C5-VERT

Just got this today. Cars been burning oil somewhere or losing it. Not exactly sure where yet. Will have to get it up on lift and maybe pull plugs and valve covers. Could be valve stem seal. But today when I drove an hour getting on it a few times, it ran fine. When I pulled up to an exit off the interstate and it got to idle my oil pressure dropped below 10 psi. Not good. Told me to shut car off. Luckily I was right at my house. I drove it a few more mins off idle around 2k rpm pressure pulled up to 25 or so. It just happened so I need to ask around here if anyone has any ideas? Oil feed pump going bad? I didn’t see any codes or check engine life I will check via HP tuners. I filled my oil just before I left it was at top line. Been burning oil so I always keep it topped off. Could be a sending unit but I think it’s worse. Mostly because I am losing oil somewhere.

Anyway I will keep this post updated but any help is appreciated.

Z06Norway

I am afraid you have an engine change coming.
Same thing happened to me, less than 1600 miles, oil pressure dropped to 10 psi ask me to shut down....
I did and started her up again after a while, oil pressure back and actually higher than normal.... then fluctuated ...
Everything sounded normal, no knocking and after calling around i decided to go for a little trip to see..
So i kept my eyes glued to the oil pressure gauge (track mode) and after 2 miles, engine seized up....

Turned out to be two rod bearings and one main that was toast.....
We now have plastic bearings(composite)...

My engine was rebuilt by CCRP (Cool Chevy Race Parts in Austria), new crank, regrind of all rods to accommodate old style proper bearings.
All seals replaced with old style
Line bored, top decked and ported heads..
Katech cam shaft

Only thing i missed and was a few months early to get was Katech new high volume and higher pressure pump....


Best of luck and lets hope i am wrong, but if under warranty , go straight to dealer and ask them to drive it until it seize up

C5-VERT

I am pretty sure I am loosing oil from valve guide seal it only puffs small bit of smoke when I crank it after a shut down and after a deceleration. Those are typical symptoms of guide seal not rings etc. and bearings will go in no time If you drive on almost no oil pressure probably what happened to you. I will be tearing it down soon on my lift. I already planned on putting a cam and some valvetrain upgrades in. The bottom ends on these motors are stout as long as you have proper oil pressure etc. I don’t think it’s to that level. I won’t be driving or cranking it anymore until I figure it out. That’s a huge mistake if I did that I would be sure it would spin a bearing or worse. I do know the dry sump valves have a TSB they can get stuck open or closed. GM has a TSB on it. I will be checking that. Also the oil filter see if any metal is in the element. The dry sump feed pump can also go bad. It also could just be the sending unit. Those are known to fail. Just curious if anyone had this issue and I appreciate your feedback. If I have to rebuild the motor I will just make it better. I can do all that myself after the block is cleaned up and honed. I have a big build already F1A-94 with port injection HRFUELER and every other supporting mod you can get. So the motor was the only thing I haven’t touched yet. Plan was to enjoy it until I needed to build the motor. Sounds like it’s there.

Guess i will shoot for well into 4 digit power now :-).

C5-VERT

Im afraid no warranty :-)

C5-VERT

Well, I checked the oil level it was below the line by about a 1/2 inch or so. I filled the oil up again, cracked the car up, and it was sitting solid at 28 psi at idle. When I revved it to 1800 ish rpm it jumped to 40 psi. So this morning it's just fine???? Very strange. I will get me a new oil pressure sending unit and also pull the valve covers and replace all the valve stem seals. Been meaning to do that anyway. I may go ahead and just do a CAM and update all the valvetrain hardware. Will also look into the TSB regarding the oil pressure control valve but I believe that's for 15/16 models not '17 which I have. Either way it's burning oil so I am almost sure my valve guide seals need replacing. It's common on high horse cars from what I hear. Most do valvetrain upgrades at this power level I chose to sit on mine until an issue like this.

I do feel more at ease with my engine being fine and it back to normal pressure. The way it did this makes me point the finger towards the sensor first.

http://www.corvetteactioncenter.com/...sure-1280.html

Bill Dearborn

Did you let the engine get hot and recheck the oil pressure once the oil was up to temperature? I think your oil pressure issue isn't low oil but something wrong in the main, rod or cam bearings or maybe a failed valve lifter. The fact the oil level was a half inch oil shouldn't have caused the oil pressure to fall at idle. The level would have to be much lower than that for the pressure to drop that far at idle.

Bill

Internets_Ninja

Low oil pressure is a tell tale sign of a main or rod bearing failure. Not saying that is 100% the case, but you might have hurt the engine. By the way, burning oil lowers the fuels knock resistance and can cause real spark knock, especially in a boosted application. Repeated detonation on a forged piston can actually damage the rod bearing on that cylinder before it breaks the piston. Good luck, I hope its not as bad as the possible scenario I am suggesting.

pkincy

Happened to me twice in an LS2. Both times it was rod bearings. However my oil pressure drop was permanent. The fact that you have good pressure the next day leads me away from the rod or main bearing thoughts.

C5-VERT

Yeah ifs back to normal today?? Even at cruising with normal temps it’s around 40psi. If I had main cap or rod bearing failures wouldn’t it have oil pressure issues up top too? I have seen lots of LT4s with valve stem seal leaks. In fact my effects of only seeing a puff of smoke on accel and when I crank it is common signs for seal leaks. Oil getting down passed the valve in the guides. I won’t know for sure I am just following my gut right now. Either way engine sounds perfect and runs great I am going to get it up on my lift and start pulling it apart. Rebuilding the motors been my plan down the line anyway what’s another $8k when I have $40+ k in the car and build already. Good news is once I get the motor built it will be a bad *** build. I already have the power adders and fuel components to get me to 1250 horse wheel.

C5-VERT

Thanks for input everyone possible I just hurt the motor with the power I am pushing. Good thing these push rod motors are easy to tear down and rebuild!

C5-VERT

Bill yeah it was little lower my measuring wasn’t so accurate. It was an inch or more low I had to put almost 3.5 quarts in that isn’t good. I was at half full before I left which was just a 45 min drive. I made a few 3rd 4th gear pulls hard so it’s losing oil big time when I get on it. Still feels super strong. I think I have a valve train issue. I know it’s a weak link. Going to pull my valve covers off and do some inspecting will report back.

C5-VERT

C5-VERT

Think it’s also relevant to say I just got back 3 days ago from Orlando drove my boy and I there 5 hours each way from Savannah area averaged 90mph ran great all the way there and back. I had to fill up with 93 been running ethanol for 6 months now hated to do it but my tune supports it. I just ran it easy on pump gas no WOT at all. It runs super rich on pump gas anyway. But the cars been extremely reliable the last couple months once I got the bad fuel injector fixed.

Z06Norway

Valve seal guid will not affect any oil pressure....
My car also went from 12-15 psi back to normal 28-35 psi
Then few miles later seized up....

just a pointer, and main i sure hope you don't have the same..... but keep an close eye to pressure....
Mine was NOT under any hard load when it seized..... i did 50 mph and was breaking and downshifting when it died....

Rune

C5-VERT

I didn't mean to imply a valve guide seal would affect pressure, what I am saying it's possibly where I am losing oil. I don't know yet where I am losing pressure, I have to start tearing it down. I drove it back an hour today from Statesboro to Savannah and drove just fine. Pressure hovered around 35psi at 2k rpm cruising. It dips lower at 590 rpm (idle). Regardless I am going to take the plunge and upgrade my valvetrain and maybe throw a cam in as well. I think what you had going on is a completely different issue mine would have seized by now and also wouldn't have normal pressure back again as I said. I have torn engines down enough and built a couple of pushrod Corvette motors to have a pretty good understanding of them. My lack of knowledge is in GenV VVT and DoD. I need to verse myself in those areas but I plan on doing the DoD delete plate. It's all disabled in Tune now. Truthfully this could be any number of things. But the engine sounds great, runs great, drove 10 hours last week on a long trip, drove 1 hour this morning and a couple hours 2 days ago. If I had a major oil issue like loss of all pressure or any loss of oil around those mains or even valvetrain it would have been toast by now. I have had a motor seize up from lack of oil before believe me I know it doesn't take long with no pressure it's seconds before that sucker is seized.

So at this point, I need to just stop driving the car (sucks) and pull the plugs (check for oil), pull the Katech valve covers off, decided if I want to do ARP studs + head work, decided if I want to do a Cam (depends on what I need to replace), do valvetrain upgrades (springs/retainers, etc.), and possibly install a new camshaft position actuator and finally a Katech high flow oil pump. I will keep this thread updated as well as my build thread with any updates. Thanks once again for all input!

I have to look into this timing advanced DTC with my cam angle. I sent that to my tuner Chris Crawford hopefully he can give me a little insight. I will be pulling all that apart and see if the camshaft position actuator isn't stuck. http://www.corvetteactioncenter.com/...valve-885.html

If I have to go into the motor at all I also plan on doing a Katech High Flow variable oil pump they have a super nice one that will give me some peace of mind:
Didn't realize the variable oil pressure was so low for these RPMs. I know 5psi of oil pressure is generally enough for bearing float anything above that is for safety or RPM/Pressure based on load.

rjacobs

I know on the LS motors I believe the GM spec is 1psi per 100rpm.

So the LT motors is actually a bit less. I guess makes sense with the different bearing material used in the LT vs. LS motors.

C5-VERT

Pulled my plugs #3 and #5 have oil all down the threads. I am also loosing much more oil now than before. In 45 mins of cruising it went from top of dipstick marker to not even having oil on my dipstick (very low). That's also why my cam phaser is stuck in over advance throwing codes it works by oil pressure. All starting to make more sense. I am pretty positive now my valve seals are gone. I have a leakdown tester arriving today will do a leakdown test to ensure rings/valves are good + I am pulling off valve covers to inspect.

I've got an entire shop manual on the way on USB will be here Monday. Was $300.

Wondering if I can simply do new springs/retainers/seals and leave my cam and heads alone (leave stock lifters, etc) OR should I just bite the bullet and tear it completely down heads off do all new lifters/trunions, block DoD ports, etc. I have always pulled the heads off for valvetrain work, never did the air compressor or rope trick to hold the valves up. Should I do all that and just keep the stock cam? I know it's a PITA to pull the cam mostly b/c the front cover and rear pan has to come off. Thoughts? I really just want my car running reliably and idles smooth, drives easy on the street, but ready for track duty. I make plenty of power as is I just want it reliable.

If my only issue is valve seals I can do the trunion upgrade (https://www.michiganmotorsports.com/...4-lv3-l83-l86/), new seals, springs may be fine unless it's worth upgrading those for stock cam profile. Decisions decisions..

C5-VERT

Definitely oil on this plug. There’s my problem.

C5-VERT

Just took a closer look wow my ground strap is melted down a bit that’s not so good. Definitely hot most likely some detonation with oil in there. Got a cylinder leak down tester will see how my cylinder looks. Either way my valve guide seals are shot on some of my cylinders and gone on #5. Getting all of it upgraded with new components hope to be back up in a week.