Hey All,

I've been having this problem for 2 years now. Here's the story. I have no heat in the car. I let it warm up completely first, which is does to normal temperature. Heat comes out initially and then goes cold. The heat never returns whether driving or at idle.

- The car has never overheated
- I'm not losing coolant
- I see no smoke of any kind from anywhere

Here's what's been done to the car so far:

1. Replaced Water Pump
2. Replaced Heater Core
3. Replaced Timing Belt
4. Replaced Thermostat
5. Replaced A/C Servo (Supposedly the blender in the dash)
6. Replaced Water Temp Sender including O-Ring and C-Clip
7. Replaced Radiator
8. Replaced Bleeder Screw on top of engine
9. Replaced Plug in Engine Block
10. Replaced Climate Control Head Unit
11. Flushed several times with core attached AND unattached
12. Replaced all coolant

*On a side note, my A/C started blowing hot and cold this summer. I plugged a coolant recharge kit into the system and the pressure was in the dangerous red zone. It started at 70psi, rose to around 150psi, then dropped back down to 70psi. That just kept repeating. The dealership had to replace a fan which did fix the problem.


Now the dealership says they have to replace the head gasket. Does that make any sense given the circumstances I've listed??

Thanks in advance,

Rob

 

1.8T gaskets do go bad quite often, but I really don't see how that could affect your heating system. It does however make your car overheat because it sends the coolant into the cylinders and then it starts runing out. Have you had to refill your coolant in recent days/weeks?

 

Thanks for the reply. No, I'm not losing coolant...

 

It could affect the heater by not allowing the system to pressurize.

Does the heater work at higher rpm??

I would try watching the res with the cap on while revving the engine. If the level goes down take the cap off while holding the revs and fill it up. Then repeat that process until the level doesn't lower.

 

No, once I heat the car up I turn it on HI. It begins hot, then gradually goes cold (does this pretty quick). From that point, it only blows cold air whether I'm driving, parked revving the engine, or at idle.

I'll check the level in the reserve tank today but I've had them flush and refill the system several times...I'll let you know how it goes...thanks...

 

If the thermostat has only been replaced once it is possible the replacement was/is faulty.

 

Also, on your list I don't see coolant sensors. Have those been replaced??

 

Find the coolant hoses that run into the firewall. Get the car good and warmed up and feel both hoses. If one is hot and the other cold then your heater core is plugged up or possibly the replaceemnt was installed incorrectly. Hot coolant isn't flowing through hte core properly if this is the case...if you got the car good and warmed up and didn't run the heater for awhile you would get heat out of the vents for a minute or less after turning on the fan, but it would cool off the heater core faster than the hot coolant heats it up.

If both hoses are hot then your probable is more likely the blend door that allows you to select hot air adn cold air. Its not opening properly and allowing hot air to come into the cabin from the heater core.

Based on your description I'm betting on the core being the problem. It sounds like thye're replaced like $3000 worth of parts at this point for you...I bet they made a mistake when hooking something up or used a bad part.

When the system was flushed, was it flushed or backflushed? When you flush a system and you have crap in there you're only wedging it in tighter, the couple times I had a situation like this I was only able to get the blockage out by backflushing.

 

Personally, I'd look at the temp sensor in your cabin. If its bad, it'll tell the climate control its too hot and make the blended air servo go to cold.

 

Wow, thanks for all the quick replies so far...

Yes right now they actually want to replace the head gasket and the thermostat. If the thermostat was not working correctly, would my car heat up to normal temperature??

The coolant sensors were apparently replaced after talking to the mechanic...I'll ask about the temp sensor in the cabin...

I was present when it was bled and both hoses to the core were hot. I saw a steady stream of coolant streaming out of the bleed hole in the hose so the coolant was definitely flowing.

As for the flush, the dealership said they did it a few times but I'm not sure about backflushing, I'll ask them today...