I have a 1996 SC4 that's had it's water pump and timing belt changed about a year ago but now it's having overheating problems.

The car's condition:
117,xxx miles
1yr old water pump
1yr old timing belt
Both main cats are throwing codes
It had a broken Thermostat housing but that has been replaced
New Thermostat

It'll warm up pretty normally but as I'm driving down a city street the water temp will rise and rise. The only thing I've found that helps is to ride with my Overdrive off and accelerate quickly. The accelerating actually drops the temp from near the 'H' to normal temps pretty quickly.

Steps I've taken to remedy the problem:
1.Check my coolant levels
2.'Burp' the air out of the system

I was finally able to get some sort of sloshing/burping action from the radiator cap yesterday after about a dozen tries. Even after that my problem still exists.

The only thing that I can see is that there is a needle size gap in the thermostat gasket between the housing and the engine.

Any ideas? I need them!

-Martin

 

Martin, have you considered your radiator cap?

 

I've been asked that before, but it seems to seal pretty well. I've loosened the cap while the car was hot (I know, a dumb thing but I didn't take it off) and it made no noise until I moved it. One thing that has kind of bugged me was that there is a tiny amount of what seems to be coolant left on the 'skid plate' below the front of the engine.
There aren't any signs of coolant coming out of the rad cap though, I've been all in there with flashlights and haven't seen anything worth noting.

I really wouldn't think it's the t-belt or water pump since those typically last ~100k miles.

 

I put on the cap and same ol' same ol'. Seemingly no change in temp problems.

 

Is it possible that even though my stock electric fan is working that it may not be pulling enough air through the radiator?
Is there a way to check for airway blockages without removing the front bumper?

I'm still pretty new to the SC so I haven't gotten to know all the in's & out's yet.

 

Found out some possible bad news today.
I took it to an authorized Lexus repair shop here in Dallas. They seem to think it could be a bad head gasket (1 or both). If it does turn out to be both gaskets then I may just have to go with a swapped used 1UZ-FE.

This sucks! The guy who sold me the car probably knew there was something up and sold this to me really quick.

F'n sucks, man. F'n sucks.

 

Sorry to hear about that. On the bright side the 1uze is quite inexpensive and sometimes people actually give them away...

 

Well I finally got an answer to my problem from Davenport Automotive here in Dallas. It was the cheap autozone parts that I had installed that didn't quite play well with the 1UZ. They looked like they would have worked but I guess the slightest of differences does in fact matter.

Long story short, the car is fixed and I no longer have a temperature issue so now not only can I breathe a sigh of relief but I can also look forward to making some modifications to the car.

First up, getting my HIDs installed. I got the brackets from lexus4jess.com and the bmw projectors as well as my actual hid kit so I'm in business!

Thanks for the help with the temp issue.

 

Oh, come on Martin . . . give it up! What was the (specific) cause already; was it that thermostat?

 

Yes. Cheap parts are not good.