Leaking head welch plug & missing manifold studs

[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 :angel:

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 :eek:

https://www.aulro.com/afvb/images/imported/2012/10/1294.jpg

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


https://www.aulro.com/afvb/images/imported/2012/10/1295.jpg



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! :D 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 ...

https://www.aulro.com/afvb/images/imported/2012/10/1296.jpg


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.


https://www.aulro.com/afvb/images/imported/2012/10/1297.jpg



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 ? :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 ... :angel:

[SiddersC]

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 ... :angel:

I notched my turbo heat shield last time it was off, now I just have to loosen the bolt and lift it off, :) I didn't have a problem getting a socket onto it, but it was a major PITA to get the bolt started when refitting.

You may also find that more studs let go when you try to remove them, I had 1 snapped and ended up with another 3 sheared. :(

[Fluids]

I notched my turbo heat shield last time it was off, now I just have to loosen the bolt and lift it off, :) I didn't have a problem getting a socket onto it, but it was a major PITA to get the bolt started when refitting.

. :(

Brilliant idea ! Thanks. I was wondering about getting the bolt restarted.

I'll add that to the "What else to do while the exhaust manifold's off" thread.

:thumbsup:

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[strangy]

Hey Kev, if you change to green coolant for December, it would be a lot like Christmas under there:angel:

[BIG O]

Or you could have ground out the webbing on the manifold at the threaded plug and closest to the lost stud nut. Cut an Allen key to 20 mm long used it with a ring spanner to undo the plug ,,cleaned the plug,, applied some sealant ,,re tightened with Allen key and ring spanner,, put a new nut on the naked stud and hope for the best. All without disturbing the manifold. Did both our D2 TD5's that way 4 years ago and no sign of either leak. Getting rid of that pink crap helped too. Confidently I won't service my Td5's without removing the turbo heat shields first...much more room.

[gazk]

Just spent the weekend replacing my TD5's head gasket. It had been pressurising the coolant system for a few months usually dumping some out of the coolant tank cap overflow but recently also leaking some fluid near the water drain plug you have pictured above. The TD5 has done 226000km and the head has never been off. I found the plastic head dowels partially sheared (about 1mm movement) and evidence of a leak on the turbo side of #3 cylinder. On inspecting the head gasket I suspect that the leak I had seen near the plug could also have come from the coolant gallery adjacent to #3 cylinder. Your leak is much worse than mine was.

I had the exhaust manifold machined flat about 18 months ago when I found broken studs on #1 and #5 cylinders. This time the manifold was flat with no broken studs but one nut on #5 was missing. I have now cut the webs on the manifold and slightly enlarged the holes on #1 and #5 cylinders.

While the head was off and everything was easy to access I cleaned the inlet manifold, fitted a new fuel pressure regulator to head hose (EU3) replaced the alternator with a almost new spare I had lying around and replaced some of the plastic tubing on the wiring looms.

If I were you I would remove the manifold, check that it is flat, cut the webs, fix the studs and reseal the water drain plug (part no LCM100170) with Loctite 243 (blue). If you still have a leak in that area it is probably head gasket time.

[LOVEMYRANGIE]

Leave the heat shields and engine covers off alltogether. The turbo really isn't close enough to anything to overheat something and the increase in airflow around everything increases immensely dropping temps.


Using Capitals, the difference between helping your Uncle Jack off a horse or helping your uncle jack off a horse...

[Fluids]

Or you could have ground out the webbing on the manifold at the threaded plug and closest to the lost stud nut. Cut an Allen key to 20 mm long used it with a ring spanner to undo the plug ,,cleaned the plug,, applied some sealant ,,re tightened with Allen key and ring spanner,, put a new nut on the naked stud and hope for the best. All without disturbing the manifold. Did both our D2 TD5's that way 4 years ago and no sign of either leak. Getting rid of that pink crap helped too. Confidently I won't service my Td5's without removing the turbo heat shields first...much more room.

Thanks BIG O ...

Yeah, I could, but have nothing to grind the webbing in situ, and the leak seems to have ceased (for the moment at least) ... and both the missing studs are sheared off level with the head, so the manifold has to come off eventually, so the welch plug can wait till then.

Good idea about the welch plug though. Thanks!

[Fluids]

Your leak is much worse than mine was.

If I were you I would remove the manifold, check that it is flat, cut the webs, fix the studs and reseal the water drain plug (part no LCM100170) with Loctite 243 (blue). If you still have a leak in that area it is probably head gasket time.


Thanks Gary ... it looks WAY worse than it actually is ... I know the head gasket is OK. Cooling system doesn't pressurize from exhaust gas, and when the engine cools, the hoses are all soft. It's just the welch plug.

... it's been leaking for over 10,000km, so there's a long term build up of RED, and with a bit of moisture, and the camera flash, it looks catastrophic :eek:

It was leaking just by gravity, as the header tank is above the welch plug ... garage floor is dry yesterday & today.

...but yes, the manifold is coming off soon, and I'll do a full once over on the welch plug, manifold, studs, fit the provent, drill exh' manifold for an EGT, change hoses, etc, etc, etc ..... that's alot of etc's :p

[Fluids]

Leave the heat shields and engine covers off alltogether. The turbo really isn't close enough to anything to overheat something and the increase in airflow around everything increases immensely dropping temps....

Sounds like a plan Andrew ... but ... I have an Optima Yellow top on a battery tray a few inches away from the turbo .... :eek:

Heat sheild mightn't make it back on for this weekend, but I think it's a safer bet to refit it to protect the Optima.

I'll slot the rear bracket like SiddersC suggested, so it will be a quick easy job to refit/remove.

[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.


I'll slot the rear bracket like SiddersC suggested, so it will be a quick easy job to refit/remove.


I notched my turbo heat shield last time it was off, now I just have to loosen the bolt and lift it off, :) I didn't have a problem getting a socket onto it, but it was a major PITA to get the bolt started when refitting.

You may also find that more studs let go when you try to remove them, I had 1 snapped and ended up with another 3 sheared. :(

[Pedro_The_Swift]

This explains why the green bonnet was kept firmly closed last weekend--;):p

[Franz]

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 :angel:

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 :eek:

https://www.aulro.com/afvb/images/imported/2012/10/1294.jpg

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


https://www.aulro.com/afvb/images/imported/2012/10/1295.jpg



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! :D 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 ...

https://www.aulro.com/afvb/images/imported/2012/10/1296.jpg


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.


https://www.aulro.com/afvb/images/imported/2012/10/1297.jpg



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 ? :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 ... :angel:
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

[Fluids]

This explains why the green bonnet was kept firmly closed last weekend--;):p

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 ?

:p


:twisted:

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[Fluids]

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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[Fluids]

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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[Fluids]

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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[Pedro_The_Swift]

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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Urine.
Guiness.
:p:p:p