Radiator replacement and flushing.
- Thread starter Bluesplit
- Start date
cheechy
A2OC Donor
Ok so beginning to think the clowns (aka mechanic) that made so many mistakes on my car have made another i haven't spotted until now.
Should I be seeing a green sensor from the bottom ... this is the pipe that links with the thermostat. I'm thinking it should be blue?
Should I be seeing a green sensor from the bottom ... this is the pipe that links with the thermostat. I'm thinking it should be blue?
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Cheechy,
Forgive my amnesia - is yours a 1.4i or a 1.4tdi?
Just to clarify my understanding at this end as I'm having difficulties working out the orientation of the photo. The parts diagrams also confound the issue because it looks like there are a couple of competing layouts of pipework and temp sensors at various build dates for the AUA/BBY and these differ again from the Tdis.
On the Tdi, the green sensor (two channel coolant temp sensor) is the one around the back of the right hand end of the block as you look at it standing in front of the car number plate (once you've taken off a few bits to gain access). I think I've read somewhere that early ones may have been black.
The Tdi thermostat is on the front of the block immediately behind the alternator - see diagram.
(https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121010/). There is a sensor in the pipe right by the radiator that leads to the thermostat housing in AMF and BHC engines that is the "dual thermo switch" that activates the radiator fan, and if I'm not mistaken, this is blue (same part number as the blue one I did on our AUA 1.4i).
On the 1.4i, the thermostat and green sensor are in the same multiple pipework assembly up between the engine block and the expansion vessel, and should be next to each other. This doesn't sound like what you are describing.
What I can say having done both the blue one (by the radiator) in the AUA and the green one around the back of our BHC (https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121038/ part 21) is that they do seem to be the same standard size and use the same clip type, so it is conceivable that the other green sensor could fit in this location and could have been put in in error. Can't remember if they have the same connector type though. On this next diagram it fits into the mounting collar of the end of part 8 where it fits to the radiator (only in cars after a certain build date). However - be very cautious at this point. On the same diagram, go down to part 23 (retaining spring clip) - and the optional part directly after : this is the same dual temperature sensor part code that is optionally plumbed in next to the radiator but in some layouts is plugged into the thermostat housing. As I said - on our AUA this was blue by the radiator and I think there is a green one higher up by the thermostat housing.
AUA https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121030/
BHC https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121038/
in the latter diagram it is part 4, corresponds exactly to the same component in the AUA diagram.
So - in short - is it the sensor by the radiator outlet you are talking about that is green?
Forgive my amnesia - is yours a 1.4i or a 1.4tdi?
Just to clarify my understanding at this end as I'm having difficulties working out the orientation of the photo. The parts diagrams also confound the issue because it looks like there are a couple of competing layouts of pipework and temp sensors at various build dates for the AUA/BBY and these differ again from the Tdis.
On the Tdi, the green sensor (two channel coolant temp sensor) is the one around the back of the right hand end of the block as you look at it standing in front of the car number plate (once you've taken off a few bits to gain access). I think I've read somewhere that early ones may have been black.
The Tdi thermostat is on the front of the block immediately behind the alternator - see diagram.
(https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121010/). There is a sensor in the pipe right by the radiator that leads to the thermostat housing in AMF and BHC engines that is the "dual thermo switch" that activates the radiator fan, and if I'm not mistaken, this is blue (same part number as the blue one I did on our AUA 1.4i).
On the 1.4i, the thermostat and green sensor are in the same multiple pipework assembly up between the engine block and the expansion vessel, and should be next to each other. This doesn't sound like what you are describing.
What I can say having done both the blue one (by the radiator) in the AUA and the green one around the back of our BHC (https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121038/ part 21) is that they do seem to be the same standard size and use the same clip type, so it is conceivable that the other green sensor could fit in this location and could have been put in in error. Can't remember if they have the same connector type though. On this next diagram it fits into the mounting collar of the end of part 8 where it fits to the radiator (only in cars after a certain build date). However - be very cautious at this point. On the same diagram, go down to part 23 (retaining spring clip) - and the optional part directly after : this is the same dual temperature sensor part code that is optionally plumbed in next to the radiator but in some layouts is plugged into the thermostat housing. As I said - on our AUA this was blue by the radiator and I think there is a green one higher up by the thermostat housing.
AUA https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121030/
BHC https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/121-121038/
in the latter diagram it is part 4, corresponds exactly to the same component in the AUA diagram.
So - in short - is it the sensor by the radiator outlet you are talking about that is green?
cheechy
A2OC Donor
Yup... I had an old blue sensor that I bought I think from Steve last year as part of the thermostat pipe assembly. That both clarified to what should have been in there (fan motor sensor) plus the fact that the worst and most dishonest of mechanics from carnoustie had fitted the supplied green sensor into this on the basis that " it fitted "
Thankfully they are now gone as the owner passed away but for the record monifieth motors was the company in question....
For info I've an atl
Thankfully they are now gone as the owner passed away but for the record monifieth motors was the company in question....
For info I've an atl
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Mine now appears fixed with new green and old crummy (but looks to be working) blue sensor near the radiator pipe bottom outlet. 90 degrees within 5 mins odd driving which I have never had in 18 months of owning the car.
Good luck bluespit if I can fix then you'll manage
Thanks cheeky, have you changed both thermostat & green sensor?
audifan
A2OC Donor
Do not just rely on the gauge. There are 2 channels in the temp sensor ( green ) one for ECU other for dash gauge. Always have a scan done to verify the sensor as it could be reading low on both channels indicating the thermostat is at fault. TBH if you are in doubt or, as you will be disturbing the coolant system I would change BOTH the thermostat and the temp sensor together. Bit more cost LOT more reassurance.
Right got all the parts ready and waiting, before I go and buy a radiator is there anyway if I jack the car up I can see the bottom/back if the radiator, see below pick taken from underneath the front bumper . My leak is getting a lot worse and I can see the area in the bottom left of the rad where the leak is coming from. I need to know if it’s from pipe or the actual road itself, may aswell do it all as a job lot!
And finally my car has been left standing for 12 hours but when I undid the coolant cap the pressure blew coolant out of the gas release hole, should I have this much pressure from a cold engine?
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And finally my car has been left standing for 12 hours but when I undid the coolant cap the pressure blew coolant out of the gas release hole, should I have this much pressure from a cold engine?