new nissens radiators with expansion tank overflow??

16th October 2011, 01:21

hi all, having some issues and wondered if anyone could help me out.

Basically had a hole in my old nissens rad so had to buy a new one, bought it from the same place but it seems to be a new design (different header tank cap, which is silver instead of the old blue one, also there is a small hole at the top of the tank for overflow)

Now i was under the impression that the coolant system was meant to be pressurised? so why the hell this stupid hole has to be there i do not know.

Have been having a problem with it pissing coolant all over my manifold.

We've bled and filled the system a few times, taken it for a drive, all seems fine, i.e sits at half way when driving, creeps to 3/4 when stationary, then fan kicks in. hot air from heaters etc.

all seems fine, until you turn the engine off and water comes streaming out of the little hole for about 10 seconds or so

as a result it then runs warmer, and sits below the minimum line in the header, fill it up and same crap again!!

why is it doing this? is it because of an airlock? i just dont understand why they would change the design of the rad to incorporate that bloody little hole when the old model worked perfectly fine!

any help will be much appreciated

thanks

why is it doing

16th October 2011, 01:41

pics? its squirting out as the water is boiling when you turn the engine off and it stops circulatiing the coolant system..

16th October 2011, 07:14

After its done it once just leave it, the hole is there to allow overflow, it's only an expansion tank so the system itself will still be pressurised. 10 seconds sounds like a long time though, might be indicative of another problem, but the design of the rad is fine

3/4 sounds high though, my fan used to kick in before that

Have you bled it properly? Raised the height of the expansion tank with a bottle?

16th October 2011, 14:08

It sounds like you've been given the 206 rad what has the extra slot for the expansion tank.

Post a couple pics.

16th October 2011, 14:51

Sounds like it's got the wrong radiator cap - ideally the cap should block the hole, they when pressure rises too much, a spring in the cap raises and let's some pressure out?

Only explanation I can think of - pics would be useful though!

16th October 2011, 18:16

Pictures of this retarded rad.....pissing me off.... bled it the same way i done mine...and it just not working...also mine has no stupid hole......

16th October 2011, 18:53

Im pretty sure the cap should block that hole until the pressure gets high then the cap lets the pressure out via that hole

16th October 2011, 18:57

Quote:

Originally Posted by raunchz

Im pretty sure the cap should block that hole until the pressure gets high then the cap lets the pressure out via that hole

This would make sense mate... They may have sent wrong cap?? My rad is not like this... it has a tiny hole at the top of the cap.

16th October 2011, 19:05

Thats the old style nissens rad.......ive heard a few issues with this design.

The new ones use the original screw on cap.

16th October 2011, 19:21

So have nissens changed the design since this rad because it's crap? I had one with a blue cap, no hole which I bought about 2 years ago, had no probs with it until the hole in the fin. I bought this current one in the pic about a week ago, both were from 106 parts.co.uk
Is it likely that nissens have changed the design to one that works and 106 parts have flogged me one of these things? Must be laughing at the opportunity to get rid of them and get the new ones in??

16th October 2011, 19:38

Quote:

Originally Posted by paxo89

So have nissens changed the design since this rad because it's crap? I had one with a blue cap, no hole which I bought about 2 years ago, had no probs with it until the hole in the fin. I bought this current one in the pic about a week ago, both were from 106 parts.co.uk
Is it likely that nissens have changed the design to one that works and 106 parts have flogged me one of these things? Must be laughing at the opportunity to get rid of them and get the new ones in??

Is hard to say, I'd definitely get in contact with them to complain

16th October 2011, 19:50

i had this problem when i replaced my old vtr rad for a nissens rad. Kept on pissing out the little hole when i parked up. bled it so many times and the water level kept going up and down as if there was always an airlock somewhere. I replaced the cap with my original black cap, bled the system out by blowing through the top of the bottle with my mouth (

) and its been fine ever since.
both caps are different. the nissens one is more flimsy smaller, the black one just seems so much more of a better fit.

shame really as the shiny silver cap looked quite smart

original black cap

16th October 2011, 20:11

Sounds like time for a new cap

17th October 2011, 18:53

I know it's a odd question but can I have the part code for the rad?

I'm getting a new rad soon as mine is a 1.1 in my vtr.

17th October 2011, 19:36

I can't understand why you're having this much trouble. If the system is bled properly and there are no issues with the HG then the water level should remain pretty much the same once you've done the first run in and it has settled

I've had a rad with that hole on every one of my ax's with and without Saxo engines and never had this problem. Maybe your cap doesn't have a strong enough spring on it but still, my water level never gets anywhere near the top

18th October 2011, 10:04

Have you bled it using the header tank method? It sounds like its still airlocked to me. My VTS spec rad uses the same kind of cap and tank with no problems at all