GolfGTIforum.co.uk

Model specific boards => Golf mk4 => Topic started by: ryanbrook on 07 November 2012, 22:41

Title: thermostat nightmare
Post by: ryanbrook on 07 November 2012, 22:41

replaced the thermostat because it was stuck open and making the car not heat up, so tried repcaing the thermostat and it just kept leaking from the housing. but now the bottom bolt what attaches the housing to the engine is just turning. I think the treads have fecked:\ Absolute nightmare. anyone any ideas what i can do?

Title: Re: thermostat nightmare
Post by: james2 on 07 November 2012, 22:56

my nightmare was getting a stage 1 power zone head only to find someone rounded a spark plug hole. You need someone that can put a helli ,i cant think what its called, its like a spring in the thread??????  :huh:

Title: Re: thermostat nightmare
Post by: ryanbrook on 07 November 2012, 22:58

haha. I have just googled that and found the helicoil method. How does this work? Do you just screw the coil into the hole and screw in a new bolt. Cant be that simple haha.

Title: Re: thermostat nightmare
Post by: ryanbrook on 07 November 2012, 23:30

does anyone know what size bolts are used for the housing. 10mm but like what length and width?

Title: Re: thermostat nightmare
Post by: rockmonkey69 on 07 November 2012, 23:46

It's not the size of the bolt head that you need, it's the size of the actual thread and it's pitch i.e. M6x1.2

To insert a helicoil you first need to prepare the damaged hole, it requires you drill out the damaged thread and over-size slightly, you then tap a larger thread into the hole by hand and then you can insert the helicoil. The helicoil itself is your new thread.

To decide how much to drill it out by and what size helicoil you need, first find out what size bolt it is for the housing. Should be quite easy as you have the bolt at hand.

Title: Re: thermostat nightmare
Post by: ryanbrook on 07 November 2012, 23:50

could using a longer bolt work? because the longer bolt might reach further where the threads aren't damaged.

Title: Re: thermostat nightmare
Post by: rockmonkey69 on 08 November 2012, 00:03

The bolts that came fitted are of the ideal length, any longer and you run the risk of bottoming out, perhaps causing further problems. The threads are damaged and I can see your eager to get this fixed but this is not a solution.

Any good machine shop will be able to helicoil the block for you for not much money depending on access to the site - as it does require drilling and tapping.

Title: Re: thermostat nightmare
Post by: ryanbrook on 08 November 2012, 00:07

thanks for your reply. Will see what i can sort out.

Title: Re: thermostat nightmare
Post by: rio_gti on 08 November 2012, 07:58

Jb weld the hole up then re-tap it  :lipsrsealed:

Title: Re: thermostat nightmare
Post by: harlemex on 08 November 2012, 16:51

find the correct size tap and just re tap it. should be good enough.

Title: Re: thermostat nightmare
Post by: EsSeX dAn on 08 November 2012, 17:55

does the bolt look ok? id go for running a tap to try and revive the hole, then go the helicoil route