Heater problem
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Heater problem
I have a 2004 U.S.P. A4 1.8t quattro which is having a heating issue. When I have temperature set at 72 or above, it is blowing cold air. Every once in a while, the blower will stop for a few moments and the start blowing cold air once again. I had the timing belt replaced this past spring and also had the water pump replaced at this time. The temperature gauge is showing a proper running temperature and the car, for the most part, runs as it should. Please advise!
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Joined: Feb 2010
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From: Fort Worth, Tx
Miles and coolant system maintenance record?
Reason I ask is I have an 02 with 197K and it's heater core was clogged. This is typically the issue. I attempted to replace mine this weekend and failed to get the clamps back on the aluminum lines and new core (car was towed sans coolant to my favorite indie this morning), but when I poured water backwards through the old core, lots and lots of small sediment came out and continued to come out until I got bored with playing with it. The passages in the core are very very small and highly susceptible to dirty coolant, hence the miles / coolant question above.
The one thing in you description that is odd is the fact that the blower quit and then started again. Is this with the system in the Auto mode? If so, take it off Auto, set it to 72, and crank the fan. Drive it like this for a while and see if the fan goes off then back on.
Reason I ask is I have an 02 with 197K and it's heater core was clogged. This is typically the issue. I attempted to replace mine this weekend and failed to get the clamps back on the aluminum lines and new core (car was towed sans coolant to my favorite indie this morning), but when I poured water backwards through the old core, lots and lots of small sediment came out and continued to come out until I got bored with playing with it. The passages in the core are very very small and highly susceptible to dirty coolant, hence the miles / coolant question above.
The one thing in you description that is odd is the fact that the blower quit and then started again. Is this with the system in the Auto mode? If so, take it off Auto, set it to 72, and crank the fan. Drive it like this for a while and see if the fan goes off then back on.
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Lyle,
Again, thank you for your quick response. The car currently has a few ticks over 93,800miles and from what I know has never had a coolant system service performed. I contacted a friend of mine who agreed with you on the heater core being clogged. I am taking it to him and doing a system check to see if any codes come up.
As far as the blower motors goes, it was on auto set at 72. I will do just that tonight and see if it goes off again.
Again, thank you for your quick response. The car currently has a few ticks over 93,800miles and from what I know has never had a coolant system service performed. I contacted a friend of mine who agreed with you on the heater core being clogged. I am taking it to him and doing a system check to see if any codes come up.
As far as the blower motors goes, it was on auto set at 72. I will do just that tonight and see if it goes off again.
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Not necessarily the heater core. It could be you got air in the coolant line somewhere. I had the same problem after I had the rear coolant flange replaced. It'll be even worse for the belt job as they have to drain the coolant completely.
The tech just revved the engine and flexed the coolant pipe at the front of the engine by hand and about 10 minutes later it started blowing hot. I had air coming out of the system for about a week afterwards. Had to keep topping up. But it's fine now.
The tech just revved the engine and flexed the coolant pipe at the front of the engine by hand and about 10 minutes later it started blowing hot. I had air coming out of the system for about a week afterwards. Had to keep topping up. But it's fine now.
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It is the heater core. We are going to drain the coolant and fill it with CLR, run it for a bit, and see if that unclogs anything. I have heard of this a few times and look forward to seeing what happens.
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Thread Starter
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It worked!!! I have heat once again! They drained my coolant completely, replaced it with the CLR, ran the car for a while, drained the CLR and put an airline down the reservoir to blow out the rest of the rust. I can't believe it. What would have been a $1,400 fix turned out to be a $200 fix!
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