97 LC A/C Overheating

[LANsCom]

The A/C in my 97 with 100000 miles just stops working and then the engine starts to run hot. I have change the thermostat and the belts are all new. I am leaning towards the compressor and chock because the A/C just shuts off and I believe the compressor locks up and puts presure on rest of the engine. I cannot duplisate problem at the shop because it only dose it under heavy driving conditions.

I changed the Viscous Coupler toady on a recommedation and things seem to be O.K. but the problem seems to be so inconsistent. I was hoping someone could set me at ease because my wife and 4 kids are the main passangers.

Thanks,

Joe

 

[Beast II]

This is exactly what happened to my 97 before the head gasket blew and the cylinder heads cracked. A/C only blows warm air - right ? Engine easily overheated too. I wouldn't drive it until you get it figured out. Cost me ovr $3k.

 

[LANsCom]

I have heard this can get ugly. So all who want to get in on this here is what has been done so fa.
New Thermostat, Belts, Viscous Coupler, Coolant. There are no leaks at all. The vehicle is running at normal temp with the A/C cranking on my last travels and it is 90 degrees. What was wierd, when the A/C did shut off the temp gauge went between half and red line so I am awsuming the auto shut off kicked it off but then the A/C would kicked back on at the high temp and the temp would immediately dropped to below half. I am hoping the Viscous Coupler was the problem but.

Thanks,

 

[Junk]

Should be the fan, but take it easy till you get this nailed down.

In a pinch if you have to, temporarily turn on the heat, then go back to vent.

Sounds exactly like the way mine was acting when it was the fan (or more accurately the vc) for the fan.

 

[landtank]

any mysterious coolant loss? That's one of the first things I'd look for. If you are loosing coolant and nothing is wet then it could be going out the tail pipe.

If the coolant is holding it's own then don't get to worked up just yet.

It does seem strange that 2 separate sensors are seeing the coolant temp differently.

 

[clownmidget]

I'd add the following comments for thought:
What is the general condition of the rest of the truck? The drive train, especially the transmission fluid. If it is old or low. It has quite a resevoir at the bottom of the radiator and can possibly start overtaxing your cooling system that way. I'd also make CERTAIN that the radiator is in top notch shape. It has been mentioned by several folks that the 1997 version with the plastic tops/bottoms develop leaks along the seams and generally don't fxn as well as the 1993-95 all metal ones. IIRC, the a/c clutch is electronically controlled to cut out under hard acceleration and under high engine temps. Good luck and if you don't know enough about the radiator better call C-Dan and get one you trust!
Mike R

 

[cruiserdan]

Has it done this since the new clutch? Is the new clutch OEM (16210-66020) ?

 

[Scamper]

Lanscom: it's only been a couple of days since you posted this on UBB. So you've only had the new VC in for today I take it.

Given the speed that you got that part, did you get it at a dealer or aftermarket as Dan has asked? Anything is probably better than what you had, but OEM is the way to go, and Dan can get you the parts you may need at a very good price.

Since you said the VC previously spun freely while cold or hot, you needed this part replaced, so it won't hurt. If you're no longer seeing the temp rise, that's a good sign. I still wouldn't go on any long trips until you're sure this is cured. And watch that temp gauge like a hawk, and if it even thinks about moving off the normal position, pull over.

 

[IdahoDoug]

How long have you had this truck? I'm thinking the previous owner neglected the cooling system and your radiator is significantly blocked with sludge. Perhaps they even did the worst possible and mixed two different coolants at some point and it's got the well known sludge problem.

Do not, repeat, do not treat this lightly. Were it my truck, I'd pull the radiator tomorrow and have it boiled out and professionally cleaned, then slap it back in and put fresh Toyota Red coolant back in it. A cooling issue will turn this reliable mill into a money pit. It's about the only way to destroy this engine.

DougM

 

[LANsCom]

Thanks to all of you, I am so impressed with this very useful site. This is great. Vehicle history for you is, Purchased in 2000 with 50K miles, Did the full 60K mile maintance right away, the 97 model has and still is my dream car and I treat it that way, I am maticulaous with all maintance in and out.
The vehicle is showing no signs of heating up but it's early. The radiator has been flushed at least 4 times since I have had the car and the coolant test the Mechanic did yesterday came was good. I purchased the V/C direct from Toyota and for some reason they gave me a discount $ 105.00. Good thing I go to Mass very day. I appricate all your advice and will watch the temp like a hawk.

 

[MTNRAT]

if it still heats up after the VC change, my guess is change the RADIATOR pronto. IMHO.
Cheers,
Sean

 

[SUMOTOY]

Assuming your mechanic did a system pressure test? That should eliminate the head gasket (or include it). If he did, then the VC is the first in the diag tree. I'd also buy a new radiator cap, IME with the 4R, they have a half life of about 3.5years. Hotspots in the radiator can be checked with an IR temp gun.

HTH

Scott Justusson
'94 FZJ80 Emerald

 

[LandCruiserPhil]

To give yourself piece of mind on a possible leaking HG issue have your oil test by Blackstone labs. If there is 1 drop of coolant in your oil it will show up.

 

[LANsCom]

Thanks to everyone.

It seems the VC was the problem. The new one I put in was blue and after a very hot weekend hear @ 90 I have had no problems with the A/C shutting off.
I am still watching closely and if I have another issue CDan will be getting a order for a new radiator pronto. Thanks to all of you.

 

[MikeB]

Please use the correct term--"fan clutch". You will confuse the people who don't know better and drive the rest of us crazy.

I would suggest that you drain the radiator down enough to inspect the tubes that you can see through the fill opening. If they seem to be clean then you are probably OK. If the tubes look at all clogged, or you can see other deposits on the top of the core, then the bottom of the radiator if probably much worse and it needs to be cleaned out or replaced. It is quite possible to have a plastic tank radiator successfully rodded out and put back together, but if the price of a new one isn't a problem then that is certainly a better way to go.

Mike

 

[landtank]

Please use the correct term--"fan clutch".

Are you refering to the Viscous Coupler? Because there is no clutch in there.

 

[Rich]

I think Mike might have been referring to the fluid coupling.

 

[MikeB]

The FSM does call it a "fluid coupling" so that is technically the correct thing to ask for at a Toyota dealer. But in North America the part is commonly called a "fan clutch".

The part that we commonly call a "viscous coupling" is the thing in the rear housing of the '93-'97 transfer cases that the FSM calls a "control coupling".

I'm not trying to give you a hard time, just trying to clarify what part is being refered to. Good luck with the overheating--it sounds like the fan clutch may have solved it.

Mike

 

[Rich]

nothing but grins

 

[LANsCom]

I think with all your help we git it.

Thanks to all how had input or who helped you along the way. My wife is back driving the vehicle fulltime with the kids and loving it again. My wife shares my feelings on this vehicle as the coolest SUV body style.