- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
re: OT mechanics, question
Posted on 3/31/16 at 3:20 pm to Darth_Vader
Posted on 3/31/16 at 3:20 pm to Darth_Vader
quote:
Sounds like you've got a bad oil pump and now on top of that , you've also engine damage from oil starvation.
Yeah that's my guess too unfortunately.
1
Posted on 3/31/16 at 3:22 pm to Jim Rockford
Can you describe this knock some more? Is it a high pitch sound or low pitch? Does it knock even when idling? Does it get worse when the RPMs go up?
Posted on 3/31/16 at 3:31 pm to Jim Rockford
quote:
Silverado
Found your problem, you purchased a General Motors vehicle.
Posted on 3/31/16 at 3:37 pm to Darth_Vader
quote:
Can you describe this knock some more? Is it a high pitch sound or low pitch? Does it knock even when idling? Does it get worse when the RPMs go up?
Here's what happened--last couple of days, oil pressure has been dropping when the truck warms up, not into red zone on the gauge, but close. No other symptoms at all. Today, as I was pulling into the driveway, I heard a very faint knocking sound. Parked, waited a couple of hours, went out and cranked it again. Motor sounded "rough," with a noticeable knock. Turned it off, called the shop and they sent out a tow truck. That's where we stand at the moment.
ETA: Neither high nor low pitch. Medium, I guess. Doesn't sound like a lifter. I'm familiar with that noise.
This post was edited on 3/31/16 at 3:39 pm
Posted on 3/31/16 at 3:50 pm to Jim Rockford
Ok. Now this is just an educated guess.
1. I'd say the initial problem is your old pump has internal wear that causes it to lose the ability to move oil that has reached what would be considered "operating temperature". Basically as the oil heats up and thus becomes "thinner" your oil pump can't pump it like it should because either the oil pump has internal wear or damage like a failed bearing or gear. This leads to oil starvation which then opens up a whole other can of worms.
2. The knock you're hearing sounds like it could be from crankshaft damage. I'm guessing you've got main bearing damage. I say this because you describe it as a "low" knocking sound. If it were a higher pitch then it would probably be something like a piston, connecting rod, or lift arm.
I hope I'm wrong here and your problem turns out to be a much easier and cheaper repair.
1. I'd say the initial problem is your old pump has internal wear that causes it to lose the ability to move oil that has reached what would be considered "operating temperature". Basically as the oil heats up and thus becomes "thinner" your oil pump can't pump it like it should because either the oil pump has internal wear or damage like a failed bearing or gear. This leads to oil starvation which then opens up a whole other can of worms.
2. The knock you're hearing sounds like it could be from crankshaft damage. I'm guessing you've got main bearing damage. I say this because you describe it as a "low" knocking sound. If it were a higher pitch then it would probably be something like a piston, connecting rod, or lift arm.
I hope I'm wrong here and your problem turns out to be a much easier and cheaper repair.
This post was edited on 3/31/16 at 3:52 pm
Posted on 3/31/16 at 4:10 pm to Darth_Vader
Posted on 3/31/16 at 4:17 pm to Jim Rockford
Just to prepare you for what you might be looking at (and again I hope I'm wrong), but it sounds like you're about to be faced with a complete engine rebuild. Now I'm far more knowledgeable about Cat Diesel engines than automobile engines so take that for what it's worth.
Look on the bright side, if you had a Cat instead of a pick up, you'd be facing at least at $20,000 to $100,000 bill depending on the size of the engine. Your truck's engine will be far less.
Look on the bright side, if you had a Cat instead of a pick up, you'd be facing at least at $20,000 to $100,000 bill depending on the size of the engine. Your truck's engine will be far less.
This post was edited on 3/31/16 at 4:19 pm
Posted on 3/31/16 at 4:44 pm to Darth_Vader
Yeah I'm waiting to see what the estimate is. Hopefully I'm wrong about the sound and it was just a lifter. It was just odd that it went from no problems at all to fubar practically overnight. Depending on what they quote me, I'll consider a new vehicle instead of sinking a ton of money into a rebuild or new motor.
Posted on 3/31/16 at 4:49 pm to Jim Rockford
These things can happen quick, especially once your oil pressure starts messing up. It's best that at the first hint of any abnormal oil pressure drop or fluctuation you stop and turn off the engine and get the problem addressed right away. That way hopefully you can get a "before failure" repair rather than an "after failure" repair. The before failure option is always far cheaper.
Posted on 4/1/16 at 9:02 am to Darth_Vader
Welp, I'm still waiting to hear from the shop. On the one hand, maybe that means they found something they could fix. OTOH, maybe they just haven't gotten to it yet. Meanwhile, I stayed up late last night torturing myself with youtubes of engine noises. 
I still can't tell if it was a rod knock or a lifter, or something else.
I still can't tell if it was a rod knock or a lifter, or something else.
Posted on 4/1/16 at 9:08 am to Darth_Vader
quote:I'm still saying the o-ring.
Ok. Now this is just an educated guess.
1. I'd say the initial problem is your old pump has internal wear that causes it to lose the ability to move oil that has reached what would be considered "operating temperature". Basically as the oil heats up and thus becomes "thinner" your oil pump can't pump it like it should because either the oil pump has internal wear or damage like a failed bearing or gear. This leads to oil starvation which then opens up a whole other can of worms.
2. The knock you're hearing sounds like it could be from crankshaft damage. I'm guessing you've got main bearing damage. I say this because you describe it as a "low" knocking sound. If it were a higher pitch then it would probably be something like a piston, connecting rod, or lift arm.
Posted on 4/1/16 at 9:09 am to Jim Rockford
It is more than likely the pickup tube O-ring. A guy at work was having the same symptoms as you and just had the O-ring replace and has not had any issues since then.
Posted on 4/1/16 at 9:46 am to meauxjeaux2
Hope you're right, my man. That would make me very happy
Posted on 4/1/16 at 10:05 am to Jim Rockford
I am no mechanic at all but my Chevy started making an unbelievable noise about 1 1/2 years ago. Sounded like a diesel engine. I called a mechanic friend that told me it probably was my lifters. He suggested to change oil to shell rotella diesel oil. It immediately quieted back down to normal. I have been in the spend as little money as possible / drive the truck till it dies mode for about 3 years now. 260k miles and still going. Fingers crossed.
Posted on 4/1/16 at 10:14 am to meauxjeaux2
quote:
Wonder how many LS motors Darth has been into?
Zero. Never claimed I had. In fact I even said I know a lot more about Cat Diesel engines than I do about automotive engines. I just gave my best guess based on the limited info we have to go on. I never said anything declaritive or insinuated anything I was saying was more than a guess.
quote:
I've been into dozens of them and each time the knocking is present it's always a cut o-ring.
And I hope for his sake you're right.
Posted on 4/6/16 at 6:58 pm to Darth_Vader
So, it was a perfect storm of misleading symptoms. Bad oil pressure gauge while at the same time the alternator was going out. Needle reading zero while a knocking noise is coming from under the hood=oh shite moment. I'm back on the road, very happy it was only $500 worth of repairs.
Posted on 4/6/16 at 7:09 pm to Jim Rockford
Does your truck have the cylinder de-activation? If so, there is a good chance that there might be a ptoblem with the cam/lifters.
Posted on 4/6/16 at 7:53 pm to Jim Rockford
My guess is the oil pump.
If true, don't run it or the motor will self destruct.
If true, don't run it or the motor will self destruct.
Page 2 of 2
Popular
Back to top
Follow TigerDroppings for LSU Football News