Slow Oil Pressure At Start-up

[gndd1997]

I changed my oil about a week ago and over the last few days I've noticed my 'check gauges' light stays on until the oil pressure suddenly rises to +/- 65 lbs...I've never really paid attention before as to how long it takes for the oil pressure to build on start-up but the 4 to 5 seconds it takes to register on the gauge after the engine starts has me a bit worried. Does anyone else have a similar 'lag' time from start-up to pressure build-up? The engine only has +/-50000 miles on it and I've always ran synthetic...that being said, the oil change I just did changed my oil brand from Royal Purple to Mobil 1 full synthetic (both 5w-30), if that matters...also, I have a 1997 K2500 Suburban with 7.4L engine. Any and all information is greatly appreciated!!

 

[Ruger_556]

I have oil pressure as soon as I release the key cranking. What filter did you use?

 

[woody31]

x2 on the oil filter,,i have 45lbs soon as it starts,,could possibly be sending unit to

 

[great white]

Cold start can get my diesel up to 65 psi. But it's nearly instantaneous. Def no check gauges time.

Filter is suspect if it's fram. Could be stuck in bypass. I believe it bypasses at 5-10 psi.

The other possible issue could be the oil pump bypass. Highly unlikely though....I'd look in to the filter first, as ruger mentions.

Could also possibly be the pressure sender if it was transferred from the old engine to the new. potentially coked/sludged, passage is pretty small. Long shot, but possible.....

 

[gndd1997]

Sorry, should have mentioned filter brand too...duh ...I've been using Wix almost religiously since getting new engine, Fram has had enough of a bad reputation that I've stayed away from them. I was suspecting oil pressure sender and I do have a new one in the garage waiting to be put in when I change intake manifold gasket (I've had a small oil leak from rear which is slowly getting worse since engine swap...new engine was put in by dealership and they did such a sh*ty job, long story) but it seems strange that all of a sudden since last oil change last weekend I noticed the slow pressure build-up...once it hits +/- 65 lbs it's totally normal through warm-up where it sits at +/- 20 lbs at idle and jumps back up when accelerating as it always has in the past. I'm taking all of your advice to heart and changing filter ASAP, thank God it's the weekend...have a great Memorial Day everyone and thanks for the input!!!

 

[gndd1997]

So I finally had a chance to pull the new oil filter off and barely any oil dripped out of it!!! Usually the filter is full and I have to wait a few minutes to let it drain before completely removing it...looked like hardly any oil got into the filter, looked down the in and out lines and nothing is blocking them and there was oil inside them...if the filter anti-drain back valve was stuck could that cause the filter to block oil from going through it even at the 65 lbs of pressure at cold start up? And how would I be able to check to see if the filter is bad? I know it's not the pump and this just started since I changed the oil last week so I'm thinking it's the filter but how do I check to be certain? Any and all info. is greatly appreciated!!!

 

[great white]

So I finally had a chance to pull the new oil filter off and barely any oil dripped out of it!!! Usually the filter is full and I have to wait a few minutes to let it drain before completely removing it...looked like hardly any oil got into the filter, looked down the in and out lines and nothing is blocking them and there was oil inside them...if the filter anti-drain back valve was stuck could that cause the filter to block oil from going through it even at the 65 lbs of pressure at cold start up? And how would I be able to check to see if the filter is bad? I know it's not the pump and this just started since I changed the oil last week so I'm thinking it's the filter but how do I check to be certain? Any and all info. is greatly appreciated!!!

They're cheap. Spin another on and fire 'er up.

See what ya get.....can't be any worse than what it was or at least it should be the same.

 

[gndd1997]

They're cheap. Spin another on and fire 'er up.

See what ya get.....can't be any worse than what it was or at least it should be the same.

Leaving right now to get another filter...I'll have an update in about 1/2 hour, pray for the best!!!

 

[gndd1997]

OK, a little more than 1/2 hour but good results!! Bought an identical filter (Wix 51060) and checked it versus the old one...visibly the same but when I gently pushed down on the Anti-Drain Back on both the new one seemed stiff enough but with the old one the whole filter unit (inside the can) moved down thus I was only pushing down on the pressure spring in the head of the filter, the ADB was stuck open?!?!?! So the oil was just bypassing the filter and all of the oil was draining back into the case when I shut off the truck thus every time I restarted it the oil pressure would read as if I had just changed the filter and it had to 'pump up' again even when warm (I freaked the first time I started it with the new filter because it had to 'pump up' again but soon realized, DUH, the filter was empty!!). So I gave the truck a bit to cool down and let the oil drain back, if any before starting it up again and with fingers crossed she started right up and the pressure gauge jumped right up to 65 lbs...realizing I was holding my breath I let go a huge sigh of relief!!! Gonna cut open the filter with my dremel in a bit just to see what the heck happened because I've never had this problem before and, by God, I'm gonna figure out what caused it...I'll keep you posted. Have a great Memorial Day weekend, y'all, and stay safe!!!

 

[great white]

Pre installation failure or "PIF" in aircraft terms.

New one in and life is good again.