2006 LLBean 3.0 EZ30 with 140,000 miles on the motor. Bought it with a bad motor and replaced it a couple months ago. Car has run great since motor install.

 

Last night in the California rains, we drove 6 hours from santa cruz to Los Angeles. About halfway into the trip, noticed that the temp needle had moved up to about 2/3 mark. I pulled over at first opportunity and checked fluid levels. Did not seem low. topped off radiator and it took maybe 1/4 cup. Hardly anything. Reservoir  was half full. added a smidge there too. Drove an hour and the same happened. I double checked and still the same. Was raining in sheets at this point, so we took it a little further including some very steep and long grades.

 

Under heavier acceleration the needle goes right back to just below halfway where it has always been/belonged. Any idea what this might point to?

 

Coasting, idling it stays normal.

 

Under mild load it occasionally creeps up to 2/3 but not higher.

 

Pulled over at a gas station and spent a good half hour double checking. Idled for 5 minutes warm - no bubbles in overflow. No external leaks to be found. Looks dry as a bone. Oil levels full and no burning smell. 

 

Fans were running.

 

As I rolled it around in my head it would seem that the thermostat should be the most likely culprit with a radiator blockage being a possible 2nd most likely. Anything that you guys can think of besides that? I'm in L.A. through sunday and would like to have it figured out before making the trip home.

recommend you replace the thermostat and radiator cap. If you do so, buy the most expensive thermostat at a parts store, or an OEM from a dealer. Subarus do not do well if a cheapie thermostat is used.

I'll pick up a new Tstat and radiator cap tomorrow. There's a dealership 10 minutes down the road that should have factory parts.

 

Will be carrying extra coolant and keeping AC off on the way home until I'm confident it's 100% Any other possibilities / precautions? 

Why was the engine replaced?

 

Are the fans coming on properly?

 

Clogged radiato - it sounds like it has lessened cooling ability.  If it varies with loading - A/C, up hill, acceleration - then maybe it's just reduced capacity of a clogged radiator.

 

Cap/thermostat

as said, t'stat must be OEM-style (Stant makes one too)

 

 

any electrical problems? might be worth checking out the charging system.

Replaced the thermostat with one from Subaru. Bought a radiator cap, but couldn't get it to fit on the rad. maybe a difference between the Ej25 and EZ30 radiators? the thermostats were the same part #.

 

Drove home last night and the temperature gauge never read above halfway, so I think it's in the clear.