Thread: 300 Tdi Heater Fault

Is it connected or has it been bypassed?

Have a look at this thread: Heater core 1997 Disco.. DIY or Workshop ?

I'll have a look tonight Ron when I fet hime from work I thought there might be a tap or something ti turn on. PO had it all serviced before his caravanning holiday. Might be a cold winter driving to work :-o

Sent from my GT-I9505 using AULRO mobile app

I don't remember if mine had one (mine was a '95 Update).

However, the workshop manual indicates there is one:

Heater and ventilation operation
The heating and ventilation system contains a heater
matrix, which is connected to the engine cooling
system, and a 4 speed fan for air distribution. Engine
coolant is circulated through the heater matrix
continuously, except when the temperature controls
are set to COLD.

Heater emits cold air.
1. Engine running: Check coolant valve opens as a
temperature control is moved from COLD.

I have no idea where that valve is because I saw no sign of it when I did my heater. The coolant pipes connected directly to the heater core.



These drawings appear to show the V8:



Yours is a Tdi so the following won't apply:

V8 Engine: When both controls are in the cold
position, the coolant valve is turned off.

V8 Engine: When both controls are at COLD, 2
micro-switches are closed and operate a vacuum
valve which closes the coolant valve.

No tap on a disco, 1/3 is too cool . Sure the tstat is present and correct , has the heater been bypassed ?

Sent from my GT-I9300 using AULRO mobile app

Thanks everyone for the input. I'll have a closer look under the hood tomorrow and see what I can see, I'm not certain if it has a thermostat installed, but the engine warms up quickly in just a few minutes. The last car I had that had a faulty heater had no heater core at all! Really, who would check to see if it's there?


I'll need it sorted before winter for de-icing and demisting on my early drives to work.


Hopefully something simple.

Originally Posted by WillsTdi

G'day All,
98 300 Tdi. Heater doesn't get warm at all. Dials on dash make no difference. Fan and aircon work fine though. Is there something I've missed? Temp gauge sits at about 1/3 cheers Will.

Looking at your posts I see this is a recent purchase. Is there an opportunity to contact the previous owner? May be the quickest route to solving the issue.

Originally Posted by Discofever

Looking at your posts I see this is a recent purchase. Is there an opportunity to contact the previous owner? May be the quickest route to solving the issue.

Yep, did that and am waiting for a reply.

At my local mechanics. Heater bypassed. :-(. But that's the least of my problems.

Sent from my GT-I9505 using AULRO mobile app