Problem: Often upon startup, you will have NO oil pressure---clattering lifters verifies that the gauge and dummy lite is correct.
1. 2003 Vortec 5.3L, 5300 Z (E85 fuel), bought used from one-owner with 78000mi, and it now has 98000mi. Runs perfectly, 18mpg on the highway.
2. Never had a seconds problem until this Saturday:We had driven it only 5miles down the road with a carload of adults, to look at a house. I shut it off for 40mins.
I then started it in order to go back home.
Immediately at startup, the dummy was dinging loudly, and the oil gauge showed ZERO, and the lifters were clattering.
It sat there for ~20 or 30seconds, (while I was in disbelief), until I revved it gently to ~1500rpm---instantly pressure returned to normal at idle, and lifters hushed instantly.
3. Since then, it has done it randomly 2 more times, always after having sat idle for at least 3hrs.
4. Each time, if you rev it up once to ~1500rpm, it will instantly began working, and the lifters, etc, will all hush as the oil hits them. Oil pressure is normal, even at idle.
5. I changed the filter and oil back to conventional Rotella, started it stone cold, but it STILL has no pressure, so I immediately shut it off and WROTE YOU GUYS!
"Side Notes/Clues": When I switched to the synthetic, my oil pressure increased tremendously, almost by an additional 18psi at 70mph on the highway (it will read 60+ psi). Could this have anything to do with the oil-pump/oil-pump check valve?
I have always used conventional Rotella 15w40, but last oil change I used Rotella 5w40 SYNTHETIC---and the car's "dummy lite" did not tell me to change the oil until only two days prior to this "no oil pressure" problem---and the synthetic oil had a staggering 8,000 miles on it/filter! That is the last time I rely on the "dummy oil-change lite".
Thanks a million guys! My one solitary dealer in this town does not know much more than me, and that is at $65hr!
have the same problem?
Tuesday, October 20th, 2009 AT 5:19 PM