2003 4.7 Dodge Ram 1500 Oil pressure problem

Skeeterco · Dec 13, 2017

I have a 2003 Dodge Ram 1500 with 4.7 engine that has a new oil pressure problem. Just started having this issue. When I start up in the morning truck runs perfect with no issues what so ever. When the truck warms up and driving it has no problems until I stop at red light or to pump gas the oil pressure drops. Also, If I shut it off and crank it back up it will have no pressure. If I let it set for an hour and crank it again it is fine. What do you suggest the problem is? Thanks in advance with any help with this issue.
SC

BigBlue05 · Dec 13, 2017

Have you checked your oil level yet? Also I would look into the oil pressure sensor. They usually cost around 5 bucks and take 2 mins to change.

Skeeterco · Dec 13, 2017

I have checked oil level. I changed oil last weekend and put 5-30 oil in the motor. I am still having same issue. I have not replaced the oil pressure sensor but plan on replacing it this weekend along with another oil change. Thinking of flushing the engine as well.

fastf · Dec 13, 2017

I'm thinking your oil pump maybe going bad but try a new sending unit first.The reason i said that it sounds like the pump is getting where it isn't holding pressure or when you changed your oil you have crud stopping up your oil pump tube.If you could hook up a pressure guage outside the pump to check and see if you are getting good pressure.The oil pressure uses electricity to make it work but a real oil pressure gauge uses the oil pressure from the engine the oil pressure guage on your truck is like a idiot light.

CostaRam · Dec 14, 2017

I had the same issue on my 98 Dakota.
I thought to do good to use full sythetic Castrol Edge 5-30 but exactly this problem showed up and the engine started to leak oil everywhere.
I switched to 20-50 high milage and everything turned normal.
Chris

fastf · Dec 14, 2017

CostaRam said:
I had the same issue on my 98 Dakota.
I thought to do good to use full sythetic Castrol Edge 5-30 but exactly this problem showed up and the engine started to leak oil everywhere.
I switched to 20-50 high milage and everything turned normal.
Chris

Something you might consider CostaRam this person lives here in Georgia not Costa Rica big difference in temp here and where you live believe me I live here and that effects oil also.

CostaRam · Dec 15, 2017

this person lives here in Georgia not Costa Rica big difference in temp

Yes, that is true, but engine oil has/should have the same temp when engine is at operational temp here and there,
the ambient temp affects cold start.
OP wrote that the problem occurs when the truck is warm not while cold starting.
Chris

Skeeterco · Dec 15, 2017

I am running 5-30 oil now and when I change it this weekend I will put 20-50 in it. The truck runs perfect other than the issue I am having at the moment.
SC

fastf · Dec 15, 2017

Go by you viscosity chart for different weight oil and what weight you can use as far as temperature start up and running.You are actually running a heavier weight oil but if it works ok i say go for it.But I don't think the oil is your problem i believe you may have a sending unit problem or your oil pump isn't doing its job if I'm wrong i will be the first to admit it.

fastf · Dec 17, 2017

Hello,Were you able to get your pressure problem fixed?

Casper · Dec 18, 2017

You may want to drop your oil pan and see what is lying on the bottom of it. If its full of "mayonnaise" your pump may be loosing suction. 4.7L's from that era are sludge pumpers in cold weather with a lot of short drives. That sludge can hide out in the pan even when you change the oil. If not, as stated your sending unit or your pump may be failing.

Skeeterco · Dec 18, 2017

I did not work on it this weekend at all. I was busy working overtime Saturday and family things Sunday, Anyway, I did however pour two bottles of STP oil treatment in to build the viscosity up a bit. This fixed the stopping at red lights and idling for seconds at a time problem. I can stop at store and pump gas without any worries. The problem still exists when I shut it down and re-start it in 20 minutes or so. I crank it and it has no pressure for around 30 seconds or so when I rev it and drive around. There is no knocking or rattling at all so hopefully it is the sensor. I will change it this week and let you know the outcome.

fastf · Dec 18, 2017

If you poured STP oil treatment if it the same stuff that use to come in a metal can you just made things worst that stuff is like molasses.When It came in a metal can we use to sit it near a heater to make it thin out to pour in a engine and draining the stuff out of the oil pan is worse.Your oil pump is starving for oil the tube inside the oil pan has sludge and with this oil treatment you may have made thing worse that stuff is for engines that are burning oil or leaking oil .I wouldn't put that stuff in my engine unless it was the last thing .When you get ready to change that oil make sure the engine is hot or that stuff will take for ever to drain.It will make lifters quiet down for a little while but not for long.

2003 4.7 Dodge Ram 1500 Oil pressure problem

Skeeterco

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BigBlue05

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Skeeterco

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fastf

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CostaRam

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fastf

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CostaRam

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Skeeterco

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fastf

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fastf

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Casper

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Skeeterco

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fastf

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