Oil Pressure Concerns

Hey everybody I was riding down the Turnpike yesterday and notice my oil pressure was fluctuating much more erratically than normal.

I first installed an oil pressure gage last year when the oil pressure sensor was letting the oil seep through to the electrical side of the sensor thus causing the dreaded low oil pressure alarm in the car to come on. I flipped out because I was on vacation around 500 miles away from the home base. Well it was just the sensor so keeping with my style of not just replacing the OEM and going on, I placed a hose extension where the sensor goes on the oil filter housing, and then adding a manifold so that the pressure sensor and a pressure gage could be utilized.

Anyways, now I have real time oil pressure readings and until yesterday when I start up the car, the oil pressure will go up to 85-95 psi until the engine is warmed up. At that point the pressure will go all the way down to around 25-35 psi when just idling at a light or stop sign. The pressure will then rise up to around 75-85 psi during turnpike constant 80mph driving. Typically during cruising the oil pressure will not fluctuate much more than a few psi during constant cruising. Yesterday, the pressure was regularly spiking about 10 more psi at irregular intervals. The oil pressure never really reduced from typical levels and aside from the pressure gage I could tell of no other noticeable clues of any problems with the vehicle.

I did stop and check the oil levels, and everything was fine.

I haven't check the gage as of yet for faulty readings, but has anyone had issues with oil pressure spiking during driving, and what eventually happened with the vehicle due to prolonged usage.

Has the car had a catastrophic cam follower failure at some point in its life?

banshee365 said:

Has the car had a catastrophic cam follower failure at some point in its life?

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The car in question isn't a PD.

Kevinski4 said:

The car in question isn't a PD.

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I didn’t even look at his info under his username. Ugh. My bad. I get so used to BRM chatter on here.

Yeah, I never know where to put questions about my car. If you look at the descriptions for each section, people with a 2010 Jetta Sedan are kind of left out of the sections. They tell me that my vehicle is like a 5.5 version with some things being in the version 5 area, while others will be more consistent with the section for version 6.

As for problems with the vehicle, I have about 202 K on the clock and I have never had an engine related issue other than a bad oil pressure sensor. I have tuned the vehicle with a Malone stage III, a larger turbo with the rolling coal set up there after. EGR is history and a south bend SMF clutch to handle the additional power, with a short shifter. I also have the micron tech fuel filter and isolation setup, and probably a few other mods that I forgot I did and can't remember at the moment.

There are some electrical things that are quirky in my estimation, but they stem mostly with the OEM radio, I changed that to an Alpine with actual knobs and the issues went away.

I am going to hook up another gage to compare with the one I have installed in the car to see if they match.

The car is due for a new timing belt, so since the pressure doesn't go above the startup values and doesn't go lower than normal, I'm gonna keep driving it and see how it goes. I'll take note if the timing belt has any effect on the situation. I don't think it should, but things behave in strange ways and any change of the situation can cause seemingly unrelated things to change as well.

Just to update on my oil pressure spiking issues. I attached another oil pressure gage and went out for a spin around the block. I didn't take it for my usual commute because I am too lazy to install through the firewall so I just had the wire draped across the hood and into the car through the window. BTW it is still cold here in PA, but I had to take it in the name of science.

Between the 2 oil pressure gages, they are in agreement sort of. The second gage regularly measures the oil pressure at around 3 - 5 psi lower than the original, and it also spikes along with the original, but at a lower amplitude. I checked the original's packaging, and the glow gage doesn't list a tolerance, but this seems like it may be within the limits although the gage readings are constant. This means when the gage registers 20 psi, that could be a 25% difference in measured data. At 90 psi, a 5 psi difference is 5.5%. This is more likely than not a introduced error in the sending unit but whatever nobody but geeks like myself care about this stuff.

The original spikes about 10 psi, and the check gage spikes around 5 psi. I rather believe that the oil pump couldn't spike that quickly if it wanted too, but the 5 psi spike is more believable although I find it hard to believe that a oil pump would spike up.

Isn't the oil pump chain driven? If so, I believe that there is some kind of valve issue going on. At this point, it really doesn't seem to be a problem, but what would be the effects on the engine if I had a valve failure that allowed a full pressure situation all the time?

I am only familar with the 2006 BRM which has a 30 percent increase in the oil pump rpm over the previous BEW and ALH motors. It's maximum oil pressure is in the 55 psi range and reaches this at about 2000 to 2100 rpm range. In other words the relief pressure is set in the range of 55 to 60 psi. The older engines have the same oil pressure but take about 2400 to 2500 rpm to reach it.

I used a direct mechanical non-buffered guage(not oil filled) to test mine and there are no spikes.