LScowboyLS

keep in mind that refrigerant overcharging can be the hidden contributory or even the sole cause of these kinds of problems - and fan clutches (while being reliable on the LS400) are one of the most overlooked maintenance items on a car!

Finn

C4 generation Corvettes tend to gather debris and such between AC condenser and radiator until it hurts cooling. Has this been problem with LS?

LScowboyLS

No, debris in between the two hasn't been a problem, but you would be surprised the crap I find embedded in the fins of the average LS400 condenser! - have you guys been driving through mud and bugs for years without inspecting this critical area?

Finn

I think many people just don't realize how much insects and other stuff gets stuck in there during years.

Gene01

Yes, it is quite easy to build a fine collection of debris between the radiator and condenser (I think I got it right this time, LScowboy :-)
When I checked mine, some unspeakable excuse for a mechanic had also used it for his personal ash tray.
I would love to have a brief chat with him if I could ever find our who it was.

LScowboyLS

when I ran the largest A/C shop in Arizona in the mid-90's, you would not believe the cars we fixed just removing plastic "wal-mart" bags, bugs, dirt and all kinds of crap from condensers, as well as straightening bent fins

and replaced so many fan clutches!

when the temps can get to 130°F (55° C) and you have to make the A/C get cold for the customer, you would be surprised how you learn what will increase head pressure on an A/C system!

lexusrolex

i wanted to check on what greg50H said and i opened my hood and i lightly held on to the fan with one finger and i had some one turn the car on and the fan did not spin, i was holding it for a bit, does that mean my fan clutch is not working?????

LScowboyLS

it may be working, but really weakly!

if your car has over 180K, I would be thinking of getting a new one!

lexusrolex

hopefully its the fan clutch, i dnt think i should be able to stop it like that

LScowboyLS

well the real Toyota (Aisin) fan clutch is $195 at Sewell, but you can get the same OEM Aisin fan clutch for ~$85 online at amazon, rock auto or other places! - I would not advise using anything but the Aisin/Toyota fan clutch, the aftermarket ones are junk!

lexusrolex

but is there a real way of knowing if its working or not???

tonyisme

Ok I have a 95 LS400 in Arizona.
I do my own coolant carefully, and 1 year ago did OEM Thermostat Lexus, and Toy Long Life Red, 65% mix. My reservoir
is full, no leaks.
New aluminum radiator 8 months ago. AC worked all summer, outside temps 115 F
Its October, outside is 92F. The front Cig Lighter is shorting to ground when pushing a phone charger into it, its a 15A fuse. It is tied into the AC somehow. AC only works when I replace the 15A Front Cig Lighter Fuse. So with new fuse in, my AC works but motor temp creeps up the temperature gauge quickly. Almost to RED.
So I remove the 15A fuse, no AC. Motor temp returns to normal, at city and freeway driving. Been watching for days. Do you think I may have a bad relay which activates the AC cooling motor? BTW I have a 1 year old radiator fan clutch and its working, and firm. Its no weak. I am not losing coolant. This motor likes Toy Long Life Red not pre-mix.
Any suggestions?....Tony BTW I have the 4" thick Factory Service Manual for a 1996 LS400...its a masterpiece in service documentation.

400fanboy

Oh **** you're the perfect person to ask then. Hey @LScowboyLS

My LS overheated this summer. 100 degree day, A\C on full, car temp started creeping up at the stoplight. Fan clutch is only a few years old (OEM unit) and sounds like it's working just fine. The fan spun like crazy once I got moving, felt like I was dragging a boat anchor and the temps came right down. My problem is my radiator is chalked full of bugs and gunk and grime. I think the cooling system is working fine, but a solid 20-30% of the surface area of the radiator is completely clogged up.

I'm worried that even a garden hose spigit has enough pressure to bend radiator fins. And, most of the gunk is on the interior side of the radiator inbetween the two cores where idk if water can cleanly reach. And I'm worried about spraying water around my engine bay.

Could you offer a new kid on the block like me some tips to cleaning this out? Are there chemicals which can make the garden hose method work by etching into the accumulated bugs and debris? How do I reach inbetween the two cores. Obviously one can remove the radiator, but that is quite a significant undertaking to just clean things out. Thanks.

paulo57509

When diluting concentrated coolant, use distilled water.

Cleaning the radiator core of dirt and debris is covered in the FSM. The best way is to remove the radiator and blast it from the engine side. Read here (maybe do a site search too) https://bobistheoilguy.com/forums/th...ndenser.42894/

I'm tempted to try a siphon gun the next time I have a need to clean out radiator debris:
I'd also look at the fan clutch; there should be testing/inspection procedures on the internet.

There's also the electric fan. It's tied into the temperature sensor that's located in the bottom tank, driver side corner of the radiator. I don't know how to test its operation.