When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Have had this 01 WS6 since 2007, generally running fine. Mostly stock with 107k miles. A little noise that sounds like detonation at WOT above 4500rpm. Decided to pull the intake manifold (what a pain) and replace the knock sensors in case that was a factor. Figured it would be a little dirty, but after removing the intake manifold the valley cover area is downright filthy and has gunk and what looks like oil clumps all over. I can’t imagine this is good at all for my engine. I plan to shop vac the clumps out and wipe everything down, but while I have this apart what should I be doing to get my engine properly addressed in light of these photos?
About all you can do is get in there with a plastic scraper and maybe a flat head screwdriver to scrape the gunk away. Have the shop vac ready to remove the crap. I stuff shop rags in each intake port to help keep dirt out of them, but it’s inevitable. Some dirt will get in the ports. A shop vac will get it out of them, just be patient and use the shop vac liberally after your done, and the rags are removed from the ports. Unfortunately all LS engines look this way after many years of use.
Before cleaning I’d remove the rocker stand on both banks to ensure all intake valves are closed. Shop vac first and some lint free rags/towels and maybe some engine degreaser. After it’s clean some compressed air to blow everything out including intake runners. Pretty straightforward not much to it. Multiple correct ways to do it, I’m sure you’ll get a lot of suggestions
Just a thought you could also do a tune up on the car while you’re in there if you’re concerned about your situation. If you have access to a scan tool you can see if you’re picking up any knock retard under heavy acceleration. There might not be anything wrong
Just a thought you could also do a tune up on the car while you’re in there if you’re concerned about your situation. If you have access to a scan tool you can see if you’re picking up any knock retard under heavy acceleration. There might not be anything wrong
Meaning my knock sensors might be fine? Debating whether I should replace them anyways given what a pain it was to get the intake manifold off
Knock caused by sucking oil into the cylinders?
Those intake ports are worse than filthy.
I can only imagine what the intake looks like.
Agreed, I plan to remove the intake entirely and deep clean it. I recently installed a catch can, should this in theory stop this from getting this bad in the future?
Meaning my knock sensors might be fine? Debating whether I should replace them anyways given what a pain it was to get the intake manifold off
Knock sensors have a high rate of damage any time you take off the intake and clean stuff. Definitely worth changing out even if they were good before you started. And absolutely do not exceed the recommended torque when installing the new ones.
This. I change the harness regardless what it looks like on a gen3, it’s usually toast. Good advice above on not over-torquing the new knock sensors. It will ruin them.
Cascadesys, the engine cleaned up nicely. Good job!
This. I change the harness regardless what it looks like on a gen3, it’s usually toast. Good advice above on not over-torquing the new knock sensors. It will ruin them.
Cascadesys, the engine cleaned up nicely. Good job!
If it helps people in the future, I'm happy to report that the knock that led me to do this project is now gone, but not sure if it's partially because my knock sensors are pulling timing due to codes.
I replaced both sensors and the harness (Delphi sensors, Dorman harness). Delphi was a division of GM and spun off as a separate company around five years ago, so it's my understanding that they are similar to AC Delco in a sense that they are reputable and not the problem here generally. I got low voltage codes for both knock sensor banks. Pulled the intake manifold again (much faster the second time, but still a pain) and replaced both sensors yet again with brand new Delphi ones, and checked the harness and didn't see any damage or areas it looked pinched. I torqued the new knock sensors to 11ft/lbs aka 132in/lbs and put it all back together. Took it for a drive and the code for knock sensor bank 2 is gone, but bank 1 (the front) is still coming up. At a loss, so frustrating. Here's a photo of my harness when I pulled the manifold the second time, doesn't seem pinched does it?
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.
7 Most Reliable High-Performance Engines GM Has Ever Built
Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
Valley cover filthy, correct way to address? 
