Although temp is hot, heater does not blow hot air.

Mike Butler

• 6674 Answers
• Posted on Dec 12, 2008

SOURCE: Heater Troubles

possibly/most likely, a restriction of some type to core or in core, more than likely corrosion internally. Cheapest & best thing to try is complete cooling system flush, & reverse flush, to move that out of there if it will come. If that fails, I would circulate C.L.R. through heater core to help remove any calcium etc deposits.

Paul W

• 404 Answers
• Posted on Feb 24, 2009

SOURCE: Nissan Altima no cool air blowing or hot air blowing

Hi!
It appears we have an Air lock scenario and you will need to perform a system Bleed.
Park the vehicle on level ground, when cold remove coolant filler cap, start engine and leave to idle, turn heater on full and blower to max. When engine reaches operating temperature watch and listen near coolant filler, keep clear as gurgling and hopefully a boil over should occur. Top up with very warm coolant and wait as it may do it again.
Check for heat inside vehicle if warm replace coolant cap but keep an eye on temperature gauge as the ~Air lock may have moved on from heater matrix/core so proceedure needs to be carried out again from COLD.

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Paul 'W' U.K

SOURCE: 2000 Xterra intermentantly overheats

sounds more like the thermostat may be failing. generally a water pump starts leaking out of the "weep" hole in the casting before it quits. just look at the front of the water pump for a greenish streak or an obvious leak.
if you also suspect you heater core may be getting plugged now would be a good time to back flush it to get rid of some of the gunk.

SOURCE: heater only blows cold air when idleing but blows

you have air trapped in cooling system. Go to a shop that uses evacuate & fill equipment and have them flush system and burp air. SHould cost about $65. Make sure they have evac/fill equipment

SOURCE: 2002 Nissan Sentra Heater does not blow hot air

check your coolant level. if level is ok, i would suspect a head gasket problem. this era of these cars had some issues with the gaskets leaking into the cylinders, particularly cylinder # 1. symptoms of this can also be long cranking times, and random cylinder misfires. before assuming the worst, have the problem verified by a shop that you trust. good luck!