New Rad, New Heater Core: Coolant Smell Still There with Heat On

[G-Cat]

1999 US Spec 100 Series, 315K miles

Started getting smell of coolant through vents with heat on. Pressure test indicated small leak in radiator. Replaced with Denso.

Smell still there with heat on, and heat goes luke warm after 20 seconds.

Front heater core replaced with OEM Toyota. New heater Ts and hoses.

Heater blows hot…but strong coolant smell still there when heater turned on. Strong at first, then goes away…but ALWAYS strong when heat first engaged.

Coolant level in radiator low (maybe 10-12 oz) after running heater for 5 minutes.

No dampness on interior floor areas.

Any help?

 

[Eyedaho]

Unless I'm mistaken, the 100 series has no valve to control coolant flow to the heater core, and controls cabin heat output by regulating airflow across the core. So, it's seemingly irrelevant whether your heat is turned on or off.

 

[G-Cat]

If the above is correct, why does it smell like coolant only when the HVAC is on heat (not when on A/C), and the coolant level in the rad only goes down after HVAC has been on heat for some time?

Forgot to mention…new fan clutch, as well.

How would a faulty thermostat impact/contribute to the above, if at all?

 

[3_puppies]

do you have rear heat?

 

[G-Cat]

do you have rear heat?

Yes…rear heat through the floor vents at the bottom of the center console. No leaks I can see from the lines to the rear.

 

[saucebox]

Coolant level in radiator low (maybe 10-12 oz) after running heater for 5 minutes.

Is this part repeatable?

 

[G-Cat]

@saucebox great question. So I topped of the rad and overflow (full/cold) and ran the Cruiser for about 8 minutes.

About a minute with rear heat on high and front A/C on until air was cold, then switched front to hot.

Immediately got strong smell of coolant through vents.

Let it run (both heaters in high, both blowing hot) while I observed all hoses, heater t’s, thermostat housing, rear heater hoses…for about 7 minutes.

Nothing noticeably leaking.

I let is sit for 3 hours. Just checked the rad…it is full and overflow is at full mark. So not repeatable…but only second experiment since new heater core installed…so 50/50 on “losing” coolant.

The one constant, before/after the new radiator, before/after the new fan clutch, before/after the new heater core: strong smell of coolant from vents when front heat is turned on. Wife and kids confirmed the smell (making sure I haven’t lost my mind).

Thoughts?

 

[saucebox]

You mentioned a pressure test early on—does the system hold pressure now? I'm kind of grasping at straws—with that many new parts (like...all of them) there shouldn't be a leak. I wonder if it's just old spillage?

 

[G-Cat]

Update: 10 minute drive with A/C on high.

CEL pops with P0141 O2 Sensor Heater Circuit Bank 1 Sensor 2, P0161 O2 Sensor Heater Circuit Bank 2 Sensor 2.

Radiator/tank, after 2 hour cool-down, low by 11 oz of coolant.

Again, no visible leaks.

No white smoke from tailpipe, but I’m starting to wonder if I have a blown head gasket. Coolant is going somewhere and I can’t find a leak. Two cooked O2 Sensors seems like a clue…and burned-off coolant makes sense to me…but I am a 1 banana at best.

Truck is being towed back to shop.

 

[G-Cat]

Here she sits waiting on a tow truck…was going to go with my oldest for the first semester of his senior year in college (thus the stripes) but now he will be car-less until I can get this Cruiser sorted.

 

[saucebox]

That's a really good looking ride, hope they get you sorted out pretty quick.

 

[nukegoat]

Could be just a leak anywhere in the engine bay and turning on the HVAC begins circulating it. Since you said it's in the interior I kind of doubt it's a head gasket. Sucks. Hope you get it sorted shortly. Don't let it ruin sending your kid off to college

 

[hoser]

You could probably isolate which heater (Front vs Rear) by capping off one pair of outlets of the heater Tees.

 

[Michael Scarn]

Hello, happen to come across your thread about heater, and hope you don't mind me asking some questions about the heater in my 2000 lx 470.

I have had the lx for the past 2 or so years. The heater never functioned properly since I purchased it. In winter time, it blows maybe room temperature air. When the temp drops below 50 degrees, the air becomes cooler. Took a ski trip to CO last winter, and the heater was pretty much not existing, had to layer up in the car for the whole 14 hour drive.

I have brought it to a few mechanics about the issue. One mechanic suspect the airflow vent director is not functioning properly. However, I can hear a motor turn when i change the temperature from cold to hot. Another mechanic suspects the coolant line to the heater core is clogged, but he is reluctant to flush it. He mentioned that flushing it could unclog the line and lead to a leak, and he suggested to replace the whole heater core.

I just want to see what you guys think the problem is. Is it correct that it requires pulling the whole dash to replace the heater core? The mechanic told me the whole job will be $3k to 4k, is that right?

Thank y'all so much in advance!

 

[G-Cat]

Both shops I dealt with quoted the labor at 7 hours, @$120 per hour = $840.

OEM Toyota Heater Core, plus heater Ts, clamps and new hoses were about $540 from one of the online discount Toyota parts dealerships…and took 3 weeks to arrive.

So $1300-$1400 max, all-in. It does involve a complete dash de-construction…but $3-$4K is ludicrous.

DO NOT buy a $60 heater core from Rockauto or similar. The amount you are paying in labor is t worth replacing with crap parts that won’t last.

 

[divejoe]

Both shops I dealt with quoted the labor at 7 hours, @$120 per hour = $840.

OEM Toyota Heater Core, plus heater Ts, clamps and new hoses were about $540 from one of the online discount Toyota parts dealerships…and took 3 weeks to arrive.

So $1300-$1400 max, all-in. It does involve a complete dash de-construction…but $3-$4K is ludicrous.

DO NOT buy a $60 heater core from Rockauto or similar. The amount you are paying in labor is t worth replacing with crap parts that won’t last.

I just got a quote for $1400 to replace the heater core and all that goes with it (recharge ac lines, adding coolant, parts, etc). Tech said the heater core is clogged.
Is there a way to flush the system to unclog it???

 

[3_puppies]

I just got a quote for $1400 to replace the heater core and all that goes with it (recharge ac lines, adding coolant, parts, etc). Tech said the heater core is clogged.
Is there a way to flush the system to unclog it???

I've disconnected the hoses, fill with CLR or similar and let sit for a while, then flush with water to get all the stuff out.

-13F in Helena this morning, heat/defrost is kinda important

I don't think the a/c needs to be touched, it can be taken out thru the top.

 

[fjfar80]

I just got a quote for $1400 to replace the heater core and all that goes with it (recharge ac lines, adding coolant, parts, etc). Tech said the heater core is clogged.
Is there a way to flush the system to unclog it???

If the heater core is "clogged" I would replace - but, that also means you may have something else going on in your coolant. Is your coolant running low or do you have any other leaks?

 

[divejoe]

I've disconnected the hoses, fill with CLR or similar and let sit for a while, then flush with water to get all the stuff out.

-13F in Helena this morning, heat/defrost is kinda important

I don't think the a/c needs to be touched, it can be taken out thru the top.

You in Helena??

 

[divejoe]

If the heater core is "clogged" I would replace - but, that also means you may have something else going on in your coolant. Is your coolant running low or do you have any other leaks?

No leaks and coolant level is fine. I think I will try flushing it and see if there is any improvement. I recently replaced the Heater T’s so I’m wondering if some of the crumbled pieces got into the system. I tried to be careful but they just disintegrated in place.