Coolant cap

[FD3UK]

Bob, Mazda did the recall to change to .9 from 1.3 so they must have been problems.

I have converted to Evans NPGR and run zero pressure

[Jono FD3]

To be honest with you guys.... you could run any cap on the filler point as if the coolant pressure exceeds the cap pressure, yes the spring will lift, but the water hasn\'t got anywhere to go aslong as the top seal is sitting on to the filler neck properly!!! My car came with a .9 on both ast and the filler point & I haven\'t had any problems with overheating or loss of water (well only when I fitted my temp gauge!!)

Jono

[ro284]

Thanks Kev, I will go for a .9 today,
cheers
Bob

[Laeeq]

I\'ve been running 1.3 cap on mine for the past 3 years with no issues, not sure if i change it to 0.9 one...:2Confused

[agroupuk]

Well I picked up the cap and its a sprung cap with 0.9 written on it.

So - confused lol.

think im gonna order one from Pip anyway just to be safe and just use this to get home with lol.

Glad to see I started a lively debate

Edd

[FD3UK]

I have attached a snap shot of recall details on coolant system.

[MillSpeed]

I\'ve been running 1.3 cap on mine for the past 3 years with no issues, not sure if i change it to 0.9 one...:2Confused

If your car\'s been running fine with a 1.3 bar cap then I\'d leave it. All you\'ll do by dropping the pressure of the cap is lower the boiling point of the coolant. You could argue that the higher pressure puts more strain on components in the cooling system but if it hasn\'t been bursting pipes off then you\'re probably ok. This sh*te about the engine running hotter just doesn\'t add up...the cap itself won\'t make any difference to the running temperature of the engine. What it does mean is that if there\'s a problem in the cooling system that causes the coolant temp to rise (e.g. blocked rad or broken water pump), the coolant at 0.9bar will start boiling before the coolant at 1.3bar...in which case I\'d say you were better off having the 1.3bar cap. Another example is the boiling sound a lot of people hear after shut down, which is basically heat soak causing the now stationary coolant to boil. This is not a good thing as it will lead to hot spots developing in the engine. I put a 1.1bar cap on my 7 and it stopped this boiling sound presumably by giving the coolant a slightly higher boiling point....the way I see it, after you shut the engine down, it\'s better to have a slightly hotter engine that\'s uniformly hot (if you get what I mean) than a cooler engine with pockets of boiling coolant and hot-spots.

[Laeeq]

If your car\'s been running fine with a 1.3 bar cap then I\'d leave it. All you\'ll do by dropping the pressure of the cap is lower the boiling point of the coolant. You could argue that the higher pressure puts more strain on components in the cooling system but if it hasn\'t been bursting pipes off then you\'re probably ok. This sh*te about the engine running hotter just doesn\'t add up...the cap itself won\'t make any difference to the running temperature of the engine. What it does mean is that if there\'s a problem in the cooling system that causes the coolant temp to rise (e.g. blocked rad or broken water pump), the coolant at 0.9bar will start boiling before the coolant at 1.3bar...in which case I\'d say you were better off having the 1.3bar cap. Another example is the boiling sound a lot of people hear after shut down, which is basically heat soak causing the now stationary coolant to boil. This is not a good thing as it will lead to hot spots developing in the engine. I put a 1.1bar cap on my 7 and it stopped this boiling sound by giving the coolant a slightly higher boiling point.

Yep, thats exactly what i thought.  I also have a colder thrmo, may be that helps too and its been ok as with 1.3 cap.  My water temps, even in hot summers days will never go above 87.

[MillSpeed]

Of course the best solution is to run Evans NPG+ like FD3UK.....low or atmospheric pressure cooling system and coolant that won\'t boil until something like 370 degrees farenheit PLUS the benefits of running waterless coolant in terms of corrosion prevention.