88 SPL still hot

[eFish]

I've done a lot of work and not seeing any benefits except alot of knowledge. Replaced the water pump, complete, thermostat with new stanless steel, new head gaskets, head cover gasket, exhaust gasket and the water cover gasket, cleaning all as going. It wasn't too messy and the heads are good I had them checked out. Put it back together, started it up, water flowing nicely from water hole and it ran for 15 minutes at idle then the alarm went off. I felt the water and it wasn't too hot until I turned off the engine. I think I covered my bases but something I'm missing. Any ideas?

 

[Okee Jimmy]

Re: 88 SPL still hot

Did you replace the deflectors? (2 per cyl. bank) they are the little rubber hoses in the block, you would have seen them when the cyl. heads were off. They should be round, if they are elongated then they are no longer deflectors, but restrictors. If they are elongated then they will need to be replaced. They simply pull out, a pick will be handy when these are removed. Clean out all the corrosion, and spray a little carb cleaner on the new deflector, (they will go in 100% easier) they will stick up a little, even when installed properly, just trim off the excess flush with the block.

If you did replace the deflectors, then at what speed does it overheat? the thermostats only effect the motor at low speed for better idle quality, and longer spark plug life. At speeds somewhat above idle, the bypass valves open and there is no thermostatic temperature control.

Also, the head gaskets have arrows that point to the exhaust cover, make sure that they are properly installed.

Hope this helps, Jimmy.

 

[emdsapmgr]

Re: 88 SPL still hot

There are two small pinholes in the thermostat valve body. One for each thermostat. They feed warmed water to the thermostats and cause them to open. If these are plugged (not an unusual) the engine will overheat at idle.