I rebuilt my 90' 2.5L engine and it used oil from day one. The compression rings seated just fine and leakdown numbers were good. I put 50,000 miles on the engine like this and finally retired it when the oil consumption got to be too much. The engine never would come up to temperature going down the road. In the summer I was lucky to get 170* out of it with a 190* thermostat in it, I'm fairly certain this is why the oil control rings did not seat. I tried everything to correct the issue and in the end it stumped me. When I went to pull the engine out I found my problem, the heater hose connections were hooked up backwards. It is hard to determine because in the van the heater hoses are routed via steel tubing down the frame rail to the drivers front. There is a three way valve at the firewall that they connect to. My question is why did reversing the heater hoses cause the engine not to come up to temp properly? I've looked at the flow and I don't see how it could cause this to occur. Any insight would be greatly appreciated. Thanks.