Nissan-Navara.net banner

1 - 8 of 8 Posts

·
Registered
Joined
·
88 Posts
Discussion Starter #1
Hello I have not been on here much recently , but I need help please .
I have a problem in that I am getting no heat out of the heater when on hot .
When the engine gets up to temp and the car is being driven there is no heat from the vents however , if I have been driving and then get home on the drive and leave the engine running the vents get hot .
The pipe that appears to be going to the heater in the engine bay is hot when I feel it .
I have tried driving g with the cap off the expansion tank to see if it is air locked but this does not seem to have worked .
Any ideas anyone please I am wondering if the engine thermostat may have failed
A couple of months back I had the alternator pulley fall of which caused the coolant to spray out of the expansion tank as it overheated so not sure if this has a thing to do with it .
 

·
Registered
Joined
·
4 Posts
if you've lost coolant id be suspecting you have air in the matrix and not coolant. I am not sure how leaving the cap off the expansion would help here.

I usually get the front high on a car so the matrix is lower and run the car with the heaters on. I then squeeze or massage the coolant pipes to help dissipate the air. This can take a bit of time.. make sure you don't boil the engine in the process.

if you have an air lock you might not have enough coolant.

I am by no means a Nav expert but ive swapped a few engines in cars in the past and lifting the front usually helps.
 

·
Administrator
Joined
·
12,118 Posts
Agreed, that an air lock in the matrix is possible.

Leaving the expansion cap off is indeed the procedure to bleed air out of the system, but as above the squeezing of the hoses is a good idea.
 

·
Registered
Joined
·
88 Posts
Discussion Starter #4
Ok so today I have changed the stat but I think it was actually working ok , I gave managed to get a hose pipe on to the heater matrix pipe and as far as Ican tell this is not blocked .
The hoses around the inlet/outlet are all hot or warm the only one that seems to be cool is what I think is the outlet of the matrix .
But I still cant get any heat out of the heater vents . To make things slightly more complicated it is a pathfinder so has the rear heater and the extra pipework for this .
One thing I have noticed is that with the engine running and the radiator cap off I dont get water coming out of the radiator , so question is should I expect water to be being pumped out of here .
I am wondering if the water pump may be the problem .
Any ideas anyone please
 

·
Administrator
Joined
·
12,118 Posts
I would expect you to get some water escaping with the rad cap off.
Have you got it filled to the brim?

Somebody on here did have the impeller separate from the shaft, so the water pump is an outside possibility.

Saying that, the most likely problem is a blocked heater radiator.
 

·
Registered
Joined
·
4 Posts
I'll check my expansion in my path when I get home tonight. Id expect to see a return but I am going by past car experience.

you'd think if the water pump had lost its prop then you'd be boiling your engine.

I'd still be looking at either an Airlock or possibly a stuck matrix Valve. Again limited knowledge on these cars just thinking about others i've worked on.

i'll get a look at mine around supper time and report back
 

·
Administrator
Joined
·
12,118 Posts
Worst case, my experience anyway, is a leaking head gasket.
I had a small almost unnoticeable leak just above the thermostat housing. I lost the heater, it would eventually bleed, but only lasted an hour or so.

Hopefully it is an airlock though.
 

·
Administrator
Joined
·
2,363 Posts
You all sound like you’re on the right track, but looking back to the original post, in the absence of any other symptoms a failed thermostat is unlikely.
 
1 - 8 of 8 Posts
Top