Hey everyone, I need some help figuring out an issue with my GTO. I purchased it end of may. The car had a previous build of a 408 done late 2018/2019 at 89k miles by an owner that drove it about 3k miles then sold it to another owner, then myself. The car currently has 107k.I have put 800miles on the car since I bought it. 220mile drive home and then 500 mile trip to a show and some around town driving. When I picked the car up it had the SLP loud mouth exhaust on it, which was too much drone and too loud for me, so last month I change it to a Borla exhaust. When I picked the car up from the exhaust shop, I heard a "tick" noise from the valve train that was masked by the loud mouth previously, I drove it home and it did get a bit more quiet as it got warm, but when i went past a barrier or bridge I could still heard it.

So, the car sat for a few weeks and finally had some time to pull the valve covers with a friend and check the car out. This is were I need some help, everything looks good visually. It appear the noise might be on the back side of the drivers side so cylinder 5/7 maybe. However I think I have an oil issue, when running with no covers, no there is no oil spurting from the pushrods ( I have good pressure, 40-45psi at idle). I'll attach video's below. I'm just at a limit of where I should check first? I have been told check pushrod length to make sure they are even correct. I talked to the owner that built it and he said TSP suggested the pushrods based on nothing was milled down is what he said. he also stated in the 3k miles he drove it, there was no such noise before he sold it. I was also suggested I drain the oil and drop the pan and check for metal and the O ring on the pick up line.

Any advice or suggestions would help. I have searched and finding a lot of these things happening when a fresh build is done and preload etc being wrong. but like I said this build is 17k miles old now and I'm 2nd guy to have it after it was built.

Here are some stats of the motor and parts used to help anyone and also link to video I uploaded. side with coils is the driver side where my noise is. I did passenger side to check and no coils to clearly see.

Passenger side https://imgur.com/a/46WPJM2

Driver Side- https://imgur.com/a/dFblB0P



Lunati Voodoo H-Beams LS Rods 70361251-8 - 6.125" x 2.100" x .927"
CP Bullet LS 4.030 Bore 4.000 Stroke -3.0cc Flat top Piston and ring kit
CPI-AP031N-CS24 1 piece seal internal Balance Forged 4340 Steel, 4.0in Stroke 2.100in 24x Crankshaft
TSP Camshaft 235/248 .649"/.615" 111 LSA 109.5 ICL
TSP 7.40 Chromoly Pushrods
TSP 97-tvs-2187p-PAC polished .660 dual valve spring, nano peended 160lbs @ 1.80", 415lb @ 1.15", CB @ 1.015"
LS7 Lifters
BTR Trunion upgrade kit
GM High Performance oil Pump,Wet Sump
LS3 manifold
LS3 heads
LS3 fuel rails
LS3 Injectors

 

You have idle video? Dont know why you would check oil pick up o ring when you have solid warm idle pressure? Drivers side rear is number 7.

 

you're correct 5/7 sorry. and yes I have idle video's with the covers off in the original post and here you go as well if they didn't show up. I have one of the car with everyone on cold as well if you need it.

https://imgur.com/a/46WPJM2

 

I'm no expert by any means but that looks pretty friggin dry to me.

 

Lets not over react. It's hard for me to believe you have good oil pressure, but not oiling the top end for as many miles as you say have been put on the motor. It looks like you are getting some oil out the tip of the pushrod. It's not a lot, but I do see some oil. It wouldn't take a lot of miles of not oiling before the tips of the pushrods should blue. Check the coloration on the tips of the pushrods if no discoloration you are probably fine. If it was something like bad lifter/bore clearance or lifter issue causing it not to oil the top end you would have had a problem long before now if it has the miles on it you say it does. That's also a lot of lift on the cam and they can be noisy with LS7 lifters especially since preload was never measured it's probably fine, but could be on the end of the spec range.

Just throwing some things out there to consider before you start tearing things apart. Sometimes we over react and think of the worse things first. I do it myself sometimes LOL

 

I don't disagree and yes there is some oil. And correct the build was done around 90k miles. what I was told is or at least searched and found as well is the O ring on the feed if pinched etc "could" allow air in and still show good pressure..... I take that advice with a grain of salt.

One of the best tuners in town for LS motors, I contacted VIA Facebook to get some advice. his fist observation was that's not enough oil at start up. then I asked him about oil pressure and he said " 60 on cold start, 50 when warm at 1900 rpms. 40 at idle when warm". However I'm using a Bluetooth OBD reader from a buddy and phone to measure it. so he suggested I get a mechanical one to rule anything out. cause he also mentioned if it was the o ring when it gets warm pressure would be lower than expected.

I'm defiantly going to check the pushrods first. Rule length issues, which I would think if they were too short that this long there about have been issues long before, especially at 487WHP. Just looking for some guidance on things to check before thinking the worse and pulling the top end apart this weekend.

 

Sounds like you got the best tuner on it so I'd go with what he says. Surprising it just showed up now after 17,000 miles on it. Only way to know is check that o-ring make sure it is the correct oring for your style pick up and isn't pinched/torn etc. Good luck, hope it's a simple fix for you.

 

Well, i would say its more or less been there a while at least. the loudmouth exhaust was so crazy annoying i couldn't even hear it till i got the borla on the car. once i know what to look for and went back to the videos the guy i bought it off sent me, I can defiantly hear it there. But if he was like me and so loud and didn't really pick up on it, who knows how long it has been that way. I can just tell you the guy that owned and built it said after 3k miles that was defiantly not there from the video's I sent him with the loudmouth on. he's been good with sending part details etc that I didn't have.

 

No way. Air is compressible. Oil is not. If its sucking air in it would show a drop in pressure.

 

Hey sorry didn't see this. So I did some more testing today. I got a manual oil pressure gauge from a buddy and put everything back on to do some testing for one of our local Tuners/LS shops here in KC. Top picture is cold start then middle is revving to 2k as you can see and bottom is at warm idle temp. Which I was told that is "a bit low for my liking on your build". Then we pulled the cover back off and I will link a video for that for you. But it was warm and started and took it up the RPMs up slowly, about 1k-1200rpms noticeable oil started to come out of the push rods and about 1700-1800 it squirted out. So now what im trying to track down is where it is being lazy at for the pressure. going to start with the O ring and pickup tub first.

https://imgur.com/a/ijsZQWU

 

I also responded to another member with tests today and new video.

 

I am not doubting you may have an o-ring/pickup issue, I'm doubting you have great oil pressure that increases with rpm AND an o-ring/pickup issue.

 

well I tested this 2 times now, first was with a ODB Bluetooth reader and now manual and pressure was the same. I can't say it will get better either once I check the o ring/pickup. I very well could have a failed pump which is GM high flow pump and was done with the build. Just checking the boxes as I go to figure it out. then i'll address my tick/sewing machine noise

 

the video is kinda hard to see on my end, but it doesn’t have much oil flow from what it looks like on my phone

 

Replace the o ring

 

So i did some more testing today and put the video in a reply above and some pics of my oil pressure with a manual gauge vs the OBD reader.
40PSI cold, 44 revved at 2k rpm when warm and 36 idle warm. Then pulled over and had my buddy slowly rev the motor. about 1k rpm noticeable change in oil from the pushrod and once it hit that 1600-1800rpm oil spurted out all over the place. So tomorrow im going to drain the oil and pull the pan and check my ) ring and pick up tube hopefully.

 

Why are you pulling the pan? That’s quite a job in a GTO with a front sump. You can get to the o ring without pulling the pan. I’m still not even sure you have an oil pressure problem. I have a built motor with a Melling pump and have 60 cold and 40 hot oil pressure using driven 10w40 conventional hot rod oil. 36 warm idle pressure with a gm pump on a built motor seems normal to me.

 

trying to chase this all down. Yes I have a GM high performance oil pump in the car. Based off a few people I’m “low”. Something is being lazy that’s not allowing that oil to come up the pushrods. Been told by a few people and tuner/shop I should check the o ring. That it very easily could be this issue.

 

Im just trying to save you some possibly unnecessary work. My pump is 10 percent over stock per the manufacturer and I have 10 percent more warm idle pressure than you so that seems normal. My truck with 180,000 on it has 30 psi warm idle and I’ve never second guessed it.

You don’t need to remove the pan to check the o ring. To remove the pan on a GTO you have to drop the cradle or pull the motor. You can drop it a little to do a gasket but that’s really half assed and you risk having gasket leaks doing it that way.

 

ya I get that , after looking into I didn’t realize these need the subframe dropped. A friends nephew is a mechanic and did offer ona weekend if I want it done we could use his shop and he’ll help for small fee. I really don’t want to drop the front of the pan and change it and mess up the gasket. Not my intention at all.