ac problem on 07...

[tacoduck]

Im having an frustrating issue on my 07. truck sometimes blows cold from ac, but other times blows hot. dealer said it was prob low on freon and said he would recharge. today I met with the mechanic who did the work (had small cooling system leak) and we tried to problem solve the AC

Compressor is working...

freon is flowing clean and clear in the window...

condensor is hot to touch on the top, but cool towards the bottom...

double checked for AC leaks, and none are present.

AC line from condenser to truck is cool to the touch, but not cold. (mechanic said it should be sweating and ice cold)

condenser is burping water at bottom of engine bay...

This is my wife's truck, and she aint happy driving around in a hot truck. Im pissed because I was told it was fixed.

Im wondering if I need a new compressor, or if I need a new condenser and radiator? HELP!!!

 

[tacoduck]

PO took it to lexus in june of 2016 with AC complaints. this was at 255k miles on it. truck is now at 261k.

 

[nissanh]

If the high side is very hot then your compressor is working.
The condenser is doing its job right according to your description.

Have you checked the pressure with a regular DIY type pressure gauge? The filter glass can be clear if there is not enough gas as well. Check the pressure and add gas if needed. This will be my starting point.

 

[tacoduck]

The glass is clear and I see bubbles. I think I'm good on gas. Im going to try cleaning the condenser fins. couple how to's on youtube. This is theory should drop my high side pressure and allow the condenser to work more efficiently. if it doesn't work, I'm out 10 bucks and 30 minutes ofmy time...

 

[DirtDawg]

Have you checked your blend door?

 

[tacoduck]

nope. where is that?

 

[PADDO]

The glass is clear and I see bubbles. I think I'm good on gas. Im going to try cleaning the condenser fins. couple how to's on youtube. This is theory should drop my high side pressure and allow the condenser to work more efficiently. if it doesn't work, I'm out 10 bucks and 30 minutes ofmy time...

You should only see bubbles when testing the system (AC on max cool, fan on on high, doors open, engine @1500rpm, ambient 85-95F) if the outside air temp is very hot as per the FSM diagnostics. The dealer's repair notes say the system was blowing air at 38F after an evac and recharge so you'd have to rule out a slow leak in a line or shraeder by doing/having pressures checked again. You can put the AC system in diagnostics too and get it to cycle through its sensors and servo valves to check the mixer servo (blend door). Have you checked the cabin sensor (the one behind the cowl grill adjacent to drivers right knee) to make sure it's free of fluff and dust and it's air tube is connected? The system will store DTCs that might reveal something, check by pushing in AC AUTO and RECIRC buttons and turn ignition ON. Any stored codes will be displayed in the clock display. When it's done cycling through the sensors push just the RECIRC button again to get it to do the servo actuator test.

 

[DirtDawg]

nope. where is that?

Haven't messed with it on the LC/LX because i haven't had to yet, but it's going to be back behind your dash by the blower box, not exactly sure where.

Anyway the blend door is what controls your heat range. It's where the air from the heater core and the air from the AC meets and the door controls how much of each is used. I've had issues with motor driven units like ours before. Just an idea.

 

[tacoduck]

You should only see bubbles when testing the system (AC on max cool, fan on on high, doors open, engine @1500rpm, ambient 85-95F) if the outside air temp is very hot as per the FSM diagnostics. The dealer's repair notes say the system was blowing air at 38F after an evac and recharge so you'd have to rule out a slow leak in a line or shraeder by doing/having pressures checked again. You can put the AC system in diagnostics too and get it to cycle through its sensors and servo valves to check the mixer servo (blend door). Have you checked the cabin sensor (the one behind the cowl grill adjacent to drivers right knee) to make sure it's free of fluff and dust and it's air tube is connected? The system will store DTCs that might reveal something, check by pushing in AC AUTO and RECIRC buttons and turn ignition ON. Any stored codes will be displayed in the clock display. When it's done cycling through the sensors push just the RECIRC button again to get it to do the servo actuator test.

I tried holding down the climate and Recirc button and it didn't jump to the diagnostic screen. I looked at 5 of these 05-07 trucks and every one had an issue with the AC. there has to be something going on here. My 01 LC blows ICE COLD... I live in the south, dammit! I need cold AC!

 

[PADDO]

Hold in AUTO (not the CLIMATE button) and the RECIRC buttons and turn IG on - it should enter diagnostic mode and flash any DTCs.

 

[tacoduck]

update... put a half can of freon in the low side. instant ac. then I saw a funny thing. the engine lugged a bit, the low side pressure went up, and then the compressor stopped spinning. truck goes back to normal RPM. 30 seconds later the same thing happens. I wonder if I overfilled the low side, or if the compressor clutch is bad.

Either way, Im pretty sure I have a r34 leak somewhere on the truck...

 

[Ninja Cruiser100]

update... put a half can of freon in the low side. instant ac. then I saw a funny thing. the engine lugged a bit, the low side pressure went up, and then the compressor stopped spinning. truck goes back to normal RPM. 30 seconds later the same thing happens. I wonder if I overfilled the low side, or if the compressor clutch is bad.

Either way, Im pretty sure I have a r34 leak somewhere on the truck...

You put in half a can...what was the low side pressure? High side pressure?

 

[tacoduck]

I set it to the outside temp and then added gas. never looked at high side pressure.

 

[PADDO]

Those gauges that come on the can will cause you more trouble then they are worth. From experience its just far to easy to overfill when you don't have L and H pressures simultaneously.

 

[tacoduck]

Those gauges that come on the can will cause you more trouble then they are worth. From experience its just far to easy to overfill when you don't have L and H pressures simultaneously.

Yeah, I need to take it to my mechanic and make sure the pressures are right.

 

[CanadianRockyCruiser]

Could be the wrong type of coolant: Use R134A and do not use R12. Lots of hack-job mechanics will use R12, because it is easily available for the home mechanic. Take it to a pro shop that uses R134A, and I'll bet you'll be the coolest kid on the block.

 

[tacoduck]

the lexus dealer serviced it 3 months ago and refilled with coolant. I have bigger problems...

 

[tacoduck]

here is a link to what the compressor is doing. Thanks guys for you help!!!

IMG_5576.MOV

 

[nissanh]

Your AC system is without freon. After half can recharge the compressor comes on when the temp goes above the set level, and stops when it reach the set temp. Try keeping the temp about 65 and see how long the compressor runs.

You said the low side pressure went up. This could be due to freon you added to the system. Probably you have a bigger leak somewhere.

Before adding the gas, did the AC compressor come on?

Do you know why and where the dealer services the AC system? The leak is probably there.

 

[tacoduck]

the mechanic said the high side tube is hot, which means its pressurized. the compressor is also dribbling coolant which the mechanic says means its "working".

do I need a black light to check for leaks? dealer added freon plus gas a couple of months ago. if its a rear leak, ill just cap the rear AC and move on down the road. Hard to test AC when the high in NC is 70 degrees w 0 humidity. Cant bitch too much about the weather...