SonnyD

First post, great board, hope you guys can help me out.

My wife called me a few hours ago and said the AC suddenly lost it's strength, that it wasn't blowing ice cold air as it normally does. She was waiting for my daughter and said the car was idling for approx 5-10min. It was about 80 degrees at the time here in Chicago. I asked her what the temperature gauge looked like and sure enough she said it was close to the red marker. At that point I told her to turn the AC off, shut the car down and check for any leaks or overheating coming from the engine compartment, of which there was none (besides the normal condensation/water from the AC). She waited approx 20mon, turned the car back on and drove immediately home with the temperature at it's normal halfway reading all the way home.

The car has 56k miles on it and of course it's out of warranty. I'm not very good at diagnosing car issues nor am I all that handy at fixing them. Ask me to hit a golf ball, play softball or do anything sports related and I can hold my own. Working on cars, not so much.

It's too late in the evening to do anything tonight, but first thing tomorrow morning what should I be looking for? What are some of the things that could be wrong with the car?

Thanks in advance for the help.

rcy

Seeing as the temperature went up while she was idling, but was fine while she was driving home (the vehicle was moving, thereby causing airflow over the radiator), I would suspect some sort of fan problem. You didn't say whether she drove home with the A/C on or off.

Turn the A/C on and check the two fans behind the rad. They should both come on when the A/C compressor is running. They should also come on without the A/C running when the coolant reaches a specific (hot) temperature and shut off after the temperature falls again to a specific level.

The fans could be completely pooched, it could be the fan relays. It could also be possible that the fans cycle on and off normally as the coolant temperature rises, but don't come on with the A/C. Again, some sort of relay or sensor problem. The other possiblity (I had this happen to me on a Nissan Maxima) is that one fan is working, and the other is not. You will need both running when the A/C in on to remove heat from the refrigerant via the condensor (the thinner rad in front of the main rad).

Anyway, that's would be my first guess - the fan(s) are not running right.

SonnyD

Thanks for the feedback, I'll check for that in the morning. BTW, she drove home (approx 20 min and about 15 miles) with the AC off.

salimshah

^ good advice..

This what i would do in the morning .. engine needs to cold so do it before you start the engine.

Check the level of coolant in the overflow reservoir and also take of the radiator cap and look in there to see the level. If low, you can add preferably distilled water to top. If too low then you may have a leak ... have the system pressure tested by a radiator shop or dealer.

Sonnyd is right as the next suspect will be the fan(s) and or blocked radiator. Blockage happens as the fins get clogged up and pressurized air can blow it out. A stuck thermostat can also be a problem and at times a weak (collapsing) radiator hose can give you trouble.

Tip: You can safely drive the vehicle to about 75% hot display. To help cool the engine, turn on the HEATER of the cabin.

Salim

MRKilroy

the 04 did have a TSB on the AC that needs a new wiring harness, but that was for the AC not blowing cold anymore after about 45 min of being on.

But I would agree that the cooling fan in the front isnt comming on.

tromly

Hope you solve your problem SonnyD, just stick with CL and we'll get you through it, the guys here really know their stuff!

SonnyD

Thanks guys for all your help!!

Well I got under the hood and the coolant level is way low, as in almost empty. Honestly it's been a while since I performed a visual to check the level, and there haven't been any signs of any leaks whatsoever.

Reading the manual, it appears I need "Toyota Super Long Life Coolant". Since the dealer will probably want an arm and a leg for this stuff, anyone know where I can get some of this stuff? Either locally here in Chicago or ordering online if need be?

The service log states to replace the engine coolant at 90k/72 months. I was always a little leery about waiting this long. Is that what most of you do or do you replace it sooner? I also read somewhere that simply draining the radiator and refilling (without a complete flush) is also a good option. Is this true and should I do that now and then simply refill?

Anyway, thanks again everyone for all your help.

Edit add: MRKilroy, I didn't realize there was a bulletin on the AC harness. Of course luck would have it now that it's out of warranty, I might actually need to replace it. Thus far though, the AC has been ice cold even after long, extended periods of driving. That is until last night, of course

tfischer

Something similar to me happened last year to my '04 RX. (Overheating while driving or even on idle, and then back to normal for a while.)
I thought the thermostat was at fault, but the service techs said that there was a leak in the radiator, so it was replaced. This was covered because the car was still under CPO warranty, but they said that there was a batch of bad radiators in some cars (I think there is a list of VIN numbers involved) and Lexus will replace these should a problem develop, regardless of warranty (the cost probably being paid by the radiator supplier). If that's a problem with your car, be sure to have the service dept. check out the radiator replacement issue.

salimshah

You do need to fill it up, but the question remains as to what happened to the coolant?

You can buy the coolant from Lexus or Toyota ... I would not buy over the counter equivalent.

My suggestion would be to buy couple of jugs of distilled water and top off for now and take it to Toyota/Lexus or a competent radiator shop to have the leak investigated and fixed. Then buy the expensive stuff and flush out the distilled water. [this the shop can do for you when they are done with repairs]

*The above advice is OK for weather like now ... non-freezing temperature .. in central Texas we are at 100+

Salim

SonnyD

tfischer, thank you so much for reminding me about that! I just checked my file and sure enough, there was the Warranty Enhancement Notification. Says the radiator may crack at the base of one or more of the radiator tubes, resulting in coolant leakage. They extended the warranty for this to 7/90k. Says they'll replace the radiator including coolant. I'm going to call the service department immediately and take the car in.

Salim, should I indeed add a couple jugs of distilled water in the coolant resevoir tank so I can safely drive the car to the dealership? I assume if the radiator replacement is the issue, they'll flush out the system during the repair?

Thanks.

Rainbird

Just use tap water. The shop will need to totally replace the coolant to do the repair.

salimshah

^ I disagree. Spend the $5.00 to make sure no contaminants get in. The system is finicky and to get long life out of it.
[ps: this is the reason why you dont need to change water-pump at 90k]

Salim

mandyfig

I agree with salim, minimal investment, great return.