Heater lukewarm after coolant replaced

I just had the coolant replaced on my 2003 Matrix (33k miles) and I noticed
that when I drive my car the heater air is lukewarm for about 3-5 minutes
and then abruptly it gets hot. I'm not 100% positive but I think before I
had the coolant replaced, the heater air didn't take *that long* to get hot.
If this is true, I'm guessing that somehow the thermostat is taking longer
to open up. How could changing the coolant have affected this? Could the
mechanic have screwed up something? (I went to an independent garage).

Thanks.

-john
(remove the pachyderm)

"john" <johnbkim@myfastELEPHANTmail.com> wrote in message
news:120nnotflbc0a65@corp.supernews.com...[color=blue]
>I just had the coolant replaced on my 2003 Matrix (33k miles) and I noticed
>that when I drive my car the heater air is lukewarm for about 3-5 minutes
>and then abruptly it gets hot. I'm not 100% positive but I think before I
>had the coolant replaced, the heater air didn't take *that long* to get
>hot. If this is true, I'm guessing that somehow the thermostat is taking
>longer to open up. How could changing the coolant have affected this? Could
>the mechanic have screwed up something? (I went to an independent garage).
>
> Thanks.
>
> -john
> (remove the pachyderm)[/color]


It is normal to take 3 to 5 minutes for the coolant to get hot enough to be
able to heat up the air flowing past the heater core.


--

Ray O
(correct punctuation to reply)

Ray,

Do you think this mechanic failed to purge the system of air and maybe
that might be a factor ?

J



Ray O wrote:
[color=blue]
> "john" <johnbkim@myfastELEPHANTmail.com> wrote in message
> news:120nnotflbc0a65@corp.supernews.com...
>[color=green]
>>I just had the coolant replaced on my 2003 Matrix (33k miles) and I noticed
>>that when I drive my car the heater air is lukewarm for about 3-5 minutes
>>and then abruptly it gets hot. I'm not 100% positive but I think before I
>>had the coolant replaced, the heater air didn't take *that long* to get
>>hot. If this is true, I'm guessing that somehow the thermostat is taking
>>longer to open up. How could changing the coolant have affected this? Could
>>the mechanic have screwed up something? (I went to an independent garage).
>>
>>Thanks.
>>
>>-john
>>(remove the pachyderm)[/color]
>
>
>
> It is normal to take 3 to 5 minutes for the coolant to get hot enough to be
> able to heat up the air flowing past the heater core.
>
>[/color]

"Joey" <J_nospam_ls@moultriega.net> wrote in message
news:120po7a330t7144@corp.supernews.com...[color=blue]
>
> Ray,
>
> Do you think this mechanic failed to purge the system of air and maybe
> that might be a factor ?
>
> J
>
>[/color]

Air in the cooling system is a possibility that is easy enough to check.
The next time you park the car for 4 hours or so, turn the heater control
all the way to hot a minute or two before you turn off the engine. After
the engine has cooled, look at the coolant level in the overflow bottle. It
should be filled to the "cold" mark. If the radiator has a cap, remove it
and take a look inside the neck. The radiator should be filled to the top.
Do not attempt to remove the radiator cap while the engine is warm or you
may get serious burns!

The heater is basically a mini-radiator in the passenger compartment, and
instead of getting rid of heat in the outside air like the radiator does,
the heater core passes its heat to the air flowing into the passenger
compartment. The heater control valve controls the amount of coolant
flowing through the heater core. When you start a cold engine, the coolant
is the same temperature as the ambient air and the rest of the car. It will
take a few minutes for the engine to warm the coolant to 140 degrees or so
and open the thermostat, allowing the coolant to flow through the radiator.
It will actually take a little longer for the coolant to reach operating
temperature if it is flowing through the heater core because it is trying to
give what little heat is built up to the passenger compartment.

IMO, 3 minutes from cold startup to heat flowing from the heater core is not
unreasonable.
--

Ray O
(correct punctuation to reply)

[color=blue]
>
> Ray O wrote:
>[color=green]
>> "john" <johnbkim@myfastELEPHANTmail.com> wrote in message
>> news:120nnotflbc0a65@corp.supernews.com...
>>[color=darkred]
>>>I just had the coolant replaced on my 2003 Matrix (33k miles) and I
>>>noticed that when I drive my car the heater air is lukewarm for about 3-5
>>>minutes and then abruptly it gets hot. I'm not 100% positive but I think
>>>before I had the coolant replaced, the heater air didn't take *that long*
>>>to get hot. If this is true, I'm guessing that somehow the thermostat is
>>>taking longer to open up. How could changing the coolant have affected
>>>this? Could the mechanic have screwed up something? (I went to an
>>>independent garage).
>>>
>>>Thanks.
>>>
>>>-john
>>>(remove the pachyderm)[/color]
>>
>>
>>
>> It is normal to take 3 to 5 minutes for the coolant to get hot enough to
>> be able to heat up the air flowing past the heater core.
>>[/color][/color]

On Mon, 6 Mar 2006 23:57:54 -0600, "Ray O"
<rokigawa@tristarassociatesDOTcomn> wrote:
[color=blue]
>
>"Joey" <J_nospam_ls@moultriega.net> wrote in message
>news:120po7a330t7144@corp.supernews.com...[color=green]
>>
>> Ray,
>>
>> Do you think this mechanic failed to purge the system of air and maybe
>> that might be a factor ?
>>
>> J
>>
>>[/color]
>
>Air in the cooling system is a possibility that is easy enough to check.
>The next time you park the car for 4 hours or so, turn the heater control
>all the way to hot a minute or two before you turn off the engine. After
>the engine has cooled, look at the coolant level in the overflow bottle. It
>should be filled to the "cold" mark. If the radiator has a cap, remove it
>and take a look inside the neck. The radiator should be filled to the top.
>Do not attempt to remove the radiator cap while the engine is warm or you
>may get serious burns!
>
>The heater is basically a mini-radiator in the passenger compartment, and
>instead of getting rid of heat in the outside air like the radiator does,
>the heater core passes its heat to the air flowing into the passenger
>compartment. The heater control valve controls the amount of coolant
>flowing through the heater core. When you start a cold engine, the coolant
>is the same temperature as the ambient air and the rest of the car. It will
>take a few minutes for the engine to warm the coolant to 140 degrees or so
>and open the thermostat, allowing the coolant to flow through the radiator.
>It will actually take a little longer for the coolant to reach operating
>temperature if it is flowing through the heater core because it is trying to
>give what little heat is built up to the passenger compartment.
>
>IMO, 3 minutes from cold startup to heat flowing from the heater core is not
>unreasonable.[/color]

It really depends on the car. I have a geo prizm (corolla) and it
heats up in about 3 minutes (the gauge does at least). I've had other
cars that took a lot longer, even brand new ones. I guess the capacity
of the coolant system also plays a part in it.

I did what Ray outlined, and there was no coolant in the overflow bottle nor
inside the neck. I filled the overflow bottle to the "full" mark and
repeated the test the next time I parked the car. The coolant had gone done
a little less than a pint. So all in all I think it was underfilled by about
1/2 gallon of coolant by the mechanic. I had driven my car that way for
about a week -- could that have done any damage to my car? (I doubt it; but
thought I'd ask).

Thanks.

john



"Ray O" <rokigawa@tristarassociatesDOTcomn> wrote in message
news:23499$440d2477$180fead6$12695@msgid.meganewsservers.com...[color=blue]
> Air in the cooling system is a possibility that is easy enough to check.
> The next time you park the car for 4 hours or so, turn the heater control
> all the way to hot a minute or two before you turn off the engine. After
> the engine has cooled, look at the coolant level in the overflow bottle.
> It should be filled to the "cold" mark. If the radiator has a cap, remove
> it and take a look inside the neck. The radiator should be filled to the
> top.[/color]

On Sat, 18 Mar 2006 01:43:29 -0800, "john"
<johnbkim@myfastELEPHANTmail.com> wrote:
[color=blue]
>I did what Ray outlined, and there was no coolant in the overflow bottle nor
>inside the neck. I filled the overflow bottle to the "full" mark and
>repeated the test the next time I parked the car. The coolant had gone done
>a little less than a pint. So all in all I think it was underfilled by about
>1/2 gallon of coolant by the mechanic. I had driven my car that way for
>about a week -- could that have done any damage to my car? (I doubt it; but
>thought I'd ask).[/color]

If they flushed and drained the cooling system and didn't 'burp' the
heater on the final fill (some cars need this, most don't) it would
take more coolant over the next few days and warm-cool cycles as the
air worked it's way back to the radiator and out. But then the level
in the recovery tank should stabilize.

As long as there was enough coolant to circulate into the radiator,
it shouldn't hurt the engine.

Try that in August when it's hotter than hell and you are pushing
the engine, and the results might have been a bit different - you want
to check the coolant level daily (as well as everything else under the
hood) for a few days after doing any work on the car. Things don't
always leak immediately.

--<< Bruce >>--

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.