2002 Explorer XLS 4.0L SOHC oil pressure loss!

[Nate0234]

Hello, I am a tech and have a 2002 Explorer XLS with the 4.0L SOHC. Do they have a habit of the oil pickup screens getting clogged? I know they have timing chain guide issues but this one runs great and the engine is quiet then all the sudden it's oil pressure goes to 0 and you can hear the valve train rattle. If you shut it off and let it sit for a minuet you can start it and its back to normal. again I am a experienced tech in all areas, I just didn't know if the Explorers had this as a common problem or not?
Thank you in advance!

 

[2000StreetRod]

not common

From what I have read on this forum it is not common for the oil pickup screen to get clogged enough for low oil pressure. Does the pressure drop slowly as the engine warms or does it suddenly drop when warm or cold?

 

[Nate0234]

From what I have read on this forum it is not common for the oil pickup screen to get clogged enough for low oil pressure. Does the pressure drop slowly as the engine warms or does it suddenly drop when warm or cold?

I was only driving it for about 10-15min and kicked it in to passing gear for a second and when I let back up the oil pressure just dropped to nothing and the engine started rattling in the top end, I shut it off instantly and let it set for a min while I checked the oil. It was full so I started it back up and it's been fine ever since, I was thinking timing chain guides since these things are prone to them failing but its quiet as can be even at all rpms. I just bought this thing and don't know the history behind it, it has 181,000 miles on it and I doubt the timing chain guides and tensioners are original with that many miles. I think I'll pull the lower oil pan and check for debris. Of it is the guides I'll replace them since I bought the vehicle so cheap. Thanks for your reply!

 

[2000StreetRod]

sludge?

I burned up my Grand Cherokee V8 when the sludge built up in the heads and oil galley enough that the oil accumulated there starving the oil pump after about 30 minutes of highway driving. It was hard to figure out why the oil pressure was dropping because by the time I stopped the vehicle, opened the hood and checked the oil level it had drained back into the pan. And when the engine was restarted the oil pressure was back to normal. If the thermostat has been removed or is defective (sticks open) the engine will rapidly build up sludge.

The oil tube pickup screen has a fairly large area. There would have to be a lot of debris to block the screen enough for the oil pressure to drop significantly.

 

[Nate0234]

Sounds like I need to pull the valve covers and check for sludge, if found ill clean it out and pull pan and clean it as well. Thanks for the help!

 

[Hinchy65]

I just noticed this post and thinking maybe the temp gauge here could be caused by a thermostat problem like you mentioned above, any input would be appreciated.
Hello Everybody, I'm hoping you may now be my new best friends. My story is that I bought an old 98 Explorer of a work colleague 2 days ago, he had just had the water pump replaced and then he said a few gauges started playing up so he took it back to mechanics, was told some story about sensors. Then he said it was running rough when cold (like on 3 or 4 cylinders but seemed good once warmed up, but he didn't to play with it any more, so I went along to have a look and it started and was running on all cylinders so I decided to drive it home. I soon noticed the temp gauge rising to the high end of the scale but then it started to go back down so I thought I would just monitor it and keep going. A little further along I notice the oil pressure gauge started flicking like crazy and settle at the bottom of the gauge, I figure thes must be the gauge problems he had mentioned so I continued for about another 20 Kms until I thought I heard a bit of a rattling sound and decided it best to pull over and shut it down. I left it on the side for an hour or so before returning with a tow vehicle, when I returned I started it briefly but it made a screeching noise along with quite a rattle, so I'm thinking the oil pressure gauge was correct and I had lost oil pressure possibly due to oil pump failure. So now I have a job ahead of me and hopefully you guys can help along the way with info and would love it if someone had a workshop manual they could post up to make life easier. Thanks for listening and look forward to your input