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Hi

 

I was having problems with my rad and the guy at the garage swapped the cap with another Zed that was parked out the back.

 

I'm still having problems, but I was wondering about the cap.

 

Are the all the same or are they different? ie is the pressure capacity/ size etc the same.

 

If not does anybody know somewhere near Kingston where I can get one tomorrow (Sat)?

 

Thanks

 

Spencer

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  • Author
Hi

 

I was having problems with my rad and the guy at the garage swapped the cap with another Zed that was parked out the back.

 

I'm still having problems, but I was wondering about the cap.

 

Are the all the same or are they different? ie is the pressure capacity/ size etc the same.

 

If not does anybody know somewhere near Kingston where I can get one tomorrow (Sat)?

 

Thanks

 

Spencer

 

Hi

 

There are some many clever people on here I can't believe no-one knows about rad caps.

 

Anyone?

 

Spencer

Did you check for the bubbles? I wouldn't have thought a rad cap would be enough to lose the entire cooling system (or a good proportion of it)...

  • Author
Did you check for the bubbles? I wouldn't have thought a rad cap would be enough to lose the entire cooling system (or a good proportion of it)...

 

Hi

 

Yeah I check for bubbles and nothing.

 

I'm really stumped with this. I though I would get a new rad cap to start with, but if they are all the same then there doesn't seem to be much point does there.

 

Any ideas?

 

Spencer

All the uprated ones I've seen don't actually fit properly and cause leaks ;)

  • Author
what problems are you having with your rad bud?

AFAIK all rad caps are the same, although you can get 'uprated' ones.

 

Hi

 

I fill my rad up and the water leaks from the rad cap.

 

There is a little groove in the plastic neck that the rad cap turns onto and what appears to happen is that when the system gets hot the cap gets forced into the groove and water comes out under the cap.

 

Spencer

  • Author
All the uprated ones I've seen don't actually fit properly and cause leaks ;)

 

Hi

 

I'm just going to go outside and take a pic. Maybe you guys can tell me if it is an original or and upgrade.

 

Spencer

  • Author
Hi

 

I'm just going to go outside and take a pic. Maybe you guys can tell me if it is an original or and upgrade.

 

Spencer

 

Hi

 

How do I inser a picture.

 

Spencer

Hi

 

How do I inser a picture.

 

Spencer

 

why dont you just go to nissan and buy a new 1 :)

if it is weak it wont hold the pressure putting another old 1 on may not solve anything as that may be weak too, if the engine is over pressurizing it usually means the head gasket gone or you have an air lock in the system

Do they have them in stock, or will I have to wait weeks?

 

its possible they may have 1 in stock or or there might be another modle that has the same cap. Thats an impossible question to answer bud as i dont have access to there stock list best thing to do is phone around, usually they can get parts in a day or 2 :)

or you may still have an airlock from when the weak cap loosed the water out? or a dodgy thermostat? partially blocked rad? are the cooling fans working? when is it pushing water out? after standing or when driving or from cold or all the time?

si.

just a thought, but from what you said about a grove could your rad neck poss be damaged in some way, So not making a tight fit when the cap is screwed on.????.

  • Author
just a thought, but from what you said about a grove could your rad neck poss be damaged in some way, So not making a tight fit when the cap is screwed on.????.

 

Ok here is the full story.

 

I drove the car back from Oxford to London. On the way she over heated. I stoped and got towed of the motorway. The guys at the garage said that they could find a problem but they changed the rad cap with another zed sat in the yard as mine was a bit loose.

 

No problems for the rest of the way home.

 

Next weekend I drove to plymouth. She over heated on my four times on the way down. Most of the time I let her cool down before I filled her up, but the last time I took the cap off before she had cooled down and it was like a fountain several feet in the air. I then filled her up with water and went on my way. Oh I was driving during the day, it was hot and I had the AC on.

 

On the way back from Plymouth she didn't over heat once. It was the middle of the night, I had the temp up high, no AC and windows open.

 

Then she over heated on me again on the way to a friends hous about 5 miles away. Again during the day, but no AC on.

 

Last weekend I took of the rad cap and the cap at the other end. I then filled with water. I then screwed in the cap at the other end. Then I started the engine and put the AC on at 40. When the fan cut in the water level dropped. I then filled with water again and put the rad cap on.

 

Drove the car for a while and she was leaking water from the top of the cap. Like I said there is a groove in the plastic and the cap pops into it and I think that there is a gap where the water comes from.

 

But am I correct is saying that the water shouldn't expand and only if there was air in it then it would expand?

 

Anyway today I took of the cap, used plyers and squeezed the cap tighter. I filled the car using the same procedure as before, but didn't put the cap on at the other end until the fan kicked in. All that appeared to happen was the water kept coming out the other cap end. I screwed the cap back in and the water level remained constant. So I put the rad cap back on.

 

I then went to the rear and there was a lot of water in the pipes and there was smoke come out which I think was actually steam. Does this mean I have blown the head gasket?

 

Does anybody live near Kingston and have the correct equipemtn to check to see if I have blown the HG. Don't you just put a pump where you put in the oil and check the pressure?

 

Anybody.

 

I have been trying to get in touch with Zen Garage, but I think they must be really busy.

 

Anybody................ help.

 

Spencer :cry:

if you have over heated more than likely you blown the head gasket, if you have water and white smoke/steam coming out the exhuast then 100% you blown the head gasket, is the car a pig to start as well now, like its trying to build up compression before it starts?

Sounds like a head gasket problem, most garages will have a cooling system pressure tester and will be able to tell you in a matter of minutes if thats the problem. Good luck.

Get a pressure test....any decent garage should have a test kit! However, sounds like you might also have a worn rad neck so your system isn't sealing properly to pressurise......when i first bought my Z the cap i had sat awkward on the rad neck. I know that the risers/runner/guides were worn and so i never used to do the cap right up but tighten to the highest point on the guides.

AFAIK all rad caps are the same, although you can get 'uprated' ones.
They aint all the same. N/A rad caps are rated at 0.9 while the TT rad caps are 1.2.

rad neck do wear out....try putting cap on half cocked to get a better fit...decent pressure is require as coolant systems need convection to circulate fluid...the pump does a little bit of mixing

i reckon you have an air lock in the matrix....wait till car is cool..park on steep hill...take lots of spare water...take cap and bleed screw off...run engine and set fan on full blast at 40c...run and fill till all bubbles have burped out...can take a while

if air lock comes back prob the rad neck...if it was gasket you'd get oil in the water

HTH

rad neck do wear out....try putting cap on half cocked to get a better fit...decent pressure is require as coolant systems need convection to circulate fluid...the pump does a little bit of mixing

i reckon you have an air lock in the matrix....wait till car is cool..park on steep hill...take lots of spare water...take cap and bleed screw off...run engine and set fan on full blast at 40c...run and fill till all bubbles have burped out...can take a while

if air lock comes back prob the rad neck...if it was gasket you'd get oil in the water

HTH

 

you dont always get water in the oil only if gasket blown on an oil way:)

if its not overheating when you got the heater on and its cool out but it is when you're in the sun with the heater on cold that says blocked rad and/or thermostat.

matrix cant be blocked as its helping to cool the engine and keeping you warm.

headgaskets not gone or it'd do it all the time, not just in the warm.

easiest thing first, swap the thermostat over, they're VERY common on any car and the symptoms point to it.

if that doesnt cure it try the rad. even if its not totally blocked, when the car gets hot the pressure will build up (the water will ALWAYS expand - the pressurised system is there to stop it boiling, not expanding - thats what the expansion tank's for) and the cap is the weak link (and its designed to be - otherwise it'd blow a major water system component) so it'll leak.

dont try to put more pressure on the cap cuz you're only putting the pressure on all the other parts in the water system and you're not curing the fault.

swap thermostat, flush rad (like take it off and flush it out properly, not just bung rad flush in and hope) then top up with coolant.

they need coolant, not neat water, partly to lubricate the water pump, thermostat and rest of the system and partly to help cool the car.

HTH

si.

  • Author
if its not overheating when you got the heater on and its cool out but it is when you're in the sun with the heater on cold that says blocked rad and/or thermostat.

matrix cant be blocked as its helping to cool the engine and keeping you warm.

headgaskets not gone or it'd do it all the time, not just in the warm.

easiest thing first, swap the thermostat over, they're VERY common on any car and the symptoms point to it.

if that doesnt cure it try the rad. even if its not totally blocked, when the car gets hot the pressure will build up (the water will ALWAYS expand - the pressurised system is there to stop it boiling, not expanding - thats what the expansion tank's for) and the cap is the weak link (and its designed to be - otherwise it'd blow a major water system component) so it'll leak.

dont try to put more pressure on the cap cuz you're only putting the pressure on all the other parts in the water system and you're not curing the fault.

swap thermostat, flush rad (like take it off and flush it out properly, not just bung rad flush in and hope) then top up with coolant.

they need coolant, not neat water, partly to lubricate the water pump, thermostat and rest of the system and partly to help cool the car.

HTH

si.

 

He he he

 

I don't know if it's the fact that you think I haven't blown the HG or the good points you raised in your e-mail, but I think your thinking.

 

Thanks for the advice.

 

Spencer

  • Author
He he he

 

I don't know if it's the fact that you think I haven't blown the HG or the good points you raised in your e-mail, but I think your thinking.

 

Thanks for the advice.

 

Spencer

 

Sorry that should have been

 

"I like your thinking"

 

Spencer

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