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I'm in Southern Ontario, so pretty far . If you can figure out shipping I could send them after I disassemble. Not sure about the too rich thing , mine ran low 10s AFR many times in the early stages of tuning and no hint of problems . I just thought of something else though, are you using the oem fuel cut rev limiter? And have you hit the limit ? In my early reading on this site there were a few that had engine damage after hitting the limiter, could be it cuts fuel part way through a cylinder's injector pulse - don't know
Ive never felt or heard spark blow out, so I did my research and watched videos of it and that is the conclusion I came to. It went away when I closed the gap on the spark plugs, could having weak coils cause the spark plugs to not fire properly?
Weak coils could 100% cause the plugs not to fire properly, same with low quality wires. I only run D510C coils, I don't think early LS1 coils are as strong. This past summer, I had a misfire under boost and nothing would fix it. Turns out the cheaper spark plug wires I installed ( which work great on my N/A Camaro, so I won't knock them ) just weren't up to the task of firing my plugs. I bought a set of Taylor 10.4MM wires and the misfire was fixed.
I'm in Southern Ontario, so pretty far . If you can figure out shipping I could send them after I disassemble. Not sure about the too rich thing , mine ran low 10s AFR many times in the early stages of tuning and no hint of problems . I just thought of something else though, are you using the oem fuel cut rev limiter? And have you hit the limit ? In my early reading on this site there were a few that had engine damage after hitting the limiter, could be it cuts fuel part way through a cylinder's injector pulse - don't know
Hello,
Work started to pick up so I havemt had a chance until now to look at my old tune and my fuel cut off is at 6950 rpms. I am confident I didnt spin it that high.
I did look into shipping and have a rough idea of the cost. If youd like i can private message you for more info to get a more accurate price to ship.
Originally Posted by LS1Formulation
Weak coils could 100% cause the plugs not to fire properly, same with low quality wires. I only run D510C coils, I don't think early LS1 coils are as strong. This past summer, I had a misfire under boost and nothing would fix it. Turns out the cheaper spark plug wires I installed ( which work great on my N/A Camaro, so I won't knock them ) just weren't up to the task of firing my plugs. I bought a set of Taylor 10.4MM wires and the misfire was fixed.
I do have cheap NGK wires from Canadian Tire, they were just replacement wires for a stock engine. So I will look into upgrading those as well
The weather got a little warmer so I finally pulled the intake and driver side cylinder head.
Found more oil than i expected around the intake gasket and to my surpise the pistons and cylinders cleaned up fairly good with quick brake kleen and rag. Im wondering if I blew the turbo seal and it was sending oil through. The catch can only had what looked like water with a tiny bit of oil on the top.
Valves look good at a quick glance but i will get them looked at.
There is no hole in my #7 piston like I thought with the crappy bore scope picture. The ls9 small bore headgasket was very wavey when I pulled it off.
It was getting a little chilly again so I gave up and will have to do some more investigating.
So what was the original issue, was it missing or something? Could you have just fouled out a spark plug or two?
The engine was down on power, blowing alot of smoke out of the exhaust. Compression was down on both banks of the engine. So I assumed it was a ringland or a hole in the piston in cylinder #7. A head gasket issue on the passenger side since every cylinder is at 100psi on that side. From the bore scoped picture I thought I had seen a hole in the #7 piston but the quality of the picture had deceived me.
When this all happened i noticed that my oil pressure was stuck at 60psi either at idle or driving it didnt move. Im curious what would be causing that.
I also had oil leaking out the back of the engine so im also guessing I have a damaged rear main seal.
Im still planning on pulling engine to go through it at this point.
Work started to pick up so I havemt had a chance until now to look at my old tune and my fuel cut off is at 6950 rpms. I am confident I didnt spin it that high.
I did look into shipping and have a rough idea of the cost. If youd like i can private message you for more info to get a more accurate price to ship.
Yes , message me about the rods /pistons , will be a week or 2 before I'm able to get that block torn down , tons of work in the shop and my engine lift is out on loan .
I do have cheap NGK wires from Canadian Tire, they were just replacement wires for a stock engine. So I will look into upgrading those as well
I ran the ngk wires for a few years with no issues, I did switch to moroso wires last yr when I planned on upping the boost. Another thing to mention is that I started with br7s gapped at .025 , after about 25000miles I put in a fresh set , the old ones the gap had grown to. 034 but it still ran fine and did a personal best at the time. You may have a problem with the coils or wiring/ grounds
Had another response in there but it got left out somehow, yes you can message me about the pistons /rods . Will take me a week or two to get that block apart as I'm backed up in the shop and my engine lift is out on loan but I can get that back soon I think
Had another response in there but it got left out somehow, yes you can message me about the pistons /rods . Will take me a week or two to get that block apart as I'm backed up in the shop and my engine lift is out on loan but I can get that back soon I think
Im not in a rush to get them, let me know whenever you have them removed.
On another note, I started looking into my cylinder heads and all the exhaust valves were leaking, some worse than others. I started pulling the #7 cylinder valves out and upon doing so I found the valve seal was pushed up on the exhaust valve and was floating on the valve stem. Secondly I starting cleaning the surface to start lapping when I found a Crack between the exhaust and intake port.
Now ill be sending my spare set of cylinder heads out to be resurfaced and checked over.
If that valve seal was off and that cylinder was sucking oil in past the valve, that could cause detonation.
Im thinking my entire issues from me simply not emptying my catch can and it froze up, Im turn caused the crank case to pressurize. But also the amount of exhaust valves that leaked terribly didnt help the situation.
I finally had some nice weather after another snow storm hit and was able to drop the oil pan and found the #7 connecting rod bent. The piston was in good shape other than the wrist pin was a pain to get out so I am replacing both the connecting rod and piston. Cylinder and rod bearings looked amazing so I wont have to do anything with them.
Next task is to drop the transmission to redo the rear main seal.
I also ordered a 4 port steam vents kit to help with the heat at the back of the heads.
My conclusion is to turn this truck into a summer only vehicle and find a beater for the winter since it can get down to -50 with the windchill for weeks.
So all the exhaust valves were leaking? What do you think caused that ? Did they get too hot ? Haven't heard of this happening to anyone before, has anyone else ? So you don't need these pistons and rods ? I have my lift back but haven't gotten to stripping this engine yet
So all the exhaust valves were leaking? What do you think caused that ? Did they get too hot ? Haven't heard of this happening to anyone before, has anyone else ? So you don't need these pistons and rods ? I have my lift back but haven't gotten to stripping this engine yet
3 out of the four on one cylinder head were leaking pretty bad. The heads did have about 360,000km with about 70k of those being boosted. Im guessing they have seen to much heat since i boosted them.
I will still take the rods and pistons, so i can put my spare block together and sell it since I bought an old work van from shop for $500. It has a 6.0 and 4l80e with 120k km on it. I plan on building a forged setup with that.
Which Walbro 450 pump are you running? There is a low and high pressure version and at 60psi base pressure and 15psi your pushing 75psi which kills the fuel flow on those but pushes you close to the max pressure on the low pressure pump.
700cc injectors should be fine for 15psi. I run 650cc FIC (aka 60lb or 72lb at 58psi) Bosch and I have been up to 15psi on a 5.3 with a stage 2 cam. Going to a 80lb would give you more headroom and allow you to drop the fuel pressure to keep the pump in its sweet zone.
I run wiper fluid (water meth) on both my turbo 5.3s but I also run FMIC... the WM is just to help with detonation.
On the holley Term X I generally make the #7 cylinder 1% richer than the others due to the issues it has. Not sure if you can do this on the factory ECM. I might even take out 1* of timing on that cylinder too... I can't remember
Are you running a check valve in the PCV system? On the oil catch can side you should have a check valve to close off when the engine sees boost otherwise you will pressurize the crankcase. I do a fresh air breather on Pass side and a stock PCV with oil catch can with check valve on the driver side. I do not like putting PCV into the turbo compressor inlet as you don't want oil vapor/mist getting into the turbo or intake charge for detonation reasons.
Glad you found that crack... thats annoying for sure. Make sure you pressurize the entire engine/turbo system after install to verify boost leaks. With all the rockers off you can test all the valves as well.
I had a MLS head gasket leak with less than 1k miles and it only did it when it was HOT on my turbo 5.3. I ended up pulling the head gaskets and used the same ebay cheap MLS (3 layer) but sprayed with copper coat and seems to have fixed it. Both the heads and block had some low spots on 2 cylinders. I wasn't getting coolant in the engine but I was pushing oil and combustion into the cooling system. Very hard to diagnose as it was only after the engine was good and hot that it would do it.
Lap all the valves after you get them back to make sure they are sealed and leak free.
I run one engine with 4 port coolant (came that way) and one with the rear blocked off (came that way) and I don't see any differences. The engines are tilted back so the air wants to move to the front and I doubt air will get trapped in the back. Also the 4port only fits under the truck intakes... and the aftermarkets look clunky and terrible.
Valve stem seal should have been held down by the spring anyways so I doubt that was an issue.
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