The great not getting to and or not staying at 90 saga for the 1.4 tdi

audifan

A2OC Donor
Well my climate 1.4 tdi has GENUINE Audi thermostat and coolant temp sensor. It does get to 90 but this time of year takes about 15-20 minutes of driving and it does drop back when less engine heat is available. This is I believe perfectly normal as the thermostat STARTS to open at 87 which is near enough the gauge 90. When the engine cools it is obvious only a small drop in temperature will start to close the thermostat and it will be completely closed again at 87. Once the thermostat is closed the radiator will quickly cool down and next to no heat will be available for the cabin heater if required. Audi must has spent considerable time and money when developing the cooling system so doubt much can be done to improve it.
I do not think permanently blocking the air path to the radiator would be beneficial. I do not think a differently rated thermostat would help either. I have said before it would be nice if the Webasto or electric PTC heater could be modified to operate to provide heat in these circumstances.
Perhaps someone can develop a water jacket that fits onto a section of the hotter parts of the exhaust and into or around part of the cooling circuit without being over complicated and failsafe in operation in a similar way the water cooled egr valve works on the BHC and ATL. Certainly less of those owners experience the cooling down and slower warm ups the AMF experiences.
Your thoughts please....
 
"Once the thermostat is closed the radiator will quickly cool down and next to no heat will be available for the cabin heater if required."

Hm, i admit I do not own a 1.4TDI myself but I think the radiator is in the thermostat controlled outer circuit while the cabin heater matrix is in the inner, always flowing, circuit.
 
Not sure there is a solution, but I have ideas...

Modern cars have motorised venetian blinds to allow fast heat up.
Cold countries have electric coolant preheaters, that sounds good
Modification to webasto settings to kick in when below 12 degrees instead of 7?

Best thing is to the more people know its okay the better.
 
Occasionally on fitting a thermostat the o ring can not quite sit right causing very slow warm up but that probably isn't the case here as I agree 15 - 20 minutes of driving to get to 90 in the winter is pretty normal. I do indeed use a carefully shaped bit of 4mm ply to block off air flow in the winter. I'm aware that if the thermostat is working then no heat is getting to the radiator during warm up anyway but it also reduces the cold air flow through the engine bay. I think it makes warm up a few minutes quicker. Just have to remember to remove it before I want to use the A/C.
 
The style of driving you’re doing whilst the engine is warming must have a big effect, as mine is warmed through within 10-15 mins, but the first few minutes of that time I’m going up hills ranging to very steep at first (2nd gear with 5-7 bar of boost) to moderate (3rd / 4th gear with 4 - 5 bar of boost).
 
The style of driving you’re doing whilst the engine is warming must have a big effect, as mine is warmed through within 10-15 mins, but the first few minutes of that time I’m going up hills ranging to very steep at first (2nd gear with 5-7 bar of boost) to moderate (3rd / 4th gear with 4 - 5 bar of boost).
Off topic and purely out of curiosity, do you have an aftermarket tool for measuring boost whilst you drive? Always thought a turbo gauge on an A2 would be quite nice.
 
Off topic and purely out of curiosity, do you have an aftermarket tool for measuring boost whilst you drive? Always thought a turbo gauge on an A2 would be quite nice.
VCDS or Colour DIS are your friend here. The latter is obviously more convenient for every day use!
 
You can also bluetooth OBD adapters and phone apps such as Torque Lite or Car Scanner to display the turbo boost which can be a cheaper alternative also useful for reading EML codes
 
Well my climate 1.4 tdi has GENUINE Audi thermostat and coolant temp sensor. It does get to 90 but this time of year takes about 15-20 minutes of driving and it does drop back when less engine heat is available. This is I believe perfectly normal as the thermostat STARTS to open at 87 which is near enough the gauge 90. When the engine cools it is obvious only a small drop in temperature will start to close the thermostat and it will be completely closed again at 87. Once the thermostat is closed the radiator will quickly cool down and next to no heat will be available for the cabin heater if required. Audi must has spent considerable time and money when developing the cooling system so doubt much can be done to improve it.
I do not think permanently blocking the air path to the radiator would be beneficial. I do not think a differently rated thermostat would help either. I have said before it would be nice if the Webasto or electric PTC heater could be modified to operate to provide heat in these circumstances.
Perhaps someone can develop a water jacket that fits onto a section of the hotter parts of the exhaust and into or around part of the cooling circuit without being over complicated and failsafe in operation in a similar way the water cooled egr valve works on the BHC and ATL. Certainly less of those owners experience the cooling down and slower warm ups the AMF experiences.
Your thoughts please....
I have TDI 90 and experience the same issues especially on the colder mornings. I tend to leave the climate control switched off until it hits 90. Once there if you maintain a constant speed it doesn't drop, however if you experience downhill journeys on low revs the temperature will drop. I believe the stat and sender are both working ok and has been the same since I owned the car. The previous owner rebuilt the top end and also changed the stat and sender as well as an EGR delete so I am not sure if this has an impact on engine temperature.
 
"Once the thermostat is closed the radiator will quickly cool down and next to no heat will be available for the cabin heater if required."

Hm, i admit I do not own a 1.4TDI myself but I think the radiator is in the thermostat controlled outer circuit while the cabin heater matrix is in the inner, always flowing, circuit.
I believe this to be the case too. I've not checked my TDi but certainly my Golf measures the temperature in the inner always flowing circuit. If that temperature is dropping below 90 due insufficient engine activity then the engine is running cool and there is less heat available to the cabin heater. Running the cabin heater will cool the engine further.
The only cure I've found for my TDi is to drive it enthusiastically, the engine stays hot, the cabin is heated and I also assume the thermostat is open.
 
The style of driving you’re doing whilst the engine is warming must have a big effect, as mine is warmed through within 10-15 mins, but the first few minutes of that time I’m going up hills ranging to very steep at first (2nd gear with 5-7 bar of boost) to moderate (3rd / 4th gear with 4 - 5 bar of boost).
That pressure is very high, I assume you mean psi?
 
Off topic and purely out of curiosity, do you have an aftermarket tool for measuring boost whilst you drive? Always thought a turbo gauge on an A2 would be quite nice.
I have colour DIS and it has the functionality to have turbo boost visible all the time.
 
"Once the thermostat is closed the radiator will quickly cool down and next to no heat will be available for the cabin heater if required."

Hm, i admit I do not own a 1.4TDI myself but I think the radiator is in the thermostat controlled outer circuit while the cabin heater matrix is in the inner, always flowing, circuit.
That is absolutely correct
 
Well my climate 1.4 tdi has GENUINE Audi thermostat and coolant temp sensor. It does get to 90 but this time of year takes about 15-20 minutes of driving and it does drop back when less engine heat is available. This is I believe perfectly normal as the thermostat STARTS to open at 87 which is near enough the gauge 90. When the engine cools it is obvious only a small drop in temperature will start to close the thermostat and it will be completely closed again at 87. Once the thermostat is closed the radiator will quickly cool down and next to no heat will be available for the cabin heater if required. Audi must has spent considerable time and money when developing the cooling system so doubt much can be done to improve it.
I do not think permanently blocking the air path to the radiator would be beneficial. I do not think a differently rated thermostat would help either. I have said before it would be nice if the Webasto or electric PTC heater could be modified to operate to provide heat in these circumstances.
Perhaps someone can develop a water jacket that fits onto a section of the hotter parts of the exhaust and into or around part of the cooling circuit without being over complicated and failsafe in operation in a similar way the water cooled egr valve works on the BHC and ATL. Certainly less of those owners experience the cooling down and slower warm ups the AMF experiences.
Your thoughts please....
The webasto range can be changed to run when the temp is higher that 7C, talk to @timmus
 
Does your car have the undertray and the sound deadening over the top of the engine. If they are in place and it’s a good working OEM stat then it is really worth trying a blank on half of the rad.
 
Not sure there is a solution, but I have ideas...

Modern cars have motorised venetian blinds to allow fast heat up.
Cold countries have electric coolant preheaters, that sounds good
Modification to webasto settings to kick in when below 12 degrees instead of 7?

Best thing is to the more people know its okay the better.
I like the idea of a motorised Venetian blind Edd, what cars have you seen this on.
My 3L A6 Allroad heats up in 1/3 of the time of an A2, I wonder what is so different in the cooling system?
 
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