Papagoose

So here is my situation. When you listen to the engine with hood open, there is a slight knocking sound even after warmed up (not piston slap I think) and is a deeper sound than the famous LS1 valvetrain. Seems to be coming from the lower front of the motor but I cannot isolate it, and if you rev the motor it becomes inaudible, or at least the engine sound/exhaust drowns it out. Also, on Torque (an awesome scanner app for android BTW) she is showing quite a bit of knock retard, but only under certain conditions really... on a flat road, if you hammer it at 30, it shows maybe .4-.5, and thats not every time, but if you are, say, ascending a hill slowly and lightly accelerate up said hill, I will see as much as 6 deg KR. I get none on decel. I also wonder why when I hammer it from a dead stop the tires will barely bark/only slight spin unless i powerbrake it (BFG gforce super sport a/s). Car has 154k. The rest of the info is in sig. Any help would be appreciated.

Edit: Also, last time I took car to the local 1/8th (month ago), she ran an 8.6 with a 2.0 60ft with the rear seats out.

johnny6

What grade fuel are you using? How is your oil pressure? Exhaust leaks also make knocking sounds. With 154k miles the engine sounds pretty tired, when was the last time you did a good tune up?

Papagoose

oil pressure is around 45 most of the time unless she gets really hot. Always premium, although i kinda question a few stations around here. I did plugs and wires last month.

johnny6

Does Torque pull OBD codes? With these engines it's too many things that can cause timing issues, i would check over all the plug wires to make sure they are seated all the way and just move on from there.

Papagoose

yes, torque reads/clears trouble codes, and also show any info your comp is getting, and can give you a nice set of extra gauges, and if there is something it doesnt do, you email the creator and its there like the next day. Best investment I ever made. Anyway, I'm not getting any codes whatsoever.

Papagoose

No more thoughts? I am worried cuz she is my DD and I have to make her last at least till the end of next year, when I deploy again and can dump more money into her.

cars3

If your car is stressing you out then get rid of it. No car is worth stressing about.

Papagoose

I wish I had that luxury. Can't afford anything else atm. I am just new to the LS engine, and don't know messed up from normal. Still trying to learn the thing... And I don't know many, esp around here, who have any experience with this engine.

cars3

Well, if this is your only car and you depend on it for work, then I totally understand where you are coming from. If I have a problem with 1 car I just grab another one, or my truck, 1 of my 2 motorcycles. But I have this option after many years of working under me. Good luck with getting things resolved.

AL SS590 M6

I hate to even think this. But without being there to hear the motor in person the sounds you describe point me towards worn main bearings.

BadgeZ28

my power steering pump makes a clacking noise. You can remove the accessory drive belt for a short start up test to see if the noise disappears.

Evolution223

you can lease a brand new Honda Civic now for $149 a month. Gets better mileage than an LS1 too.

Papagoose

I put this thread up a LONG time ago... but think I have it figured out, so no worries. Pretty sure its a combo of a messed up tranny mount, bad tensioner, and a really old timing chain. Working on fixing that stuff. And I have no complaints about my mileage, most days without ac on i get 28-29.

JeeperSC

My LS1 always had knocks that came and gone. I miss them almost as much as I miss my LS1, dont let it worry you to much. As long as it runs like a bat out hell its all good.