2000 Chevy Impala Cylinder Head Repair Log

C0RR0SIVE

Golden Master
Messages
9,213
Location
Lexington, KY
So, this is sort of gonna be my work-log for this repair, if anyone remembers, approximately 3 years ago I did a Lower Intake Manifold Gasket repair on this car, and it came out nice. I decided to eventually buy this car off of my brother as he was wanting a different car. All pictures can be found in this facebook album, the link is a public version from my understanding, will update as things progress.

Link to Pictures:https://www.facebook.com/media/set/...073741828.100000887370048&type=1&l=536c0a0b24

Day Zero:
On my way to work one night, already running late, I noticed my car started going from 140F to ~200F fairly quickly, far faster than what is normal while on the highway. I pulled over and noticed that the hoses had no pressure, and was not warm at all. This indicated something horrible, and not just a faulty water pump, but a total loss of coolant. Looking around, I saw virtually nothing because of how dark it was. Eventually I decided to pull the radiator cap, and sure enough, it was bone dry. I had a family member bring a few gallons of water so I could attempt to limp my car home.

The next morning, I filled it up, bled the air out, and took the car for a test drive. Worked beautifully, no issues at all. This didn't explain the reason that I lost coolant.

Day One: I drove the car to work that night, but on the way home, I noticed the same thing, a quickly overheating engine, but no steam, or anything of the sort. I quickly pulled into a parking lot and killed the engine. Opening the hood, I looked at the radiator cap, it had shot OFF of the radiator, and the engine was spewing out tons of water. Immediately I thought the worst, blown/cracked heads, or a bad head-gasket. Due to the overheating, I am leaning towards bad cylinder heads at this point. The coolant wasn't pouring out because of heat, it was actually slightly warm water, not hot enough to start boiling out, but because of air being forced into the cooling system, causing the coolant to back out in the only place it can, the radiator cap.

Day 2: Spent a good chunk of the day cleaning my garage, and trying to round up all my tools that have sat around the last year or so.

Day 3: The tow-truck that brought my car home, parked it a good 50 foot away from the garage entrance... No way to push it that far, nor steer it due to the way the land is around my garage. I had to start my car, it started instantly, but, it had NO power what so ever, it was almost as if the transmission was busted (still not sure on that, but if that tow-truck driver damaged my transmission, he is going to be in a world of pain). Looking behind me as I give my car even more fuel to try and get it to budge, I noticed thick heavy white smoke, a sure sign that water has been leaking down profusely into the cylinders, thankfully I don't think I did damage from hydrolock, as the engine did start.

Day 3.5: I started to rip things off, finally ending up where I did a few years ago with the LIM replacement. Sourcing things out, this will either be a $350 job, or a $1200 job, depending purely upon if the heads are good or not, or if they can even be saved. Heads still are on the engine, as it looks like it's going to be a royal PITA to get the two engine mounts off that wrap around one of the cylinder heads, just to get to the exhaust to head bolts.

I decided to go ahead and start cleaning parts. A few years ago due to a lawnmower having issues with it's carburetor I looked up a way to clean them, without having to spend tons of time with sprays. Finally found something called Berrymans Chem-Dip, for about $30/gallon, this is the best stuff I have EVER used to clean engine parts. It takes time, but, the results are beautiful. Just have to keep some motor oil near-by, and plenty of water, as the parts need to be washed off, then dipped in oil, this chem-dip will eat away at metal, and WILL cause serious personal injuries if not handled properly.

Everything removed looks GOOD at this point from when I did the LIM repair last time, except one thing, I am still seeing oil getting sucked up into the intake. The throttle body had a nice little pool of it. Not sure if it's due to coolant/overheating or what. But the oil wasn't there 6 months ago when I replaced the thermostat, which requires the throttle body to be removed.


At this point, I have done decided, that if the heads are able to be machined and saved, then I will be replacing the push rod lifters on this engine. They are hydraulic, and over-time can collapse, causing an intensely annoying ticking sound from the engine. I am also CONSIDERING the replacement of the rocker-arms, though, I am unsure, as there are 12 of them, and the ones I want are roller type arms, coming in at $64/per arm. Might save that for another day, because it isn't really needed unless I want every ounce of power possible out of this engine, and I am really not going for that.

Costs at this point:
1 Gallon of Chem-Dip - Already had, might need to buy a new can though, this stuff is starting to look nasty, and has a metallic substance in it...
2 Gallons of coolant down the drain - $14/gallon
5 quarts of fresh motor oil - $3/quart (for lubricating parts)
New work light - $25
Towels - $3
PB Blaster - $4.00 (SO much better than WD40... You know, WD40 isn't meant to break rust down... Was never the intended purpose.)
Package of Razor Blades - $2.00 (Don't use these for what I am doing, it's very risky, and dangerous, not just to the soft aluminum, but you as well if you slip)
Package of Nitrile Gloves - $8.00 for a package of 100.

Future Possible Costs:
Head Gasket Set - $250 - Includes ALL gaskets for a head gasket repair.
Head Bolt Set - $50
Intake Bolt Set - $40
Lifters - $15/each, need 12

Heads - $400/EACH
OR (not sure if they are beyond repair or not)
Machined/repaired $250 for both to be fixed

Resurfacing of Lower Intake Manifold $80
Resurfacing of Upper Intake Manifold $50 (it needs more cleaning than I can give it, a shop can clean the EGR passage much faster and cheaper than I ever can)
First Oil Change : $30 (cheap oil, just to help get gunk out of the engine, and let parts do an initial break in)
Second Oil Change at 250 miles: $70 (Using Royal Purple and Mobile One filters)
 
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Day 4:
So far today, I have removed the induction air tubes for the emissions system, and gotten some of the exhaust heat shields off, only to find something I didn't want to see. The bolts holding the exhaust manifold onto the heads are loose, and some studs fell out, meaning the threads stripped... Either someone has worked on the heads before and did a **** poor job of tightening bolts/studs, or the heads got so hot, that the exhaust manifold forced the studs out, and trashed the threads. Will update as I go on through out the day.

Day 4 Update:
Well, got one cylinder head off. Good news: Gasket wasn't blown... Bad news: gasket wasn't blown... Seems the head has a slight warp to it, that, or two bolts somehow loosened up. All the bolts on one side of the head was loose, while two was broken. All in the same area of the head. I am willing to bet, that the head is warped, and the warp is in that one spot. Looking down at the cylinders, they have been getting uneven fuel or something for awhile, two are damp, another one is dry and the carbon is crackly. Got stuck getting the exhaust manifold on the other head off, as part of the heat shielding is in the way, and the bolt can't be gotten at from the top, and the ground in my garage is soaked in coolant, so no go from the bottom. Gonna be a little while before I can get the culprit head off... Really hoping these heads can be saved, they LOOK ok, but, haven't checked them out yet. Album on Facebook is updated.
 
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Day 5:
Today I removed the second head, after several hours of breaking sockets on the exhaust manifold, I finally got it free. I rocked the head and noticed that coolant seeped out as pressure was put down onto the gasket and removed. As the head came off, I saw that each cylinder on the back side of the engine was flooded with coolant. After two rolls of towels, I soaked the water all up, sprayed carb cleaner into all cylinders, then lubed all cylinders up with assembly lubricant. Then, for 20 minutes, I rotated the engine by hand, wiping the cylinders, and putting more lubricant onto them. After that, I took a high powered drill, and started to spin the engine slowly, then increased the RPM's enough to get oil flowing through the crank, and to start squirting up the lifters. I let it sit, doing this for about another 10 minutes, to ensure everything was lubricated and that rust wouldn't easily form on any components while the engine is exposed to the air. Afterwards, I put more lubricant on the cylinder walls as the rings wipe the walls dry.

Calling around a few shops to get quotes...

Things to do:
-Send the right side head off for a rebuild, all new valve seals, valve seats re-cut, two exhaust bolts extracted, and have it machined flat.
-Send the left head off for a machining and cleaning, all the bolts came out of this one, will also have valve work done.
-Finish cleaning parts... Went ahead and decided to buy a 10 gallon drum of chem-dip to dip my intake manifolds into, sadly, aluminum is much harder to get clean this way, as chem-dip eats aluminum faster than it does steel. So I will have to do short dips, and possibly agitate the chem-dip.
-Finish removing the exhaust manifold
-Clean the block
-Once I know for sure the heads can be repaired, I will order all the remaining components, if not repaired, I will be having to order new heads with everything else...
-put things back together.


My next update is probably gonna be in 1-2 weeks from today sadly. Facebook album is also updated with 2 or 3 new pictures.
 
Yeah, they do, 200,000 miles and 100,000+ with stop-leak in them doesn't help a damned thing... We never did rip the heads off when I was inside the engine last time, as they appeared OK... Really not a happy camper right now...

I swear, I ever see an idiot put stop-leak into a car, I am gonna take a hammer to his/her wrists.
 
Those 6 cyl chevy engines are notorious for leaking head/intake gaskets. I've had a couple of those engines with the same problem....I think if I were you I would fix it as cheaply as possible and sell it. The gaskets will fail again. It's from a poor engine design
 
Those 6 cyl chevy engines are notorious for leaking head/intake gaskets. I've had a couple of those engines with the same problem....I think if I were you I would fix it as cheaply as possible and sell it. The gaskets will fail again. It's from a poor engine design

It's actually from a poor gasket design, and it's actually the LIM gasket that fails, and idiots keep driving, and because of the LIM failure, letting coolant out, and air into the cooling system, the heads eventually fail due to heat spotting. 40% of the issue is on GM, the other 60% of the issue is on idiots that try to fix things cheaply. Oh, and in some cases, it's from a sticker saying the dexcool will last 150,000 miles, and people driving to that point and the coolant is acidic and has ate the LIM gasket. Pretty sure at this point Dexcool is only known to last 75,000 miles/5 years before going acidic while the regular coolant doesn't last above I am thinking 25,000/2 years. In either case, I blame most of it on the drivers for not doing preventative maintenance, and GM for using a ****-gasket design in the first place.

In this case, it is an issue that stems from an idiot putting stop leak into this engine over 100,000 miles ago because of the LIM failure, before we ever got the car. I have found that crap hardened all around the back on the block near head in various spots where the gasket blew out at.

On a down-side, I rotated the engine, and knew I had piston slap, but, this appears to be a really bad case of the slap.... I don't think I will be able to get by with machined or reman heads... Gonna have to see if I can custom order some head shims if worse comes to worse...

Reason I am keeping it? The body and frame are in damn near perfect shape at 200,000 miles, and I only paid $600ish for the car a year ago. Sorry, but you can't buy a GOOD car that is roomy for $600 around here often. Even crappy cars here are in the $3000 range anymore. I thank the cash4clunkers ******** that wiped out a large chunk of good running cars.
 
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I hope you have much better luck, My Chev Venture 3400 engine had 30K on it while it was still under warranty when it went, then two more times after it was out of warranty. My wife's Malibu was going is on it's third...we already sold it. From what I have researched, it has something to do with the 60 degree angle of the heads and the gasket material. I have heard that they have come out with a steel gasket material that's supposed to be more reliable today....But I no longer own any V6 GM engines. Although you got a great deal on your car, how much have you had to put into it in order to keep it on the road?
 
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Makes me worry about the 3400 in my Monte Carlo... Didn't know that line of engine had issues =\.
 
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