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Long story short, it looks like a 14k mile LS2 in a friends GTO (Dave “BRZN”) is beginning to consume itself.

We’ve been chasing an intermittent random misfire for years. All the typical electrical items were checked (plugs, wires, coils) to no avail. Swapped on some new Kooks headers last month as well as some new plugs. Winter hit here and didn’t get a chance to take it out for a drive and do some data logging to see if somehow the headers and new plugs miraculously fixed the issue.

Last week Dave decided to do an oil change as it’s been awhile since he last did one (roughly 1k miles and a couple of years as it’s a summer garage queen). Found some crap on the magnetic drain plug and thought he’d open up the oil filter.

I can’t upload the video, but attached is a still picture of the video. There’s a lot of glitter in there. Took the valve covers off and saw what you see circled on the passenger-side. These are SLP 1.85 rockers if that makes any difference.

We’re already prepared to pull the engine in the spring, but anyone want to guess what’s going on? This is a bolt-on LS2 with the stock cam and heads, so nothing more than the aforementioned rockers and headers on the car.

Rockers deteriorating? Lifter failure resulting in taking out a cam lobe? Bearing failure?

We did a compression check last weekend and all cylinders were down 5-10lbs from when we last checked the compression in 2016. Began a leak down test before I had to leave and those results all seemed around the same as previous and within the normal range, so we don’t believe it’s a dead cylinder somewhere.

Planning to pull the rockers next to see if one of those SLP rockers is destroying itself.

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i would bet money that it's the rocker trunnions.

i had my hands on a used set of SLP 1.85's and the trunnions were chewed to :poop:

stripped them and ended up just reselling the bare rockers. kind of wish i kept them long enough to install a che trunnion kit. it would have been a long wait, tho.
 
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Yeah, thought about that too. Say it is the rocker trunnions. What's the chance the whole motor doesn't need to be pulled and gone through to make sure the bearings/cam/lifters are OK?
 
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Yeah, thought about that too. Say it is the rocker trunnions. What's the chance the whole motor doesn't need to be pulled and gone through to make sure the bearings/cam/lifters are OK?
the way oil is supplied to the valvetrain, i don't think you constantly have metal dropping in your motor. some of it can obviously making it back down in your pan, you just gotta hope the filter catches all of it. i think the majority of it would stay up in the heads, kind of like the picture shows.

don't know of any tricks to check a lifter roller other than pulling the heads and yanking them out.

a few of the lobes you could visually check if you pull the valley cover off. there's a few small windows that you can see through.
 
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Yup, that was next to check (pulling the intake and valley cover to see if we can peek at a few cam lobes).
 
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There are metal flakes in the recess around the center head bolts on the passenger’s side. Same side where the most metal flakes are on the trunnions.
yeah, that's worrisome. they're probably getting gradually washed down into the engine. it'll go into the recesses in the block were the lifter bores are. hopefully they are getting stuck at the bottom corners of those, and not going through the drain windows in your block and maybe right onto the camshaft, or getting stuck in the lifter bores.

i'd pull the heads at this point. this sucks.
 

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You didn't hear any ticking? I think the filter caught everything. Take off the rockers carefully first to see whats wrong. You can clean up the head and spray down the area with brake cleaner. Dump the oil and add 4-5 quarts of oil and top off with diesel and idle the motor for 5-10 minutes. Change it again and later after one hundred miles.

Replace the rockers with OE (1.7) CPP rockers. The cam was designed for 1.7 rockers. If you want higher lift, order a different cam. I don't think the bearings are scored or at least not bad enough to change out. I turned two lifters over the years with an ocean of debris and the filter trapped most of it. Good luck and lets us know what you found.
 

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You didn't hear any ticking? I think the filter caught everything. Take off the rockers carefully first to see whats wrong. You can clean up the head and spray down the area with brake cleaner. Dump the oil and add 4-5 quarts of oil and top off with diesel and idle the motor for 5-10 minutes. Change it again and again later after one hundred miles.

Replace the rockers with OE (1.7) CPP rockers. The cam was designed for 1.7 rockers. If you want higher lift, order a different cam. I don't think the bearings are scored or at least not bad enough to change out. I turned two lifters over the years with an ocean of debris and the filter trapped most of it. Good luck and lets us know what you found.
 

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No ticking at all, but a random misfire. There’s also metal on the end of the magnetic oil drain plug. The stuff on the end of the drain plug isn’t the flakes seen around the rockers but a black goo. After I put in the magnetic drain plug it looked like an Afro on the next oil change (2,000 Mike change) covered in flakes, no flakes again since, just the black goo.
 

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I hate to sound like sloppy mechanics with a just send it attitude but I would clean up the mess in the heads best you can, install stock rockers with stock trunnions and put it back together.

Change the oil obviously and monitor oil pressure.

If oil pressure looks good maybe change it every 500 miles for a while just to make sure everything is happy.

I wouldn't take that engine apart based on pictures provided.
 

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well, you got 2 votes for just sending it.

i guess i change my vote to just cleaning it up and sending it as well. (maybe crossing my fingers. :ROFLMAO: )

it is true these motors can take a lot and still run well.
 
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I'd inspect the rockers first, then replace them with CHE trunnions on stock rockers. How is the oil pressure?

If the car gets driven a lot (which it sounds like this one doesn't) those aftermarket trunnions can just give you a different kind of wear that should be checked and monitored.

For a driver I always recommend stock rockers stock trunnions unless you are seriously racing with high RPM or have a cam that is hard on the valvetrain.

Stock trunnion failures don't happen as often as people want to believe.

I know far more people that have had stock oil pumps fail trashing the engine then those that have had a rocker arm trunnion failure.

Just my .02
 

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If the car gets driven a lot (which it sounds like this one doesn't) those aftermarket trunnions can just give you a different kind of wear that should be checked and monitored.

For a driver I always recommend stock rockers stock trunnions unless you are seriously racing with high RPM or have a cam that is hard on the valvetrain.

Stock trunnion failures don't happen as often as people want to believe.

I know far more people that have had stock oil pumps fail trashing the engine then those that have had a rocker arm trunnion failure.

Just my .02
I should probably check mine, as they've been on for almost 2 years and 20k miles. Might be a good spring time project...
 

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If the car gets driven a lot (which it sounds like this one doesn't) those aftermarket trunnions can just give you a different kind of wear that should be checked and monitored.

For a driver I always recommend stock rockers stock trunnions unless you are seriously racing with high RPM or have a cam that is hard on the valvetrain.

Stock trunnion failures don't happen as often as people want to believe.

I know far more people that have had stock oil pumps fail trashing the engine then those that have had a rocker arm trunnion failure.

Just my .02
i'd personally always go with a che kit on anything but a stock or mild cam setup, anything that uses much aftermarket springs, but i completely agree with you otherwise. Any bronze type bushing is going to wear out eventually. it just has a softer failure mode than a steel trunnion getting chewed up, and che has so far proven to be the longest lasting bronze bushing type trunnion kit out there.

he's running aftermarket springs. those will be harder on the trunnion, i would do the added step of getting a nicer spring to play with, but a stock rocker set should last him the life of the engine.

the RPMSpeed MAX EFFORT rocker arm kit is are another option, too. not anything like the trunnions in the SLP setup, which are almost exactly like the comp trunnions.
 
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he's running aftermarket springs.
You picked up on something I saw but couldn’t confirm: Those green striped springs don’t look stock. The Pontiac dealer he bought the car from new installed the SLP 455 Bobcat package on the car. From research it came with new rockers, springs, retainers and keepers. Can’t find any info on those springs at all, but look like LS6 springs as I believe some LS6’s came with green striped springs, but can’t confirm what these springs from SLP are.

The engine is stock other than headers and a FAST 92 intake, so should we find the trunnions to be the issue, and are able able to save this motor by replacing the rockers, do you also suggest all new valvetrain or are they OK to leave on an otherwise stock block?
 

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I'd inspect the rockers first, then replace them with CHE trunnions on stock rockers. How is the oil pressure?
Oil Pressure's fine. JHP gauge on dash shows around 47psi. Skipopeye and I took her for a romp last spring connected to his HP Tuners and confirmand good oil pressure. We did see the random misfire on most all cylinders but worse on cylinder 3 which is where my scan tool shows the misfire coming from.
 
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