No heat on passenger side, shop says blocked heater core

[CA-RJ]

I bought a 04 4runner just recently and recently noticed that I've got good heat on the drivers side but cold air on the passenger and rear air vents. I've taken it to a local shop and they said that the heater core was blocked and want to back flush it. I figured a blend door motor was bad. Can a blocked heater core cause the heat to not work on one side of the truck? Seems most of the info I am finding when Googling it's no heat period.

 

[NinjaOne]

Dual Climate control?

 

[CA-RJ]

No. They told me that the blend door motors were fine, but I'm kinda thinking they want to sell me the flush and when that doesn't work they're going to say it needs a new core.

 

[CA-RJ]

Just talked with them again. They said they checked the motors per Toyota's instructions and that they all tested fine. They ordered some flush stuff that will be there in the morning and are going to flush it (again I think).

I guess I don't understand how a restricted heater core could cause partial heat when everything I've read that it should be all or nothing.

 

[JEL]

I would try and find a new shop, or verify it for yourself, as there is hardly a rash of heater core failures on these trucks, BUT there are TONS of actuator motor problems (mine is included in that group).

 

[emoore924]

Half blocked heater core? I think that's a crock...

 

[iBison]

Half blocked heater core? I think that's a crock...

That's what I'm thinking. Look for a good shop.

 

[CA-RJ]

Shop called. Said they were able to clear most of the blockage but that the drivers side air is still 10-12 degrees warmer than the passenger side. Their next option was $1100 to replace the heater core.

Thoughts?

 

[jasonochs25]

Like others have said...sounds fishy. The air that is heated flows over/through a heater core like a radiator works to cool the engine. Its not a blockage IN the heater core, but maybe the ducting or the fins/vanes themselves? it anything, get someone with a compressor and access the heater core and blow it off

 

[BlackWorksInc]

[MENTION=74889]CA-RJ[/MENTION] What year & trim/engine do you have?

 

[cmoua]

If you are getting some heat then it's not a heater core issue. It's probably the blender door. It looks like they are trying to get as much money out of you. I would go else where for a reputable shop.

 

[CA-RJ]

Sr5 v6.

[mention=74889]ca-rj[/mention] what year & trim/engine do you have?

 

[CA-RJ]

I'm taking it to Toyota this week.

If you are getting some heat then it's not a heater core issue. It's probably the blender door. It looks like they are trying to get as much money out of you. I would go else where for a reputable shop.

 

[fullboogie]

Rip off in progress - get your truck away from those criminals and bring it somewhere else. And spread the word far and wide about those crooks.

 

[BlackWorksInc]

Sr5 v6.

So... I don't know exactly how Toyota set-up the air mix doors in the SR5 according to their FSM. I also haven't see one out in detail enough to compare to a Limited's (which I also haven't seen in detail).

According to the FSM the only difference between the Dual Air and Single Air HVAC housings is that there's a plate for the heater core in single and a second motor for dual... which makes no sense to me...

 

[CA-RJ]

Update:

Got the truck back and the passenger side vents are no longer blowing cold air but now luke warm air.

I have an appointment at Toyota for tomorrow morning. I'll update when they fix the problem.

 

[CA-RJ]

Toyota Update:

The news is not good. In fact, pretty awful. Toyota not only confirmed that the heater core is plugged, they said it's plugged with radiator stop leak because apparently the radiator is/was leaking as well. They recommend replacing both since the radiator still has stop leak in it and they are concerned that it would just plug up a new heater core. I need a drink right about now...

 

[BlackWorksInc]

Toyota Update:

The news is not good. In fact, pretty awful. Toyota not only confirmed that the heater core is plugged, they said it's plugged with radiator stop leak because apparently the radiator is/was leaking as well. They recommend replacing both since the radiator still has stop leak in it and they are concerned that it would just plug up a new heater core. I need a drink right about now...

That sucks, I'm sorry... Yeah, I've always been wary of use stop leak in anything beyond a temporary measure; even then I've been concerned about this exact issue. Whoever does the replacement may want to flush the system with the thermostat out to try and get as much of that stopleak out of the block and pasaages as possible.

 

[YotaDriver]

I blocked my own heater core in a 1992 Saab 9000 once using that aluminum powder you drop into the expansion tank to fix coolant leaks. I wonder if a previous owner attempted to mask a possible coolant leak (hopefully not on the head gasket) using the same type of product.

EDIT - I guess I should have finished reading the thread before posting here. Again, I'd run through a battery of tests to make sure your head gasket - particularly around cylinders #4 and #6 - is still in tact. If not, then the previous owner pulled a fast one on you and should be hunted down like an animal.

 

[Sungod]

If it clogs up your radiator I could only imagine how bad it must be inside the block and heads. That stuff should really be banned. There is no redeeming value to it.