LB7: Difference between 02 and 04 lb7
- Thread starter 1chevy02
- Start date
01-02 used an actual oil pressure sending unit that was wired from teh sender to the cluster and teh guage only goes up to 80. 03+ uses a pressure sensor that is read via teh ECm and that info is transmitted over teh data bus to the cluster where it decides to tell you what it wants you to see for oil pressure on a guage that goes up to 120. It is deceiving do to the guage change from 02 to 03, but the oil pressure of the 2 should be the same.
Ok ferm I knew there was a difference on the guage reading to 120 vs 80. I did not know about the direct guage wireing, I guess thats why I can't log oil psi on an 02. It just that we have had 2 04's that have the low oil psi dinger comeing on and I know of a lot of 02's with higher mileages and the seem to hold 20 or better at idle. Got an 04 now only makeing 7 psi at idle and only has 200k on it. My 02 with 220k and hot tuning for the last 100k holds 20psi easily. I don't know just trying to learn.
I guess I'm lucky as my 01 even with 5W40 oil towing on a 95 degree day has yet to drop below 30 at idle(even with mine set at a 600 idle). Most days it holds right at 35 at idle and always jumps up to 50 going down the road.
I noticed my 02 oil pressure is a lot higher then 03-04 too. Idles cold at 70psi and warm at 35psi. This is during the summer months with 15-40.
i pulled a motor from an 01 and saw it run, had almost 40 psi at idle, put it in my 04 and the gauge barely read 20
the reason you see different oil pressure on an 01-02 vs an 03-04 is NOT because the ECM "lies" or the cluster "shows you what it wants and not the real thing".
The 03+ sensor is accurate, and if you watch the actual engine oil pressure reading over the databus with a tech 2 and then look at the gauge on the cluster, you'll find that it is perfectly accurate.
The location of the sensor is what makes the difference, thats the only thing I can think of. The 01/02 trucks have it mounted in a different location in the oiling passages than the 03+ trucks' sensors'.
Also, the fact that the 2003+ trucks have a 120psi oil gauge might make it initially appear that 01-02 trucks have "higher" oil pressure, because the 01/02 clusters only go to 80psi.
ben
The 03+ sensor is accurate, and if you watch the actual engine oil pressure reading over the databus with a tech 2 and then look at the gauge on the cluster, you'll find that it is perfectly accurate.
The location of the sensor is what makes the difference, thats the only thing I can think of. The 01/02 trucks have it mounted in a different location in the oiling passages than the 03+ trucks' sensors'.
Also, the fact that the 2003+ trucks have a 120psi oil gauge might make it initially appear that 01-02 trucks have "higher" oil pressure, because the 01/02 clusters only go to 80psi.
ben
Ok makes sense on the different location of the sensor because I have logged the newer 03-04 trucks and they are lower than my and other 02 trucks show. I can't log the 02 because the ecm does not register the oil psi. I just have two friends with similar miles than me whose low oil psi dingers come on if they idle them hot. I logged one and it only showed 7 psi at idle