I've got a problem with oil pressure. The oil pressure in my 350 has been steadily going down for the past few weeks, ever since I changed out my timing chain. At that time I also switched to a synthetic oil, though I'm not sure if that would make a dramatic change in usual oil pressure. While I'm driving it stays around the 30 mark, but the longer I drive the lower it gets when I stop at a red light. So if I drive for only like 10 minutes it'll drop down to the 15ish mark. I drive for 30 and it hovers over the red line on my gauge. Today it dropped to zero when I got to work. Zero. I didn't hear any clanking, tapping, or knocking in the engine so I'm wondering if it's my oil sending unit... but the one I have is only about a year old. I've got plenty of oil and my last change wasn't too long ago, less than 1000 miles. Any ideas on what's going on?

 

I forgot to mention, the car is not smoking and if there's a leak it's very minor as i don't seem to be losing any. The pressure does go up when I increase RPMs. Sorry for the wall of text, I'm having to write this from my phone.

 

The first thing you need an answer to is "what is the real oil pressure". You can't get that from the factory gauge. Install a real OP gauge for a while and see if you really have a problem. If you don't, start with a new sender.

 

Sounds like a plan. Where should I hook it up at? Same place as the sending unit?

 

Im having the same problem. Did you figure out what it was? Where do you hook up the gauge at?

 

Unfortunately no. My oil pressure appears to be adequate but I'm planning on a rebuild anyway. When I do that I will also replace the oil pressure sending unit since it's not that expensive. If you haven't replaced it I would do that first, since I already had to once on my car last year. This is also why I don't think it's my sending unit.. not going to dismiss the possibility of a crappy part though.

I have multiple threads floating around out here concerning not only oil pressure but an odd misfire during acceleration that I can't seem to track down which has been happening since well before the oil pressure issue. I also have a small coolant leak at the intake gasket right below the thermostat (not the thermostat gasket itself) and an exhaust leak where I must not have attached the exhaust back properly when I lowered the oil pan to change out my timing chain (which didn't fix the misfire and is when the oil pressure issue started).

At 208k miles it's pretty much time for a rebuild anyway considering all the issues I'm dealing with. Maybe she'll run smoother with more power and hopefully better mileage when I'm done.

 

My engine only has 12k on it. So I am thinking it must be the gauge or something.

 

Look on the front of the block above the timing chain cover, right below the intake manifold/block interface. If there's an 1/8" pipe plug there you can tap off there to get an oil pressure reading.

 

What type of gauge? What parts would I need to connect the gauge to the engine? Anyone have an affordable parts list?