Let it cure without the header bolted on? That's weird as hell
LS swap update and questions
- Thread starter Longhorn84
- Start date
Let it cure without the header bolted on? That's weird as hell
that's what i did originally, one side no problems, one side has a leak around one of the exhaust ports. I'm not sure if the downstream exhaust leak (has leaked from the get go 5 years ago) maybe added to the engine issues and potentially contributed to an early header leak. But oh well, I'll just get in there and start disassembling to try it once more.
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If we have to use Sanderson's we re-face the flange on the belt sander to make sure its flat and use the Remflex gaskets as Wildman Suggested. That fixes them.
We are all different but over 25 years ago a builder of NASCAR headers tough me to use clear RTV and no gasket. It's worked great on 15 to 20 builds and no problems.
I had an exhaust shop replace the cat (he said the old cat was broken inside) and fix the other leaks, I was able to just retighten the header bolt and after getting home from the shop and smoke testing, it was completely sealed which is great news. I bought the knock sensors, harness, and intake gasket ready for the install. For now, I cleared the codes and went for a test drive a few miles, the performance off the line was far more normal, I'll see if I can get a video tomorrow. I still need a tune but if the codes hold off for a while I can get it tuned. Then, if the knock MIL comes back after the tune, I can just replace those sensors and it shouldn't affect anything. So, for now, all is well. Really appreciate all the help!
yes! 6k though which is very aggressive for me, I don't typically mash on it but with top on doors on it's way more manageable. I'll get a video before and after the tune and post here.
Sorry, late to the game.
My stock 4.8 is exactly what the Jeep should have come with. It’s sufficient, but it’s not fast or thrilling by any means. I don’t really know that I am happy I chose the 4L60.
curious to see how this is playing out? Those 5.3's are good for big power with pretty good reliability. id be curious of these that you can check yourself:
- compression test
- fuel pressure @ idle
- fuel pressure at WOT
If the knock is still occurring, that will pull big timing (and in turn power). If the knock is real, could be detonation/fuel delivery, or timing issues. If its a false knock, it'll still pull timing without reason.
Even a factory torque converter shouldn't hinder performance as you describe. and a higher stall could make your 'low rpm' acceleration even worse depending on how loose or tight it is.
But im curious... was this motor/trans combo original to each other? On my mustang i swapped from manual to auto, and with the increased load of the torque converter my computer was pulling major timing thinking something was wrong.
Texas should have several local options for a good LS tuning shop. Taking it to one and allowing them to data log & dyno tune it will answer many of your questions. Headers, a nice cam, and a tune should net you nearly 100hp to the tires.
All this to say, with the work you've done i would NOT abandon the 5.3. it can be a power house... you've just gotta get the last 5-10% figured out now.
- compression test
- fuel pressure @ idle
- fuel pressure at WOT
If the knock is still occurring, that will pull big timing (and in turn power). If the knock is real, could be detonation/fuel delivery, or timing issues. If its a false knock, it'll still pull timing without reason.
Even a factory torque converter shouldn't hinder performance as you describe. and a higher stall could make your 'low rpm' acceleration even worse depending on how loose or tight it is.
But im curious... was this motor/trans combo original to each other? On my mustang i swapped from manual to auto, and with the increased load of the torque converter my computer was pulling major timing thinking something was wrong.
Texas should have several local options for a good LS tuning shop. Taking it to one and allowing them to data log & dyno tune it will answer many of your questions. Headers, a nice cam, and a tune should net you nearly 100hp to the tires.
All this to say, with the work you've done i would NOT abandon the 5.3. it can be a power house... you've just gotta get the last 5-10% figured out now.
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