials, current engines will run to considerable mileages so a head gasket failure may well be the first significant failure an engine will see. The old "all iron" engines would have been lucky to run anything like as far before some other problem (valve grinding, perhaps) necessitated head removal and gasket replacement.
Finally, diesel engines have higher cylinder pressures (you don't get all that beautiful torque without it) and now have alloy heads. As there are more small diesels in service,the incidence of gasket failure as a proportion of the total for all vehicles will be greater.
659.
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I suppose that makes sense :). My car is done almost 83k now and as far as I know the rocker cover has never even been removed (chain drive). On an older car it would have been removed lots of times.
So head gaskets are now more likely to fail because engines last a lot longer and they don't need to be maintained as much as they used to. Makes sense.
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I'm not sure they fail more often just people expect the whole car to be more reliable and never fail.
Years ago a head gasket failure would just be considered a minor maintenance issue and wouldn't have been commented on. I used to carry a couple of gaskets around in the boot, change them at the side of the road and carry on the journey.
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ask not what your headgasket can do for you
but what you can do for your headgasket
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>ask not what your headgasket can do for you
but what you can do for your headgasket<
Shoot that man...
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208,000,
origional head gasket
on a 1.9 TDI & tweeked diesel.
origional radiator and water pump too
holds temp perefectly too
I had to top up the coolant until I traced a wee leak at about 180,000 thou.
Took a BX to 168,000, then cooked her one hot August day( acting on advice received from a mechanic.....doh)
So No
head gaskets are probably BETTER nowadays
assuming one lifts the bonnet and preforms regular routine checks
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IIRC head gasket failure used to be a common topic of conversation amongst us motorists.
Recently, unless you were a Rover owner- zilch. IMHO.
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Still don't see why some cars don't come fitted with a good old coolant temp gauge this 06 astra of mine does not have one eventually you get used to it but it's still much better to have some warning when you can see it creeping up to the red rather than a warning light coming on when it's about to explode, if the bulb still works.!!
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I agree Bigtee, at least you have a idea that something is going wrong instead of alight coming on when its too late, another way of penny pinching and the ever increasing removal of the driver from the mechanics and involvement of the car if you ask me
The new Astra (Astra I) and its re-introduction of a temp guage was discussed at some lengh on here not so long ago
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To be honest, the only recent head gasket failures I've heard of have been on Rover K series lumps, or elderly Peugeot XUD turbos which haven't had regular coolant changes. The last one I personally changed was on a Pinto engined Sierra back in mid 90's, which had been run low on coolant, apparently for several months, and then finally succumbed on a local hill where it cooked itself to the point of seizure and wouldn't so much as turn over. How many modern engines could survive that, be fitted with a new head gasket, and not only run perfectly first turn of the key, but return factory spec compression figures afterwards? Great old lump of pig iron, and unburstable. But back on topic, nobody I know has had HGF on any other car in recent memory.
The Rover K-series is a unique case, given that it has a number of design "features" that make it prone to HGF. As far as I'm aware, those in the know still argue over exactly which of these is the main cause. But let's face it you don't stand much of a chance with an engine which has so little reserve coolant capacity, was stretched so far beyond it's original planned cylinder capacity, has the thermostat arranged in such a way that ice cold water from the rad thermally shocks the head with each warm up cycle, has a standard of casting quality which is most kindly described as "lacking consistency", and an engine construction which relies on exacting tolerances in terms of cylinder liner protrusion and head casting quality to avoid overloading the head gasket. A quality of casting that Rover couldn't consistently deliver.
I don't think this engine could be more of a ticking timebomb for HGF if the designers had done it deliberately, and for the purposes of analysing modern engine HGF patterns, it is wise to ignore it completely.
Edited by DP on 05/11/2009 at 16:29
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On marine engines there is an audible alarm for overheat, which will also put the engine into limp home mode - why aren't there the same for car engines ?
MVP
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I thought the same thing. It must be possible. Many performance cars vary their rev limiters based on oil temperature, so it shouldn't be hard to build something like this in.
I seem to recall one of the big US V8s (a Cadillac perhaps?) was designed to run without coolant if necessary, by keeping its cylinder temperatures under control by shutting individual pots down by ECU control until they'd cooled enough to be fired up again. The engine ran at vastly reduced power of course, but run it did. Indefinitely too.
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On a train engine there is a oht overheat temp switch the engine runs at idle, same for transmission tot, these very simple switch devices save either the engine from overheating if all the coolant leaks the engine shuts down, same if it leaks all it's oil.
But you won't get this fitted to a car, dealers and indies would lose thousands of pounds on repair work new engines they would get smaller jobs.
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The difference there is in having a solid iron block with an iron head, versus a wet-liner alloy block with an alloy head.
With the first you may well "get away with it", with the second it's unlikely.
Incidently, of the same vintage is the Jag XJ12. Boiling one of those was instant death, requiring heads off, gaskets and a head skim if you were lucky......
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