I have a LQ4 with MP T76 turbo in my 89 RS. Everything is running great but I'm a little concerned about my coolant temps. I have tried using a 160, 180 and even no thermostat and my temp will creep up to about 210 after driving for a while.

I currently have a stock looking radiator (I don't know much about them to be honest). It's four rows but it isn't aluminum and I'm using a Lincoln Mark VIII fan. My IC sits in front and I didn't gut the nose of the car to install it. Do you guys think an aluminum radiator will help me control my temps? Also any recommendations? Thanks!

 

No t-stat will cause you to overheat. Seen it many times. You need a minimum of atleast a restrictor, if not a standard t-stat

When does the temp creep up? Moving or stopped? You have to drop the fan turn-on values in the PCM when switching to a lower temp t-stat for it to do any good

You dont need a high dollar fully aluminum radiator to keep your temps under control. Even stock uses a pretty efficient heat exchanger core, end tank material is irrelevant

Last but not least, make sure all the air is bled from the system. Pull the steam line off the engine just under the TB and crank the engine. Once the stream becomes 100% fluid, reconnect

 

Also make sure that the air dam under the front of the car is in place, this is what forces the air up into the radiator when you are driving, the grills just won't cut it to keep it cool.

 

I just tried the no t-stat for comparison but I had been running the 160 t-stat with same results. Ironically it seems to do it more while moving at highway speeds with or without the fan running. That’s why I thought my intercooler might be the problem. I have a toggle switch to control the fans so my PCM settings never come into play. I will double check the steam just to be sure and let you know.

 

The air dam is there but I'm not sure it is doing enough. I may try to change the angle to see if that helps....I will keep you posted.