BstrdC4

If I have an oil pump failure, is there an electrical override to prevent engine from starting?

Oil pressure is 1.67 PSI with accessories on.

3boystoys

I don't think so.

Bill Curlee

Only a common sense shutdown. The C5 does NOT have a LOW OIL PRESSURE shutdown.

Disable the spark or fuel. Remove the oil filter. Put your THUMB over the pipe that the oil filter screws on to.

Have someone CRANK but do not start the engine. IF, your oil pump is working, you will have gobs of oil flow and pressure at that opening. Enough that you will not be able to stop it with your THUMB!

IF,,, there isnt any pressure or flow, you could have:

A stuck oil pressure reliefe valve (inside the pump)
Bad oil pan pick up tube O ring (at the base of the pump)
No Oil
Bad pump.

Cut a Way showing O ring and tube in pump:

Bill Curlee

" Oil pressure is 1.67 PSI with accessories on. " ???????????


I reread your post??? Is that with the engine running? OR, with the engine OFF key ON????

BC

leadfoot4

Yeah, I was thinking the same thing! If the engine was "running" with only 1.67 PSI of oil pressure, the lifters would be clattering like a bunch of nuts being shaken in a coffee can!


One thought...if you switch the dash readout to "metric" units, does that effect how the oil pressure reads?

BstrdC4

Engine off key on. Accessory mode.

I asked because my engine stalled, check gage light, no oil pressure. Try to crank.. tried to turn off but get a weird noise. All days needles sweep but the oil pressure goes to zero. I got the 1.67 PSI from a scanner.

Maybe a snapped timing chain?

Bill Curlee

You will NOT see oil pressure during engine cranking (on the dash Oil pressure gage) During CRANK, the IPC gages are disabled)

You can read it mechanically thru the FRONT oil pressure port. The port is near the front drivers side of the block below the coolant temp sensor on the head and to the front of the block. Its a HEX head plug.

You will need a mechanical gage and a adaptor to fit.

What DTCs do you have. Please READ and POST the DTCs


READING YOUR Engine Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine. NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix!!

Bill Curlee

The low pressure you are seeing could be an error with the oil pressure sensor. With the engine OFF,,, you should have ZERO PRESSURE when the ignition switch is ON (engine OFF)

BstrdC4

I have no codes. Only prior is 02 sensor.


Oh, and LS6, 114K miles.

Bill Curlee

Will it crank and run?

BstrdC4

Cranks but doesn't start. I have fuel, spark, and air. When I crank, it sounds like it'll start and then I hear a weird noise. Doesn't fully turn over and start. Almost like a starter ticking but it's a bit louder. Clearly audible from the cabin.

Bill Curlee

Have the battery fully tested and make sure that it 100% good. You may just have a bad or weak battery.

If you bturn the headlights on and crank the engine, what does the headlight do??? They should stay BRIGHT!


BC

BstrdC4

Not a battery problem. Also doesn't explain shutting down while driving and the oil pressure gauge or the no start

But... it did just start when it's cold. Idled extremely bad when it started though. Oil pressure at 50 PSI.

Bill Curlee

NO DTCs and engine running bad, I immediately would suspect that you have a bad or failing ignition switch. Give that a look see.

Heres a post to you to examine:

- C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html

BstrdC4

Ignition switch is good. Replaced that and the starter a month ago. Scanner says I have a cylinder missfire. Don't know which cylinder. Still no codes. I was able to get passenger side valve cover off and everything looks good. Driver side will be more complicated since the alternator bracket is in the way of the coil bracket bolt. But I was just checking for anything broken. Being an LS6 with yellow springs, it's a high possibility.

But, I have factory wires and plugs..on an engine with 114k. I'll take those out this weekend and inspect when I check the driver side springs.

Bill Curlee

OH MY LORD! If you have OEM orignal wires and plugs,,,,,,, ,, Get some new GM Performance Red Wires and new Irridium Plugs ASAP...

Also look at ALL the intake manifold rubber fittings ESPICIALLY the PCV fittings for cracked / broken couplers.

BC

martysauto

See if you have access to the misfire monitor on your scanner. It will show you current and history misfires for all 8 cylinders.

BstrdC4

Misfire #1 intake.... broken valve spring. It's an LS6 with the bad yellow springs, 114k miles.

3boystoys

Hopefully no carnage inside the engine.