GT shat itself today, cylinder head bye bye!

[oscar]

well, possibly. spark plug blew out haha. threads stripped! cylinder head off > helicoil repair job i recon? if that doesn't do the trick then it's going to need a new cylinder head.

i swear the little ba****d is just doing it's best to let me know that it's time for a new engine transplant!

 

[singlespeed]

1.4TCe

Problem being thats another minority motor

 

[oscar]

haha grim times neil, i've had it stripped down today and the thread is just completely gone on it so i'll need to tap a new over-sized thread and use a timesert which is just basically a sturdier version of a helicoil.

i really don't enjoy re-threading cylinder heads

 

[AS_BO]

Oh dear Dave, sounds like it's thrown it's toys well out the pram! What caused it?

 

[oscar]

one of the apprentices where i work done the spark plugs for me last week whilst i was working on a customers car and he's hammered it in with his big monkey hands without hand turning the spark plugs first to ensure they don't end up cross threaded and it appears he done it over 2 plugs as one is stuck in the cylinder head.


it's fine though. the boss is covering the cost of any repairs plus my hourly pay with overtime, as well as the cost of a replacement cylinder head second hand if needs be. it's just going to be crap cutting around in the works van.

look at the upside though, replacement cylinder head means the old ones being sent off to cat-cams for GT cams but we shall see how it pans out. i'm convinced it'll just be a thread repair

 

[singlespeed]

Maybe worth while getting all four holes fitted with Timeserts if two are fubar and the others arent perfect.

Dont even entertain the thought of heicoils as the next plug change would probably end in tears as a bit unwinds stupid poxy things !

 

[sullii94]

Ahh that's **** man! Even worse that it wasn't your fault! :/ hopefully some good will come out of it though
Good job it didn't happen to a customers car!
When changing mine my dad was adamant that I put them in by hand first, then tightened, now I know why

 

[oscar]

Ahh that's s**t man! Even worse that it wasn't your fault! :/ hopefully some good will come out of it though
Good job it didn't happen to a customers car!
When changing mine my dad was adamant that I put them in by hand first, then tightened, now I know why

aluminium in the cylinder head is very soft, spark plugs aren't! the thread on the plugs are steel, so they can just chew through the cylinder head threads like suarez against the english defence

 

[poweller23]

just going to be crap cutting around in the works van.

I know that feeling I'm in the works van as my gear box decided to sh*t it's load lol

 

[oscar]

aye, plant your foot down and you may as well be going backwards! haha vans are crap. how those transit drivers kane it is beyond me. slow as anything!

so tomorrow is going to comprise of :
1 - ensure that the engine is on it's compression stroke close to TDC ensuring both valves are closed
2 - barbarically remove the cross threaded spark plug, threads already humped so no worries about butchering!
3 - cut the new thread with the timesert tap & insert the timesert itself over the two cylinders
4 - use an air line with a thin vaccum / brake bleeding bottle hose to blow the swarf out of the cylinder
5 - engine will be as good as new and the timeserts going nowhere

the lady was due a service anyway, new NGK's all round and some petronas oil. at least i hope that this is going to be the case as second hand twingo tce heads aren't very common. infact, i couldn't find one & i don't want to fit a clio tce head as the bolt lengths are slightly different

 

[oscar]

that's me finished it, went in at 7am on my day off. managed to remove / repair / replace the cylinder head as well as reset the timing in 4 hours working quickly. the thread repair was quite nervy, i really wish i'd taken some pictures now but as you can imagine with such a delicate procedure i wasn't in a very festive mood.

i went with the timesert option. the strange thing is that it's a permanent / interference fit, meaning it's going nowhere fast. because it's made of steel, it eliminates the real world possibility of ever cross threading again! however, the compression test has resulted ironically in the two cylinders ironically holding a better pressure than the other two cylinders which is a strangely satisfying bonus .... makes me wonder if i should have cross threaded the other two lol.?
so in a sense i'm glad this has happened because it's good to learn new things wherever you can. i have been extremely lucky here though guys and i'd always advise that you tackle changing spark plugs with caution. a 30 pound set of spark plugs could quickly develop into a grands repair bill!

 

[oscar]

and she's back!

 

[Martin_172]

sorry to hear about that! common on the 172's too with people who don't torque the plugs up properly!