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General >> Give/Need advice to/from others >> Thermostat,   worth replacing ?
(Message started by: mr._floppy on Apr 15th, 2006, 6:52pm)

Title: Thermostat,   worth replacing ?
Post by mr._floppy on Apr 15th, 2006, 6:52pm
The temp guage  is taking  8-10   miles to reach  optimum  position    ( although  warm air is aplenty after  1  mile,   strange )  indicating that the  thermostat  has stuck open.
         
                    After a  tentative  attempt at undoing the three  housing  bolts , and mindful of other poster's  broken  bolt   calumnies,   I'm   afeart   to   force them  should  they  snap.

Should   I   persist   or   leave  well  alone ?  

 What are  the disadvantages of a  stuck open   stat?

Title: Re: Thermostat,   worth replacing ?
Post by craig on Apr 15th, 2006, 6:58pm
could also be the temperature sensor needs replacing,if the heater is working ok in the car,and it appears to be running at normal temp,could well be your problem....
what engine is it on?
the reason for asing is that the gauge on my 2.3 did exactly the same,replaced the thermostat,and had no effect,replaced the sensor for the gauge (not the one for the engine managment),and all is well now,gauge goes up to half way within a few minutes..

Title: Re: Thermostat,   worth replacing ?
Post by Mickey_2.9 on Apr 15th, 2006, 7:32pm

on 04/15/06 at 18:52:38, mr._floppy wrote:
The temp guage  is taking  8-10   miles to reach  optimum  position    ( although  warm air is aplenty after  1  mile,   strange )  indicating that the  thermostat  has stuck open.
         
                    After a  tentative  attempt at undoing the three  housing  bolts , and mindful of other poster's  broken  bolt   calumnies,   I'm   afeart   to   force them  should  they  snap.

Should   I   persist   or   leave  well  alone ?  

 What are  the disadvantages of a  stuck open   stat?


If you are changing the thermostat run the engine up to normal working temp first. Then try to undo the bolts but only 1/2 - 3/4 a turn each one to start with just to get them moving, DO NOT UNDO MORE UNTILL ENGINE IS COOLER TO AVOID BEING SCOLDED WITH HOT COOLANT. Then when the engine is cooler try removing the bolts. The ally housing will exspand more than the steel bolts when hot and hopefully allow the bolts to undo without shearing off. The other way is to locally apply heat to the stat houseing using a electric heat gun but be carefull not to melt any wiring. when you get the bolts out give them a good clean with a wire brush or some emery cloth and refit with some grease or copper slip on the shank and threads.  Clean out the holes as well.

Runing with a stat that is stuck open will make the engine run rich, the most noticeable thing is the mpg will drop.

Hope this helps

Mike.

Title: Re: Thermostat,   worth replacing ?
Post by mr._floppy on Apr 15th, 2006, 8:37pm
In reply to Craig,  I replaced the temp sender  as  it  was  not working at  all ,  it works  fine  now as do the cooling fans but,  as I say,  it   takes  a few miles before any guage movement takes place.

  Thing  is,   the  housing   bolts  are  only   10mm  and  rusty  and will         "round"    as  soon  as you   look at  the   b****rs. :-[

I shall try Mickey's advice    (   I don't know about applying heat to the  stat housing , ain't  it   plastic ?  ??? )

Title: Re: Thermostat,   worth replacing ?
Post by Mickey_2.9 on Apr 15th, 2006, 9:06pm
opps sorry mate :-[ what engine you got?

Title: Re: Thermostat,   worth replacing ?
Post by mr._floppy on Apr 15th, 2006, 9:18pm
 A     '96   2.0   litre     16V

Title: Re: Thermostat,   worth replacing ?
Post by Mickey_2.9 on Apr 15th, 2006, 10:29pm
Guilty of typing reply without thinking :-[ I still think it would be a good Idea to try undoing the bolts with the engine hot but dont use a heat gut if the housing is plastic. Mines a 2.9 12valve and made of old school ally!

Hope you sort it mate.

Title: Re: Thermostat,   worth replacing ?
Post by jonnycab on Apr 15th, 2006, 11:08pm
Another way of getting the bolts off without rounding them is to actually tighten them up very slightly (so breaking the rust), & then undo them. Or you could try 'Gunk-liquid wrench', it comes in a spray can with tube.



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