Audi A6 Heater Blowin Not Very Warm

[Rob Steele]

A6 1997 P REG
Bought the car in the summer when ididnt realy notice if it worked or not
It does blow warm after awhile but not warm enough for thistime of year :confused:
Could it be poss thermostate prob or blocked rediator hose??
Checked colant level , ok , did seem slightly rusty/dirty though.
Any ideas ?????

[Crasher]

Hello and welcome. Is this a diesel?

[Rob Steele]

Alright there Crasher its Petrol

[Crasher]

I would suggest a coolant flush first but blocked matrix's and weak water pump delivery are common problems.

[dean warren]

I have a 94 A6 TDi AAT with very little heat, i have back flushed the matrix which appears clear all that came out were a few bits of what appear to be lime scale, i have also noiced that with the engine running there is not much water being pumped, and it appears in squirts not a smooth flow of water, i have ordered and am awaiting the new water pump and will report what difference it makes.
Rgds Dean Warren

[Crasher]

If the matrix is blocked it is virtually impossible to clear it due to the vertical core design.

[dean warren]

My Heater was working fine, however i put some bio Diesel in from a Place outside Colchester In Essexs, the car started missfiring within minutes, on the drive back to the west midlands i noticed the heat just drop off, i've cured the missfire, injector with needle lift sensor has been replaced, but the heater never picked up again. Any idea's?

[dean warren]

If the matrix is blocked it is virtually impossible to clear it due to the vertical core design.
what blocks it? has anyone tried that lime scale remover that you put into kettles?
you'd just need to boil a kettle, put some pipe onto the matrix flanges and fill it with the boiling solution.
i may give it a go the weekend, unless anyone knows of a reason not to, of course i'll check the packaging to check it wont harm the matrix, they are alloy aren't they?

[Crasher]

The trouble is the design of the matrix, its "U" tubes are fed from above and the fine debris (which is old G12 turned to powder, lime scale, rust etc) sits at the bottom of the tubes as silt. Lime scale remover isn't going to hep shift the silt as the matrix flows across the top of the tubes if the bottom of the "U" tube becomes blocked. I have tried everything I know to deal with this since it became a problem on the Golf 2 in the late 90's and a pressure wash, air line (150psi) and any chemical I have tied will not shift the silt. The only way to move it is to turn the matrix upside down so that means rolling the car over or removing the matrix. The former isn't practical and the second means you may as well fit a new one whilst it is out. This doesn’t happen on the Golf 1 as the matrix lies on its side so the silt never blocks the tubes. This is a problem on the Golf 2, 3, Corrado, Passat (88 onwards) Audi 80 (87 on), A4, A6 etc etc…

[dean warren]

any chemical I have tied will not shift the silt.
Have you tried Cilit Bang? lol

[Crasher]

You know his real name isn't Barry Scott don't you? Any man who lies about his name is not worthy of trust over his cleaning products.

[dean warren]

still not changed my matrix, but i have fitted a new set of injector nozzles, and wow what a difference its made! also i have heat back but only if i don't go above speed two on the blower, guess this points firmly at the matrix partially blocked??