Morning all...truck sailed the mot so making a list of todos for the winter....K74 4d56 155k miles guaranteed no service history..The temp gauge sits bang on, even long hills towing a trailer..Is it inevitable the head gasket going to go and possibly knacker my head? Did anyone ever find out what makes them go? Not changing the coolant or what? Are replacement ones better? Your thoughts and experiences are much appreciated ! Nik

never had any issues with the head gasket on my old truck nor did the next guy I sold it to so it's 17 years old now and 120 odd thousand miles and has never missed a beat
some are fine some aren't , dont think anyone has found a 'cause' over the years

Mmmm...got plenty to do else where on the truck so may leave well alone. Thought the HG was inevitable , as you say you sometimes only hear the bad stories on the net so you presume all 200's HG's blow....Just back from very north Scotland ...l200's everywhere! God its cold up there...Those Scots are made of granite..!

the cause is lack of servicing and abbuse! drive with a failing cooling system u are asking for trouble

Quote: 123hotchef wrote in post #4

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the cause is lack of servicing and abbuse! drive with a failing cooling system u are asking for trouble

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your must have been a friday assembled engine!

Lol, very likely! Bit seems to me Mitsi worked more Fridays than any other company lol

ha ha maybe Friday was engine assembly day and the rest of the week was something else on the line

Just taken the head off 160k miles,bubbles in the coolant...several cracks I can see and maybe a few more I can't. The bore has plenty of cross hatching and there only a tiny lip at the cylinder tops ...but piston 1 and 3 have pitting in/on them....The plan is new head kit from miners...rebuild it and see how it behaves....Just before i press the money button ,KS international do a similar kit, anybody any thoughts or experiences re my plan...many thanks as ever..Nik

yeh neither get it from lym engeering tell them/simon i/lee sent you for a forum discount

Ta for that ...theyre only around the corner from me...I'll call tomorrow...Just a thought..where do you think the metal " speckeled" piston tops have come from??..THe bores look good...Ta Nik

pop down there then ask for simon worthington. spekeled what u mean? any pics

Ill get a couple of pics tomorrow.....basically two of the pistons have the typical carbon deposits/build up...then the other two have roughness to then like 40 grade sand paper...It looks like something metallic has had a free for all and gave them a battering! but the bores have no scoring from what I can see and very small lips...Nik

......like a pitting on the crowns.....

glow plug tip maybe?

As promised I've included a picky of one of the piston crowns...thoughts as to cause of the pitting? Thanks L re the source for a new head.... awful nice guys and very helpful..good price too... He said/laughed that you've had "many "cylinder heads off him in the past! Nik
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Looks to me like it's started to melt due to overheating rather than pitting. Personally I'd be lifting the engine now and checking the rest of it mate.

Thanks for that.....i think ill put the new head back on and see how it goes..strange only cylinders 2 and 4...1 and 3 no probs...I don't fancy taking apart any more than this!!!...I might do a compression check at the end and make my mind up from there!!!!! Ill keep you posted..nik

probably a duff injector dripping fuel onto the piston rather than atomising it into the chamber

Aye, by overheating i was meaning on the piston crown , rather than general engine overheating. As Lee said was probably caused by a dodgy injector, could also be a problem with the atomising chamber though.
The damage could possibly extend down to the rings, that's why i suggested having a deeper explore

This is a pretty good guide to piston damage diagnosis.
https://www.memoparts.com/img/cms/Docume...on%20Failue.pdf

my bitch truck pushes the temp up to the red on long hills might just be a injector

With 160k miles on board /i might clean the injectors....good call guys!

Just a quickie...Putting the cam cover on for the final time hopefully...instructions were to torque up the head ..warm it up ..then check the head bolts again...Ive Dirko for the sealant...How long should I wait after fitting the cam cover till I run it up and wiz it down the motorway...nothing on the instructions! Ta Nik ps gutted re the final!

yeh a whiz up the mway will suffice some people check after a week,