i have a 95 ls400 and it over heats i cant find the problem. i changed the thermostat and checked for leaks. it's none of them cause it still over heats. can it be the sensors going bad or a radiator cap. i know the head gasket isn't blown cause it cools down when I'm driving above 40mph. but when i sit at a red light it starts to get hot but it never goes into the red. please help with any answers

 

Maybe your electric fans aren't kicking on or the fins on your water pump are deteriorated and need more rpms to cycle the coolant. I had the same issue with my 97 ls and after replacing the water pump it didn't overheat.

 

X2... check to see when it gets hot, that they come on, if they don't, you will need to figure out why. If they do, you'll likely having other issues. I can't remember if whether the 95' has a mechanical fan. If there is, the vicious clutch maybe worn, but if there isn't a mechanical fan, you likely have an e-fan problem.

It is possible to have a worn waterpump, but you should eliminate the things you can see like the cooling fans, than start to go for the bigger stuff.

 

I would start with checking the top tank on the radiator make sure its not cracked and not allowing the system to build pressure then make sure that you have properly bled all the air out of the system.

 

If you turn A/C on do the radiator fans turn on?

 

It could also be the radiator itself clogged up, do you use the recommended coolant/distilled water mix?
Another is the pressure cap they have been known to fail.

 

i vote for fan as you indicated the temp would drop at higher speeds. if they turn out fine, i would bleed the coolant, or add more as necessary. do the simple stuff first before pointing to the water pump which is last.

 

Instructions for bleeding the coolant system should be printed on top of the coolant reservoir. If not:

https://www.clublexus.com/forums/ls4...der-valve.html

 

Check between the radiator for any leaves and debris that get caught there. I wish I could find the pic of the 2GS that had a fall leaf collection between the A/C condenser and radiator.

 

i have a clutch fan. i didn't think of that thanx. and i just changed the thermostat again yesterday to make sure. and it stil;l over heats.

 

and another thing i can't find aftermarket exhaust systems nowhere. there's a website i found but there expensive. does anyone no where i can find not so expensive ones, like in the $500 range and not in the $2000.00 range

 

Soounds like you are throwing the same ole solutions at the same problem. Now that youhave eliminated the thermostat, time to move on to other simplier solutions before going extreme. As noted above,, check the radiator clearance and make sure that there areno leaves and debris collected there. Next, pressure caps on the radiator (known failure),,,next flush and fill radiator to eliminate possibility of clogging. The ULTIMATE last thing you will need to change, sans the other solutions not working, will be the water pump. This is gonna be themost expensive option, by far, and since you are already there, you might as well throw in a timing belt since you are right there in the area, and you have to release the timing belt to free the water pump. Start simple and work up to big as suggested above.

 

If the system is properly bled, I would bet on the clutch on the mechanical belt driven fan. I currently have a 96 with the auxiliary fan temporarily UNPLUGGED because it runs constantly. The car does not overheat in the slightest even in the 90-100 degree heat we have been having. However, I can tell the mechanical fan is pulling a lot of air in those temps because I can hear it "roar" as I take off. I am waiting for a break in the weather before I change my radiator temp sensor, and if I got stuck in traffic, I'd simply plug the fan back in.

Do a search on how to test the viscous fan clutch, and if it's bad it is not that hard to change.

 

these guys have covered just about everything, so just walk down that line and tell us which worked.

 

Let's keep your thread focused on overheating before branching out. Spending money for fun goodies when there are operational-maintenance issues is the priority first. You'd hate to spend $800 on an exhaust to find that the car needs a timing belt.