I am getting a slight coolant smell in the cabin but ONLY when the car is at idle. cant find any drips or wet patches on the matt under the heater matrix so dont think that is leaking.

 

What could it be that only shows itself when at idle and not at all during a long motorway journey?

Have you checked your coolant levels, are you losing any?

 

When was the last time you renewed your rad cap?

not sure when it was last changed. would that cause the faint smell at idle? think coolant levels are ok. deffinitely full rad but not sure of exact expansion tank level if it is changing. If it is only this slight bit of vapour escaping very occasionaly it wouldnt loose much would it. If the rad is staying full does that mean the rad cap is functioning ok and letting the fluid expand and contract not drawing in air.

 

sounds like a good thing to change though if it hasnt been done for a while. where is the cheapest place to get one? is there any advantage in the nismo ones i have seen on ebay? I notice they are 1.2 bar instead of 1.1 bar (i think). Does this affect cooling performance?

To keep the cooling system healthy change the coolant every year and change your rad cap for a brand new one!

and the nismo one? read a few things in the search saying that some people have had problems with the nismo ones from ebay but also some problems with the replacement stock ones.

what problems where?

nismo cap with probs:

http://www.300zx.co.uk/forums/showthread.php?t=71923&highlight=nismo+radiator

 

some dodgy nismo rad caps and oil caps

http://www.300zx.co.uk/forums/showthread.php?t=59690&highlight=nismo+radiator

 

extra pressure from higher pressure nismo cap causing hoses to blow

http://www.300zx.co.uk/forums/showthread.php?t=48868&highlight=nismo+radiator

 

from yourself about stock ones

http://www.300zx.co.uk/forums/showthread.php?t=38515&highlight=nismo+radiator

 

 

think i will just go for a normal one. Surely nissan cant charge much for one direct from them.

The warning thread I started eons ago, should be updated, the problem was with wear on the plastic end tank where the rad cap engages, it had worn away and would'nt engage with the lug on the rad cap!

 

The problem with stock rad caps is they wear out and the spring releases too much coolant into the reservoir!

 

This leads to inferior cooling of the engine gradually over a period of time.

 

The problems with the hoses leaking would have been causes anyway IMO, because the system has not been up to par for a while but due to the cooling system not working up to pressure, they have not been working to spec, so no leaks!

 

If you are worried about nismo get a new stock one then, but if the hoses leak to an extra increase in pressure of 0.1 bar then imo they are fubarred anyway.

ok i have changed the rad cap to a nismo one and this smell is still occuring.....

 

just to recap it is when the car is fully up to temp, say on a motorway journey, with the heaters on, and slowing down to idle for a couple of mins in a traffic jam or at a traffic lights and a smell of coolant comes into the cabin. Not a strong smell and my girlfriend didnt notice it until i pointed it out but coolant smell is a bit of a sickner of a smell so it has started to get to me when this happens.

 

Dont appear to be loosing any coolant (when cold, 3 or 4 blocks above H in the expansion tank and full rad) that i can notice but it might only be small amounts that i dont notice.

 

no leaking from heater matrix. coolant in good nick and have earth kit. rad in good nick with no cracks. no problems with hoses rupturing under the slightly higher pressure of the nismo rad cap.

 

this smell only occurs under idle which must have something to do with the problem.....

any ideas guys. definitely seems to be happening everytime. espeacilly when heaters turned up to hot.

 

I am starting to accept it can be a problem with my heater matrix. Is there a way of checking whether it has a problem without taking all the gubbings apart.

 

i have done the heaters diagnosis and it is fine.

 

Any help?

try looking at the control valve on right hand side of heater matrix, mine was leaking (smell of anti freeze) you can check this without taking dash out, but if item needs replacing 2 of the screws are inpossible to get to (dash out) hope this helps

try looking at the control valve on right hand side of heater matrix, mine was leaking (smell of anti freeze) you can check this without taking dash out, but if item needs replacing 2 of the screws are inpossible to get to (dash out) hope this helps

 

 

thanks mate looks like this could be the answer. What do i look for on the RHS of the matirx. Is there a page in the manual that shows it becuase i cant seem to find it.

thanks mate looks like this could be the answer. What do i look for on the RHS of the matirx. Is there a page in the manual that shows it becuase i cant seem to find it.

you are correct its not in the manual, its a square white plastic valve asy with a lever attached held in by small pozi screws. as far as i can remember.any problems pm your phone number(evening) and i will phone you back.john

thanks John. subscription has lapsed so cant PM. had a look up there this afternoon but could see anything. I guess best time to look would be when the car is warm (stat open at least) and idling and then look for drips of coolant??? My email address is tom.ventham@mwkl.co.uk email me if you can and i can send you my number.

Ta again.

Tom