Re: 23 Series - Overheating 288 engine

Posted by Owen_Dyneto On 2008/7/22 15:21:42

Despite all that you've been thru, and much, much more, we've never found the problem with overheating in that 23rd series Eight, and the owner has reluctantly ordered an electric radiator fan. I hate to see this because it's just masking the fundemental problem, but we finally just ran out of ideas and patience. The owner thinks it may be from a shifted core when the block was cast, and I don't have any experience to either accept or reject that hypothesis.

But it's an excellent idea of check your water distribution tube because if clogged, it does indeed restrict cool water flow the the rear exhaust valves seats (which can lead to cracked engine blocks) and the temperature sending unit. Unfortunately for you, the time to check it was before the radiator was reinstalled because to get it out you have to remove the radiator and water pump. But I'd still do it, removing the radiator isn't fun, but isn't all that bad either. If the front engine mount has deteriorated much, you may have to put a jack under the oil pan and raise the engine a bit to get the lower waterpump bolt out. Then with the pump removed, use a hook or piece of coat hanger wire to pull the water distribution tube out. Inspect, clean or replace as necessary, and I'd further suggest that while the pump is off, you remove one of the rear core plugs and blast the water jacket with a hose and nozzle in hopes of removing any built-up sludge.

Other things we considered and some of which we checked include cracked cylinder head or block, blown head gasket, faulty gauge or sending unit, undersize exhaust or tail pipe or overly restrictive muffler, fan belt too small and bottoming out in the pulley rather than gripping the flange sides, and more.

The Custom 8 used a much more efficient fan with 5 blades; don't know if it will fit and have clearance, but the hub on the water pump shaft is larger so you'd have to change that to try it out. How far is your fan blade from the radiator? His was quite far compared to other cars we looked at and measured, more than 1-5/8 inches, and we considered making a spacer to move the fan closer, but did not do so. I still like the idea.