Thermostat renewal the hard way!

A couple of weeks ago I took a friend for a blast up in the hills and all was well, except I noticed the engine temps were low on the highway and were rising in traffic. The car had always behaved before so suspecting the thermostat is the culprit I decided to change it myself having been encouraged at how “easy” it would be from some of the other threads on here.

Now here in France and especially close to the Italian border garages are called boxes and there is a reason for that, because they expect you to box you car awayat night and never work on it. My 1983 Euro 308 GTS QV just fits in with the passenger side tucked in with around one inch clearance from the wall and one foot clearance from behind. There is around one and haft feet on the drivers side to get down and get in and out of the car. No room for jacks or lifts and other luxury's!

I first had to work out how to get my coolant out of the system or at least below the thermostat level without flooding the garage or doing permanent damage. For this I bought via eBay a simple hand pump around six Euros and used this to pump out the expansion tank into a washed out Soda bottle. I filled a two litre one to empty the expansion tank.

Now the expansion tank is empty I disconnected the lower hose connecting the cooling line to the expansion tank and inserted around three feet of 8mm bore plastic pipe down the hose through the "T" connecter and into the heart of the engine. I then connected the 8mm bore pipe to the hand pump and pumped out another one and a half litres of coolant (three and a half litres removed in total). The 8mm hose was then removed and the cooling system hose reconnected to the expansion tank and its hose clamp tightened.

I then turned my attention to the thermostat, which of course is on the side of thecar against the wall, so all‐work had to be done from the rear of the car. First I removed the air filter top cover and the gator connecting it to the air intake (takethe gator off entirely as when putting it back on its easier to fit it on the air inlet tube first then fit the air filter cover to the gator).

Next I disconnected the two electrical plugs nearby the thermostat you can see in the pictures and tucked them under the air inlet tube out of the way. Now I took some rags and pushed them in under the thermostat housing to soak up and coolant that might be in the housing (turned out to be nothing). Then unscrewed the thermostat bleed screw (13mm) being very careful to ensure I had the washers and nothing dropped down. I then unscrewed the three thermostat housing nuts (10mm) and removed them with their washers. The pipe clamp around the hose connector from the thermostat to the radiator was then removed and the hose pulled off carefully, take note at this point on how close the down pipe is to the water pump pulley so when you put it back you have the same clearance and don’t end up cutting through your pipe with the pulley.

The thermostat housing cover came off after some gentle persuasion and expletives! The gasket was obviously put on without any copperslip or other gasket sealer and so had welded itself to the faces of the thermostat housing. The thermostat that I took out was a Ferrari original with its bleed hole in the 12 o’clock position. The lower hosing was plugged with a rag to prevent any debris entering the system.

A long time later shaving and cleaning the faces off with a razor blade and brass wire brush the housing was ready to reassemble. I bought a new thermostat and gasket from superperformance and noted the hole was notpresent but on closer inspection I found a crimp had been made in the thermostat housing to act as the air bleed through and warming hole. So I then fitted the thermostat back into the housing with the crimp in the 12 o clock position.

The new gasket was then lightly vaselined (as someone had helped themselves to my tube of copperslip!) and fitted the housing went back in place and was bolted down and the hose connector refitted and hose clamp tightened. The thermostat bleed screw was refitted and then I refilled the expansion tank and system using the soda bottles. I filled the system with the two litre bottle first and then bleed the thermostat housing. Once the air was out I added the remaining one and a half litres of coolant and screwed the expansion tank cap
back on.

Next the electronics plug’s near the thermostat were refitted and the air filter refitted and its cover put back on. Sounds easy doesn’t it, however I found that keeping the gator on the air filter cover just does not work after many attempts. In the end I took the gator off fitted it to the air inlet pipe first and then by pushing the filter cover into it at a downward angle it fitted in nicely. The gator pipe clamps were refitted and tightened.

The engine was then restarted and warmed up all the while bleeding off any air that may still be trapped which was not allot. As I put back in exactly the coolant I had taken out it made things easier in the bleeding process as after cold bleeding the expansion tank level was almost the same as when I started so I already knew that not much air was trapped.

Below are some photos of the process to help anyone else trying this! Oh and I also found out that my cooling hoses need renewing. I’ll have to put those on my Christmas list from Mr Helms.
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The overspray was from the PO. The intake plenum was sprayed up by a local garage earlier this year, when I had asked them to take off the plenum and do a wrinkle paint respray. This was the interim paint job as they ran out of time, but will be done during her next service.

 

You are welcome, it's nice to give something back to this community, after reading so much information stored here.

 

One of the things I was a little concerned with using this thermostate was the underside. On the original there is a white resin disk which seals the bottom in the housing, this has a return spring externally mounted on it. This was solid and not moveable by hand. Where as the new thermostate had a metal disk that was resin wrapped and had a internal spring mechanisum, that moved easily by hand independent of the main thermostate plate. Has anyone else seen this with different thermostat makers for the 308? At the weekend I'll see on a long run how it holds up.

 

None of the photos are similar as the bottom has an internal rather than external spring. I did take a photo of the bottom but it did not come out for whatever reason these things dont, just a black screen when all the others were fine.

There was no noticable marking or codes stamped on it and its not the one shown on the superperformance website either i'll have a cast around the internet and see if i can track it down and then i'll post it.

 

No luck on finding a picture on the internet, but Matto's description sounds the same and if he's had no issues with it then that gives me piece of mind.

I'll found out at the weekend for myself either way.

 

Bought it online from superperformance uk and came in the mail a couple of days later. I tested it and it works ok in the pan. I have used them for allot of items over the years and they have always been good. Had a slight glitch one time with a new expansion tank but they sorted it out straight away. I have no doubt they supplied an equivalent fit for purpose item.

 

Yep, the one on the site looks like an origional Ferrari part, but i think it depends what they have in stock at the time that gets sent. I doubt they update the website pictures too frequently.

 

Necessity is the mother of invention I am frequently reminded. Nice fix for the problem! I am sure others have more solutions as well.

 

Just to update everyone, had bad weather around here recently, not as bad as over in the U.S but not the weather to take my 308 out in.
Today was beautiful and so I took her for a good drive this morning and all was well. Car is running normally around 85 degrees celcius indicated and in traffic moving to around 88 degrees Celsius indicated. And even in the garage with no wind sat quite happily at 88 degrees Celsius indicated. I'll have to verify what indicated is to actual some time but happy with the result. The outside temperature has dropped around 8 degrees Celsius since before changing the thermostat to around 18 degrees celcius in the day, but I am quite happy with the thermostat and the result.