Hello, and 147 overheating issues

[colcol]

The thermostat has an o ring to seal where it bolts on to the end of the cylinder head, if it is not too hard and brittle, you can reuse it, but i would go to bearing service and get a new one for fiddy cents, but i reckon you will be buying a new thermostat, and they come with a new o ring, shop around for thermostat prices as they all vary, and as i have found, the cheap ones don't have the temperature sensor on it, so you have to use your old one, the Genuine Alfa Romeo ones are BEHR, or use a brand name such as Behr, Facet, Quinton Hazleton, Tridon or a good known brand, i forgot to say that you can use Burson pink/red or Castrol, Mobil, Valvoline, Penrite or any brand name coolant, the green coolants are more suited to earlier cars and haven't got the long life that the red/pink coolants have, Colin.

[fasty80]

Thanks for that guys. Finally had a chance to look at the car..

Colin, I read your post after I took my stat out, but I was ready with some silicon gasket anyway. Looks like you were right. I bought the Nulon red coolant, but I will probably exchange it for Penrite, unless others have had success with this coolant?

Here's what I found. Thermostat before being boiled:


Thermostat after being boiled:


Correct me if I'm wrong, it hasn't opened completely and it should have. The engine return should be completely closed? Am I wrong to say this? By my logic, half of the water would be going through the radiator, the other half recirculating through the engine. Eventually it would boil up. This would explain why it takes approx. three weeks for the car to start overheating?

I got a quote from repco (as I was getting the silicon gasket) and they quoted me $215!!! 

On a side note... I have replaced all these annoying clips with jubilee clips - I broke a few of them, must be my strength  . Are they single use?

[colcol]

Put the thermostat in cold water, it should be closed, or take it out of a cold car and it should be closed, boil it up and when the water starts to boil at 100c, it should be open, drop it in cold water and it should close, $215 sounds a bit expensive, most likely the recomended retail price, try a few Alfa Romeo spare part places like The Spare Place or Turin Imports, EB Spares, or The Alfa Workshop, and get some quotes, i use the Nulon Red Coolant in my 156 and it works fine, also a major Alfa Repairer in Melbourne also uses it as i have seen it on his shelf, Penrite is good also, but use the Nulon as you have it, the clips are a one use only, some are torqued up at the factory, and then the heads break off at a preset torque, then during the warranty period the dealers know if the engine has been swapped over or fiddled with for any warranty claims, put some good Norma or Tridon stainless steel hose clamps back on it, if the coolant is dirty put a radiator cleaner through it, Colin.

[fasty80]

Yeah I decided to take a picture of the other side of the thermostat.. so the first picture is when it is closed, second is when it is open. But is it open enough??

I'll look around tomorrow, I'll post up how I go. I will need to buy and bolt it up tomorrow as my fiance is without a car atm.  The coolant was quiet dirty too, so i'll probably do as you suggested.

Hopefully a new stat and coolant will fix the problem.

[colcol]

Usually the thermostats jam shut or open, but sometimes they open too quick or close too slow, if it is more than 5 years old it most likely needs replacing, try also, some of our service providers here in Victoria for a thermostat, Marranello Pursang Motors, Monza Motors and Mauceri Motors, just make sure it is a brand name thermostat, cannot beleive what a short life these thermostats have, 33 thermostat lasted 20 years, 156 thermostat lasts about 3 years, anyone who has one older than 3 years, keep a check on your temperature, should be to 90C in about 5 kilometers, Colin.

[fasty80]

I agree with the thermostats normally being stuck in open/close. This one isnt, but like you said, it doesn't make it faultless.

I'll give those places a ring.. mauceri motors is in clayton which is very convenient for me that will be my first point of call!

I will assume this thermostat is the original judging by the single use hose clips and how hard it was to remove the hoses themselves. I could be wrong, the car had been serviced at alfa all its life, they might have put new single use clips onto them...

[colcol]

The single use hose clamps are usually a factory only fitment, i doubt, [but i could be wrong] that the dealers would fit these once only use clips as they would most likely cost $20 each, as opposed to a Norma or Tridon at a couple of $$ each, as you wouldn't be able to tweak them up once the rubber hose has settled, or 6 months later the customer comes back after the rubber has settled and there is a leak, The RACV hate these type of hose clamps as when they are called out to a car with a burst radiator hose they have to mongrel the clamp off without damaging the plastic radiator or coolant hose, i find they are best attacked with snippers that you can get under the hose clamp and snip away until the clamp falls off, oh and then they have to carry a replacement clamp or use a cable tie before taking it to a mechanic, Colin.

[fasty80]

Went to Mauceri motors today and bought a thermostat from them, installed it, flushed the cooling system with some radiator cleaner, refilled the system.

Before installing I tested the thermostat and compared it to the old one. After a second inspection I found that the old thermostat failed to close completely when I boiled it yesterday. I assume sometimes it also failed to open.

I think this car has had this problem for a while, when I put the new coolant in I realised how pink it is, you can't miss it. That's not what was in the car when I drained the old coolant. My assumption is the previous owner just kept filling it up with water and diluted the coolant to the point that is really was only water. As a consequence I also noticed some signs of rust on the thermostat connection to the engine. Only time will tell if the radiator is affected.

Thanks for the warm welcome to the Alfa club guys, I'll be sticking around and learning more about these amazing cars!

Colin, I replaced all of those with adjustable jubilee clamps. Makes it so much easier 

Fasty

[colcol]

What was the brand of thermostat from Mauceri Motors did you get?, i am going to use a different brand of thermostat every time i replace one in the 156, just to see how long the different brands last, the Genuine BEHR brand was unimpressive, so now i have an Italian FACET brand, any rust you have in the system will be loosened off by the new coolant, keep an eye on the temperature gauge, i have often thought of putting in one of those coolant filters that are for sale on ebay, but just something more to go wrong, Colin.

[fasty80]

I believe the brand was QR, but I'll double check when I get home. I drove it around all day yesterday it seemed fine, now it's up to my fiance to make sure she notices any rise in temperature