coolant level and pressure cap

[whitewolf]

Previously my taimar has ran a 15psi pressure cap. Recently I heard it hissing after running for twenty mins - I assumed the seal was failing so ordered and fitted a new 13psi cap.

Never before have I had 'problems'
The new cap feels a bit crap at nipping up, also sometimes I've pulled up after a run and the top hose (thermostat to swirl pot) wasn't pressurised or red hot. (So far it always has been)


Today I went to chatsworth for a run out, temperature on dash and for the kenlowe sensor always fine, never goes past 92-95'c (therm is a 87'c)

When I first pulled up I was curious, undid the pressure cap and had a whoosh of air, not un normal so I though problem solved.


Later every time I stopped the car, water would leak from the expansion bottle as if pressure is too much or ill fotting cap.


I left the car to leak and cool, when I looked again, the swirl pot was about 3" from the top (to level with pipe from thermostat) and some water in expansion tank.



Guys - my question - chance that new pressure cap is the problem (I think so)

And

Can someone clarify the swirl pot. The original handbook says swirl pot full, expansion tank half full.swirl pot had a seal cap and expansion tank has pressure cap.

Or does it matter too much as I've seen over cars run swirl pot half full.



Many thanks

[DavidY]

Which radiator, original low one, or a fatter low one?

[whitewolf]

Low early type, 8" tall and about 4" front to back and width of front grill.

[prideaux]

whitewolf said:

Low early type, 8" tall and about 4" front to back and width of front grill.

Mike go back to 15psi cap if that worked then don't mess with it some of the after market replacments are Crap especially if they are from BB?
A

[anonymous-user]

And while you're busy, swap out that stat for one that opens earlier!

[whitewolf]

I read somewhere that adrian@ had suggested an 82'c stat. It's always been ok even it hot days of summer but I guess it all helps!

[bluezeeland]

Hi Mick,

Hope alls well ?

yep, get a 82°c one, much better !

grtz

Frank

[whitewolf]

Hi Frank, yep all is well thank you :-)
Filled the swirl after work, expansion with a little bit of water and ran - 20 miles mainly motorway. Dash temp stayed around 80.


I wonder if possible there wasn't a problem other then me over filling and the car just finding its own level...

[bluezeeland]

yes, Mick, that did cross my mind.........still i would fit a 82° and the 15psi cap

greetings

[whitewolf]

I shall change and see. Tested the 13psi cap tonight. Haven't checked as dark now.

15psi cap never failed before. Etc.

[DavidY]

My car with the standard rad would run fine with expansion tank empty and header tank 3/4 full. If you put more in it would return to this level.

When I changed teh radiator for one of Venny's fat ones, I had to run two expansion tanks in series (I suspect that the expansion of teh increased amount of water in teh system was too much for one tank), and the header tank would settle down to half full.

I ran a 74deg stat is the summer and a 82deg stat in the winter. I also drilled a couple of holes in the 74deg stat, so that the whole system warmed gently up. Yes it would take a few mins extra to warm up, but I never had any overheating issues in 12 years of owning the car (and it regularly did 100 track miles in a day!!!)

[whitewolf]

I filled the swirl pot last night and expansion tank with a tiny bit in. Did 40 miles round tripand to work this morning, all seems ok. Perhaps I was the problem!


I always carry a 2litre pop bottle of water anyway and some oil so if I do get caught short I have some backup, howeverI have plenty of faith and trust in the tvr.

[Grantura MKI]

Hi Mike,
The header tank should never be filled to the top after running. The system needs to puck extra out..needs room to expand. I use 175s on this side of the pond.
Regards,
D.

[whitewolf]

Well I've ran her as told and all seems fine :-)
Cheers D.