Sx4 overheating???!!

[olymunch]

Ok so I've got a 4.2 with about 145k, new 195 thermostat, two row radiator, fan clutch is in great shape, fan cowling is in place, no wobble on water pump, with cap off I can see that the fluid is flowing quite nicely, nice color fluid, checked with a laser thermometer to confirm it wasn't my sending unit-also new, hoses don't collapse, the intake is routed to the stock location sucking in air from outside. and no leaks.

There is scale in my radiator but it seems to flow well. Checked the face of the radiator with the laser and the temps were all over the place. When it's overheating the thermostat housing reads 240. With the radiator cap off when I hit the gas there is obvious foaming. When I turn on my heater the temp drops. The temp gauge shows a steady rise in temp.
Please help, I REALLY want to drive my car everywhere!!!
Thanks

[eagleman]

Sounds like you may have exhaust going into a water passage. Possibly a blown head gasket or cracked head or block

[olymunch]

Yea the more I look it up the more likely that seems. I'll do a leak down test and if I have a leak, keeping in mind I don't go thru ANY antifreeze, I'll use bars leaks with carbon fiber to "repair" it. Should be done by Saturday. I'll update my results.

[carnuck]

Loosen the coolant sensor to "burp" the motor. Mine ran hot till I did that. I also drilled a tiny hole in the thermostat plate so it was upwards when installed. That helped burp it too.

[olymunch]

I'll try that. Remove the sensor when cold I imagine?

[carnuck]

Loosen when cold, start the car and allow the air out then tighten. If your cat is clogged it can back up exhaust pressure and cause it to overheat too.

[olymunch]

I did burp the system but no air came out. My bird has no cat, bought it that way . Ok so I used a block tester and no leaks in the head!! Did a pressure test and found out it has a slight leak on the top of the radiator and tried to have it flushed but the radiator was to clogged to do a flush. Guess I'll be needing a new, hopefully three row, radiator.
Thanks everyone

[carnuck]

Check the aluminum CJ7 rad swap thread.

[olymunch]

I haven't looked at it in depth yet but from what I can tell I think I'll be going that way. I was also thinking of an aluminum body radiator with a plastic top and bottom. Now I know plastic sucks but with the way it goes together I can take it apart and service it myself in the future with just one tool if I need to.

[olymunch]

Ok so actually I think I'm going to remove the old radiator, take it apart, clean it, solder it back together and keep using it for now. It looks super easy and I'll take pics to post here as a guide.