2000 Chevy Impala Cylinder Head Repair Log

Ehh, sorry, been a hectic week for me. I will try to post an update soon, haven't had a chance to really work on the poor thing. Last time I was working on it, I got a nice slice along the length of my arm, elbow to wrist on a piece of gasket for the exhaust manifolds. May not be able to do much as my arm really bothers me right now. Bad enough I was transported in an ambulance and didn't get stitches... Ended up having staples. Metal was as sharp as a scalpel, didn't feel it at all, then I look and see a massive pool of red.


Day 8 and 9

I decided I would go ahead and install the exhaust, my only words are that sheet metal gaskets, and heatshields are your worst enemy. Ended up in ER over these after getting the last thing installed. Called it a day.

9: Finished installing exhaust components, mostly the cross over and front manifold heat shields, wasn't that bad compared to the back side of the engine.
I have also installed the LIM gaskets, AIR Induction tubes, one engine mount bracket, spark plugs, right side push rods and rocker arms. I took a note of the rocker arms as they are installed in the same order as removed. Remember how I said the left side of the right head had loose head bolts and had serious damage? Well, even the rocker arms are in horrible shape. Chem-Dip isn't enough to get them back to the new condition they should be in. Needless to say, I am going to deal with it. When I get money (approximately $900) all the rocker arms are being replaced with roller types for better fuel mileage. Not going for power, but instead of sliding on the valve stems, the rockers would roll across them. This will free up some power (not enough to matter), but should significantly help with fuel mileage.

Remainder to do today;
Install left side push rods and rockers, clean the LIM, install the LIM, replace fuel injectors (got a good deal on brand new ones at GM as I was buying a full set, got 30% off) install fuel rail, install various other things. Might even think about finishing up my upper intake manifold. Actually, I think I will play with the upper first since that is the easy part right now. Have had virtually no sleep the last 3 days.

Almost looks like a brand new engine, doesn't it?
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Day 9 Update
Well, lets get some stuff updated, got on a role after tons of pain medications.

Got the 3400 on the LIM sanded smooth and clean, end result, I messed up the paint on my LIM, trying to fix it... Makes it look worse... Might take it and get it sand blasted in the future to start over on the paint job.

Installed the LIM, and ran into an issue... a critical bolt that holds it tight where a precious coolant passage is, is refusing to tighten... it never even once got snug... I suspect the machine shop didn't check the threads on these heads like they was supposed to... Gotta figure out what to do about that, but, here is the LIM installed. By the way, this is why it's important to install the rockers and rods and the gasket FIRST, THEN the LIM. You can't see the lifters at the bottom of the valley to put the rods in...

Update for the update
Well, got a valve cover installed, and still working on the upper intake... I think it's starting to look nice... What's everyones opinions?


Final Update for today @ 5:00 PM Eastern
Welp, got the fuel injectors installed, fuel rail installed, coolant bypass installed, among some various other parts. Decided before I installed all that to take one last picture for today, with the UIM sitting in place, not installed, just sitting so I can see how this might turn out.
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Update: It's refusing to start... Horrible backfire... I am about to mother ****ing kill the machine shop operator that worked on my heads... pistons slammed into valves...
Update: Sent camera into engine, every piston has a small nick from the exhaust valves (longer duration) but all valves are sealing good when I pull vacuum on the exhaust manifolds and intake manifold. Next up I am doing a compression test. Rather annoyed as I heard the valves hit the pistons, and I have marks in the pistons (more like a scratch?)... It is highly possible the compression is too high on this engine now, it's not a high compression engine, and the computer is programmed for what is essentially low compression... I know these engines have serious issues with people that build them up when it comes to the computer needing re-programed.

If the idiot had told us the truth about how much he took off, I could have shimmed the heads up enough to keep my exhaust valves from kissing the pistons...
Ok, another update I guess...

I just checked the compression on all cylinders, and sent a camera down into all cylinders and checked things out, everything looks GOOD. I am getting ~135PSI on each and every cylinder almost exactly. Book calls for ~145PSI, but, they are all holding at 135 equally so that should be fine.

Checked fuel pressure, it's good.

Checked injectors to make sure they are firing properly, and they are.

Checked MAF as this issue is a lot like a faulty MAF, and it's good.

Spark is good on all cylinders.

Does ANYONE have any idea why this thing refuses to start? I am almost at the point of ripping it back apart and redoing it again just to make sure I didn't screw something up.
Timing isn't adjustable... The chain was never touched as it's a single cam OHV engine, no reason to touch the chain.


I decided to go outside today and fiddle around with the car some, knowing I most likely did a good job I decided to remove the wiring harness from the engine and inspect it, as every sensor, injector, and so on is running through this harness. I took note of wire-loom damage, and inspected the wiring with a continuity and resistance test to make sure they all passed. Numerous wires reported resistance (should be near perfect zero resistance) after where the loom was damaged, and the other point being at the ECU (Engine Control Unit).

After looking closely I noticed that the wire insulation wasn't really rigid anymore, it was more of a mush... I ended up cutting out the wires and replacing them all (close to 80 wires, and two was the fiberous type) with some new wiring. I peeled the insulation off the old wires and noticed they had oil in the wires, most likely from a bad valve cover gasket near the firewall. I also noticed some wires that had no oil, had heavy corrosion.

I then went ahead and decided to crank the engine, and it fired up perfectly... Not a SINGLE miss, no pop, no clacking around, NOTHING. Gave it a bit of gas and it sputtered out. I am going to assume the fuel is a bit on the very old and stale side.

On to the machine shop issue. I ended up having my "step-father" invite the owner of the shop out to our house, and I convinced him to take a look on the inspection camera of what his work did to my pistons. He was rather angry that I pointed the little nicks in my pistons at him as he shaved WAYYY too much off of my heads, and that if he told me about how much he shaved off instead of lieing, it would have only cost me an extra $25 in materials to shim the heads up. In the end, we wrote out, and he signed a contract that if the valves, or pistons suffer a failure in the next 5 years, he will replace the engine as a whole using a new block and new heads from MY supplier choice. He knows the pistons are weakened, and the valves aren't sealing PERFECTLY anymore because of his little blunder, I think the last thing he wants is to end up in small claims court. The contract is also notarized by a mutual friend between the owner and my family.

Tuesday I will probably re-write this log, and include links to the pictures with-in the log and re-post it for everyone to read through one final time, and ask the mods to close this thread or delete this thread when I have done so. Thanks to everyone for support/advice given along the way.
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