Thermostat and Housing

[angelorange]

Mine has corrosion issues - anyone got a spare for sale?

Have heard of Renault Thermostat part being used by cutting out old one and putting inline with top rad hose?

Viva Lancia pages suggest Wahler:

http://www.wahler.ro/Info%20technice/Crossliste_Wahler_OE_2008.pdf

3029.83 225.070 DAF
77 00 575 874 RENAULT
77 01 348 376 RENAULT

[fay66]

Omicron supplied one for me about 3 years ago, I took the housing off, put it in the jaws of my black & Decker workmate, prised the valve open, and cut through the shaft with a junior hacksaw.
then using a hacksaw blade very carefully cut slots through the inside of the thermostat, don't cut too deep or you will destroy the tread in the housing as the thermostat screws into the housing, I then found after I had cut the slots I could collapse the thermostat body inwards to remove it with out damage to the housing and thread.
Cleaned up the housing and the thread, then found a few corrosion holes in the Aluminum, filled these with plastic padding, fitted new thermostat,then housing to engine.

Brian
8227

[ncundy]

Simple little blighters to remove aren't they  I cut a slot in mine across the top, heated the assembley up in a bath, then applied freeze spray, did this about 4 times then using a cole chisel, hammer and pipe wrench persuaded it to come loose - took me about 3 hours.

[Richard Fridd]

 i have housing s/h used cond. fitted with thermostat which opens and closes in hot +cold water taken from S2 /3 fulvia1300 no visible corrosion to hose connection points/thermostat fitting but very minor pitting 35mm from thermostat mating face £30 inc uk p+p if any use to you.best regards richard

[angelorange]

thanks all

Wow they are tough nuts to crack!

Richard - any chance you could send me a pic or two or put them online e.g:flicker?

[Richard Fridd]

apologises but not up to date with photo equipment .parts in good used condition from low milage engine which i am keeping as spare. i dont think minor pitting mentioned would  show in photo but please call on 07957 292 127 :8 -4 daytime if you need further info.full refund offered on returns if parts are not as described. best regards richard

[ColinMarr]

I have an interest in this problem too. I think my thermostat is sticking open because the temperature gets to normal (about 160degs F) when poodling about, but then goes down (to about 150) when running at higher speed.

I haven’t yet attempted to get the old thermostat out, but my memories of trying to do this on a 1967 Flavia some 20 years ago are not encouraging. I remember doing all the careful bits with hack-saw blades and gentle easing, but the outer aluminium housing just disintegrated and I had to source another unit. I think it all depends on the history of your particular car and how good the corrosion inhibitors have been over more than 30 years.

My preferred route would be to cut out the old thermostat so that it doesn’t block the flow and then fit a modern thermostat in the top hose. I too would be interested to hear of others’ experience with this and which in-hose thermostat they might have used.

Colin

[nistri]

Removing thermostats can be very difficult and it is often easier (depending on access)  to remove them while the housing is still on the engine. Harry Manning used to sell a special big box spanner for this job.
If the housing has to come off, it may help to dip it for at least a couple of days in penetrating fluid (inside too). The alloy material might not be too happy with flame heat. Descaling fluid (overnight) helps a lot to clean the inside.

The thermostat can be tested in the kitchen by attaching a piece of string and using a small pan full of water and a thermometer calibrated to 100 degrees. It is easy to see when it opens and closes.

The original thermostats were made by a company called Savara. They are out of production. Wahler makes thermostats which are quite similar (including the temp rating) BUT they have an important difference, namely once fully open their opening is significantly smaller than the Savara ones. Hence, the flow of water is more restricted and can lead to overheating in summer (maybe not such a problem in the UK...).
Ciao
Andrea
Before discarding the old thermostat I suggest to test it as above because it is rare that they go wrong. 

[nistri]

By the way, old thermostats can be cleaned by leaving them overnight in a solution containing denture cleaning fluid (no, I don't wear one, yet).
Andrea

[lancialulu]

I have to say that Brian's method which I also arrived at by first principles has been used by me on 3 occassions with success (one car at least had not been touched for 30 years). As the thermostat was brass provided the mini hacksaw blade was of good quality - not bought at the market stall 10 for £1 - then this works fine - just a bit tediuos. I remember after cutting twice, close to each other the thermostata body collapsed a bit with a stilson turning it and cleaned the thread as it came out!

On reassembly I put copper grease on the threads and was amazed even with this precaution how tight it had become after five years when I wanted to change the stat for a higher rating.

Tim

[fay66]

Like Tim,
I also put mine back in with copper grease, but so far haven't needed to take it out again & hope I never have to

My thermostat had also been in situ for about 30 years but replacing it didn't cure the peceived problem!
What did surprise me is the amount of thread remaining even when the thermostat is fully home.
Can't remember where I read it but somewhere it was once suggested that an extra hole be drilled in the thermostat to allow a better flow?

My temperature gauge needle also runs close to the 212f at the top end nearly all the time, and has never been lower when hot than the 160f middle mark on the gauge; removing the radiator shutter never made a blind bit of difference or indeed did "water Wetter" that proudly boasted that it would drop the coolant temperature by 10f. the only time I ever achieved something like a normal reading was when I forgot to put the rad cap back on, puzzled as why the temperature coolant was showing what I would have expected it to read, the penny dropped and I realised that I had left the cap off, on opening the bonnet the cap was where I had left it, after replacing the cap, I was back to my normal high reading
Last year I bought myself an digital infrared hand held temperature gun ( can't think of the right name) which finally convinced me that the coolant wasn't getting anywhere as near hot as the gauge indicated.

I've added more photos
Brian
8227

[Richard Fridd]

i think one name for the hand held device is an infared thermometer

[lancialulu]

or a pyrometer?

Tim

Re gauges Huib (from Holloand) is always going on about needing them recalibrated after 30+ years. My thoughts were sender mismatch as my gauge always indicates on the  cool side. But calibrating a couple of different senders on the stove with a meter, termometer and pan of hot water showed this to be irrellevant.

[rogerelias]

Now, we're not doubting the accuracy of italian electrics/ guages surely.

[fay66]

i think one name for the hand held device is an infared thermometer

Thanks Richard, That's it 

Brian
8227