b16crx

A little back story here, I have a 2001 coupe Manual. The car is stock except for some Borla straight pipes from the axle back, and a LS7 clutch. The car has 220k miles on it now. This thing has been crazy reliable, i have only had to do a few basic things other than change the oil. I only changed the stock clutch last year at 204k. Most everything I have done has just been general maintenance issues.

So I have had a oil leak for a while now, It seems to run down the back of the motor and drip onto the exhaust. I really only notice it when i stop at a red light. Sometimes I see a lot of smoke coming out from under the car. The Oil pressure sending unit has been relocated, I swapped the PCV system to the LS6 style, and the rear main seal was replaced at the time of the Clutch install. The oil leak still continues and the bottom of the pan is covered. I was thinking it may be the front main seal leaking and blowing back onto the exhaust. I didn’t have much time to work on it so I took it to a shop. They let me know that I actually had several leaks. Front main seal, both oil pan gaskets, and possibly some from the back of the motor still.

The cost to have all the leaks fixed was going to be over 4k, and I would still have a 220k mile engine. I decided to do the work myself and swap the engine out for a L92 converted to a LS3.


here is what I have so far.

The must have to complete list:

L92 engine 65k pullout from an Escalade
LS3 / L76 intake
LS3 / L76 Fuel Rails
LS2 Timing Cover with Cam Sensor
Cam ( 3 bolt)
Cam Sprocket (58x 3 bolt)
Cam Bolts
58x-24x Crank Sensor Trigger Conversion Module from Lingenfelter
Knock Sensor extensions
Map Sensor extension
Cam Sensor Extension ( this is part of the Lingenfelter Trigger conversion module)
LS1 to LS3 throttle body adapter
LS3 to LS1 injector adapters
ECU Flash/ Tune


These are just parts that should be changed:


Fuel Filter
Air Filter
Serpentine Belt
AC Belt
Water Pump
Powerbond underdrive pulley
Crank Bolt
Oil Pump
Pilot bearing
rear seal
Rear cover seal
upper radiator hose
lower radiator hose
thermostat
Anti freeze
Oil
Oil Filter
Oil Pan Gasket Upper
Oil Pan Gasket Lower
Valve Cover Gaskets
Exhaust Manifold Gaskets
Exhaust Manifold Bolts
Headers ( not actually needed, but wanted)
C5R Timing Chain
Motor Mounts
Spark Plugs
Spark Plug wires
Spark Plug wire heat boots

Do you guys see anything else that would be smart to change at this time?

So here is where the questions come in.

The L92 has the flat valley cover, no DOD. It only has the Boss where the PCV should connect but no nipple there for the hose to connect to. I was thinking about using the LS6 valley cover that I put on the LS1 and just plugging up the knock sensor holes with a bolt, does this sound reasonable? Or do I need to buy the LS3 valley cover?

I have a Vengeance Racing VRSP-2 Camshaft- 227/235 .614/.621 115+4. I got their basic kit that includes push rods, .660" Lift Dual Spring Kit with Tool Steel Retainers. I have not purchased the Comp Cams Trunion Upgrade yet. Some people say you need it others say the stock rockers are fine. I was kinda hoping to hold out as my funds are hurting pretty bad at this point. This is a daily driver, I do play around from time to time but for the most part just normal driving. Is it a ticking time bomb if I wait a couple of months after the engine swap?

I also am planning on using my stock LS1 throttle body for budget reasons. I bought an a 3 bolt to 4 bolt adapter so it should bolt to the LS3 intake. How much horsepower will I be leaving on the table?

I have read that any LS pilot bearing will fit in the engine, but if you use the wrong one it may cause damage to the engine. Is there a way to verify I get the correct one?


I have been reading about the Torque Tube, and I guess I should try and replace the Rubber couplers and the bearings while everything is out. The rubber couplers seem to be pretty straight forward. From what i have read on the bearings they need to be pressed on. It sounded like some people had possibly accomplished this without a press, is that possible? I couldn’t find a decent walk through for the bearing install. Does anyone have a link that may help?

Thanks for help!

tommypenguin

I would add a new starter, oil pickup tube o ring and crank pinning kit.

Also here to subscribe to your experience as this is a long term goal I'm interested in doing myself. Not sure how to handle the valley cover dilemma would like to find out.

Last C5

Good luck with your build

b16crx

Thanks for the replies!

I defiantly forgot to add the o ring for the pick up tube.

I did have a new solenoid installed on the starter that came with the engine. the guy said the brushes and everything else looked brand new, so I think the starter should be good.

I thought a lot about pinning the crank pulley, but would i really need to if I'm not going to supercharge/ turbo it? (at least not for a long while)

I kinda figured I would have to swap the valley cover, now that I think about it I'm not sure that the L92 block would even have a place to put a bolt to plug up the knock sensor holes on the LS6 valley cover anyways.

It's not so much that the Comp Cams Trunion upgrade is expensive, it just seems like some people have had failures with the upgrade as well, and I have read where some people say that the stock rockers are fine. I'm wondering if anyone has any kind knowledge as to how long the stock needle bearing would last with a stage 2 type of cam?

Does anyone have any input on the torque tube bearing install?

Thanks!

Murphy27

What oil pan are you going to use? I thought I read that the Gen IV engines have more bolt holes than the Gen III "batwing" pan

b16crx

As I understand it I should be able to use any LS Corvette oil pan. I Think if I switch to a Corvette LS2/ LS3 pan it will make more room, but you lose some oil capacity. I am planning on just using my stock batwing pan to save money. It would be nice to have more room, but I figure I'm installing the headers while the engine is out so hopefully the space shouldn't be an issue.

b16crx

So I finally got the car up and running!




I got it dynoed...







not all fun and games though, I am having some issues.
made it Vengeance and had to use a jump box because the battery was going out.
So I drove it 50+ miles home from Vengeance with no issues until the last 1/2 mile. I got on it a little bit then it started running pretty rough.
I made it to my drive way and shut it off. then it would not start, even after I put my jump box on it. So I went and got a new battery, now it starts fine. Still runs kinda rough though. When I start it the throttle does not want to react right away, when I step on the gas it tries to die. If I keep my foot on it it will eventually start revving up. that's when I noticed this:



When I talked to the tuner he said it looks like a bad ground causing the coils to misfire. So I need to check the drivers side ground on the head, and the coils.

So after a couple of days I start looking, i can see the ground wire with a mirror, it does not appear to be pinched, I looked at connections and what not, all seems OK. So I start it up and it seems fine, throttle reacts right away and I can back up the drive way with no issues. I drove it around the block just fine. No more sparking near the coils. So I park it run inside for a minute, then go for a drive. I stop at the store, then when I start it, it goes back to throttle acting funny and running rough. now it is backfiring like crazy. So I park it over night, this morning I wiggle the wires, then it starts and drives fine, stop at the gas station, starts running rough and backfiring.

So here are the codes:

10-PCM
P0103 HC Mass Air Flow (MAF) Sensor Circuit High Frequency(the tuner said this one will always be there since it is set to run on speed density)
P0522 H Engine Oil Pressure Sensor Circuit Low Voltage (the gauge seems to be reading just fine)
P1514 H TAC System MAF Performance
P1635 HC 5 Volt Reference #1 Circuit

28- TCS
C1214 HC Sol Valve Relay Contact or Coil CKT Open
C1296 HC

60-IPC
U1255 H U1255 Serial Data Line Malfunction

99- HVAC
U1160 H

A6-SCM
U1300 H
U1255 H
U1160 H

B0- RFA
U1000 H Loss of Communication Undetermined
U1255 H Serial Data Line Malfunction
U1064 H Loss of Communication with BCM

I could not find all the codes. this is a 2001 6 speed with a L92/LS3 swap btw.

So it certainly seems like I have a ground issue. I would guess this all points to the ground on the driver side head, but if the wire is bolted on tight, what is the best way to determine where the break would be?

When it is running it sounds and drives awesome.

Thanks!!

tommypenguin

If it were me the first thing I would do is verify all grounds are torqued down, verify all the spark plug wires are in the correct direction and pushed onto their boots tightly. Build a checklist and go through them, checking them off after doing so.

Did you reconnect the ground strap that was disconnected that runs on the driver side near the headers connecting to the block? IIRC isn't there one ground on the lower portion of the block driver side as well. Been getting close to a year since I tore down, forgive me for not vividly remembering every detail. Edit: Just saw in your post you said you checked the back of the driver head.

Then I would see if the issue has been reconciled.

If not, do you have torque app/obd2 dongle to log with? Specifically can you monitor cylinder roughness count to find out if you are getting a misfire just on one cylinder or multiple cylinders? If it were one cylinder, I would try swapping plug wire and see if the cylinder roughness count moves to another cylinder, then potentially swapping coil packs with another cylinder and checking to see if the cylinder roughness moved, lastly spark plugs. What you are looking for at this point is, is the issue electircal hardware related and that you can pin point what electrical component is the culprit.

b16crx

Yes all the plug wires are on and snug, they are brand new plugs and wires. The coils are sketchy though, they do have some cracks, mostly around the mounting bolts, one has a crack down the side opposite of the wires. I may put my stock LS1 coils on temporarily and see if that makes a difference.

The ground on the Drivers side head appears to be fine.
I have two wires attached to the block on the drivers side.
G106 on the passenger side is questionable though.
I think I only have one wire grounded there, after some research this morning it looks like there should maybe be two wires there. One big wire to the battery, and another smaller wire. I will have to check for the smaller wire when I get home. Those wires were kinda of brittle so I think the smaller wire could have possibly broke and i didn't realize it. Does anyone know where that wire goes to from the block? I may just run a new wire to be sure.

Also I do have the the torque pro app, however I am not really sure which gauge shows misfires?

tommypenguin

If the coil(s) are cracked that could easily be the culprit. I did a little searching the other day for your issue and I found of a few threads where others posted about not having their plug wires plugged in all the way or having a cracked coil pack.

When I have some time today I will hook up my dongle to my obd2 and check for parameters. Thought torque pro could log misfire count or cylinder roughness, will look.

b16crx

Thanks for the help! Yea after I saw the one crack I felt a bit silly that I had not noticed it before then.

I think I may have a couple of issues going on, new coils certainly won't hurt anything. I still have a bad feeling about that G106 ground though, I will check that when I get home tonight.

tommypenguin

That would be great if it is something simple like a cracked coil. Fingers crossed for you.

b16crx

OK, so apparently there is a really good reason I don't work on cars for a living...because I'm not good at it! lol

So I rechecked G106 after realizing that I should have two wires grounded there, sure enough only one wire. but I didn't see any extra wires not attached....after a while I notice the big gauge battery wire goes to the area where the starter goes into the bellhousing, but I can't see it after that. after a few minutes of trying to get my hands on it i discover that it is not hooked up to anything. so a couple of minutes of trying to get it to come out from behind the starter...as soon as it is free it springs right for the positive terminal on the starter! of all the places it could have gone!
of course I was just looking around so I had not disconnected the battery!
it only hit for a second but it sparked real good, I hope I didn't fry anything!

So I had to take the header off to get the ground bolted up, now I am fighting to get the header back on, Hopefully tonight I can finish getting it back on and see if that makes a difference.

tommypenguin

Ah man, hopefully no other damage was done. When reinstalling the header put a jack underneath it to hold it up so you can get the bolts in the head.

I foolishly spent a couple hours one night trying to get my header installed on the passenger side holding it up by hand while trying to get the bolts in. Ultimately failed and crossed threaded a bolt hole until retapping and using a floor jack to hold it in place. Not that it's a ton of value now for you but I wrote a lessons learned thread when rebuilding my ls1 you can check out in the link below. Maybe you'll pick up a couple tricks that might save you some headache in the future from it. Keep us posted on the progress.

https://www.corvetteforum.com/forums...s-learned.html

b16crx

yes I had blocks of wood holding the header up, it was the collector bumping into the x pipe that was keeping it from lining up. I got it all bolted back together now. But when I first put the new engine in I did recall that tip from your post! It made the initial install much easier, so thanks for that!

So since I had a ground that was not connected at all I figured that would have been the problem, so I did not try my old LS1 coils yet, but the ground wire made no difference at all.
when I started it up I had no check engine light, and the throttle acted normal. I drove it around the block and all seemed fine. I went in the house for a second, when I came out and started it again check engine light came on and the throttle is not right. when you step on the gas the RPM drops to 500 or below and tries to stall. when I take my foot off the pedal, it returns to idle. if I let it run for a couple of minutes then it will rev up and allow me to drive. after 15 minutes or so of driving that's when the backfiring in the exhaust starts.

the codes that came back are:
P0103 Mass Air Flow (MAF) Sensor Circuit High Frequency (I think this is the code the tuner said I would always have since it is running a SD tune)
P0522 Engine Oil Pressure Sensor Circuit Low Voltage
P16355 volt Reference #1 Circuit

Can these two codes cause the symptoms I am having? The oil pressure has been reading fine, and it is a brand new sensor.

If the coils are bad, could they somehow trigger these codes? I will try the stock LS1 coils tonight and see if that changes anything.

Thanks for the help!

tommypenguin

The low voltage on your OPS shouldn't impact driveability, that CEL could be from potentially having a bent pin on the plug going to the sensor.

I'm not familiar with P1635 and potential root causes, based on a quick search it sounds related to the OPS code.

https://www.corvetteforum.com/forums...ode-p1635.html

I have no experience tuning for SD. In general with regards to MAF if it isn't dialed in you can get all kinds of driveability issues.

Would still say to swap out the cracked coil packs with good ones to rule that off as a culprit for your issues.

Haven't had time to drive my car this week and check torque pro, have you had any luck finding a parameter to log cylinder misfires? You really need to be logging when driving the car to get an idea as to what is going on. Without a log we are basically shooting in the dark.

b16crx

Well, I put my stock LS1 coils on and nothing changed. I reset the codes before starting but the same 3 codes came back.

I had said previously that the oil pressure gauge was working fine, turns out I was wrong. It does read pressure when I first start up, but at some point it did go to zero.

I did figure out how to load the misfire counters in Torque. I thought when I loaded the GM PIDs that it would automatically add the gauges, but it just adds to the list of gauges available.

So I added all 8 current misfire counters, but they all stayed at 0.0 while I drove, it was backfiring at this time, and was connected reporting rpm and other info.

I have been reading a lot about the P1635, and getting a little confused. I think I finally realized that it may refer to different components on different cars. So I finally found this:

2001 corvette
The powertrain control module (PCM) uses the 5-volt reference A circuit as a sensor feed to the following sensors:
•The manifold absolute pressure (MAP) sensor
•The engine oil pressure sensor

The PCM monitors the voltage on the 5-volt reference A circuit. If the voltage is out of tolerance, the PCM will set DTC P1635.

So the p1635 includes the oil pressure sending unit and the MAP sensor.
the P0522 code is for the oil pressure sending unit, but that should not cause it to run rough and backfire?

If the 5 volt circuit is bad between the PCM, oil pressure sending unit, and the map, could that cause the MAP to not work but not throw a MAP code? Could the MAP not working cause my issues? backfiring while driving and throttle problems on startup?

What I am having trouble finding out is do the MAP and oil pressure sending unit share the same ground location? since they were both located behind the intake I would think the ground on the back of the drivers head would be the one to check. Mine is bolted down and does not appear to be pinched, but I haven't actually taken the manifold off yet, I just used a mirror to look back there.

If the PCM wasn't grounded wouldn't I have many more issues?

I guess my next step is to follow the trouble shooting tree, and test the MAP sensor and the Oil Pressure sending unit.

I know next to nothing about tuning, but i was having trouble getting the car to start after the engine install. I was having trouble with the MAF (maybe the ground that wasn't connected) but he said he could set it to run on speed density rather than using the MAF. as I understood it the MAF is useless in my car now and I could just remove it. But the computer will check for the MAF each time I start the car and throw a code, which I assume is the P0103 code I get.

tommypenguin

Did your oil pressure ever come back up? If it did not I would not drive the car till being able to hookup a mechanical gauge and verifying you have oil pressure. If you end up having to pull the manifold to revisit the plug/wiring for the OPS I would relocate it under the valve cover for easy access going forward.

Given you’re don’t have any misfire CELs or misfire counts that rules out coil packs and wires as your culprit.
Unfortunately I don’t have a lot of ideas aside from double checking more mechanical issues. Based on your problems it sounds like you are having tune related issues, could be from faulty sensors incorrectly providing readings, a vacuum leak, could be from how you have your pcv plumbed. The fact the tuner could not tune your car on MAF but could on SD because your maf was having issues makes me think you should revisit what could have been causing maf issues. Did he say if it wouldn’t read air flow or was reading erroneously? Any chance you have a wideband o2 sensor installed and know what your afr is doing when the stumbling/back firing occurs?

As far as mechanical issues to add to the checklist, you can look into nipple on the ls3 valley cover and ensure it is plumbed correctly for pcv, not sure how it needs to be routed coming from an ls1 given I haven’t done it but you might want to double check that. Would make sure there are no vacuum leaks, double check back of the intake manifold. Would also rule out sensors tied to the 5v circuit cel you have. MAP is used for speed density, if that sensor were not functioning correctly it could cause all types of drivability issues, however I haven’t read of any map failures.

At this point the only real suggestions I have is to make that checklist to rule out as many mechanical possibilities as possible in one shot. I would create a thread on hptuners and ls1tech to see if others with more knowledge than myself have some better ideas. Assuming you have oil pressure, I would not be getting on it or driving the car much as all until you can reconcile these issues. Good luck and keep the thread updated, I will chime in with any other ideas I have based on the information provided.

b16crx

well it was just that last time that I had it running that the gauge went to zero. All other times I drove it, it was reading normal pressure.

On my original engine I had relocated the oil pressure sending unit next to the coil packs, but I used hard brake line bent into shape. the new coil pack brackets are shaped different so the line didn't really work. I was in a bit of a hurry by this point, since this is my daily driver, so I just put it back in the stock location. Now that I had to take the manifold off again I wish I had the time to fix that, but I didn't. I want to make a new one with some steel braided line, maybe extend the connector and move over by the fender somewhere or something.

Anyway the good news is I found the issue finally! the ground wire for the sending unit had a small piece of the insulation that had wore through showing bare wire. I guess it was grounding out and eventually shorted out the sending unit all together. when I disconnected the sending unit I got 5 volts back to the MAP, but with the unit connected I only got 3.4 volts to the MAP. Lucky for me I got the sending unit with the life time warranty, so I swapped it out, fixed the wire, and all is good now!

It is so different now!! this was the first weekend I could really drive it.
compared to the stock LS1 I took out it feels like a monster now! It has always been a fun car, but now it's just insane (I know 428 hp really isn't much compared to a lot of cars). When I first got this car I had the biggest grin that never really went away, that was 10 years ago. I think the grin is twice as big now!

Thanks for the help Tommy!

I also have to give a huge Thanks to David and Mike at Vengeance Racing!! They both helped me a bunch! Also my Dad!! I never would have made it without him!

tommypenguin

Glad to hear you got it fixed and are back in business!