Just a quick question.....When i rebuild the mv6 i was thinking of cutting a tiny amount from the spring in the thermotat to make it open at a slightly lower temperature (extremely inaccurate i know), in an attempt to make my own DIY cool running thermostat. What are peoples opinions on this? Bad idea?

I know some people may say leave it be, but doing a lot of town driving my engine reaches temperature quite quickly, sucks in a load of hot air and feels a little bit 'flat' because of this. So i've been considering a cool running stat for a while....Any thoughts?

Cheers 

hotel21 wrote on 10. Aug 2006 at 19:17:

That is a right good idea Bruce.

Why didn't i think of doing that when i just changed mine last week.  Especially when my old one was doing exactly what you said, sticking shut.

There's a product called water wetter which is supposed to lower running temperatures but ive never tried it.

dont see how it could hurt so long as you dont go too big, at the end of the day you will just need a new one, you could of course do a trial run with no stat in to see if it makes a big difference before drilling holes

Redline Water wetter.  "Cooling system heat transfer agent for use with coolant to "wet" heat transfer surfaces by 50%. This provides significantly better coolant contact in cylinder head and can reduce coolant and head temps by as much as 30degF. does not alter freezing point.

335ml bottle approx £16.50.

not yet used it myself, but have heard it does what it says on the bottle.   

Hmmm, ok. Well it would probably be best to leave it alone then.....I will definately be trying water wetter though!

It's just it runs and perform's much better at around 92.5 degree's rather than 95 or abit higher.....I know cutting the stat spring is dodgy though lol

I'll have a look for a cool running stat, do they work by just having a softer spring fitted though? So it'll open earlier?

Its not the springs that change, its the wax temp sensitive insert so modifying the spring will probably only result in it being permanently open.

As for cool running stats, my personal opinion is that they offer no benefits given our climate etc.

And water wetter realy only has a place in older cars, modern anti freeze has it any way and it does little more than break down the water surface tension in pretty mucy the same way detergent does...

One thing that springs to my mind is: is the car running slightly warm or perhaps is the temperature gauge / sender slightly out......

I think that before you go modifying anything you need to check the coolant temperature with something accurate.