Coolant system issues

Hi, everyone. I’m the owner of a P -registered  MGF in the US. I’ve had the car for about three years and I truly enjoy driving it. Recently, I’ve experienced some hot running issues with the car. It’s a non-VVC model with absolutely no options added to it. It shows 68,000 miles on the clock and the MOT records bear this out. During the last couple of outings, the coolant gauge runs to the top of scale and the engine smells hot. The temperature needle will then drop to near the normal mark, but will then rise to the top. No change of driving (open road, stop/go traffic) seems to have any bearing on the issue. The radiator cooling fan does run.  There is no evidence of head gasket failure. I installed a low coolant alarm from Rimmer Brothers and that kit came with a coolant tank and pressure cap. 

G'day and welcome to The-T-Bar.
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First things first.........Has the cooling system been bled at the 3 bleed points, as per the proper procedure? and always suspect the coolant cap even if its new!

Which supplier has the correct pressure cap?  

Hi,
the general consensus is the yellow caps are good for not much, the best is the black cap as shown on the rimmers site
https://rimmerbros.com/Item--i-PCD100160A
hope that helps.

judiths handyman wrote:

Hi,
the general consensus is the yellow caps are good for not much, the best is the black cap as shown on the rimmers site
https://rimmerbros.com/Item--i-PCD100160A
hope that helps.

 

I don't know about that, the yellow caps are very good at failing and destroying engines, they are unsurpassed at those tasks !🤣🤣🤣
Not all of the black caps are equal either.............The black caps made by some mob in Germany are best, I don't recall the brand name.
There is also a mob doing alloy caps, they're anodized in blue, I dunno how good they are, as I've not tried them.

All noted Cobber, I got mine from Rimmers and it seems to do the job ok, I didnt look at the make.
When one is up to ones arse in crocodiles one does not stop to feel the temperature of the water, very appropriate given the subject, anyways up I got lucky with Rimmers.

Someone did a YouTube video on expansion caps where he took at least three apart. The conclusion was that the one by FEBI was the best  and yes that is black too.