05 R50 overheating - opinions needed!

On the end of a 90 mile trip, I pulled off the interstate for some food and as we were about to get back on the road I noticed my temperature gauge was redlining. After letting my engine cool off, I noticed the fuse under the hood for the fan was blown.

I took one of the spare 50 amp fuses and replaced it, waited for my coolant temp to reach 105 and the fan did not engage. I could hear it trying to trigger but failing. There were no leaks on the ground and my coolant was still at the Max line in the tank.

I decided to drive down the road to check the temp - it maintained 93-95 degrees on the rest of my way home - but would temp would climb back up to the redline if idling for a few minutes.

Where should I start in diagnosing my issue? I've done a bit of searching so far and have an idea on what it could be - thermostat, the housing, or simply the fan is shot and needs replacing.

I would greatly appreciate any advice or prior experiences. Thanks!

 

The problem I had with my 05/R50 was the thermostat and housing.It was leaking and once I pulled it off, the gasket was crumbly and shot. You stated the fan did not kick in, that's where I would start. Don't wait too long to get it sorted out.

 

I had this issue on my project car. At idle the temp would rise. Ended up being air pockets in my cooling system.

 

IMO I would be suspect of the fan. It's getting hot here, and if I idle at all during the day, the fan will kick on within a minute. If it's not engaging, I'd wager that your radiator can't get enough air through it to cool your engine down. The fact that on your way home it maintained temperature, and only rose at idle would tell me that something is going on with your fan(shows that coolant is at least flowing through the engine, so thermostat is ok). Looks like there's a few videos on how to test your fan, and I'm sure there is a way to test the resistor as well.

 

When I had overheating problems with my R50, it turned out to be the thermostat housing, the gasket had crumbled away and it was leaking fluid. The way that housing sits, when it leaks the fluid hits the exhaust manifold and evaporates before it hits the ground, you won't see it leaking. Another thing I noticed is that the fan would not always kick in and I would see the needle start going into the red. Once I put more fluid in, the fan would kick in. On the R50, the recovering tank is not pressurized, I'm surprised you are overheating and not losing coolant... I would do a pressure test to make sure your system doesn't have any leaks.