Thread: Leaking head welch plug & missing manifold studs

This explains why the green bonnet was kept firmly closed last weekend--

Originally Posted by Fluids

So we all know about it ... don't we ?

Mine's had a tiny leak for a while. Looked everywhere else, that I could, and couldn't find ant evidence of another leak.

Disco's been parked up for months on end since Mrs F got the new Impreza. Since using it over the last few weeks the coolant leak seems to have gotten worse (a little), and since I knew everything was OK except the welch plug, the one thing I couldn't confirm was the heater hose to oil cooler little short tapered hose under the turbo sheild, that you can't see

Decided to whip the turbo & manifold heat sheilds off to inspect said hose, only to find the hose is in good nick, still soft & pliable .... but it appears the welch plug has gotten worse



God that red OAT makes a stinking filthy mess ... (and notice no5 lower manifold stud ... is there)






So, as a temp measure (cause I'm not pulling the manifold just yet) I was able to drift the welch plug about 1/2-3/4 of turn. Hopefully that slows it down so I can get over the next two weeks Belanglo & CBG .... running the raditor cap loose will stop it from pressurizing.

Strange ... on short around town runs, it leaks ... on long runs it stops leaking (with the tank cap sealed off and the cooling system pressurized).


So while I'm in there, I notice that no1 upper exhaust manifold stud is missing ... figures! It's squeeled once or twice on full boot, so I knew exactly what that meant ..... nut's gone, along with stud, with balance of stud still in head ... sigh ...




Looks like it's been gone for a long time ... but only minor carbon traces evident.

So I figure the best bet is to check all the other studs ... bar one or two I couldn't get to easily .... they're all good EXCEPT no5 lower just sheers off like a pretzel .... BIG sigh .... looks like the stud is still there just inside the hole ... didn't breake clean against the head like no1 has.






Hhmmm ...... a bit more evidence of carbon traces around that port. That said, it only squeels if I give it an absolute kick in the goolies. Top one end, bottom the other ... twisted ?

So I'll order another hose while it's apart and replace it, just for good measure ... and the welch plug and manifold can live like it is for a while longer, 'cause that's going to be a much bigger job Thank god for the trusty Engine Saver!

But, everything I need to know AULRO has already provided me ... just gotta dig in and do it!

BTW - 2 x 8mm studs to remove on the exhuast manifold heat sheild, and the rear one in the turbo heat sheild ... why the **** did they make that 10mm ???? I spent 20min tring to get an 8mm socket on to it ...

Sounds famliar - I had upper and lower #5 studs shear off.

Machined manifold, professional bolt extraction and replacement (after having a go myself) reassembled all and then found red coolant (welch plug) grrrrrr. Pull it all apart, tighten welch plug, reassemble and all good again.

Them's the breaks!

Cheers,

Franz

Originally Posted by Pedro_The_Swift

This explains why the green bonnet was kept firmly closed last weekend--

You mean, that explains why every time the green bonnet was opened, Pedro was no where to be seen, though, one attendee did bring to my attention a short hairy figure scampering off in the fading light ..... from the general vicinity of said green bonnet.



.... Just leaves one wondering ..... Jealousy ? Envy ? Lust ?






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Originally Posted by Franz

Sounds famliar - I had upper and lower #5 studs shear off.

Machined manifold, professional bolt extraction and replacement (after having a go myself) reassembled all and then found red coolant (welch plug) grrrrrr. Pull it all apart, tighten welch plug, reassemble and all good again.

Them's the breaks!

Cheers,

Franz

Now that's a bastard ! A bit of the old measure twice cut once philosophy wouldn't have gone astray

At least once the webbing is cut out you can get at the welch plug.

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Originally Posted by bell1975

Can I hassle one of you fellas to post a photo of this mod you've done to the heat shield setup please? Or a link to another thread where it's covered?

I need to fix the bracket that the 10mm bolt goes through on mine as it has cracked through...

Cheers.

Mate, no need for a photo ... Just turn the hole into a U shaped slot by grinding the bottom side out, so it will drop vertically onto the 10mm bolt (that's only screwed about half way in) ... Then tighten the 10mm bolt.

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So, just as a finish off here, drifted the welch plug up as said, tensioned the remaining manifold studs, and ran with the expansion header tank cap eased just open so as not to pressurize the cooling system, and did the run up to Glenreagh and return for the Cross Border / AULRO 11th Anniversary.

Anna Bay to Gloucester to Uralla to Armidale to Dorrigo to Coramba to Glenreagh at the speed limit (7.5hrs drive time and 546km) + 160km day drive in the forest on the Sunday ..... 11.5L/100km

Glenreagh to Anna Bay, Pacific Highway at a leisurely 95kmhr average on cruise on the way home. 450 odd km. 9.2L/100km (cause its downhill). Loaded with gear, roof racks, tray and awning, AUTO and it STILL does just shy of 30mpg. Impressive !

No squealing manifold, and needed to topup less than 250ml of coolant when I got home.

For the time being we are good to go until I can get organized to get it all sorted properly.

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