Overheating and heater blowing cold air

Tiny
PKBRUSER
  • MEMBER
  • 2009 TOYOTA SIENNA
  • 6 CYL
  • 2WD
  • 16,000 MILES
The heater doesn't blow hot air. When I purged the radiator air never got hot. Also the coolant was doing it's thing and bubbling them when temperature was at normal temperature the coolant started to back out into the funnel like overflow. So I revved the engine and it really spit over car was getting ready to overheat still cold air from heater? So I turned it off and the coolant level dropped and disappeared into radiator. It looked like I needed to and some but something is blocked. Can you help? I didn't see any leaks before it overflowed?
Monday, December 14th, 2020 AT 12:25 PM

14 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

I need you to check something for me. If you are seeing bubbling in the coolant before it is hot, that concerns me. Often times, bubbles (other than boiling) indicate compressed air is getting into the system. Most times that is the result of a bad head gasket.

Take a look through this link and let me know if anything mirrors what you are seeing and experiencing.

https://www.2carpros.com/articles/head-gasket-blown-test

Let me know what you find or if you have other questions.

Take care,
Joe
Was this
answer
helpful?
Yes
No
Monday, December 14th, 2020 AT 5:46 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
Hi, thank you for your time. Okay, this morning when the van was cold I opened up the radiator cap and it acted like it was hot it exploded with pressure and the coolant level overflowed. I don't know I am going to look at your links and get back I just thought I should tell you that. K
Was this
answer
helpful?
Yes
No
Monday, December 14th, 2020 AT 6:54 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

It's odd that it would have that much pressure when cold. Do me a favor. Go through the link. Also, replace the radiator cap.

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Monday, December 14th, 2020 AT 7:12 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
Okay, I will tomorrow. I looked at the link I see some things I could check. I will let you know. Thanks again I hope it's the cap. Pk
Was this
answer
helpful?
Yes
No
Monday, December 14th, 2020 AT 8:04 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Sounds good. Let me know what you find or if you have other questions.

Take care,
Joe
Was this
answer
helpful?
Yes
No
Tuesday, December 15th, 2020 AT 5:12 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
Well, I haven't got anything done because I am just so frustrated. I took the van in about two months ago it was overheating. They fixed the over heating problem (the heater still didn't blow hot air). So the van was working for about 1 month and then I went through a car wash. One of the ones you drive your car through. It was hot that day and it took about 12 minutes to get through I had I air conditioner on the whole time in the wash. Well, when I left I just happened to look at my gauges and sure enough it started to overheat. Well I made it home. When my boyfriend got home I told him about it and that I was going to take it back. He said no that he would take a look and so he replaced the water pump? But the water pump wasn't broke. So we put it back together and it's the same no heat and overheats. The hoses that go into the firewall don't get hot at all and the hose coming from the radiator it gets hot the one coming off the van is warm to cold. The hottest thing is the engine in front where the oil goes. I don't have milky goo on the cap or any leaks. I am sorry for such a long reply.
Was this
answer
helpful?
Yes
No
Thursday, December 17th, 2020 AT 3:08 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

If the heater hoses don't get hot, either you have air in the system or it's plugged. If there is air in it and the system worked prior and wasn't opened or driven extremely low on coolant, the question becomes, how did it enter the system. Often times, it is a head gasket allowing compressed air to enter the cooling system. When you checked it, were there any bubbles in the coolant?

Also, I want you to try something. When the engine is cold, remove or loosen one of the heater hoses at the firewall. See if there is coolant coming from the hose. If there is none, have a helper start the engine while you watch to see if there is circulation. If there is none, tighten that hose and remove the other, and do the same thing. One is a supply and one is a return, so you may not see a lot from the return if the supply is plugged.

If you do have flow, with the return hose lose, see if you can bleed air from it. If there is no flow through the heater core, try flushing it to see if that helps. Basically, remove the return hose from the core and the supply line. Then using a garden hose, see if you can get water to flow through the heater core.

Let me know. I attached a general pic below showing what to look for as far as the heater hoses.

Take care,
Joe
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Thursday, December 17th, 2020 AT 8:42 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
That's what I planned to do just got a little frustrated. I will let you know. Thanks Joe for your help. Pk
Was this
answer
helpful?
Yes
No
Friday, December 18th, 2020 AT 8:40 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
You are very welcome. Let me know what you find or if you have other questions. We need to get your heater working for this time of the year. LOL

Take care,
Joe
Was this
answer
helpful?
Yes
No
Friday, December 18th, 2020 AT 11:02 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
Okay, so I got the hoses off the firewall and first thing I noticed is there was no coolant at all in the intake or outtake so I still flushed it and put back on. But shouldn't there had been some coolant? What does that mean? Thanks, pk
Was this
answer
helpful?
Yes
No
Saturday, December 19th, 2020 AT 7:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Absolutely there should have been coolant. We found the problem. Now we have to find the cause. If you disconnect the return line and start the engine, does coolant come out of it?

Also, when the pump was replaced, was the water inlet housing correctly installed? That distributes coolant as well. It sounds like something is blocking it. See pic 1 for what I'm referring to.

Let me know.

Joe
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Saturday, December 19th, 2020 AT 11:30 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
Okay, I will do that. If I don't see any could do I then disconnect the intake? And do the same? Thank you so much Joe.
Was this
answer
helpful?
Yes
No
Sunday, December 20th, 2020 AT 1:02 PM
Tiny
PKBRUSER
  • MEMBER
  • 9 POSTS
Joe, I am going to send two pics of a part that got broken when the water pump was getting replaced. 1, is the part blown up the other is so you can see where it's located. I don't know what this is but as you can tell I did a little repair do you know what it is? Thanks, pk
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Sunday, December 20th, 2020 AT 2:52 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

That is a VVT sensor (variable valve timing). IF it isn't working, it would set a check engine light. (See pic 1)

Yes, remove the supply hose and see if anything comes out.

Let me know.
Joe
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Sunday, December 20th, 2020 AT 9:11 PM

Please login or register to post a reply.

Related Heater Not Working Content

Heater Not Working
VIDEO
Heater Not Working
Instructional repair video
Heater Not Working
GUIDE
Heater Not Working
Step 1 - A heater cannot operate unless the engine is full of coolant/antifreeze. If coolant level is low check the system for leaks.
VIEW MORE