Hello people,

Got a bit of a problem that has been there for quite sometime but is in need to be fixed now. My Z just never seems to hit the normal running temperature. I know the stock gauge is absolutely rubbish. But my heater doesn't give out proper hot air. If the temperature does rise a little, and I give it the foot, the temperature drops back down. So I've got a Z with no hot air inside. So am completely freezing in car and the leathers don't help either.

 

Is it the thermostat that is the problem here???

does sound like it to me, change it do a coolant flush and see if that helps, Id put money on it does. That or you have a huge airlock in the system

does sound like it to me, change it do a coolant flush and see if that helps, Id put money on it does. That or you have a huge airlock in the system

 

Thanks bud..Will get onto this..:)

It could be your Thermostat is stuck open, making the car run colder?

Easy way to do. to try and solve.

Jack up car as high as possible at front. With engine cold, remove lower rad hose near the bottom of the rad, with Rad cap of.drain as much as you can. If the colour is dirty rusty brown, dont worry too much, as its old.

check expansion bottle is not full (passenger side wing under plastic cowling) if it is empty this too.

Re fill sytem with fresh water but not full up, start car, set blower to max on full heat and get to normal operating temp.

with the rad cap still off, open the bleed screw on left side of rad,

you will need to keep topping up water bit by bit.

Each time you top up, rev the engine on the cable under plenium cover.

This way you can check the bleed and rad cap and top up and rev at the same time.

Keep doing this process until all air is expelled and just water runs out.

Check all water hoses are same temp. including matrix pipes, and that heat is constant inside the car. replace rad cap and bleed screw with engine running.

Then turn off and leave to go cold.

When cold check level with both bleed and rad cap removed.

If the system is mucky, this will flush it with fresh water.

Repeat the same process from start to finish, but with the addition of anti freeze mix.

Trust me zeds can be a total PITA to bleed all air out.

But if all pipes are in good order, you will have a nice warm drive.

 

Sorry ita a bit long winded.

Stu

It could also be that your temperatures fine but your heater matrix is sludged up not allowing any hot water to flow through , hence no heat .

Mine was very clogged , replaced it and now i have to turn the heater down cos it,s sooo good :thumbup1::thumbup1:

Fit an aftermarket temp guage , at least you can see what temp your actually running at :yes:

Just in case . http://www.300zx.co.uk/forums/showthread.php?t=119753

Edited December 17, 200916 yr by boldy
missed a bit

Many many many thanks guys..I will give all these a go..Something should defo work out..:)

The stock guage does show that the temperature is trying to go up very very slowly but drops back down when I drive it and air from heater is slightly warm but just not hot to keep the inside warm..

Will update you guys..:)

Thanks again..

You can quickly prove the stuck open thermostat by starting it from cold and leaving it running. If the top hose slowly warm, and I mean slowly in this weather, then its stuck open. What should happen is the hose stays stone cold while the engine itself gets warm and only when the stat reaches the right temperature does it open suddenly and only then does the top hose heat up. There can be heat inside the car by that time but it sounds like you don't even get that.

 

Temporary measure can be a large peice of cardboard over your radiator. You can cover about 2/3rds or even more in this weather and check the gauge to be sure its not overheating. Obviously not if your doing a track day or cruising at illegal speeds!

The guage shows that it takes a long time for the car to warm up. Even when driving it does not rise by much. Normal temp on stock guage, the needle should be in the middle once hot I suppose, but mine reaches hardly a quarter on stock guage, doesn't give out much warm air via heater and the needle drops lower when driven. It's not losing water as I always check my water and oil levels everytime before taking the car out..

Check out the link below, sure this is your problem.

 

Jeff TT

 

http://www.300zx.co.uk/forums/showthread.php?t=126426&highlight=thermostat+tech

Check out the link below, sure this is your problem.

 

Jeff TT

 

http://www.300zx.co.uk/forums/showthread.php?t=126426&highlight=thermostat+tech

 

Yup..It defo feels as if it's not as fast as it should be the whole time when driving it..I did think that it would be the thermostat giving me problems..Think I'll change that to start with anyway, and if it still doesn't work out for me, I'll carry out the processes mentioned by the good people on this thread above...:)

 

By the way, where would I find the thermostat in my car?? (still a novice here after 5-6 years of ownership) lol

http://300zx-twinturbo.com/cgi-bin/manual.cgi?list=lc&dir=&config=&refresh=&direction=forward&scale=0&cycle=off&slide=11&design=default&total=15 :balloon: