Does Bentley wiring diagram show wiring going through the binnacle?
Mike’s Retrofit Aircon Cruise Heated Seats ++
- Thread starter MickyG
- Start date
So near, yet so far.......
Well, it's all in. I still need to add three terminals to the engine ECU plug to power the compressor relay, take a signal from the AC switch and pressure switch but, with it all in, time for some R134a, eh?
It held a vacuum as it should and took 826g plus some oil like a champ. For now just to test it I could power the compressor straight from battery + and whilst it worked and blew cold air the compressor sounded bloody awful. Not just that but the power required pretty much stalled the engine and the smaller diameter AC pipe got very, very hot. That's some serious pressure and the best guesses all round point to the expansion valve. So, I have a new one on order. The AC was vacuumed out again and the saga continues.
I had a 318i E36 in this week for a head gasket and once it was all done, I powered the compressor from battery + to make sure it should still temporarily run without the pressure switch and it worked fine. I have a spare compressor as well so with fit that before a second regas.
Well, it's all in. I still need to add three terminals to the engine ECU plug to power the compressor relay, take a signal from the AC switch and pressure switch but, with it all in, time for some R134a, eh?
It held a vacuum as it should and took 826g plus some oil like a champ. For now just to test it I could power the compressor straight from battery + and whilst it worked and blew cold air the compressor sounded bloody awful. Not just that but the power required pretty much stalled the engine and the smaller diameter AC pipe got very, very hot. That's some serious pressure and the best guesses all round point to the expansion valve. So, I have a new one on order. The AC was vacuumed out again and the saga continues.
I had a 318i E36 in this week for a head gasket and once it was all done, I powered the compressor from battery + to make sure it should still temporarily run without the pressure switch and it worked fine. I have a spare compressor as well so with fit that before a second regas.
Attachments
- Joined
- Dec 26, 2016
- Points
- 144
- Location
- Spaldingski, Lincs
- Model of Z
- 3 litre Z3 pretending to be Italian exotica. Two previous E89 Z4s.
If your expansion valve is faulty it will do one of two things:
Either it will be stuck open and will 'flood' the evaporator causing liquid to return down the suction line (return to compressor), or 'starve' the evaporator which will result in high return line temperatures.
If it is flooding; the suction line will show frost (or at least lots of condensation). If there is liquid reaching the compressor on the suction the compressor will frost (or heavy condensation) and would be the reason for the noisy compressor. If it is that; it will destroy the compressor very quickly, as liquid can't be compressed and will cause hydraulicing which will destroy the valves and then the pistons.
If the EV is starving the evaporator it will not cool well and the suction line temperatures will be warm (or even hot).
Neither of the two scenarios above should cause excessive heat on the 'high' side of the system (the discharge and liquid lines), unless the compressor is getting very hot (from the starvation scenario) and transferring that heat into the high side lines. But that wouldn't result in a noisy compressor.
I would get someone who knows what they are doing (not a garage; a refrigeration engineer) to put a set of gauges on and diagnose it properly. From here, with the information given, I would look at a potential faulty compressor first, not the EV.
The small bore pipe was very hot and there was smoke coming up from the compressor area. It’s likely to be shagged. I have another one coming and I’ll replace the EV anyway as it’s only £30. I just want to do this job once.
- Joined
- Dec 26, 2016
- Points
- 144
- Location
- Spaldingski, Lincs
- Model of Z
- 3 litre Z3 pretending to be Italian exotica. Two previous E89 Z4s.
It would be worth doing a test on the oil in the system too. If the temps get too high inside the system, the refrigerant oil can burn which will make it acidic and will destroy any new parts you fit. Acidic oil is extremely difficult to remove.
New Thermotec compressor fitted plus what seems to have been the faulty part, the expansion valve. With oil and 825g of gas added, it fired up and blows cold with no nasty noises. The old compressor was clean inside and was probably okay but for £150, a new one was the best idea. A Valeo expansion valve was £26 from Autodoc.