Noticed my gauge keeps jumping while driving, ive checked connection and it seems fine. But another thing ive noticed is my heating dont go that hot it sort of works up to 24 degrees but dont go any warmer. and the heater matrix was changed a few months ago so dont know if those faults are linked. Any ideas guys, much appreciated.

May be an airlock?

yeah could be an air lock, i know you've said you checked the connection, but theres two there and they are prone to causing this, mine you to go suddenly dead cold halfway round hard corner, i later realised that at high rpm the loom was moving an dit was lifting off slightly.

I'll bleed the system tomorrow and see what happens

Without being an knob, do you know how? To bleed it properly I mean?

Well i've never done it so was gonna learn as i went along but feel free to give me details, every little helps :thumbup1:

Well i've never done it so was gonna learn as i went along but feel free to give me details, every little helps :thumbup1:

 

People say about raising the front of the car, but you do not need too, just stick the heating on full and hottest temp, open the rad cap and the little bleed cap on the opposite side of the rad, start the engine then top up as necessary, it might take a while depending on the amount of air in the system. i top up till the water is coming out of the cap and the bleed valve, then put the cap back on the rad then the bleed cap.

 

Though you should be able to tell if its an airlock, as when the car is up to temp, if you set the heating to 40 and blower on full, if you rev the car to around 4k, it should bring hot air into the system and around the heater matrix.

 

The other thing it could be, is there is a thermostat on the A/C box behind the glove box, you might need to replace this as it might not be opening the valve to the heater matrix properly.

Cheers mate

sticking or faulty thermostat;)

And I take it this thermostat is inside the vehicle, taking the glove box off i should see it right?

And I take it this thermostat is inside the vehicle, taking the glove box off i should see it right?

 

there are two thermostats, one is mechanical and inside the lower metal water pipe on the front of the engine, the other is electrical and behind the glove box, on the A/C box.

 

Znut is most likely on about the one in the engine that you need to drain the radiator for.

 

The Mechanical one, basically opens at 76 degree's C and lets the water flow through the radiator to cool the engine down, once the engine has come up to temp.

 

The Electrical one, senses the air flow temperature for inside the cabin.

 

two completely different systems.

there are two thermostats, one is mechanical and inside the lower metal water pipe on the front of the engine, the other is electrical and behind the glove box, on the A/C box.

 

Znut is most likely on about the one in the engine that you need to drain the radiator for.

The Mechanical one, basically opens at 76 degree's C and lets the water flow through the radiator to cool the engine down, once the engine has come up to temp.

 

The Electrical one, senses the air flow temperature for inside the cabin.

 

two completely different systems.

 

:yes:

Understood, went to bleed the coolant system today and when I opened the radiator cap i noticed sort of cooper grease residue in the whole system. i paniced a bit and on futher investigation it was actual cooper grease, i dont know what the previous owner done but it will have to be a full coolant flush tomorrow.

Might be k seal , that looks like what you`ve described.

Ok santa, is this a bad thing tell me what needs to be done. cheers

Well turned out that my thermostat was faulty, failed in the open position. So the new one went in then i bled the system. Heater works perfect and for some reason the jumpy temperature gauge works fine now, stays just around half.

Glad it was an easy fix.

 

Paul

Well turned out that my thermostat was faulty, failed in the open position. So the new one went in then i bled the system. Heater works perfect and for some reason the jumpy temperature gauge works fine now, stays just around half.

 

http://www.300zx.co.uk/forums/showthread.php?168726-Coolant-temperature-gauge&p=1722032&viewfull=1#post1722032 :thumbup1:

sticking or faulty thermostat;)

 

Good call znut!

 

http://www.300zx.co.uk/forums/showthread.php?168726-Coolant-temperature-gauge&p=1722032&viewfull=1#post1722032 :thumbup1:

 

Big head :p

Big head :p

 

ile report this post to my social worker...she said it would be good for my self-esteen to be right this month:no:

He is isn't he lol, but on a serious note cheers Znut she works like a dream now. i'll be taking her for a drive to southampton tomorrow can't wait for that big smile on my face..:biggrin: