unsmooth idle after cooling system recall work.
08-15-15, 07:36 PM
#46
Lexus Fanatic
Thread Starter
Would getting the car INSANELY hot at a race track increase the pressure. I noticed for 3 days after they topped her off the engine was idling smooth. Flogged the car at the track this morning and it did it for a few minutes and stopped and is idling normal again. I will keep an eye on it.
Thanks again for your time and input
Thanks again for your time and input
08-16-15, 12:01 AM
#47
Tech Info Resource
iTrader: (2)
The A/C is a lot more complex than most techs realize. The compressor has a variable displacement unlike the vast majority of systems out there, so the pressure in the system will be equally variable depending on a whole lot of conditions. We talked about this years ago ('06 if I remember right) when we first got these new compressors. I had to do a whole lot of reading to understand what goes on with it.
Unlike classic systems, this one moves only the amount of refrigerant it needs to move based on operation algorithms Denso figured out more than 10 years ago. All refrigeration systems work on some fundamental gas properties, and Denso designed a system capable of running without a clutch cycling on and off to start and stop a fixed heat transfer activity. So, it is more efficient, and unlike the A/C in your home, the thermostat is not a simple temperature controlled switch.
Is it possible the charge was low? Sure. Every system leaks some amount of refrigerant even when all the seals are working as designed. I have a leak detector, and every time I remove the plastic caps, it detects leaking refrigerant from the connections for servicing the system. I added refrigerant to mine this year because the indications on my gauges (which I calibrated minutes before) were not where they should be according to the Factory Service Manual. Despite being low, the system's performance was still good, more than likely because of the magic compressor Denso made to deal with the available charge.
Yes, it is possible the system pressures fell outside normal and the system forced idle changes while at the track, but it isn't because you were at the track, it's because the radiator was not allowing enough heat to be released from the condenser which sits directly in front of the radiator.
Keep in mind, ALL refrigerant systems can only move heat from one place to another. In our cars, they extract heat from the cabin and release it in front of the radiator. If the condenser is unable to release the heat effectively, performance will suffer, and you will see unusual operating conditions which may compromise performance or may cause the engine management to behave differently than normal.
Again, this system is not like anything most techs have worked on, so it doesn't surprise me they are having problems with diagnosis despite Toyota using this technology for quite some time. FWIW, the compressor is a Denso 7SEH17C and you can get one for about
Unlike classic systems, this one moves only the amount of refrigerant it needs to move based on operation algorithms Denso figured out more than 10 years ago. All refrigeration systems work on some fundamental gas properties, and Denso designed a system capable of running without a clutch cycling on and off to start and stop a fixed heat transfer activity. So, it is more efficient, and unlike the A/C in your home, the thermostat is not a simple temperature controlled switch.
Is it possible the charge was low? Sure. Every system leaks some amount of refrigerant even when all the seals are working as designed. I have a leak detector, and every time I remove the plastic caps, it detects leaking refrigerant from the connections for servicing the system. I added refrigerant to mine this year because the indications on my gauges (which I calibrated minutes before) were not where they should be according to the Factory Service Manual. Despite being low, the system's performance was still good, more than likely because of the magic compressor Denso made to deal with the available charge.
Yes, it is possible the system pressures fell outside normal and the system forced idle changes while at the track, but it isn't because you were at the track, it's because the radiator was not allowing enough heat to be released from the condenser which sits directly in front of the radiator.
Keep in mind, ALL refrigerant systems can only move heat from one place to another. In our cars, they extract heat from the cabin and release it in front of the radiator. If the condenser is unable to release the heat effectively, performance will suffer, and you will see unusual operating conditions which may compromise performance or may cause the engine management to behave differently than normal.
Again, this system is not like anything most techs have worked on, so it doesn't surprise me they are having problems with diagnosis despite Toyota using this technology for quite some time. FWIW, the compressor is a Denso 7SEH17C and you can get one for about
Last edited by lobuxracer; 08-16-15 at 12:37 AM.
08-16-15, 06:19 PM
#48
Lexus Fanatic
Thread Starter
unsmooth idle after cooling system recall work.
Originally Posted by lobuxracer
The A/C is a lot more complex than most techs realize. The compressor has a variable displacement unlike the vast majority of systems out there, so the pressure in the system will be equally variable depending on a whole lot of conditions. We talked about this years ago ('06 if I remember right) when we first got these new compressors. I had to do a whole lot of reading to understand what goes on with it.
Unlike classic systems, this one moves only the amount of refrigerant it needs to move based on operation algorithms Denso figured out more than 10 years ago. All refrigeration systems work on some fundamental gas properties, and Denso designed a system capable of running without a clutch cycling on and off to start and stop a fixed heat transfer activity. So, it is more efficient, and unlike the A/C in your home, the thermostat is not a simple temperature controlled switch.
Is it possible the charge was low? Sure. Every system leaks some amount of refrigerant even when all the seals are working as designed. I have a leak detector, and every time I remove the plastic caps, it detects leaking refrigerant from the connections for servicing the system. I added refrigerant to mine this year because the indications on my gauges (which I calibrated minutes before) were not where they should be according to the Factory Service Manual. Despite being low, the system's performance was still good, more than likely because of the magic compressor Denso made to deal with the available charge.
Yes, it is possible the system pressures fell outside normal and the system forced idle changes while at the track, but it isn't because you were at the track, it's because the radiator was not allowing enough heat to be released from the condenser which sits directly in front of the radiator.
Keep in mind, ALL refrigerant systems can only move heat from one place to another. In our cars, they extract heat from the cabin and release it in front of the radiator. If the condenser is unable to release the heat effectively, performance will suffer, and you will see unusual operating conditions which may compromise performance or may cause the engine management to behave differently than normal.
Again, this system is not like anything most techs have worked on, so it doesn't surprise me they are having problems with diagnosis despite Toyota using this technology for quite some time. FWIW, the compressor is a Denso 7SEH17C and you can get one for about
Unlike classic systems, this one moves only the amount of refrigerant it needs to move based on operation algorithms Denso figured out more than 10 years ago. All refrigeration systems work on some fundamental gas properties, and Denso designed a system capable of running without a clutch cycling on and off to start and stop a fixed heat transfer activity. So, it is more efficient, and unlike the A/C in your home, the thermostat is not a simple temperature controlled switch.
Is it possible the charge was low? Sure. Every system leaks some amount of refrigerant even when all the seals are working as designed. I have a leak detector, and every time I remove the plastic caps, it detects leaking refrigerant from the connections for servicing the system. I added refrigerant to mine this year because the indications on my gauges (which I calibrated minutes before) were not where they should be according to the Factory Service Manual. Despite being low, the system's performance was still good, more than likely because of the magic compressor Denso made to deal with the available charge.
Yes, it is possible the system pressures fell outside normal and the system forced idle changes while at the track, but it isn't because you were at the track, it's because the radiator was not allowing enough heat to be released from the condenser which sits directly in front of the radiator.
Keep in mind, ALL refrigerant systems can only move heat from one place to another. In our cars, they extract heat from the cabin and release it in front of the radiator. If the condenser is unable to release the heat effectively, performance will suffer, and you will see unusual operating conditions which may compromise performance or may cause the engine management to behave differently than normal.
Again, this system is not like anything most techs have worked on, so it doesn't surprise me they are having problems with diagnosis despite Toyota using this technology for quite some time. FWIW, the compressor is a Denso 7SEH17C and you can get one for about
08-17-15, 06:33 AM
#49
OP, sorry you're going through all this! If it makes you feel better the mechanics down in Miami are no better. Lately, I felt like the service at Lexus has been such a downer. They design nice cars but they cheap out to pay to have the proper mechanics to work on their own cars. Like you said, it's the blind leading the blind. I have a CPO and you would think I would get better assistance? But I bet once the warranty runs out on our cars, the list of discrepancies would roll out from the mechanics!
08-17-15, 12:39 PM
#50
Lexus Fanatic
Thread Starter
OP, sorry you're going through all this! If it makes you feel better the mechanics down in Miami are no better. Lately, I felt like the service at Lexus has been such a downer. They design nice cars but they cheap out to pay to have the proper mechanics to work on their own cars. Like you said, it's the blind leading the blind. I have a CPO and you would think I would get better assistance? But I bet once the warranty runs out on our cars, the list of discrepancies would roll out from the mechanics!
What is even more insane is that these clowns probably fixed it by recharging the system and didnt even realize it was idling stable.
The current dealership I go to sucks quite frankly. I only go there because it so much closer than the next alternative and its right down the street from the office. Other than oil and very basic service I get nervous taking her in. The keep asking me if I want the ELF recall and I keep saying HELL NO !!!
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