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Discussion Starter #1
Hi guys,

So I bought an '07 Exige (Magnetic Blue) with 7000 miles on the clock three weeks ago. Yeah, very excited.

Getting ready to put the Elise on the market.

Problem is I have no heat. Here are some facts:

1. Temp Gauge comes on rises to no more than 170 to maybe 175 degrees (shouldn't normal temp be around 194-197?).
2. Heater Controls - No background lights, but the AC lights do illuminate
3. Heater Controls - Fan works fine and I can direct air to various areas (floor, windshield, vents, etc.)

So do you think the lack of heat is the typical stuck thermostat even though I have a working gauge, but temps are low?
Or do you think I have some type of defective heater control?
Or is it the dreaded sensor probe/heater pack in the radiator?

I have no way of determining what the thermostat's condition is. I bought a new solid metal one.

Any help would be appreciated.

Thanks,

Henry
'07 Exige
 

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Regarding the normal operating temp, my car will normally run around 180-190 street driving and will climb to 200-210 in heavy traffic. You might be running a little under that but I think (would have to re-read all the stuck thermostat threads) if you had a stuck thermostat you would have issues getting up to any temp, that doesn't mean your thermostat is not sticking or not functioning properly though.

Do any of the hoses in the engine bay get warm or hot?

Have you checked the coolant level cold and when hot?
 

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Discussion Starter #3
No in answer to all of your questions.

I guess I need to get her up to temp
and look at the heating hose schematic to see if the lines are hot.

I will also check the fluid levels.

Thanks,

Henry
 

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my best guess upon your info is that the heater (air)control servo actuated flap is stuck in the closed position. This blocks the air trough the heater matrix and only allows ambient air (or chilled air) to enter the cabin.

The feed pipe to the heater matrix is always circulating and not plumbed in the thermostat circuit afaik - in fact the heater matrix is always hot (even with the air flap closed).

with rear undertray off, you can locate the smaller hoses going in the right sill and returning from the left sill, and assess their temperature. Follow the hose from the electric heat soak pump mounted to the coolant reservoir; that is your heater matrix circuit.
 

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1. Temp Gauge comes on rises to no more than 170 to maybe 175 degrees (shouldn't normal temp be around 194-197?)....I have no way of determining what the thermostat's condition is. I bought a new solid metal one.
170-175° is warm enough for the engine and plenty hot for the heater matrix. I'd return the new t-stat as this is not the reason for no heat in the cabin.

2. Heater Controls - No background lights, but the AC lights do illuminate
Your electroluminescent (EL) board is dead. The phosphors decay over time. New ones are very pricey and are not worth replacing every 5 years or so.

So do you think the lack of heat is the typical stuck thermostat even though I have a working gauge, but temps are low?
No. Like others stated, the upper flap in the HVAC box (see image...heater matrix is in red) is probably stuck in the cool position. It's rare to have a heater matrix fail, so no worries there. Less likely, the prior owner may have installed a heater matrix bypass valve to maximize AC which could also be stuck or is simply set to the bypass position. I get plenty of heat using a 170° t-stat, and I peak around 175° in chilly weather (40s).
 

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remove the passenger access panel, remove the flexible hose and look in to see if the flap moves with the temperature control[fan on etc]

there was a recent post about this...check it out for ideas
 

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Discussion Starter #9
So the no heat problem is on an '07 Exige. I assume there is no way of accessing the flapper without a clam removal?
I pulled both access panels but the large hose is directly in the middle and not accessible.

Thoughts?

Thanks guys.

Henry
 

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Wait, what? The background on the heater/AC controls is supposed to light up? I've had my Elise for 10 years, and it's never lit up, I learned something new today :)
 

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Its been a while, I am thinking unbolt the fusebox, unbolt the plastic cover over the wiper motor, which has two bolts under the center spine of the clam that get loosened, but I think not removed and you can twist it out of the way enough to do it, i think
 
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