Re: Advice on changing a thermostat please!
The dos and do nots of replacing a thermostat
Copy and paste from a post some time ago!
At the weekend I replaced the thermostat on my 156 Selespeed, and I thought I'd share some hints and tips, might be of use, might not.
My stat has been noticably poor at holding temps since my new rad went in. It cost in the region of £25 from Shop4parts, and the temp sender cost about £12 from EB spares.
The whole operation in steps.
1. Take off all the air intake piework from the filter to the throttle housing for ease of access. Replace any of the remaining clips with jubilee clips.
2. Stare at the ridiculus shape of the stat and the bolt positions for a bit.
3. Remove the largest of the pipes from the stat (the front one, which leads to the top of the rad.) Be aware that your feet will start to get wet soon.
4. Remove the very thin connection pipe which goes to the header tank.
5. Feel positive all is going well.
6. Try to remove the bottom hose, the one that will be a stupidly tight fit, use mainly brute force and ignorance.
7. Undo the final hose clip, for the final hose which goes directly backwards to the heater matrix. (Another wet foot moment)
8. Try and find a combination of 13mm socket and adaptor to give the correct length of about 7 cm needed to get a socket in to the gap to get at the securing bolts without having to remove the battery.
9. Decide that a standard 13mm socket, plus a 1/4 inch adaptor piece will give the correct distance. Remove bolts, wonder why the stat is still very firmly attatched to the head.
10. Yank the stat off the head. (Again, more wet foot action, it just keeps on coming)
11. Clean the mating surface thoroughly with carb cleaner and let dry, then wash again with water and dry.
12. Connect the back and top hoses with new jubilee clips. Bolt the stat into place.
13. Then and only then can you refit the bottom hose, which is the tightest fit, and the hardest position to access.
14. Fit the final hose.
15, Check all bolts and clips are tight.
16. Re-assemble the intake pipework, taking a moment to clean out any dust and cack in the intake tract.
17. Re-fill the header tank to the max line, and squeeze all the hoses a lot. wait for a gurgle or three.
18. Run the engine, and top up as needed as the car self-bleeds.
19. Replace the header tank cap and run it up to temperature.
20. Check for leaks and drips and do not be scared when the old coolant on the exhaust starts to smoke a lot.
The end. All is well. Go for a thrash in it. The temperature is now climbing to 90, then the stat opens and the temp sticks at just between the 9 and the centre line. Spot on.
21. Check the coolant a couple of times and make sure it is topped up.
22. Go for a beer after rubbing savlon all over the miriad of minor abrasions, cuts and gouges caused by the old clips and sharp edges.
I thank you.