Coolant change on Sigma

[Ben Lawson]

Looking to change the coolant before winter, its a sigma engine without a heater. What is the process on bleeding the system? Cap off, squeeze Rad pipes with car idling and wait for fan to kick in while checking Temp gauge? Somehow i cant seem to find any relevant info only with a heater fan 

[W33SVN]

Hi Ben,

I changed mine at the end of last year. But I do have a heater. Once drained, I did the following;

1. Raised the front wheels off the ground as high as I could.
2. Opened the radiator bleed valve (if you have one). 
3. Filled from the overflow tank. (Although some online suggest filling from large water pipe at rear of engine)
4. Ran up to temp with valve and cap open.
5. Once bubbles stopped at radiator, closed off valve.
6. Topped up as required. 
7. Continually checked as my car was running cool, however I think this was a stuck thermostat after someone used a rad sealer of some description. 

I’m no mechanic, but this worked for me. Someone may come along with some extra info as I believe they can be somewhat problematic

Edited Wednesday at 18:48 by W33SVN

[Jonathan Kay]

There seem to be many fewer problems with Sigmas than with Ks. 

Please let me know if you'd like an Assembly Guide and Owner's Handbook.

I'd take the opportunity to measure and record the indicated temperatures at which the thermostat opens and the radiator fan kicks in.

Jonathan

[StevehS3]

25 minutes ago, W33SVN said:

Hi Ben,

I changed mine at the end of last year. But I do have a heater. Once drained, I did the following;

1. Raised the front wheels off the ground as high as I could.
2. Opened the radiator bleed valve (if you have one). 
3. Filled from the overflow tank. (Although some online suggest filling from large water pipe at rear of engine)
4. Ran up to temp with valve and cap open.
5. Once bubbles stopped at radiator, closed off valve.
6. Topped up as required. 
7. Continually checked as my car was running cool, however I think this was a stuck thermostat after someone used a rad sealer of some description. 

I’m no mechanic, but this worked for me. Someone may come along with some extra info as I believe they can be somewhat problematic

I did the same as this with my Sigma - although I think I raised the expansion tank to get it even higher which was probably unnecessary. No problems at all with bleeding it even with a heater.

[StevehS3]

4 minutes ago, Jonathan Kay said:

There seem to be many fewer problems with Sigmas than with Ks. 

Please let me know if you'd like an Assembly Guide and Owner's Handbook.

I'd take the opportunity to measure and record the indicated temperatures at which the thermostat opens and the radiator fan kicks in.

Jonathan

Measuring the temperature is a good check. The fan on my Sigma is silent from sat in the car and almost silent with the bonnet off looking in. I had to do a visual check to see if it was working.