Hello, I have a 2002 Tahoe with 228k miles on it. recently the oil pressure guage started to go low and the oil pressure low light came on. It now consistently hangs at about the second tick mark. When I rev the engine it goes up a little but at idle it almost goes to red. There is enough oil in it. The oil pressure sensor was replaced about 4 months ago. With this many miles should I consider replacing the engine instead of doing all the work to replace the oil pump and timing chain...? Thoughts?