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No Oil Pressure

Paveltolz

Paveltolz

Доверяй, но проверяй
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Location
Saratoga Springs, UT
Friend called and I'm out of town and ideas. but not without collective theorys
...
At issue, he changed oil in his 97 6.5 2500 and while hunting down tools, let it drain for 4 hours. He refilled it with 7 quarts and the dipstick showed full. However, at restart...no oil pressure!
Says the oil pressure gauge has been plagued by a dancing needle for a while so I kinda suspect OPS.
LP runs in the key on position but I know that's just one side of the OPS' function.
And yet, there's no oil pushing out of the turbo feed line when held over the oil fill tube (he only ran it for a few seconds).

Now he's reading a quart low at the dip stick.

Does he;
a) show a quart low because the oil cooler drained over the four hours;
b) have an air bubble in the system as the oil cooler needs/needed to re-fill
c) show no pressure because the oil cooler is empty
d) need a new OPS
e) need to try re-priming the system with the oil pump drive at the back of the block
f) need to stop asking me for advice?

I defer to your collective wisdom.
 
Yeah, mystery to me. I'd be tempted to swap in a new OPS, run the pump prime and see if pressure came up. I didn't have pressure on my first start up of the new motor but, we ran run it for less than a minute to see if the oil comes up the turbo feed, took a bit before it did and pressure came up. Big but, this ain't my motor and I'm not going to advise him to take risk without some good opinions from the collective.
 
If the pump drained out it might take awhile to reprime. shouldn't have anything to do with the oil cooler as it would fill rather quickly. if I was concerned I'd run the oil pump manually with a drill until you read pressure.
 
Check for leaks. Like the oil filter gasket blown, doubled up, or missing and oil cooler lines for sudden failure. Also check that the OPS didn't blow out.

You are down on oil so the 'air locked' oil pump did start to move oil. The oil is in the filter and cooler now or all over the ground, etc. where is should not be.

How long did he run the engine?

The oil filter will take a quart alone on 2WD engines. 1997 may have the LP run off the ECM not OPS.

Get another oil filter so you can remove the oil filter that is on it and check if it has oil in it. Oil filter gaskets do not like coming off and going back on and not even worth the risk of doing so. You can use the first filter for testing, but, make sure it has a fresh gasket filter before going down the road. I would prime the oil filter as much as possible in this one instance. (I do not recommend pouring unfiltered oil in the clean side of a filter. Esp from a lube truck nozzle that just went down a dirt road...)

I would use a mechanical gauge to verify readings.

Do not ever drain the oil for this long again for exactly this reason. It is bad enough the oil filter is empty to begin with on a normal change.
 
After oil changes I unplug the pmd and use the starter to get oil pressure. I do let the starter cool as I don't try to get pressure on first try. If oil pressure guage not working I disconnect turbo line and wire tie into oil fill to verify pressure. This is how I primed my Teds motor after swap as I was pressed for time on drill procedure. Not the best for starter, but cheaper than engine damage. I used to do this on my AMC gasser before stealing the scavenge pump from 6.5 TD. I don't start that engine(AMC360) ever without 40 pounds on the guage now.
 
Thanks for all the advise guys. And thank you Paul for getting this on TTS. To war wagon. In total my engine has run no more than 20-30 seconds. and the dipstick read full the entire time. it wasnt until I pulled the turbo feed line and pumped the motor over for about 2 seconds that I noticed that the oil level dropped. I had a gut feeling I shouldnt have drained it for so long and that something like this might happen.
 
hookedup50 said:
After oil changes I unplug the pmd and use the starter to get oil pressure. I do let the starter cool as I don't try to get pressure on first try. If oil pressure guage not working I disconnect turbo line and wire tie into oil fill to verify pressure. This is how I primed my Teds motor after swap as I was pressed for time on drill procedure. Not the best for starter, but cheaper than engine damage. I used to do this on my AMC gasser before stealing the scavenge pump from 6.5 TD. I don't start that engine(AMC360) ever without 40 pounds on the guage now.
Click to expand...


I am thinking this is my best option to try and prime the motor as I too will be pressured for time. I work today and have just a few hours tonight before the truck is needed for work tomorrow. I have a feeling that oil started moving around last night on my last start up attempt. That being said, you just unplug the pmd and run the starter for several seconds at a time? how are you checking for pressure when doing this?
 
Which oil filter did you put in there?

Try putting a different one and see.
There are a few instances of bad out of the box filter.

Also, try to change the OPS.
That is also a weakest link.
 
X2 on AK's post. I watched the factory guage pump up and cause I had a new A Team turbo I pulled the oil feed to verify it had oil going to it. If I thought my OP guage wasn't working I would do this to see if pressurising. Let the starter cool a few minutes between cranks. My Teds engine sat a long time before starting and it took a while to pressurize and fill cooler and fs2500 filter. X2 on OPS
 
Read codes out of ECM before doing this just in case you have any. I would just pull the ECM fuse to crank without fire rather than mess with the PMD. (Both methods work.) Oil at the turbo line is proof even if the gauges don't work with that fuse out.

30 seconds of cranking followed by 2 min cool down. I hate changing starters...

Also before you change the oil start the engine to make sure everything has oil in it. I get faster oil pressure after a change by doing this. FRAM (garbage) filters will leak down empty as well as other brands with a bad antidrainback valve on 4x4. Does not apply to 2wd with vertical mount filters. 2wd and 4wd can have the cooler empty out from sitting. (Wix, Acdelco, Mobile1, etc. are good filters. Cept bad design wix duramax plastic body fuel filters...)

The OPS is something you don't want to let give you trouble. Replace it at the first sign of trouble. Also make sure the grounds are in good shape as body to engine grounds will affect the reading on the gauge. I always recommend extra grounds between the frame, body, and engine be added.
 
WarWagon said:
Read codes out of ECM before doing this just in case you have any. I would just pull the ECM fuse to crank without fire rather than mess with the PMD. (Both methods work.) Oil at the turbo line is proof even if the gauges don't work with that fuse out.

30 seconds of cranking followed by 2 min cool down. I hate changing starters...

Also before you change the oil start the engine to make sure everything has oil in it. I get faster oil pressure after a change by doing this. FRAM (garbage) filters will leak down empty as well as other brands with a bad antidrainback valve on 4x4. Does not apply to 2wd with vertical mount filters. 2wd and 4wd can have the cooler empty out from sitting. (Wix, Acdelco, Mobile1, etc. are good filters. Cept bad design wix duramax plastic body fuel filters...)

The OPS is something you don't want to let give you trouble. Replace it at the first sign of trouble. Also make sure the grounds are in good shape as body to engine grounds will affect the reading on the gauge. I always recommend extra grounds between the frame, body, and engine be added.
Click to expand...


Thank you. I will pull the crank/pmd and run the oil that way. I still have the oil feed line off my turbo and I can verify oil flow that way as well as pressure on the guage. I am running the AC DELCO brand oil filter.

I know all too well about changing starters. Bought a cheep lifetime from a place and have since replaced it 6 times in a 4 year period. In fact they told me next time i bring in the dead starter they will refund me and not warranty it anymore.
 
Unfortunately, ACDelco oil filter brand is not the most reliable anymore as it used to.
You can check BITOG for that.
They start using what they called e-core which is actually plastic cage as supposed to metal internally.
Not on all filter so I am not sure if yours have metal or plastic.
It is made by the same company making STP filter for AZ.

I would get something like Purolator or Napa Gold for this truck.
 
JMJNet said:
Unfortunately, ACDelco oil filter brand is not the most reliable anymore as it used to.
You can check BITOG for that.
They start using what they called e-core which is actually plastic cage as supposed to metal internally.
Not on all filter so I am not sure if yours have metal or plastic.
It is made by the same company making STP filter for AZ.

I would get something like Purolator or Napa Gold for this truck.
Click to expand...


Where would I find something like Purolator? I have (just as always) purchased the AC DELCO from AZ. Is that something that is available nationwide or would it need to be ordered?
 
Walmart and Pepboys and Sears have Purolator now.

Napa Gold is at Napa.

Bosch at AZ is actually made by Purolator also.

You can take out the filter and inspect it also.
If it is the metal internal, it is probably ok but the plastic one is questionable for this truck although they are ok for sedan/smaller engines.
 
Hmm... News to me on ACDelco oil filters. I'll look at mine as they were out of stock on Wix last time I picked one up.
I avoid AZ like the plague as their no-quality parts cost me lots of time and collateral damage esp when the pad came off the backing and ate a rotor. Their firing of a 'hero' employee for stopping a robbery in their store was the last straw for me.

Powermaster makes a great new starter for the 6.2/6.5. I broke the roller clutch drive on one under warranty with (bad) sticking injectors. The replacement is ~3 years old now. Autolite reman appears to be ok so far on the other ride.
 
WarWagon said:
Hmm... News to me on ACDelco oil filters. I'll look at mine as they were out of stock on Wix last time I picked one up.
I avoid AZ like the plague as their no-quality parts cost me lots of time and collateral damage esp when the pad came off the backing and ate a rotor. Their firing of a 'hero' employee for stopping a robbery in their store was the last straw for me.

Powermaster makes a great new starter for the 6.2/6.5. I broke the roller clutch drive on one under warranty with (bad) sticking injectors. The replacement is ~3 years old now. Autolite reman appears to be ok so far on the other ride.
Click to expand...

Thank you for the info. I will look in to the powermaster starter as im sick of the random and instant flat spot zero starts I have gotten in the past from my re manned ones. Thank you all for the advise. I will be getting off work here in about 2 hours and hopefully get the beast back up and running. I will post my findings/problems once I encounter them.

I never expected an oil change to be so worry some. I also replaced the stock trans cooler with a larger 26,000 GVW fan unit from flex-a-lite and figured if anything was going to give me problems it would have been that. O well just another reason to love being the fix it guy.
 
I'm finding it hard to think ACDelco filters that are specified on all GM new vehicles would be compromised if they are installed on a warrantied engine.
 
As I said, there are 2 type of ACDelco Oil Filter.

One with Plastic e-core and one with metal.
Somehow, the one that is sold out there is with plastic e-core.

If you can find the one with metal core, that should be better.

I suspect the one coming from factory is probably the metal one.
Not surprising.

I am just relaying the info I read at BITOG.
 
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