oil pressure

[LasVegas]

I took the mall queen for its first offroad experience yesterday and had a blast...until about noon. We started out on the trails at 9:00 am and everything was running beautiful. About noon we pulled over for a break, shut it off and got out. 20 minutes later got in, started it, and got chime alarm and looked down...-0- oil pressure. Immediately shut down but the engine had sounded fine with not even lifter noise which proves there was pressure when I shut down earlier. Checked oil, full and clean. Okay, it's that sender or gauge problem and it finally failed, right?. Wrong! Restarted, same thing except now lifter noise starting. No doubt, -0- oil pressure. Now we're in the mountains on the California/Nevada line, no cell or Onstar service. The team did a wonderful job towing me to the closest (30 miles) one bldg "town" where we arrange a flat bed to Vegas. Thanks guys. It's now at the dealer waiting for them to open tomorrow & I lost a nights sleep. I've racked my brain on this and without engine knocking or other sounds I don't think it's bearings or internal engine problem. Oil pumps rarely fail at 16,000 miles and the only thing I can think of that would cause this kind of sudden oil pressure failure is the oil pressure regulator (a ball & spring) within the oil pump. If the spring failed (broke) I believe it would cause -0- psi. For those that understand internal engine workings I'd appreciate your thoughts. HummerTech or anyone else ...you have any ideas?

[LasVegas]

I took the mall queen for its first offroad experience yesterday and had a blast...until about noon. We started out on the trails at 9:00 am and everything was running beautiful. About noon we pulled over for a break, shut it off and got out. 20 minutes later got in, started it, and got chime alarm and looked down...-0- oil pressure. Immediately shut down but the engine had sounded fine with not even lifter noise which proves there was pressure when I shut down earlier. Checked oil, full and clean. Okay, it's that sender or gauge problem and it finally failed, right?. Wrong! Restarted, same thing except now lifter noise starting. No doubt, -0- oil pressure. Now we're in the mountains on the California/Nevada line, no cell or Onstar service. The team did a wonderful job towing me to the closest (30 miles) one bldg "town" where we arrange a flat bed to Vegas. Thanks guys. It's now at the dealer waiting for them to open tomorrow & I lost a nights sleep. I've racked my brain on this and without engine knocking or other sounds I don't think it's bearings or internal engine problem. Oil pumps rarely fail at 16,000 miles and the only thing I can think of that would cause this kind of sudden oil pressure failure is the oil pressure regulator (a ball & spring) within the oil pump. If the spring failed (broke) I believe it would cause -0- psi. For those that understand internal engine workings I'd appreciate your thoughts. HummerTech or anyone else ...you have any ideas?

[Dug]

The obivious answer is the oil pump puked. But i am curious what you find out. Could be clogged screen or plugged passage way etc. Good luck with it.

[LasVegas]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dug3x3:
The obivious answer is the oil pump puked. But i am curious what you find out. Could be clogged screen or plugged passage way etc. Good luck with it. </div></BLOCKQUOTE>Gee, I just don't see clogging as the cause. It only has 16,000 miles & the oil (Mobil 1 syn) has been changed 3 times and it's clean as a whistle. Clogging generally comes on slow with gradual reduction in psi, not sudden drop to -0-. That's why I thought the pressure regulator. It could have been "hanging" and finally either stuck wide open or the spring failed. Thanks for the input.

[Dan]

It either failed or the pickup fell off.

[HUMMERcustoms.com/TAZ]

Jonahs I wonder if with You having a low oil signal in the past if the draw away from the oil pan by the STS oil pump could just be exagerating the low signal from the sender. I wonder if it is taking away just barely enough pressure to make sender not read. I wonder if it is robbing the pan of enough oil to just let it drop pan oil level for the pump to pick up like normal. Just trying to think of some things more easy to fix so dealer does not start tearing things apart. One thing We were considering was adding an extra 2 quarts of oil thinking of that problem. I know You added an extra quart for the pump filter but, We were figuring it would need another just for the oil line. I know how You watch things so You filled it with oil till dip stick was right.
I'm just thinking of everything I can that I had looked at before. I'll keep thinking and go back and look at My notes. We did not have that problem occur so, like the Guys are saying it may be just a quiky oil pump I hope.
let us know
TAZ

[LasVegas]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dan:
It either failed or the pickup fell off. </div></BLOCKQUOTE>You're right. A loose and now detached oil pick up could have given the same symptoms. Thanks

[PARAGON]

So, since it started knocking we can rule out the sending or gauge. Not being a fan of coincidence, what could have transpired during an oil change that would lead to the regulator failure? I really can't imagine the pickup creating that kind of eratic symptoms, but maybe. I don't guess some contaniment was introduced to the oil during the change that kept "lodging" and impeding oil flow then coming loose and allow pressure to get back up to norm and now finally has stopped flow all together.

Be interesting to know the cause but many times they will just fix it by replacing parts and not seek the cause.

[LasVegas]

Agreed Paragon, I'm not big on coincidence either. But there just isn't much they can do on an oil change (especially with me watching over them) that would cause this. I think the pick up could absolutely cause these symptoms. The pick up is just a tube from the bottom of the oil pan up to the bottom of the oil pump on the front of the engine with an O-ring and one bolt holding it tight. Now if that bolt started to loosen, and with less "suction" from the oil pump at idle to hold the O-ring tight, bam, less oil pressure. I've always noticed that the most common time for the 20 psi @ idle was sitting in my driveway on an incline waiting for the garage door. Hmmmmm. Then with all the offroad vibrations yesterday I wonder if the bolt backed completely out but the pick up/O-ring was held tight from pump suction until I shut down, then it virtually fell off the pump. Because whatever happened it happened between shuting the engine down and starting it. Make sense to you???

[partsguy]

May sound stupid but,what kind of filter was
used.Beleive it not I had one guy use a cheap "monkey lube filter"made of paper.The paper some how got out of the cartrage and blocked an oil passage.Did almost the same thing low to
no pressure and ugly valve tap.Long story short
No damage "as far as 6 months of driving,and
no lack of performence.
Good luck let us know!
The pump pick up I think is tack welded to the
pump.

[LasVegas]

Thanks partsguy. I use a huge auto service chain here in Vegas and have for all my vehicles for 10 years. I really don't think it's the filter. I know they're name brand but just can't remember which one.

The service manual doesn't say anything about the pick up being welded. Of course we both know what that means....nothing. I'm going to personally inspect the problem when they open up the engine.

[BLOWNZO6]

The pump pick up on these trucks is bolted in two places with an oring seal on the end that goes up to the oil pump. This pump is not like the conventional back of the pan old school pump. This is a gearator pump on the front of the engine.. very reliable and always soaking in oil. If the pump went out.. it would be a miracle. If the truck is still full of oil and you have a tick, meaning no oil in the lifters... I am with parts guy.. something clogging an oil passage.

I thought the truck would not start if the ECM sees no oil pressure? Something to check out.

Hope you know your dealer.. I am seeing the "your aftermarket turbo kits taps off the factory system and that caused the failure" excuse coming otherwise.

Good luck with it.. something tells me it will end up being something simple, better safe than sorry though.

EDIT: Guess you have a picture of what I described already.. guess I should have read all the way through

[PARAGON]

I haven't seen the lower of our engines personally but looking at the service manual it looks pretty typical. There is a bolt where the tube goes into the pump (where the o-ring is) but there is also 2 nuts that hold the pick-up tube for support midway of the block. In my thinking those 2 nuts would have to come loose also for it to completely lose pressure, along with the bolt that tightens the end of the tube to the pump. I would think there would still be enough upward pressure from those two support nuts to hold the tube to the pump.

I don't know what to think about the driveway deal though. I look forward to hearing the answer.

[LasVegas]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BLOWNZO6:
The pump pick up on these trucks is bolted in two places with an oring seal on the end that goes up to the oil pump. This pump is not like the conventional back of the pan old school pump. This is a gearator pump on the front of the engine.. very reliable and always soaking in oil. If the pump went out.. it would be a miracle. If the truck is still full of oil and you have a tick, meaning no oil in the lifters... I am with parts guy.. something clogging an oil passage.

I thought the truck would not start if the ECM sees no oil pressure? Something to check out.

Hope you know your dealer.. I am seeing the "your aftermarket turbo kits taps off the factory system and that caused the failure" excuse coming otherwise.

Good luck with it.. something tells me it will end up being something simple, better safe than sorry though.

EDIT: Guess you have a picture of what I described already.. guess I should have read all the way through </div></BLOCKQUOTE>Thanks BlownZ06. I've studied this pretty hard and it's always been Mobil 1 synthetic right out of their container and that's hard to screw up. So what else could block a 16000 mile engine oil passage???? Not much that I can think of. And it would take a fairly good sized piece of contaminant to block a passage 100%. And between shut off and restart????????

[LasVegas]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PARAGON:
I haven't seen the lower of our engines personally but looking at the service manual it looks pretty typical. There is a bolt where the tube goes into the pump (where the o-ring is) but there is also 2 nuts that hold the pick-up tube for support midway of the block. In my thinking those 2 nuts would have to come loose also for it to completely lose pressure, along with the bolt that tightens the end of the tube to the pump. I would think there would still be enough upward pressure from those two support nuts to hold the tube to the pump.

I don't know what to think about the driveway deal though. I look forward to hearing the answer. </div></BLOCKQUOTE>Not trying to be funny but maybe it was Friday and they forgot to tighten both the bolts and the nuts?

[PARAGON]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by LasVegas:
Not trying to be funny but maybe it was Friday and they forgot to tighten both the bolts and the nuts? </div></BLOCKQUOTE>Funny you should say that. Look at what I just posted in the Technical Section.

http://elcova.com/groupee/forums/a/t...021#6681086021

[KenP]

LV, be thankful you have a history with this problem. The gearator won't go bad like that unless there was a tremendous amount of play that has gotten worse. It also would have a constant lowering of the OP. Not a sudden drop. You should be able to rule that out.

Is there any way in the world that something made it's way to the oil system during the TC install? During the install of the oil lines?

[Dan]

Hmm. Could be a spun bearing too.

[LasVegas]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dan:
Hmm. Could be a spun bearing too. </div></BLOCKQUOTE>You didn't have to say that Dan

[PARAGON]

What update? Hurry up typing.