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.
I recently acquired an '05 GTO with lots of miles and it needs help. Most notably, the water pump leaked something fierce when I got it, I couldn't believe it stayed cool through the last couple weeks where I'd put coolant in and it'd practically just dump it in 7 miles.
Anyway, I bought a slew of parts and prepared for a major maintenance. Yesterday I began with removal of the radiator, water pump and some other stuff up front. What I found made my heart sink:
That timing cover looks like it has a window cut for a cam swap. I immediately started worrying this was a raw deal where the seller had major issues, slapped some junkyard parts together and sold the car as "stock". However, after I cleaned up and got to the internet after dinner, I searched '06 GTO timing cover. The first image result on eBay showed one IDENTICAL to what I have. I mean, same three raised bosses on the boundary of what appears to be the cut. They had pictures of the inside of the cover, no cuts.
Since I couldn't find any additional information, I'm asking here: is that really what a stock LS2 GTO timing cover looks like? Is there a chance this cover is stock and not modified? I should know in the next few days when I can pull the cover, but I wanted to see what y'all know about this, as I've never seen it before.
That is not a GTO LS2 front cover and I don't know what that cover is from. Here is what a GTO front cover looks like: Chevrolet Performance Timing Covers 12633906 or GENERAL MOTORS12600326
That is most definitely a stock G.M. LS2 timing cover that you have in your car. The one Jontall has pictured is a replacement and will work as well, just remove the extra pigtail of wires, you can see in Jontall’s picture it has the extra pigtail for the cam sensor which is not used in the GTO application, that wire routing of the extra pigtail is used in a corvette LS2.
Not sure why they have the square window look, but it is not for a cam swap as the gear would not come out.
Thanks for the feedback. I have to wait on a new flexplate holding tool to take the crank pulley off, I'll know what's going on next week and will post pictures of the inside. Jontall, that's not the cover for a GTO. It may work, but the GTO doesn't have the extension harness.
I'm learning more and more as I dig deeper into the motor. The valve covers are just like LS3 with the long fresh air PCV nipple and the baffles inside that run the whole length. And they were so clean on the inside, I just can't believe they're original to the 160K mileage the car represents (they may not be). More as I dig.
There are so many Chinese parts now it's hard to keep up... I gave both part numbers and this is the GTO cover but either cover will work: GENERAL MOTORS 12600326
Keep in mind that the cam sensors and the knock sensors are located in a different place than an LS1. The hole in the cover is for the sensor. The 04s with the LS1/6 hybrid motor have the cam sensors mounted in the back of the manifold and the knock sensors in the lifter cover.
The cams are different too. LS2s use a single bolt sprocket while the 1s and 6s use a three bolt.
Keep in mind that the cam sensors and the knock sensors are located in a different place than an LS1. The hole in the cover is for the sensor. The 04s with the LS1/6 hybrid motor have the cam sensors mounted in the back of the manifold and the knock sensors in the lifter cover.
The cams are different too. LS2s use a single bolt sprocket while the 1s and 6s use a three bolt.
I appreciate the reply, but there's a lot of misinformation in there... the knock sensors have nothing to do with the timing cover. And I know the cam position sensor is in the front, that wasn't my question.
Before anyone is confused with your response, the GTO LS2 cam is a 3 bolt cam. Though a 1 bolt cam was available, it wasn't in the GTO and it was a different part number.
New flexplate holder is supposed to be delivered today, but I don't think I'm allowed to work on the car tonight... answer later this week.
Of course the knock sensors aren't related to the cam sensor. I indicated the sensor placement differences for both motors. The cam position is measured from the front on a 2. This makes the camshafts not interchangeable. The knock sensors are undesirable also because they are mounted on the outside of the block and can get burned by the headers.
The suggestion being that if you had to start over install an LS6 lifter cover and extend the harness to fit the new knock sensor position. If you converted the timing cover to a 1 or a 6, it would provide a wide variety of three bolt off the shelf cam grinds. Although it is improving today, there are fewer 1 bolt cam options. Also, even though your motor has a three bolt set up, the readily available three bolt 1 cams will not work with a front mounted sensor. There is no misinformation provided, rather a misunderstanding of my meaning.
Good luck.
At this point, it doesn't look like there's much of a question as to whether the cover is factory or not. However, for future enthusiasts, here's a picture of the outside and inside of the cover. It's not cut all the way through, guess that makes it original.
And a cam picture to show the GTO LS2 cam is 3 bolt, in case there was still question...
So now that's resolved, I'll elaborate on my plan. In addition to the water pump leaking, the car had bad lifter tick when cold. With that and 160K miles, I decided to undertake a refresh of some seldom accessed parts that would be touchable when the water pump was off. This includes a replacement LS2 cam (stock), new valve seals and a VJ, trunnion upgrade, new oil pump, new seals where appropriate, powder coating stuff while it was off, just a general attack of long-term consumables. I never thought I'd see a worn timing chain damper, but sure enough, the old one had a couple grooves lightly etched in on each side. In the end, it'll be a reliable, stock-ish LS2 that will handily support some bolt-ons like an intake and full exhaust.
05-08-2019, 07:49 AM
GTO Timing Cover Differences 
