So my 1989 jeep comanche has come a long way to when i got it but still isnt good enough in cooling the engine. It used to be a closed cooling system and now it is an open system. But i still have over heating problems. I left in the old coolant tank to i could fill it easily but should just bypass that? Should i completely take that out? I also put in 3 aftermarket radiator fans to improve from the stock one. But when i go 4x4 it always over heats and we end up towing it home. What else can i do? pictures would help alot.

 

Can we presume the entire/total cooling system is new? If so, I'd suspect the aftermarket cooling fans are falling short on CFM air draw thru the rad (compared to the OE fans).

Oh, and if u re-use the old (closed) tank, it must be unsealed, or vented to the atmosphere and must fill/empty from the bottom.

 

Should i just take out the old tank?

 

Either the old bottle or a replacement bottle must be correctly plumbed for the open type cooling system. Gotta have a bottle of some sort (correctly plumbed) regardless of closed/open system.

 

The radiator is different, too. But you probably already know that.

Have you checked for combustion gasses in your coolant or water in your oil yet?

 

Put stock mchanical fan with grand cheokee clutch and 97 and up electric both with shrouds youll haveenough air flowing for two jeeps