well i have a 02 4.7 4x4 and im back again with a question. i have been having problems with my oil pressure lately. its occasionally dropped all the way down when i come to a stop and then shoots right back up after literally one second. my first thought was sending unit., until today. but i honestly think its the beginning of sludge destroying my engine. now ive ran seafoam in it for about 200 miles now and go out and start my truck and the oil presure goes up, flutters, then drops down. i restart and everything is fine. first time its ever done it off a start, which is why i dont think sending unit. could it just be the foam loosening sludge and clogging screen more? what should i do about this? if you think drop the oild pan and clean the screen, how hard would that be? would i need any sort of seal to close it agian? or a new screen? im stuck guys, please chime in with ideas and sorry about length

 

I know you think it isnt the sensor but have you tried testing it or swapping it out? You could always drop the oil pan and check its contents.

 

How does the oil look when you drain it? I was told of a way to inspect your oil when you drain by using a T-shirt stretched over the oil pan. This way you could see if there is any solid particles in the oil... cause its hard to tell once you drained 7 qts in a pan.

Just for sake of conversation... what brand and weight oil are you using? Do you use the same thing all the time? Or do you switch between brands/weights? I've only used Mobil 1, 5W20 since the truck was new and this way I know what to expect when draining the oil between changes.

How many miles do you change your oil at? I've been going 6,000 and the oil seems to be very clean when its hot.

What kind of filters are you using? maybe you've had some junk filters in the past allowing things to build up inside the motor?

These are just some ideas that came to mind.

 

I'm going to be honest with you, and I'm sure ill catch some ****. But I've been using the dealerships free oil changes. Not anymore though, I drained a little bit and seems ok. Not clean but not too dirty. What does it consist of to drop the oil pan?

 

Anyone?

 

Bump. Need help guys

 

mcgoo - you mention you don't think it is the sending unit but you really don't have a good reason for "not" suspecting the sending unit. I don't know the price off-hand but a sending unit will likely be cheap ... change it and see. Second, surefire way is to get a mechanical oil pressure gauge and plumb that in instead of the electrical pressure sending unit.

If the mechanical shows you losing oil pressure, your first suspect is the filter, then look at your engine oil cooler (if installed) to make sure one of the hoses has not kinked or that the cooler itself has not been smashed causing an obstruction.

A note of caution from personal opinion and experience: if you go looking for sludge, you will find sludge ... no matter how clean your engine truly is inside ... your going to find something and then say ... "it's all sludged up". I don't know you ... I don't know your engine ... but unless you have 100K miles on it, don't pull your oil pan unless you actually are going to do some work on the bottom end.

 

(RovMan; "I don't know the price off-hand but a sending unit will likely be cheap ...").

Just bought one yesterday, From the Chrysler-ship, list 22.35 paid 15.00 +tax. for the 5.7L 2500. P/N 5149097aa , its called 'Switch-oil'. Have not installed it yet, which I dough it will solve my problem. Its just a step of elimination.