Thermostat replacement

[Reggit 0]

I've just taken 'stat out, ready to replace with new one later in week, what a bugger of a job, the Bentley manual only showed 1 bolt holding asembly to engine, took a while to find the 'hidden' short bolt!

 

What do you good people recommend to do with the hose clips, replace with jubilee clips, use originals or replace with OE clips?

 

Antifreeze - it's had blue stuff in, dunno what kind. Does VW's G12+ stuff make much difference and will it mix ok with the remnents in my cooling system, or should I run it with plain water to flush dreggs of blue stuff out, then drain and refill?

[Kevin Bacon 5]

Bentley and Haynes are often conservative with details of the true requirements of a job!!

 

Just reuse the original hose clamps unless you have a particular loathing to them and want to replace them with Jubilees. I prefer the OE clips as it's impossible to over crimp the hose and they're quick and easy to get on/off.

 

G12+ will mix with anything but give it a good flush first anyway. G12+ should be used. I've seen a few rusty VR6 blocks which resulted from NOT using proper VW coolant additive.

[Timo. 0]

G12+ plus works fine with the blue stuff. Make sure you dont get G12 only stuff as that'll cause problem.

 

How clean is your old coolant? you could some some flushing stuff, or just run a hose into the expansion tank wait untill the whole system is filled with clean water and start the engine. Leave the drain plug off so the water drains straight out.

 

I just reused the OE clips, they are a pain to undo. No harm in replacing them with jubilee clips. OE clips never seem to rust though which Jubileees seem to do eventually.

 

Timo.

[Reggit 0]

Hmm, I've just put it all back together with a new stat and coolant. Just realised the old one hasn't been right since I bought the car a year ago. Engine temperature is now around 80-90 degrees C, where-as is used to be below 70.

 

Well worth the hassle.

[Timo. 0]

Good, glad you got it sorted.

 

 

T.

[aclwalker 3]

Hi,

 

I'm going to tackle this job (thermostat replacement plus full housing and sensors etc) when I get some free time over the holidays. Anything to watch out for?

 

Did you replace the housing at all? If so, did you use any kind of additional sealant over and above the seal provided? I've heard people suggest using blue (I think) gasket sealant where it touches the block but am not sure if it's really necessary.

 

Thanks

 

Alan

[dr_mat 0]

Hmm, I've just put it all back together with a new stat and coolant. Just realised the old one hasn't been right since I bought the car a year ago. Engine temperature is now around 80-90 degrees C, where-as is used to be below 70.

 

Well worth the hassle.

 

So all that time tracing wiring and changing temp sensors was educational, great! ;)

 

You should have just trusted the wiring (and us!) in the first place.. ;) :)

[Reggit 0]

It's a bit fiddly due to lack of room, but easy enough. One thing that caught me out was finding all 3 of the bolts that hold the housing to the engine, one of them is in quite a deep part of the casting and took me a while to find. The Corrado Culb of America has quite a good write up on its tech tips section.

 

I didn't use extra sealant, but had a slight leak so I probably should have, leak now stopped.

 

Used original housings, and replaced blue and Yellow (now black) sensors. Left 3rd one alone as it's redundant on non a/c cars.

[Reggit 0]

You should have just trusted the wiring (and us!) in the first place..

 

True, you live and learn... yellow sensor turned out to be duff as well as the stat, so nothing really lost.