Heater problems....help

[z28_Bignick_z28]

ok..so it finnaly got cold enough here in texas to use the heater in my '95 Z28... i have putting the problem off for the longest time.. but now the girlfriend complains about having no heat.. the heater blows but its just not hot..or warm at all... im not sure what happen to it.. but since i have had the car it just has not worked.. im thinking heater core, or thermostat possibly. any advice would be helpfull thanks

[Trash man]

change the thermostat and make sure u get all the air out, run a 180*, i had that in my bird and it did ok, on the really cold days(-5* at bout 6am couple morns) it wasnt toasty but warm enough with a hoodie for me

[Rob B (shoebox)]

Flush the heater core. No heat is THE most common complaint when the weather turns cold.

[Jeff_in_Atl]

Flush the heater core. No heat is THE most common complaint when the weather turns cold.

ditto. Flush it from both directions. The Dexcool coolant is known for clogging heater cores. I had to do mine last winter.

[Sacius]

How would you flush it from both ways? How would you flush the system at all?

[BrdWAtti2d]

I do it the old school way. Go out and buy some radiator flush, drain and refill the radiator with the flush and tap water. Follow the instructions on how long to run the car with the flush. Let the car cool, drain the radiator and refill with water only, turn on the car with the radiator cap off and a hose in the filler on low. Let the hose and car run until the water comes out clear. Drain the radiator and refill with the antifreeze of your choice. But just a word of caution, I had the same thing happen and when I did the flush my heater core leaked like a sieve. I guess the crud was plugging the hole in the heater core and when I flushed it I had a flood in my floor board and a pegged temp guage a few days later. Just keep an eye on the passenger side floorboard for leaks. Also make sure the flush water doesn't get anywhere near your optispark.

[Jeff_in_Atl]

I do it the old school way. Go out and buy some radiator flush, drain and refill the radiator with the flush and tap water. Follow the instructions on how long to run the car with the flush. Let the car cool, drain the radiator and refill with water only, turn on the car with the radiator cap off and a hose in the filler on low. Let the hose and car run until the water comes out clear. Drain the radiator and refill with the antifreeze of your choice. But just a word of caution, I had the same thing happen and when I did the flush my heater core leaked like a sieve. I guess the crud was plugging the hole in the heater core and when I flushed it I had a flood in my floor board and a pegged temp guage a few days later. Just keep an eye on the passenger side floorboard for leaks. Also make sure the flush water doesn't get anywhere near your optispark.

I disagree with that method. The crud flows into the heater core and blocks the passages. Putting cleaning stuff in there unless it dissolves it might not clear it. It still tries to push the crud through the heater core. Only flushing it the opposite direction of the way the coolant flows will clear it good. That method might work and I'm sure it will work to some degree. I just think the best way to do it is to back flush it.

How would you flush it from both ways? How would you flush the system at all?

I bought 2 hose fittings from home depot that are used to repair broken garden hoses. I think one is 5/8" and the other is 3/4". It may be 1/2" and 5/8" I just can't remember. I do remember them being different sizes. I disconnected both heater hoses from the water pump, stuck the fitting in one end, connected it to the garden hose, and turned it on. Just point the other end away from the OPTI. Reversed the fittings and did it again. I connected it back up, filled it up, bleed it, and I had great heat.

[BrdWAtti2d]

I disagree with that method.

I promise it flowed very well all over my floorboard, lol

[Jeff_in_Atl]

I promise it flowed very well all over my floorboard, lol

Sounds like it wasn't very clogged. LOL

[screamin-eagle]

My heater core clogged i flushed the whole system and it heats now but i think i have to flush it again its still not hot. But just make sure you bleed the system good cause my car over heated when it wasn't blead good.