Valve Spring Up & Over the Retainer

[PAFirefighter11]

So for many, many months (July of last year approx.) I've had a drivability condition with one of my Trans Ams (the 1998). It started having a slight hesitation in 6th gear while on the highway. This slowly got worse and worse, to the point where the car sounded like it had a nice, big lift, lopey cam. I loved the sound at idle, but it ran like *** so it wasn't too much fun for me. I went from 22 MPG average to around 12.


Here is are two crappy videos to demonstrate what was happening (at idle at least):




Here are both of them ('98 has the TT2's):



I started throwing money at things, since I didn't have much free time to really diagnose it. I had changed:

-Plugs
-Wires
-Y-pipe & cats
-Gaskets
-o2 Sensors (Got rid of my P0420 bad o2 sensor code at least)
-Intake
-MAF
-PCM
-Wiring harness pieces
-Coil packs
-Injectors

And more!

HP Tuners / EFI Live were showing:
-Cyl #5 misfire
-Cyl #7 misfire
-Random Cyl #8 misfire
-Random Cyl #6 half fire

Some photos...

2 interesting things. First, I noticed this on the ECU I pulled from my car is a reman:


Second here's the corrosion that's all over both the ECU and the harness side (I cleaned this all up since the photo):


I had 109,XXX miles and do not think that the prior owner changed the wires. The plugs are half and half. I changed the wires to Vengeance Racing:


Also running new TR55 NGK plugs gapped to .055. The gap of the old plugs was at .085!

These were the plugs, set up in cylinder order. Top plugs are the front of the vehicle:


#8 plug:


I've never had any other codes than:
P0420 - Catalyst efficiency below threshold (original code I've had for some time)
P0300 - Random misfire detected
P0140 - o2 circuit blah blah (from when I disconnected the driver side downstream o2 sensor to check it)

Fuel trims were insane:
Fuel Trim Bank 1 Short Term = 16.406 %
Fuel Trim Bank 1 Long Term = 24.219 %
Fuel Trim Bank 2 Short Term = -5.469 %
Fuel Trim Bank 2 Long Term = 13.281 %

Took it to a few shops. This was from a former GM dealer:


Ran a compression check myself on 4 of the cylinders (Easy ones to get to):


All were within spec that I was able to check.

A buddy of mine with EFI Live checked the car and suggested a broken valve spring. The driver side valve springs looked okay (Minus the color):


But when we got to the passenger side, it's a MUCH different story:


A little closer:




Time to rip the top end apart:






Steve has his old LS1 with 55k miles on it (He has his LS6 now) so we're using his heads, springs, rockers, etc:

















Oh haiii... Found 2 of these - of course we didn't verify which cylinder(s) they were from:


Looks like aftermarket springs, retainers... Possibly a head off of a newer Trans Am, Corvette, etc.?






And a couple non-cell phone shots with my Nikon D2x and Tamron 17-55 f/2.8:






Some progress last night:

[PAFirefighter11]

This is where we currently are:



So excited to have 'er back! Need to do the same thing to my '01 thanks to a possible bad head gasket, passenger side. Fun.. once again!

Here are 3 shots I took last week now that she's back on the road:

[jag107]

That is one MINT ride, you must be very proud. What a great write-up, thanks!!

[SSE 4 2SS]

Agreed, Beautiful car,

I moved this to the 4th Gen section. More fitting...