L31MaxExpress
I'm Awesome
The fan operates when it needs to and provides a lot more cooling even at highway speed. When the thermal bimetallic element on the clutch rises in temperature it engages the clutch to speed up the fan. This is and always has been my issue with electric fans in Texas heat with towing. The electric fans cannot move nearly the CFM the clutch fan can at 2,000+ engine rpm. When I am at 2,850 rpm towing 75 mph in 3rd gear my clutch fan screams when full engagement is called for. The coolant temps will drop 10-20F in 30 seconds and the a/c system will blow so cold due to the added airflow over the condenser that it causes the ac clutch to cycle regardless of the blower speeds. I tried both leaving the electric fans off and running them on high speed in the same conditions and even my 350 despite the dual core big block radiator would run as hot as 240F requiring me to slow down and drop a gear or pull over and idle to cool it back down. I will add that my mechanical engineer uncle had similar issues with the stock E-fans on their 2010 Tahoe. He despised the EFans on it coming from prior GM products with a clutch fan that worked well. I pitched the idea of a clutch fan from a 2500 truck and he had the parts the next weekend. We ended up pulling the E-fans off and put a clutch fan and shroud from a 6.0L 2500HD truck on it. Both his engine and transmission ran much cooler pulling his 31' travel trailer with it. The ac in the Tahoe also performed better than it ever had at anything but low idle. He utilized the stock Efan wiring to add a pair of GMT400 style ac condenser pusher fans also my idea to help the idle ac cooling. Resulted in an extremely capable cooling system to cope with towing in Texas and New Mexico heat. He now has a 2500HD with a 6.6L gas to tow the same trailer. He is not a diesel fan either. He also had a 1500 4x4 with the L86 6.2 for a while. My cousin drove the Tahoe all the way through her engineering college classes and it recently had to get a new engine at 140K due to DOD lifters being wipped. I tried to talk him into one of the last new L96 6.0Ls that Summit had from GM in that Tahoe but it sadly ended up with a GM reman DOD 5.3L (LC9 IIRC). The new 6.0L was cheaper than the reman 5.3L at the time by nearly $1,000 and the 6.0L had a new intake manifold, new injectors, new fuel rail, and new water pump on it as it was the last of the production dressed Express van engines being sold off.Made it home. The burb ran great. Even thru Chicago traffic with the AC on the Trans temp never broke 185deg. Gas mileage not too bad for 68 mph average.
I did hear the fan kick on quite a few times while at highway speed. Is that normal?
Otherwise I’m quite happy with the ol’ girl.
Last edited: