Thermostat housing problem

[niks_terrano ii]

Hi guys my mates mav now has another problem the thermostat housing leaks by where the long bolt goes so we decided to remove the housing and replace gasket only to discover the long bolt is in a bad way we replaced the gasket and went to tighten it but it seems to tighten so far but then just turns am I screwed ??

 

[R1cho]

sounds like the bolt has sheered lift the top of the housing off the bolt my still be sticking out the top enough to get some mole grips or plumbers wrench on it to turn it back out

 

[niks_terrano ii]

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The bolt comes out but the problem is when I tried to put it back it doesn't seem to tighten enough like the bottom of the thread has already snapped and the bolts threads left wont tighten tight enough

I was thinking new gasket and some sealant ???

What do you guys think ??

 

[supergnome]

Has the bolt snapped ? It will have a spec, check its the correct length for the hole. Someone may have put on the wrong bolt in the past. David.

 

[R1cho]

the bolt is a long one at the back, i cant remember exact length and from memory not much thread on it, can u get a pic of the bolt, or better still check the end of it for signs of it snapping, you need this bolt in place or you wont get a proper seal on the housing

 

[rustic]

If it's only stripped the thread in the base then Helicoils are the way to go.
In the kit you get the right drill, a new tap for a thread which takes the helicoil, which looks like a spring, a winder in tool etc

When complete the thread is much stronger than the original, if the base is aluminium.
Available m6 m8 m10 and all metric sizes plus imperial too.:thumbs

 

[solarman216]

A cheap fix is buy some threaded rod same size and thread pitch screw it in till it stops/bottoms this will pick up previously unused thread in the bottom, cut it off to length and put a nut on it, job done, Rick

 

[stinka]

A cheap fix is buy some threaded rod same size and thread pitch screw it in till it stops/bottoms this will pick up previously unused thread in the bottom, cut it off to length and put a nut on it, job done, Rick

Top suggestion

Or helicoil as rustic says, which was my first thought

 

[micktheshed]

A cheap fix is buy some threaded rod same size and thread pitch screw it in till it stops/bottoms this will pick up previously unused thread in the bottom, cut it off to length and put a nut on it, job done, Rick

Exactly! But try a tap in the hole first to get the max. amount of useable thread & also to clean out the hole.

 

[niks_terrano ii]

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Hi guys thanks for the input cleaning the hole maybe an issue as the hole is about 4 or 5 in depth but I wonder if I managed to get another bolt from a maverick that's breaking at my local breakers and whack some washers in there to space it a bit would a silicone sealant work with a new gasket if we can get a few twists on the thread ?

Anyone in the south east / east Sussex who can helicoil coz I'd hate to cock up my mates engine as I've never done it before ?.

 

[rustic]

A cheap fix is buy some threaded rod same size and thread pitch screw it in till it stops/bottoms this will pick up previously unused thread in the bottom, cut it off to length and put a nut on it, job done, Rick

As Rick says, I have done this many times, even on a plastic Black and Decker drill where the original screws stripped in the body.

You can buy all thread from Screwfix, use stainless, I always keep a length of various sizes, a few washers and a nut or two, job done like Rick says.
Not suitable for high stressed fixings but perfect for this.

As a last resort you can always drill and tap with a larger bolt, but you would have to drill a clearance hole in the top housing.

Good luck,
Rustic

 

[niks_terrano ii]

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Guys today me and my mate went screw fix and bought some 8mm threaded rod and screwed that into the hole and it seemed to pick up the thread so we chucked a couple of nuts on and tightened it up but we found if we tried to tighten it to much It was just pulling back out.

We then put it back in done it up to a point just before it felt like it was going to pull back out and again tightened the nuts up again, not so tight that the thread pulls out and went for a drive got the engine nice and hot and water seems to be coming up the thread !!!

Is there anything I can do ?

Was thinking maybe another new gasket and loads of gasket sealant in there ?

It the bolt at the back that goes about 5" into the head

I think the thread deep in the head is fooked !!!

Any suggestions guys ???

 

[Terranical]

Guys today me and my mate went screw fix and bought some 8mm threaded rod and screwed that into the hole and it seemed to pick up the thread so we chucked a couple of nuts on and tightened it up but we found if we tried to tighten it to much It was just pulling back out.

We then put it back in done it up to a point just before it felt like it was going to pull back out and again tightened the nuts up again, not so tight that the thread pulls out and went for a drive got the engine nice and hot and water seems to be coming up the thread !!!

Is there anything I can do ?

Was thinking maybe another new gasket and loads of gasket sealant in there ?

It the bolt at the back that goes about 5" into the head

I think the thread deep in the head is fooked !!!

Any suggestions guys ???

Depending on how far down the original thread started, helicoiling would seem to be your only option. Problem is that the hole down to the start of the original thread is going to be clearance size, and probably too large to fit a helicoil to the top - helicoil taps are standard length i.e. around 3", and wont reach the original thread sufficiently.
If that is the case then drilling oversize (10mm?) and retapping is your only course of possible action.

 

[solarman216]

OK your thread has gone, helicoil or tap out to next size up but to do both you will need to remove the thermostat cover thermostat and the housing it sits in, the long bolt that has stripped does not bolt into the head but the ali casing below, easy then to helicoil or tap out larger size, looks like there is enough meat to take an over bore without much trouble, Rick

 

[Kishada]

When you're removing the thermostat housing (that bolts to the front of the cylinder head), use an old wing mirror glass to find the hidden bolts at the bottom of it (there are two).
Might be worth ordering the rectangular rubber gasket at the base, and metal one that joins to the head, and a new thermostat housing cover gasket.

 

[solarman216]

When you're removing the thermostat housing (that bolts to the front of the cylinder head), use an old wing mirror glass to find the hidden bolts at the bottom of it (there are two).
Might be worth ordering the rectangular rubber gasket at the base, and metal one that joins to the head, and a new thermostat housing cover gasket.

well said I forget detail, Rick

 

[niks_terrano ii]

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Hi guys sorry to sound daft but what have I got to remove ??

I thought the thermostat housing was part of the head ??

Are you saying I can remove the whole thing from the head ??

Anyone wanna give me a hand or do it for us as its my mates car ??

He don't mind paying he just wants it to stop leaking and my expertise has got this far and my skills won't be able to do it !!

We are in the south east / East Sussex and don't mind travelling to far to get it sorted

Thanks in advance guys

 

[briggie]

Hi guys sorry to sound daft but what have I got to remove ??

I thought the thermostat housing was part of the head ??

Are you saying I can remove the whole thing from the head ??

Anyone wanna give me a hand or do it for us as its my mates car ??

He don't mind paying he just wants it to stop leaking and my expertise has got this far and my skills won't be able to do it !!

We are in the south east / East Sussex and don't mind travelling to far to get it sorted

Thanks in advance guys

you have a genious on your doorstep :augie:thumb2

 

[niks_terrano ii]

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Tell me more briggie

 

[briggie]

solarman 216 and swifty ..... live on your doorstep in east sussex :naughty:thumb2:thumb2:bow:bow:bow