Have problem sometimes with my 2001 4.0. Sometimes when I crank it up the oil pressure doesn’t come up right away. It comes up real slow. It comes up so slow when it does this the check gauges light comes on for like 2 seconds then it’s up to normal pressure. When it does this it throws an oil pressure code and the check engine light comes back on. When I run it I never have low or high pressure problems. Already changed the oil sending unit and it didn’t help. Doesn’t do this all the time and I’ve noticed it mostly does it if it’s been sitting for a couple days or is really cold. If you guys think it could be something serious let me know. Otherwise I’ll just live with it. This TJ is maintained like clock work with oil the manufacture calls for. Oil isn’t low, doesn’t fluctuate much when driving, and doesn’t smoke at all. Only doesn’t maybe every 3 to 4 startups. Thank you for your advice guys. Just need to know if it’s something I need to address if it can cause me problems down the road. Still feels like it can pull a house down in 1st and 2nd gear lol. No performance loss.
Oil pressure issue
- Thread starter BamBam
- Start date
Sounds like it might have something to do with the gauge? I do know for sure that the newer TJs had dummy oil pressure gauges, as long as the sender reads above 3PSI or so the gauge displays optimal oil pressure.
Go get a grease gun hose and a 1/8" female pipe union and a 0-100 psi gauge, remove sender, install hose and gauge, check pressure directly. cost is $20 to know for sure.
The 2001 still has the real oil pressure gauge; it wasn't until 02 or 03 where they switched to a dummy gauge. Did you replace the sending unit with mopar brand? The aftermarket ones are crap. I'd hook up a mechanical gauge to see what the real oil pressure is before you start tearing out the oil pan.
I just did the 19 autozone unit, by the time I need to replace it again, I can get another for what a NOS mopar one costs.
Odds are very good your oil pressure issue is nothing more than a defective oil pressure sender. I'd replace it with a Mopar sender, definitely avoid cheap store-brand senders like from Autozone, O'Reilly's, etc. My son's oil pressure sender went bad on the Grand Cherokee we gave him and it took three trips to Autozone before we got one that worked correctly. I was doing the work on a Sunday and he was leaving Monday morning or I would have gone to the Jeep dealer to get the sender.
Similar threads
