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cylinder head gasket replacement.


Cranfield
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Makes you think why with head gaskets failing being such a common problem over many years now why the engine designers have not come up with a better gasket design that last a lot long or never fails, after all most of what else we buy as consumers improves year on year so how difficult can it be to improve the current gasket? Or is it just a nice little earner for the industry when they know one dys if will fail so why improve it.

They have tried over the years with various types of gasket, recessed heads, headless designs etc. All to no avail. When you think about it you have a 2' lump of cast iron or alloy that's sat at minus whatever in the winter, then it starts up and there's a series of explosions across the top of this lump, so close together it's just one continuous very hot flame. Bottom of the block is still minus whatever while the top is expanding rapidly so there has to be movement. Eventually, sometimes, something gives. Best advice you can ever give to anyone is when you start your car let it warm up slowly, a gentle fast tickover for ten minutes. Unfortunately a lot start up, rev the nuts off it and then thrash it up the first hill to get the heater warm :no: Very bad news for a cold engine. :good:

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They have tried over the years with various types of gasket, recessed heads, headless designs etc. All to no avail. When you think about it you have a 2' lump of cast iron or alloy that's sat at minus whatever in the winter, then it starts up and there's a series of explosions across the top of this lump, so close together it's just one continuous very hot flame. Bottom of the block is still minus whatever while the top is expanding rapidly so there has to be movement. Eventually, sometimes, something gives. Best advice you can ever give to anyone is when you start your car let it warm up slowly, a gentle fast tickover for ten minutes. Unfortunately a lot start up, rev the nuts off it and then thrash it up the first hill to get the heater warm :no: Very bad news for a cold engine. :good:

Or people who don't let gearbox's and diffs warm up before they floor it -.- my 1600 polo has 10 minutes in the morning and 15 minutes at night to warm, my ktm has 5 minutes then a steady 10 minute ride to allow engine and box to get to operating temperature (top of rad is warm) followed by a good thrashing!

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They have tried over the years with various types of gasket, recessed heads, headless designs etc. All to no avail. When you think about it you have a 2' lump of cast iron or alloy that's sat at minus whatever in the winter, then it starts up and there's a series of explosions across the top of this lump, so close together it's just one continuous very hot flame. Bottom of the block is still minus whatever while the top is expanding rapidly so there has to be movement. Eventually, sometimes, something gives. Best advice you can ever give to anyone is when you start your car let it warm up slowly, a gentle fast tickover for ten minutes. Unfortunately a lot start up, rev the nuts off it and then thrash it up the first hill to get the heater warm :no: Very bad news for a cold engine. :good:

Alloy head on a cast block are the worst for this.

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Sitting idling for 10 minutes is so 1970

 

One of the worst things you can do for an engine

 

 

Best bet is to jump in and drive lightly till it's warmed

Please explain?? Not only do I work on a variety of standard cars on a daily basis I also work on a lot of rally cars and high performance cars more often than not. An engine is supposed to be warmed before any load is put on it, it lets the oil thin and lubricate everything properly before it is driven. Is also opens up any tolerances eg piston rings and the like. I have also built many engines from again, standard engines to high spec race engines. So I may not know a great deal how ever warming an engine is supposed to be done. Just my 2 cents anyhow :)

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Because physics!

 

Engines are designed to be ran at a certain temperature, you want it to get to that temperature asap

 

Idling on your drive isn't some magic formula, the engine is still spinning at 16 odd revolutions per second, everything is still hitting each other just as hard as it would at say 3000rpm.

 

I'm not saying jump in and redline that bitch

 

Idling for 10 mins would barely raise the coolant temp anyways, whereas it will be up there in 3-4 mins if you drive around gently.

 

 

I respect you've built many engine s, but as with everything, it doesn't mean you know everything, that's not a dig, I'm fully aware I have lots to learn!

 

 

Phil MEng CEng FIET

Edited by LowStandards
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as a humble grease monkey I always had the idea that to idle from cold with a rich mixture(petrol motors) isn't to good for the bores on the thrust side as the fuel dilutes the lubrication of the cyls/pistons so start up and a steady drive away is better than idle to warm up the engine as always this is only my opinion

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Makes you think why with head gaskets failing being such a common problem over many years now why the engine designers have not come up with a better gasket design that last a lot long or never fails, after all most of what else we buy as consumers improves year on year so how difficult can it be to improve the current gasket? Or is it just a nice little earner for the industry when they know one dys if will fail so why improve it.

Head gaskets outlast car warranties...

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I have also built many engines from again, standard engines to high spec race engines. So I may not know a great deal how ever warming an engine is supposed to be done.

 

 

I too have rebuilt many engines and don't agree with you. From memory, most wear occurs on start up.

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Hendrix's rifle - no apology asked for or needed. How people mean something doesn't always come across in print. I didn't take your remarks to be condescending and nor were mine intended to be.

 

A genuine difference of opinion - which is what life is all about. It would be boring if everyone had the same opinion. After reading your post - I started to Google. It is fair to say that either side could produce quotes to support their respective case.

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Hendrix's rifle - no apology asked for or needed. How people mean something doesn't always come across in print. I didn't take your remarks to be condescending and nor were mine intended to be.

 

A genuine difference of opinion - which is what life is all about. It would be boring if everyone had the same opinion. After reading your post - I started to Google. It is fair to say that either side could produce quotes to support their respective case.

Thankyou, I see other peoples opinion as well as my own and I don't have blinkers on. Its like the old grease or oil on an oil filter o ring, many people have different ways of doing so. As for head gaskets id personally say there isn't much more that can be done in the means of adding to what we have now as things expand differently. Sorry to derail a thread aswell. Edit-and yes it would be very boring if everyone had the same opinion! Edited by Hendrix's rifle
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just do it properly and replace the head gasket 8 times out of 10 magic potions don't work. and when they do only for a short length of time......its allways in the back of your mind will it let me down..... rip the head of pressure test and skim with a decoke costs around £120 new gasket set from milners and put it back together.

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Please explain?? Not only do I work on a variety of standard cars on a daily basis I also work on a lot of rally cars and high performance cars more often than not. An engine is supposed to be warmed before any load is put on it, it lets the oil thin and lubricate everything properly before it is driven. Is also opens up any tolerances eg piston rings and the like. I have also built many engines from again, standard engines to high spec race engines. So I may not know a great deal how ever warming an engine is supposed to be done. Just my 2 cents anyhow :)

My thoughts exactly and in 35 years of driving I've never had a headgasket fail on my own vehicles, but I've repaired an awful lot of other people's vehicles who do not warm up their engines.

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It seems that the truck main dealers and manufacturers and all the haulage companies I've worked for over the years have it wrong then in saying "warm up at fast tick over". Volvo even set the exhaust brake to come on with park to load the engine slightly at tick over to warm it up. I just knew they'd got it wrong all this time :rolleyes:

 

:lol: :lol: :lol:

Edited by rodp
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There is no substitute for doing it properly

Indeed

If the car is a local run around that wouldn't be too important if it broke down then fair enough, but if you travel any distance or have to rely on the car then no, these temporary bodges ( which seem to be a favourite of the used car salesman ) are not the way forward, they are little more than a distraction and a waste of money...

 

26 years in the trade, and my neighboring business is a used car lot, for whom I won't do work for because he will always choose this 'to good to be true' type opinion first, usually making the job harder...

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It seems that the truck main dealers and manufacturers and all the haulage companies I've worked for over the years have it wrong then in saying "warm up at fast tick over". Volvo even set the exhaust brake to come on with park to load the engine slightly at tick over to warm it up. I just knew they'd got it wrong all this time :rolleyes:

 

:lol: :lol: :lol:

Years ago I worked as a truck fitter we ran a fleet of ERFs the boss after taking on a new driver would watch from the office as the new driver picked up his truck keys and started the truck if he drove straight off cold the boss would walk out stop him at the gate take the keys out a sack the driver. No ifs or buts just go.

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It seems that the truck main dealers and manufacturers and all the haulage companies I've worked for over the years have it wrong then in saying "warm up at fast tick over". Volvo even set the exhaust brake to come on with park to load the engine slightly at tick over to warm it up. I just knew they'd got it wrong all this time :rolleyes:

 

:lol: :lol: :lol:

 

So the manufacturer forced load onto the engine so it didn't sit idling...

 

Also, from the handbook from a new Volvo truck (amazing thing Google)

 

"Avoid cold starting
You can avoid cold starting by using the engine
heater.
If you start with a cold engine you should switch on
the air intake heating function in your truck. The
engine will then be supplied with preheated air which
results in an easier and more environmentally-friendly
start.
Never rev a cold engine. Warm up the engine by
driving gently at low engine speeds instead of letting it
run at idling speed while stationary."

 

Toyota back in the 90's ran a fast idle of 2-2.5k to attempt faster warm-ups, annoying when you pulled up at the lights on a cool morning and everyone thought you wanted a race...

Edited by LowStandards
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Years ago I worked as a truck fitter we ran a fleet of ERFs the boss after taking on a new driver would watch from the office as the new driver picked up his truck keys and started the truck if he drove straight off cold the boss would walk out stop him at the gate take the keys out a sack the driver. No ifs or buts just go.

 

What an utter cockwomble, even if the bloke believed that to be true, maybe mentioning that was policy to the drivers would of been a better idea...

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Well that's a first Gordon...... Last person you got heated with...... Kicked a load of doors in lol

 

 

Hendrix's rifle - no apology asked for or needed. How people mean something doesn't always come across in print. I didn't take your remarks to be condescending and nor were mine intended to be.

 

A genuine difference of opinion - which is what life is all about. It would be boring if everyone had the same opinion. After reading your post - I started to Google. It is fair to say that either side could produce quotes to support their respective case.

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