Took the old girl out for a run tonight as it was cold but dry,noticed after 10'or so minutes...temperature up to normal but when I stopped at the lights it was blowing cold air,then set of and it was fine blowing warm air again...stopped at the lights again a few hundred yards then it was blowing cold again!! Set of again same thing went warm again,after a good 20 minutes driving it went fine blowing warm all the time, I'll take it for another run tomorrow see if it happens again.

It may be due to an air lock in the cabin heater circuit. Put the heater control on full (max temp) and run the engine

off idle for a few minutes. Raising the front of the car can help (as in parked facing up a hill).

Ok I’ll try tomorrow,just been in the garage to check on it no leaks anywhere inside or outside, nothing seems untoward:)

Usually poor flow through the heater matrix.Is it original Gray ? if its scaled up this will be the result

It is original Jim yes,not had chance to see if it's still doing it....as its raining lol

Better start planning your drive back down to Jim’s, Graham!

Better start planning your drive back down to Jim’s, Graham!

 

 

I think it maybe heading that way anyway Joel :wink:

I think it maybe heading that way anyway Joel :wink:

 

Think this is the root of your problem Mr. G. G-B, you're getting hot flushes due to the amount you're spending :w00t:.

Think this is the root of your problem Mr. G. G-B, you're getting hot flushes due to the amount you're spending :w00t:.

 

Lol... Think your right Andy,but then someone has to keep jimmer in his extravagant and luxurious life style he's custom to lol

Graham, disconnect the heater hoses and back flush through with a hose pipe, never seen a 300zx matrix blocked to be honest even when the water is like brown silt, more likely an air lock or heater valve issue.

 

Jeff

Graham, disconnect the heater hoses and back flush through with a hose pipe, never seen a 300zx matrix blocked to be honest even when the water is like brown silt, more likely an air lock or heater valve issue.

 

Jeff

 

Cheers Jeff, if the weather is good I will drag it out at the weekend and have a go, if not I won’t be that bothered as it’s on it’s way to jimmers anyhow:)