Newbee with a problem. Please help. 1.9 tdi avf heater and coolant probs.

**Lee Arbuckle** · 30-03-2015,04:40 PM

Hi.
Just joined here and so far it's looking good. I have searched for my probs but can't find what I'm looking for.
Heres my issue.
I bought a 02 A4 b6 1.9 tdi 130bhp.
The night I bought it was -3 degrees so this fooled me.
The car took ages to heat up and wouldn't blow warm air. I told the seller and he put it down to the freezing conditions and revved the car and the heat came. So I thought fair enough and handed over the cash. On way home the heater wasn't great. Then the red coolant light came on dash. I pulled over and topped up approx half a litre. The next day there was no heat at all although temp hand was at 90. It would blow warm and cold with no apparent reason randomly the rest of the day. Then it started to overheat and pressurised when on the power when overtaking and going up steep hills. I put a new pump and thermostat in with new belt and coolant. Problem was still there. I ran a hose through radiator and all pipes and matrix thinking on a blockage but still no good. Took the thermostat out and it made no difference.
Im at a loss of what to do next. So is mechanic. It's not mixing oil and water. It's not circulating the water at all. The metal water pipe at right side of head will be roasting but gets cold from the small pipe that leads to expansion bottle. Radiator is only ever like warm. This was flushed. I've bleed it aswell but makes no difference.
Im thinking on removing the head and getting it pressure tested.
What else can it be?
Sorry if that's hard to read or a bit long winded.
Any help would be appreciated as I'm about to go mad.
Thanks
Lee

**arman123** · 30-03-2015,11:13 PM

Search online for heater core flush or heater matrix flush it could be blocked

**Lee Arbuckle** · 30-03-2015,11:46 PM

I have already did a full flush.

**Crasher** · 31-03-2015,01:08 AM

Complete waste of time and money, you need to fit a new heater matrix.

**Lee Arbuckle** · 31-03-2015,11:51 AM

If the matrix was faulty would it account for all my problems?

**Crasher** · 01-04-2015,12:39 AM

No, you would need a miracle for that!

**green A8** · 01-04-2015,08:37 AM

I think Lee meant his car's problems Crasher, but I digress

With regard to flushing the heater matrix I have to agree that the only way to cure this problem is to replace the matrix unit. It's not that hard to do on a B6. I've tried many times to flush out a blocked matrix core with no success whatsoever. Having chopped up a knackered A4 matrix I can understand why. The water is circulated through tiny pipes within the matrix and clog with all kind of junk. The unit I chopped up seemed to have had some kind of coolant system sealant which is what killed the heater matrix. Admittedly I was playing with a B5 A4, but I have changed a B6 matrix. The B6 is very similar except you don't need to remove the dash to get to the defunct heater matrix.

Regarding your problem as you've described it Lee I think you might either have an air lock in the cooling system, or be in need of a new head gasket. I wouldn't keep driving an overheating car if I were you. I think I'd be knocking on the door of the person who sold you the car and be asking for my money back.

One last question. I assume that you bought and fitted a genuine Audi thermostat? ebay items are well known for being cheap and are usually a complete waste of time, as they just don't fit/work.

**Lee Arbuckle** · 01-04-2015,06:15 PM

Thanks for the info green a8.
Im not driving it anymore. I've tried to go down the route of sending a letter as instructed by trading standards but he's has said he will not be offering any warranty as it was a trade sale. I want the car going so I can sell it coz I've lost heart in it then I'm gonna take him to small claims court for the total bill to fix.
The stat I got wasn't genuine but it fits and it works as I tested it first.
I may take head off and see how things look.
How much is a new matrix and where would I get one?

**green A8** · 02-04-2015,11:34 AM

I'd suggest that if you're going down the small claims route, that you make no further attempt to repair the car whatsoever. I'd be looking at getting an automotive engineer to examine and evaluate the car and produce a report based on his findings, to be presented at the court. This will sadly cost you cash Lee, and I suspect that the person who sold you the car is fully aware of that. In fact, he's probably banking on it.

He (the cars seller) will try to blame YOU for the cars problems. The old "It was purrfect when I sold it" type defence. You have to prove that it wasn't. Fixing the car defeats the object of going to small claims court, in my opinion.

**Crasher** · 02-04-2015,03:27 PM

On going back over your posts, you have a head gasket failure in addition to the likelihood of a blocked matrix. To be honest this car is breathing its last breaths. The costs of properly dealing with head gasket failure on a PD engine are so high it would easily reach the cars value if done professionally. If you want to pursue him for the repair costs, there is no way a small claims court will uphold YOUR case if you do the work and just go to court and say "I did this and that", without any professional engineers paperwork back up, you would lose. Was this a trader or private sale?