Register and join the discussion

heater problems


Ones&zeros
12-11-2004, 10:40 PM
hey guy im kinda new and my friend owns a maxima 89' with no heat the fan turns on but it wont let out hot air any suggestions.ps theres a radiator leak. thanx.

Nahkapohjola
12-12-2004, 04:32 AM
Do not drive before u replace rad. Add coolant, bleed air out.

While the rad is out, take heater tubes off [from engine] and test flush with garden hose that water runs through.

Ones&zeros
12-13-2004, 12:52 AM
Could It Not Be The Heater Core? Because He's Been Driving The Car Like This For A Month Now.

Nahkapohjola
12-13-2004, 03:05 AM
Could It Not Be The Heater Core?

If u do the test I said, thats when u will find it out.

Rad leak is not the reason for no heat. Its gonna be the reason for blown gasket. Yu'll ruin your engine by driving, but then its all yours...

Ones&zeros
12-14-2004, 03:02 AM
Head Gasket?

Nahkapohjola
12-14-2004, 04:55 AM
Engine cooling is a pressurized system. If no pressure, cooling does not operate as designed: cylider heads are hottest and you risk valve burn or gasket leak due to heat bent alu heads.

Rad leak=no pressure


Btw:
Cabin heater valve is (VG30E J30 -93) electronically controlled, vacuum powered valve inside engine compartment:
Its located on engine bay wall, under the hood. It gets it operating pover via vacuum tubes from engine(check if leaking). It is electrically controlled (check its coil resistance and that it gets its control voltage). Open and check that it is mechanically operative.

Ones&zeros
12-14-2004, 10:13 PM
Cool Cause His Temp Guage Stays At Normal Temps, And Sometimes The Heater Works But Most Of The Times It Does'nt. Ill Tell Himabout It.

Nahkapohjola
12-15-2004, 03:08 AM
Cool Cause His Temp Guage Stays At Normal Temps, And Sometimes The Heater Works But Most Of The Times It Does'nt. Ill Tell Himabout It.


"Temp Guage Stays At Normal
- Why not? Cooling system that is not pressurized as designed allows gasbubbles =airpockets formation. Those points do not adequately cool, especially at the hottest areas, cylinder head. Leaking rad will ruin the engine, question is just timing.

"And Sometimes
- gas bubbles block flow, do not have a timetable...

James218
12-18-2004, 11:10 PM
"Temp Guage Stays At Normal
- Why not? Cooling system that is not pressurized as designed allows gasbubbles =airpockets formation. Those points do not adequately cool, especially at the hottest areas, cylinder head. Leaking rad will ruin the engine, question is just timing.

"And Sometimes
- gas bubbles block flow, do not have a timetable...

My 93 nissan is having the exact same problems as one%zeros friend, I figured the problem couldn't have been many things, the thermostat, heater core, or water pump. Checked the thermostat it was fine, the water pump was fine, but what a bitch to take off and replace. Now i'm stuck with no heat in 10 below zero weather. Any suggestions for me?

Nahkapohjola
12-19-2004, 03:03 AM
Remote diag is not easy...

Figure out how your tubing is routed. Start cold engine and track how the water temp that raises gradually, seep through your tubes. (Check the mentioned valve.) If they all get hot, the air ctrl flaps might not work and blower blows always the air past the heater. Ctrl rod/wire loose, broken mech?

Heater core is almost impossible to become totally blocked, leak is known to happen in maxima. (Btw. that burns the ECU)

Tubing might collapse and form block. More propable is gas bubbles which tend to form total blocks in water circ systems. This phenomena also blows your engine head if rad is elaking. There is a bleed valve; open it slightly so that its bleeding a little, drive one hour (keep water level up). This will get all 100% air out.

Hmm...
- it is a gas bubble if cooling helps
- somehow broken rubbertubing (inner ring of the tube ripped off, blocking flow intermittently)
- Factory Installation time debris has now formed a block
- some other external force pressing/bending it closed

maximagirl420
12-19-2004, 11:59 AM
A bad heater core always floods the floorboards, even when you are not using the heater. But before it gets totally shot, it stops putting out heat adequately. If the radiator is leaking, change/fix it. But when you fill the radiatior, there is an easy way to make sure you don't get any air bubbles. Just buy a radiator fill kit that comes with the bowl and a rad. cap with a hole in the center for the bowl to set in. It's like $12. It's purpose is to keep the fluid above the highest spot of the engine, working air bubbles out itself until it's full. But air bubbles in the system cause hot spots in the engine, and you would notice the car heating up faster, and a few degrees higher. And I don't reccomend using NAPA heater hoses.

James218
12-19-2004, 02:58 PM
I probably have to replace the hoses, I'm sure it wouldn't hurt. Although the hoses seem to be just fine from the outside. The heater only working speratically, it must be some particle blocking the flow now and then. Im going to have to check for a bleeder valve, Im not formilar with this bleeder valve, so if someone could help with the location that would be awesome. (There is no leaking I've already checked.) I'm now thinking it could be an air bubble, which is making it overheat, and the cabin heater valve thats causing the heater to blow cold air. I'll be able to work on it soon, then i will get back to you all.

James218
12-19-2004, 07:49 PM
I found a cracked vaccum hose. As soon as I get some spare time to pick up the part, I'll replace it and fill you all in.

Nahkapohjola
12-20-2004, 12:46 AM
I probably have to replace the hoses, I'm sure it wouldn't hurt. Although the hoses seem to be just fine from the outside. The heater only working speratically, it must be some particle blocking the flow now and then. Im going to have to check for a bleeder valve, Im not formilar with this bleeder valve, so if someone could help with the location that would be awesome. ...

"to replace the hoses
- just check flow, condition

"heater only working speratically
- air bubbles

"bleeder valve, ... the location
- Follow the hoses, near intake. If u do not find, juts loosen the hose clamp to produce a tiny leak.

"I found a cracked vaccum hose.
- if its in the end, just cut that part off. Vulcanizing rubber 'tape' makes a temporary repair.

James218
12-20-2004, 11:37 PM
Ok I repaired the vaccum hose, that didn't work. So I completely took out the doe valve (cabin valve) and put in a plane old manual valve, from a water heater, heat still doesn't work. The heat will put out if your cruisen down the road in 2nd gear reving the engine to 4 grand, the heater will blow really hot air, but as the rpms drop so does the heat ( heat doesn't drop right away but eventually.)
My next step is to work the bubbles out (if any) if that doesn't I'll take it to some place and get it flushed, I've heard of getting it mechanically flushed or something, I don't know but we'll see. I'll also replace the hoses, I'm sure that couldn't hurt.

Nahkapohjola
12-21-2004, 02:20 AM
Ok I repaired the vaccum hose, that didn't work. So I completely took out the doe valve (cabin valve) and put in a plane old manual valve, from a water heater, heat still doesn't work. The heat will put out if your cruisen down the road in 2nd gear reving the engine to 4 grand, the heater will blow really hot air, but as the rpms drop so does the heat ( heat doesn't drop right away but eventually.)

My next step is to work the bubbles out (if any) if that doesn't I'll take it to some place and get it flushed, I've heard of getting it mechanically flushed or something, I don't know but we'll see. I'll also replace the hoses, I'm sure that couldn't hurt.

1. So now u get hot air when pump is working harder. Get the air out.

2. "I'll take it to some place"... 'Some places' do not help, getting air only helps... Read this chain from start, u can do it uself:

- There is a bleed valve; open it slightly so that its bleeding a little, drive one hour (keep water level up). This will get all 100% air out.
- If no valve found, loosen the hose a tiny bit to make a leak for air to escape...

maxwater
12-22-2004, 08:36 PM
Try just flushing the heater core itself. Find an easy access point to the inlet and outlet hoses and hook a garden hose up to flush it. That puts a lot more pressure through there than the system can alone. I just did this the other day on my maxima because I had no heat either and know it works fine. Its kind of messy though.

Ones&zeros
12-22-2004, 10:42 PM
Where Exactly Is This Heater Core, & I Might Check The Heater Control Knob, & Leak Air Out.

Ones&zeros
12-22-2004, 10:48 PM
Ill Tell Him About The New Or Used Radiator He Has To Buy, Eventully Hell Nedd It Anyways. Thank For The Input. Nahkapohjola

Nahkapohjola
12-23-2004, 04:44 AM
Where Exactly Is This Heater Core, & I Might Check The Heater Control Knob, & Leak Air Out.

The cabin heater core is deep under the dashboard. The watertubes come through from the engine compartment wall, on passenger side. Open tubes and flush with garden hose...

Maxima has lots of tiny warming hoses for example to throttle & Idle assy, look for fingerthick warm rubber hoses near the aluminium intake manifold. These may be for unknown curvy reason having the bubbles locked. Loosen one hose there also to produce a tiny leak.

James218
12-26-2004, 10:26 PM
Okay heater is working fine now. air bubbles were the problem. Thank you all for your help.

Nahkapohjola
12-27-2004, 02:27 PM
Ok I repaired the vaccum hose, that didn't work. So I completely took out the doe valve (cabin valve) and put in a plane old manual valve, from a water heater, heat still doesn't work. The heat will put out if your cruisen down the road in 2nd gear reving the engine to 4 grand, the heater will blow really hot air, but as the rpms drop so does the heat ( heat doesn't drop right away but eventually.)
My next step is to work the bubbles out (if any) if that doesn't I'll take it to some place and get it flushed, I've heard of getting it mechanically flushed or something, I don't know but we'll see. I'll also replace the hoses, I'm sure that couldn't hurt.


Somebody said that their pump was rusted off, the small wings in the rotor vanished. Weird problem, but possible. I guess its boiling in the winter...

Hot/Cool via insulation, see my page:
http://www.cardomain.com/memberpage/748507/1

Add your comment to this topic!