2G Oil pressure dropping upon braking

[ishnish]

Hey guys, so after finally rebuilding my head, changing timing components, all belts, water pump, etc. I decided to drive the car for the first time in years to test it out. I drove just a short distance around the block to see how things would go.

What I noticed was that on my aftermarket prosport oil pressure gauge, the car sat at 10 psi @ 750 rpm (which I believe is normal enough) pretty rock steady. However, I noticed that every time I would come up to a turn and depress the brake pedal, and depressed very steadily at only 15-20% mind you, the oil pressure would drop below 10 psi and my gauge warning light and beep would go off. Also, this was around 15 mph or so. At one point, when I finally got 25 mph or so in 2nd gear and depressed the breaks, the oil pressure dipped all the way down to almost 0 psi if not 0 for sure and then my factory oil pressure light came on. I immediately shut off the car and popped the hood open to check it out. Everything looked perfect.

On the ground, I noticed a leak that trailed the entire route I took my car on and suspected it could have been my oil. It wasn't my oil though. I believe it was a puddle of coolant from pulling a coolant hose when removing my tb for a rebuild. My only guess is that is what it could have Been unless of course I could have a coolant line disconnected somewhere. Because the leak only happened when my car was moving.

Anyway, this morning I decided to check my oil levels. The dipstick read I was completely fine with oil so no problem there. It was full. I parked my car over a white sheet last night and checked to see if there were any spots on the sheet that may have been from sitting over night. NOTHING. Completely clean.

So, since I know an oil leak definitely isn't an issue, what could be causing this problem? Is this normal? Keep in mind, my car has sat for 4 years or so never even started. Could it be an oil pump issue?

Thank you

 

[ishnish]

Does your idle drop below 750rpm when you step on the brake?

Do you have any tuning logs that we can look at while you drive? That would be an accurate way to see if the rpms are going way down upon braking. Ramen could of gave your answer in his post regarding the oil dip to rpm. I'd boost leak test to assure no place is leaking giving you non monitored air to make the car almost stall resulting in the oil light to pop on and go low on oil pressure since the car is trying to shut off itself. If your oil is full and if it is clean without any metal pieces, I wouldn't suspect oil pump but if you'd have time, just pack the oil pump with some vaseline and prime it from it sitting for 4 years without being started. That could rule the pump being the problem.

Also, prosport is butt for gauges. Autometer is definitely the way to gauge but yea they're all ugly. At least you can get different color condoms for their lights.

Make sure at warm idle, you verify it is idling at 750rpms.

At warm idle you attempt to tighten both sensors into the housing, more importantly the screw on the connector to the factory switch

UPDATE: Guys, thank you very much for your replies but I think I may have found out what was going on. So, as far as the leak goes, I almost believed that I had bad piston rings because the smoke that was coming out of my exhaust was pretty thick especially after I revved high. Then, I found out from a neighbor that because my car has sat for almost 5 years, a TON of condensation was left to build up in the exhaust system and especially the muffler where it probably puddled up. I thought the smoke would clear in a much shorter time than it really did.

So finally, after a long time of letting it run and then driving it, the smoke FINALLY cleared and I found out the leak was just water and the reason it wouldn't evaporate (which explains the stains) is because of the carbon buildup that came out with it. This caused very dark stains the ground that didn't go away.

Also, as far as the oil pressure, RamenPride, you're correct. The oil pressure was close to 0 but not that close. It probably dipped to 4 psi or so and I finally saw that when I hit the brakes, the car's rpms would dip down to 400-500 rpm and that's what caused the big dip in oil pressure only momentarily. This was a relief for me!! So, the leak issue is resolved.

As for the oil pressure, I'm still gonna monitor closely for any warning signs that may worry me. Thank you guys!

 

[ishnish]

Hey guys, so another update. Took my car for a drive across the town to see how it went and the oil pressure pretty much stayed at 10psi until at higher speeds (25 mph or so) where I would shift into neutral and let go of the gas, it would momentarily dip below 10 psi (at one point it got town to 4-5 psi) but then would go right back up to 10. Idk if this is normal.

Also, my check engine light came on about 10 minutes into the drive. I wanted to come back home and hook up link but had to drop the car off and go elsewhere for some errands and was in a rush. So later that night I hooked up link and my check engine light was gone.
I went to the DTC's tab and on the top section (I think it's Reported DTC's) and there was nothing there.

Any idea as to what it could have been? I'd think it would record it even though it went away but I guess not. It definitely wasn't water temp. My car was below 200*F for most of the drive and at the highest got up to 203*F or so.

 

[91tsiawdtalon4g63]

Are you running a maf or sd? I think you need to boost leak test the car to check for air leaks

 

[ishnish]

Are you running a maf or sd? I think you need to boost leak test the car to check for air leaks

Yes I am running a maf. I only boost leak tested from the intake mani. Yet to boost leak test from the turbo inlet. 0 leaks currently from the mani though.

 

[chrysler kid]

I think the light illuminates under 4 psi, at least that's what I remember seeing stamped on the bottom the last time I replaced it.

Check engine light, no clue. Should have left something in the memory to trigger the code.

 

[ishnish]

I think the light illuminates under 4 psi, at least that's what I remember seeing stamped on the bottom the last time I replaced it.

Check engine light, no clue. Should have left something in the memory to trigger the code.

Yeah so I think it hit 4 psi only once but it's been fine ever since.

When I drive it again I'll try to make sure to have the laptop on me so I can maybe check right then. Weird

 

[chrysler kid]

The only time that happened to me was the throttle position sensor wiggling loose. Being auto the car nearly shit gears out the side of the trans downshifting into first at 40mph

Pulled over, plugged it back in and the light went away

 

[ishnish]

The only time that happened to me was the throttle position sensor wiggling loose. Being auto the car nearly sh** gears out the side of the trans downshifting into first at 40mph

Pulled over, plugged it back in and the light went away

Jeezz, no don't think it's that because I made sure of it being snug but I will check. The next drive should be interesting

 

[ishnish]

UPDATE:
Hey guys, so I got to finally drive my car again and figured I'd try to get to the bottom of this whole issue.

Went for a drive and I noticed that when I get up to a higher load (around 2800-3000 rpm) in second and third gear and then go into neutral and let off the gas completely, the rpms drop down lower than idle (maybe around 200-300 rpm) pretty fast. This is when my oil pressure lights come on after dipping down to 4.5 psi (maybe lower) and the car shuts off. It happened maybe 4-5 times during my drive.

Now, I noticed when I let off at that same load but I stay in gear, it's totally fine. It only happens when I get to high load and then shift to neutral and let off the gas, the rpm needle drops pretty dang low.

I remember a couple of years ago when I had my clutch job done and what not, I had the guy install a light weight chromoly flywheel. Now, come to think of it, this could be the reason why my rpms drop so low and fairly quickly. It's not the fidanza flywheel (the super light one) but it is light (11 lb flywheel). Could this be why my car shuts off? Or is it because of the oil pressure? I figured the only reason my oil pressure dips is because of the rpm and the rpm issue could be because of the flywheel. Even then though, my buddy has a light-weight flywheel and still not the same issue.

Could it also be related to my FIAV bypass? My car idles at 750 with the bypass and I'm not sure of I should maybe adjust my idle to something higher or what.

Any input?

 

[91tsiawdtalon4g63]

Raise your base idle to 900 and drive to see if it still stalls. Mine did the same thing after installing a fidanza flywheel so I adjusted the biss and base idle with ecmlink. Also the iac was funky so I unplugged it and went with it.

 

[chrysler kid]

Yeah if it's idling low that will trigger the low oil pressure.

My car had issues with the EGR delete. After warm when cruising it acted like it wanted to die between shifts and I finally got an EGR malfunction code and reconnected the EGR and that went away.

Basically the IAC should kick in and keep the idle from dropping that low, I would double check your settings on ECM link to make sure you have EGR functions deleted. I'm not sure what that entails, but my issues were the same and went away when I pulled the block off plate off and just let the EGR work

 

[ishnish]

Raise your base idle to 900 and drive to see if it still stalls. Mine did the same thing after installing a fidanza flywheel so I adjusted the biss and base idle with ecmlink. Also the iac was funky so I unplugged it and went with it.

Okay will do thank you. My isc functions Just fine and Steve Monroe verified that as well.

Yeah if it's idling low that will trigger the low oil pressure.

My car had issues with the EGR delete. After warm when cruising it acted like it wanted to die between shifts and I finally got an EGR malfunction code and reconnected the EGR and that went away.

Basically the IAC should kick in and keep the idle from dropping that low, I would double check your settings on ECM link to make sure you have EGR functions deleted. I'm not sure what that entails, but my issues were the same and went away when I pulled the block off plate off and just let the EGR work

My EGR is all deleted but I never had an issue that I can remember after deleting it all. The IAC/ISC this is what weirds me out because I know it works properly. Raise the idle though and see how that goes!