Removing thermostat housing 1.9 DG

[Brian1]

Most of the head of the lower bolt has rusted. Any advise on removing the lower bolt would be much appreciated. I am thinking maybe cut off the plastic thermostat and then put lots of penetrating oil on the bolt and try to get it off.

[CJH]

I have an old engine on the bench and I'm dismantling it at the moment. I had the same problem, but since it's out of the vehicle I was able to take the bolt heads off with an angle grinder and remove the housing. One of the studs then came out easily because it had previously been helicoiled, but the other one is stuck fast, so I'm considering my options. Pretty sure it's going to need some sort of specialist stud extractor though, maybe something like this.

[CovKid]

Irwin bolt remover set. Exactly what I was about to post. Good kit to have anyway.

Read: https://club8090.co.uk/forum/viewtopic.p ... g&start=30" onclick="window.open(this.href);return false; Mine was metal but the problem is the same more or less.

I Wiki'd it too: https://club8090.co.uk/wiki/Co ... overhaul_3" onclick="window.open(this.href);return false;

[CJH]

Ralph, it's only thanks to your epic thermostat thread that I knew about that tool. That set goes down to 3/8", which is about 9mm. I'm not sure what size the bolt is on the later thermostat housings - M6 maybe. I guess those extractor sockets decrease in diameter as you go deeper - if you've got that set do you think the smallest one would grip a 6mm stud?

[CovKid]

Don't have it in front of me right now but yes you're right, it just goes on further. You can even shift round allen bolts with those. Quite astonishing. I can have a look when I get home after 3 if you like? We're talking about a bolt with a 10mm head I take it. If so, yes, they go down to that. For a stud on its own, you can get some fantastic stud extractors that grip like hell but don't strip the thread. Bought a set of those too.

Irwins though, are one of those tools that you very rarely have to use but there isn't any substitute. It just has to languish in your garage until its needed. Mind you, weigh up the time wasted trying to remove a bolt by other means and its price suddenly becomes very cheap indeed. I wasted almost a week with that damned bolt until I bought a set. Took 60 seconds with an irwin.

The other way, if pump has to come off to be replaced is remove both as one, then grind pump away (pump scrap) where bolts go in, to seperate the two, then deal with whats left. You just have to grind VERY carefully so as not to damage housing. Even then, you might still need an irwin...

For anyone not familiar with irwins, they're sockets with cutting edges in which bite hard - even when the head is rounded.

[CJH]

I can't remember what size the head was - 12/13mm maybe - in my case the head is now gone. For the OP though, I think one of those tools will work on the rusty head.

Just for clarity, since the OP referred to the plastic housing I assume he means the later cooling system, with the thermostat above cylinder 3. That's also my immediate concern since I'm working on my later 2.1.

[itchyfeet]

Just for clarity, since the OP referred to the plastic housing I assume he means the later cooling system, with the thermostat above cylinder 3. That's also my immediate concern since I'm working on my later 2.1.

that's how I read it and they are M8 Bolts, 13mm head, into the cylinder head, one goes right through as it's on a protruding lug

[CJH]

For a stud on its own, you can get some fantastic stud extractors that grip like hell but don't strip the thread. Bought a set of those too.

Any recommendations?

[CovKid]

Was thinking about this one the way home Chris. You may be able to remove studs with irwins but not without the risk of chewing up the thread (which they will definately do on mild steel and prob damage a hardened thread too) and maybe whats left of the stud altogether - they're fairly brutal. They're fine on a bolt head that is already rounded off, but I wouldn't use them on studs in case I ended up losing any chance of removing the stud after that.

From a local tool place I bought this type: http://www.ebay.co.uk/itm/Stud-Extracto ... 2328483830" onclick="window.open(this.href);return false;

If you look, inside the socket there are offset rollers. The more you turn the socket, the more these rollers press against the stud, gripping it tight. They are supposed to be able to remove studs without damaging the threads much. Not actually had cause to use mine yet but I did try one on a bolt end and was impressed with the way it grabbed it with ease.

However, take note of the comments in the description. You may well need heat to help ease a stubborn stud, and even then...

How much stud is left will play a part ofcourse. I got them for when I next take exhaust off.

[CJH]

Thanks for that. In my case I'm looking at several seized studs. At least one of them used to be a bolt, so I'm not trying to save it - I don't care if it chews it beyond recognition, as long as it gets it out.

Scary stuff in the blurb for that set

PLEASE NOTE: These Extractors are designed to be used on FREE (NOT Seized) Studs. Anybody lacking in experience of removing seized Studs should get professional help from time served highly experienced exhaust fitters/motor technicians. Great care should be taken when using these extractors as incorrect use will cause damage to the tool and or studs! This is not to say they will not extract seized studs but great care and experience is needed to avoid any damage. Not for the average DIYer!

[CovKid]

I think it applies to any extractor. If you've ever had cause to use easy-outs that look like the mole from Thunderbird 2, the risk of snapping one is pretty great. You still need plusgas (not WD40) and heat sometimes.

[itchyfeet]

I got a second hand head recently as a spare and it had three siezed studs, I enlisted the help of what2d to get them out with his mig welder two came out ok but the third just kept snapping until there was nothing to weld to, it apprears there are some studs that are never coming out without drilling.
drilled it and helicoiled it

[CovKid]

Would echo that although always worth battling with them if you have the right tools and where prudent (ie away from plastic or anything that could distort or melt), use heat and proper pentrating fluid. Mig welder can sometimes get you out of trouble with a nut welded on etc but its just plain difficult or impossible sometimes.

[Brian1]

Thanks to everyone for the advice. The head is so badly rusted I can't get the Sealy bolt extractors to grip it.
Current plan unless anybody can suggest a better plan!
Am going to try to turn it with a tiny mole wrench but I doubt that will work.
The will see if I can cut the bolt head off and get the thermostat housing off.
If that is too difficult I will try to cut the thermostat housing off. It is already cracked and leaking which is why I need to get it off.
Then hopefully I can get some penetrating oil in and get the rest of the bolt out.
Thanks once again for the help.

[CJH]

If the thermostat housing is already toast, go with your original plan and hack it off. It'll be a lot easier to saw the head off the bolt once the housing is out of the way, and then you might be able to get a stud extractor onto what's left. I sympathise - I've got the same problem on a head that's on my bench - it must me 10 times worse in situ in the engine bay.