At idle my coolant overflow reservoir fills up and the coolant boils/gurgles and starts to release steam. Temp gauge rises to H.
I do not see any signs of oil in the fluid or any signs of coolant in the oil, but I keep reading that it's likely the head gasket. I'm also reading possible thermostat or fans. Once the car cools I'll test the fans, but if they're fine I'm thinking of replacing the thermostat.

What do you think?

2001 Infiniti i30 with 130,000 miles.

sorry, couldn't edit title, of course means coolant not collant.

Thanks!

 

Is your lower radiator hose warm/hot?

 

If it does it when the car is cold, then it's the Headgasket.

if it does it when it's at operating temperature (before it overheats), then it's the headgasket.

If it does it only when it Overheats, then it is likely a thermostat/fan problem.

Make sense?\\


I can speculate that at 130,000 miles, it's probably just a bad thermostat or fan issue. And if I had to speculate between the two, the fan is the more likely problem. Wiring issue or dead fan motor.

 

Yup my '01 had bad fans when I first got it.

I was able to drive it from ATL -> Houston in the summer w/ bad fans, only problem was when we stopped in N.O. for something to eat w/ the A/C on driving around the city... That needle shot up like a rocket

 

Yep, the fans aren't coming on. I'm guessing relay, fuse, or motor. What's the logical steps to troubleshoot that.

Fuses are good, relays show RAD FAN1 RAD FAN 2 and RAD FAN 3, Just replace all 3?

 

1 of the 2 fans runs now (passenger side), I'm guessing I need a new fan assembly.

 

You have 2 fans.
They're dual speed also. this means they have a High and a Low function for each fan.

There are 4 wires to each fan. Run 12V positive and negative (fused at 15A) to each pair of wires, systematically. Obviously keep hands/fingers clear during this test!!!

That will check all fan speeds, do them one at a time. If they don't work you know it's the fans that are bad.

There's a specific, better suited diagnostic for htis in the FSM>> nicoclub.com/fsm

 

Fan only runs when a/c is on. when I turn it off fan goes off.

 

Again, there's 2 speeds. The fans should only run when you're NOT moving and have the A/C on, they'll cycle off and on as needed to pull air across the A/C condensor.

The low setting will run as you reach operating temperature, high speed will come on as you exceed operating temperature (overheat)

I don't know which runs when you have A/C on, but I suspect it's High speed.

Again, you need to test both speeds before you determine whether you have a bad fan or not. If the fans are good then it's a issue with the wiring.

 

Thanks.
The drivers side fan tested bad, so i'm pulling the assembly out anyway and will do a full test. The passenger side fan runs when the a/c is on.

 

Replaced the entire fan assembly and now all is well.

Thanks all.

 

Happy to hear. It's a good thing we have such good cooling systems, failures in this regard are almost always just the fans. Imagine if you would have listened to others and done a headgasket for this!!

 

OP if you're interested it look me all of 10 minutes to throw this one in.

http://www.amazon.com/TYC-620710-Rep...2003&carId=001