I have a 97 corvette, seems like the oil pump took a dump on me. It was fine one day, then the next day I started it up and walked inside to get something, came back out to 0-1 oil psi . We changed the sending unit which didn't help, jacked it up and drained the oil and found some sparkles in the oil filter. I'm guessing the oil pump died. Now I have to decide what I want to do to fix the problem, I'm guessing it ran for long enough that just replacing the oil pump won't cut it. Should i rebuild what I have ? I can get a complete ls6 with 50k miles for around 4 thousand from a reputable corvette salvage yard for around 4 thousand with 3 month warranty. I'm leaning in this direction but I'm looking for other options. I don't want to spend a bunch but want to do it right. Would the ls6 be a direct bolt on except for having my computer re-tuned. Is that even possible for my 97? I can get a decent ls1 complete for about a thousand less.

 

Are you sure that the motor is damaged (except for the pump)?

It sounds like it only ran a very short time with no pressure. The filter may have trapped the particles before they went through the engine. A motor can spin at light loads for a little while with no pressure and only the oil film strength protecting the bearings and still survive.

I would try changing the pump and see if you have other problems before I spent a lot for a new motor unless you are sure the motor is trashed.

I realize that I am optimistic and hoping for the best, but it is an expensive alternative.

Good luck.

 

It's incredibly rare for oil pumps to just die like that. I'd think it's more likely that you lost a main. You need to drop the pan and see what's up before you make any decisions.

 

The pump has a pressure relief valve inside the pump. It not uncommon for that valve to get stuck open and cause low or no oil pressure.. Here is the oil flow thru your engine:



If it were me,,, I would remove fuses to prevent the engine from running, pull off the oil filter and crank the engine. If the pump is working, oil will flow out of the metal pipe fitting that the oil filter screws on to in large volumes. Put your thumb over the fitting and it should build pressure immediately if the oil is flowing out.

Oil pump replacement is WAY MORE easier and a LOT less money than an engine replacement.



An LS6 engine will drop right in!! Yes, you will need a retune because of the cam and injectors if you use the LS6 injectors (AS YOU SHOULD) :-)


I believe that you will need to swap out PCMs also to the newer PCM. If you have an MN6 tranny, you should replace the clutch also!!

 

thank you all for the replies! I'm afraid it ran that way for about 5-10 minutes and sounded a little noisier than normal by the time I shut her off. I'm going to have to get her to my friends lift before I can do anymore checking. It's an auto so I don't have a clutch to change. I have read that changing from the older computer to the newer one is a pain, also the new computer is from a manual but I guess that can be corrected by a tune.

 

I read this before I feel asleep last night and had a dream mine lost pressure too, what a nightmare. Hope all goes well.

 

NO

Why do people always say this is a rare occurrence? It is very common and the vast majority of the time it is the relief valve getting stuck.

The noise you heard was just the lifters, I doubt you damaged anything, especially just idling. It is not like oil just suddenly disappears from all the bearing surfaces.

The C5 is one of the easier LS1 cars to change the pump on. Reason being is that you don't need to drop the pan at all. The bolt is right there. You have nothing to lose at this point by changing the pump, so you might as well. Get a new o-ring too, make sure it is the blue one.

 

1. The relief valve getting stuck open isn't the same thing as the oil pump failing. The net effect may be the same, but the pump mechanism itself failing is exceedingly rare.

2. Why would the relief valve stick open at idle? It's meant to open when pressure exceeds a certain threshold.

3. He has metal flakes in his oil most likely from a collapsed journal bearing. Yet you, "doubt he damaged anything"? Really?

4. Tapping lifters and knocking rods sound absolutely nothing alike.

5. Yes, oil damn well does just disappear from bearing surfaces when oil pressure goes away. Most cars need 5-10 PSI to float the crank even at idle. Sure an engine will putter away for awhile with the skin of oil left, but the second you put any load on it you'll know it real quick.

6. Just my personal opinion, but I'd rather drop the pan on gen 1/2 10x over pulling the balancer, water pump, pulleys, ps rack, radiator, fans, and anything else in the way of the timing cover on a C5. (I can swap the oil pump out of my C3 in ~1 hour)

 

Oh god give me a break on the semantics. Relief valve sticking is the same as an oil pump failure. Oil pump not pumping oil due to whatever = failure. The relief valve is in the pump under a spring and they don't sell replacement relief valves = you need to replace the entire pump. There is a reason this item is recommended to change during a cam swap.

I see this issue all the time in cars I work on. And what does it being at idle have to do with anything? It gets stuck...as in jammed against the side of it's casing. RPM and load have nothing to do with it.


Maybe he did do some damage but it doesn't mean his motor is automatically trashed. May as well replace a $100 part and see what you get, there is nothing to lose. The metal flakes might be from the cam/lifters, not necessarily from a main bearing. Why does it automatically have to be the worst possible outcome? Always go from cheapest/easiest and progress accordingly. Replace pump and see if the pressure comes back and the noise goes away. If not, then fine yank the motor.

All the things you mentioned that need to be removed for the oil pump are extremely easy to remove. Pulling the pan is much harder than that (on stands especially), not to mention you will probably need an alignment afterwards.

I have no idea where this mantra that oil pump failure is uncommon came from.

 

Because that's not what lifters do when you lose oil pressure. It is however a very common side effect of a collapsed journal.

You gotta be kidding me. Have you ever worked on a Gen1? Your statement was that a C5 is an easy car on which to swap an oil pump. And relatively speaking no it absolutely is not. If you think pulling a balancer off a Gen3 is easier than an oil pan off a Gen1, then you've obviously never worked on the latter. And why the f'k would you need an alignment after pulling the oil pan?

Ever torn an oil pump apart? They're very simple with just a few moving parts. For the pump mechanism to catastrophically and suddenly fail is virtually unheard of. A relief valve, which is not actually part of the pump mechanism, maybe? But again, keep in mind that this valve only opens under high pressure conditions NOT AT IDLE. Thus how are you thinking it somehow went from a CLOSED position to an OPEN position at IDLE (LOW PRESSURE) and then GOT STUCK there? Ponder that for a minute if you will.

and sorry but your statement of ...

Is horrible, bubbafied advice considering he's already seen metallic debris in his oil. He is way past the point where you just slap a new oil pump in and see. And doing so could very well cause his situation to go from bad to worse.

 

What does this have to do with a gen 1? I can get to an oil pump in about 90 mins, so yet it is very easy. Just because you have to take a handful of parts off doesn't make it difficult.

So you don't think a car will need an alignment after a cradle drop, the upper a arm and shock removed? The alignment will absolutely be off. Maybe not much, but it will be off. It is in the service manual to do an alignment after replacing the oil pan.

Stop arguing semantics, it is ridiculous. Yes I know how the relief valve works and what it is there for. But thank you for educating me oh wise one. The OP indicated that he simply started his motor and went inside. It very well could have become stuck from him driving the previous day and he just didn't notice. This is exactly how it happened in my car and others that I have witnessed. Car is fine, gets shut off, then it starts up with no oil pressure. The reason I go to the relief valve first is because it is the most common issue when these cars lose oil pressure.


You need to relax dude. Lose the internet ego for once. You and Lucky....jesus christ.

Not coming back into this thread. I gave my advice and I don't have an ego like you, so there is no need.

Good luck OP.

 

I said "relatively speaking" as in comparing it to other cars. And if you can pull the balancer, wp, PS rack, etc. in 90 minutes then congrats because you're working at about half the book rate.

Well that was kinda the point. On most cars you don't have to do that to get to the oil pan. You define "easy" quite differently from me.

If you say so. Seems odd to me that wouldn't notice losing oil pressure while the engine is under load, but then idling in your garage? uhhh ... ok