I'm a Numpty

[StevieDB9]

Argh, ok you all know the saga with the polo. I had to change the thermostat a while back which I thought I would manage to do. I made the mistake of thinking "how hard can it be?" Im sure we've all made that mistake! Changed it fine but upon tightening the bolts back up (you can see where this is going) I stripped the threads like a right plonker.:embarrest:

After a tube of flange sealant, super-glueing plastic around the joint and a mile and a half of duck tape I'm still getting a leak and have to top up the coolant with water every other day.

After fixing everything else on the polo Im too skint to send it back into the garage (its just out again but only for an MOT this time) so I was hoping to do it myself. Does anyone know i) how hard it is to get a new housing and ii) how hard it is to change them. As far as I can see its only a matter of disconnecting the radiator hoses, the heater matrix hoses, the overflow hose to the expansion tank and a couple of bolts holding everything in place. But it looks like one of those ten minute jobs that turn into 6 hours and scuffed knuckles jobbies. I was also wondering can you get some kind of filler to fill in the stripped thread and then screw the bolt in again?

Waynne: I know I promised pics of nemo with his new wheels but Im too embarrassed to show his rusty brake drums, so will have to paint them first.

 

[HDi fun]

you should be able to get a die set to cut a new oversize thread and then use an oversize bolt/screw. Temporarily get some cable ties and use them to anchor it down. Cooling system is only marginally over atmospheric pressure - it's not like you're trying to contain fuel injection pressures which can be over 1000bar in diesels

 

[StevieDB9]

Where can I get a die set?

Yeah, its scary pressures in diesel injectors. I remember reading in the Haynes manual fuel injectors can inject fuel through the skin!:blink:

 

[HDi fun]

They can as well. Apparently my car runs at over 1300 bar fuel pressure. That's over 18,000 PSI. I've also heard of a stuck open injector boring holes into the piston crown!. A die set should be availbale from a good old fashioned iron mongers. Or try screwfix direct.

I've thought further on this and it's likely that a new housing will be somewhat cheaper than a tap and die set.

 

[obi_waynne]

Wouldn't a local garage be able to do a Helicoil on that fairly easily?

The breakers yard would be a good place to go for a new housing.

 

[HDi fun]

Nice one, Waynne.

 

[StevieDB9]

Was thinking along those lines anyway, bit embarrassing though!

 

[obi_waynne]

Blame the wife!

 

[pgarner]

what have you striped the threads on ? the bolt or the housing.
if its the housing a garage ahould be able to tap a new thread in the original and use a bigger bolt like HDI said. If its the bolt then you will just need a new bolt

whats a Helicoil ?

 

[StevieDB9]

its the housing that is stripped. Im thinking its going to be easier and a lot less hassle just to replace the whole thing. ive emailed a couple of breakers about the part. will keep you updated, i can imagine it probably will end up in the garage!:amuse:

 

[obi_waynne]

It basically a new screw thread you tap the old out with a helicoil (TM tool) and then put in the new thread http://www.emhart.com/products/helicoil.asp I had this done on a spark plug which I'd cross threaded in my early modding days! DOH! It is an as good as new repair.