2ZZ-GE Engine Rebuild....need expert insight

[shaeet]

A bit of background before I get into the n00b questions: Bought a 04' Matrix XRS with 150k on the body a month back. Looking in the glovebox I saw a receipt with 98k miles indicating that the engine was replaced w/a new head/shortblock from the dealership so I assume the engine in this car has ~52k miles. Last week driving home from work I hit lift once & not long after experienced a loss of power & a strange engine sound: (video here: http://www.youtube.com/watch?v=pMdUn2_aTjQ" onclick="window.open(this.href);return false;).

I suspect I bent or dropped a valve as the #2 sparkplug was being impacted by something & the ground electrode sheared off. I still haven't torn the engine down due to time restraints but it is currently sitting on an engine stand stripped of its manifolds & valve cover & timing cover (still haven't removed timing chain yet). I was planning on doing a light rebuild assuming the piston & head aren't damaged. I assume the valve will probably need replacing. I've built a couple of transmissions before & have a good amount of mechanical know-how but building engines has always daunted me for some reason. So here come the stupid questions that I'm hoping can be answered by someone who's built a motor before:

Head questions:
I plan on removing all the valves (labeling them of course) and inspecting each for any wear/damage as well as the head's valve seats. I also plan on replacing the valve stem seals.
1: Assuming the valve seats on the head aren't damaged & the valve is straight & undamaged, there shouldn't be a problem with reusing them right?
2: If I find a damaged valve & or valve seat & replace it, a new one should fit the existing valve &/or seats correct? Or should they be replaced together?
3: Any reason to replace the valve guides if they don't show wear? or can they be reused safely...anything special to look out for w/these?

I plan on addressing the bottom-end also. Stamping the endcaps & rods with 1 2 3 4 & removing the rods/crank & measuring the journals roundness & thickness to see if its within spec. Also maybe removing the pistons & rings.

4: If the crank main & rod journals are within Toyota spec of wear, should I re-use the old bearings or replace them with OEM-thickness ones? I would think you might as well replace them if you are going this far but I may be wrong.
5: If the cylinder walls show no signs of wear, is removing the pistons & replacing the rings pointless?

I also plan on replacing the head gasket, all other gaskets & using some ARP head studs. I read here that you can reuse the old studs if they are still within spec after being stretched their first time, but I don't want any problems. Also might as well replace the water pump/oil pump and timing chain/tensioners and belt tensioner/pulley, lift bolts, cleaning ocv strainers out.

6: Am I missing anything I should be doing?

I'll upload some pictures as I get into it with possibly more n00b questions

[Chiadog]

My 2 cents. Don't throw too much money in an old car (sorry, it is). Look for a cheap engine from a junkyard, most come with a warranty. If that doesn't work, just replace what is necessary - the broken stuff. If it didn't burn oil, don't touch the pistons, etc. The seals should be fine with 50K on them, same goes for the bearings - but check them of course. Have new valves/seats installed by a machine shop, they can also check for a warped head.
good luck,
chiadog

[joatmon]

I never had one fail so, but some here have had belt tensioners make an awful noise. Not that it 's the dreadful banging sound, but a remote possibility that it was the other higher pitched noise.

Knocking like that, and the fact that the spark plug was impacted would make me suspect you lost a rod bearing, the piston is travelling to far up. Was the video before or after you found the spark plug damaged? Seemed to idle ok,

[shaeet]

video was after it had been impacted...basically I ran it to ~8000rpm hitting lift in 2nd & then started cruising down in 5th off-throttle. As I was coasting down the hill the car started making the sound & then acceling back up the hill it felt slower. (basically running on 3cyls). So i assum the plug was impacted either while coasting down or when I hit 8k rpm.

I'll start disassembling tonight if i'm not too tired from work and get some pics uploaded including of the plug.


Still need my questions answered cuz i can't find any definitive answers in my searching the interwebz. The biggest ones i have are:

if i remove the crankshaft & all the journals are within spec, should i reuse the old rod / main bearings? or should i might-as-well replace them since they are off?

also when inspecting the valve train what should i be looking for in regards to valve guides & the amount of play they have. can i reuse the old valve springs & retainers with no issues?

[shaeet]

just spent the better part of 4 hours watching this guys excellent videos on building 4G63 DSM motors:
http://www.youtube.com/playlist?feature ... F4F38CC85F" onclick="window.open(this.href);return false;

It pretty much answered the majority of my questions & taught me a couple things I had no idea to check & do.

still not sure replacing the rod bearings is a smart idea. I'll probably unbolt the caps, inspect & if it looks worn & has scoring, then i'll worry about it, otherwise i'll keep whats in there. The valves/head on the other hand should be fun. It looks like lapping the valves & cleaning them up is a very time consuming job (but one i'm up for, i like that kind of thing).

[shaeet]

Got the head off & not sure what to make of the damage. It looks like the piston impacted the plug shearing off the ground electrode which then marred up the piston & head. What could've caused this? bent rod? Spun bearing? the engine didn't knock at all so I'm not sure.

Also not sure if its normal for the 2ZZ's pistons to come slightly above the block deck but thats how mine is. you can't really tell in the picture though.

Matrix ready for engine extraction. Had to remove bumper cuz the engine crains boom didn't reach w/it on.


Came out remarkebly easy. I have a feeling getting the lower mounts aligned when I put it back is going to be a nighmare though


Engine bay needs a pressure wash & some cleaning but not bad


Cylinder head & other parts of engine look great. Journals are fantastic & cam lobes barely worn


Spark plug from #2 cylinder. Notice how the threads are screwed up. I think the piston smacked the plug & busted its threads. The sound in the video I think is air escaping through the threads of the plug


Ground electrode sheared off & there are some impact marks


Cylinder Head


#2 cylinder notice the impact marks on the top & bottom


Block, pistons look fantastic & the bore looks great with no scoring at all:


#2 piston fully down, the water drip on left is from when i removed the head. Notice the debris. I'll definitely have to remove it & clean the rings up



#2 piston full up. You can't really tell but the piston actually sits higher than the bore, not sure if this is normal for a 2ZZ or not...


I wasn't lying when I said i was buying 4 2ZZ's. Unfortunately one of them was a 2AZ-FE (2.4 camry, tc, rav4) motor but whatever. Not sure what I'll be doing with these....

[joatmon]

My advice is to replace the rod bearings. You're already in there, it could well be the source of the impact. I'll probably keep thinking rod bearings until you look at them and tell me they are fine

Sounds like the damage you are seeing so far is symptom and effect, but not a root cause.

[tpollauf]

Man .... take me back to those good ol days when I had the time to rebuild engines & transmissions This brings back memories of what I loved to do some 30 years ago. Nice work so far. Definitely open up and inspect EVERYTHING seeing how you're this far into it. As far as those spare engines ... depending on where you're located and how long you own your, you might be able to offer them up to others on this forum as there engines become old & need replaced. Keep up the good work

[KITT222]

Gee. I wish I could do that. Just decide to take my engine apart one day. Someday...

I wasn't lying when I said i was buying 4 2ZZ's. Unfortunately one of them was a 2AZ-FE (2.4 camry, tc, rav4) motor but whatever. Not sure what I'll be doing with these....

2AZ-FE swap to a gen-1!!

I'm the type of person who would buy four random engines... just to say that I have four good engines lying around. Do you know the mileage of all of them?

[tpollauf]

Gee. I wish I could do that. Just decide to take my engine apart one day. Someday...

Someday Nick, when you inherit my 2009 Vibe GT in about ....... 20 years or so Then you'll have a "back up Vibe" and you can tear yours apart and have at it

[KITT222]

Gee. I wish I could do that. Just decide to take my engine apart one day. Someday...

Someday Nick, when you inherit my 2009 Vibe GT in about ....... 20 years or so Then you'll have a "back up Vibe" and you can tear yours apart and have at it

Rear wheel drive conversion anyone?

[lannvouivre]

I wasn't lying when I said i was buying 4 2ZZ's. Unfortunately one of them was a 2AZ-FE (2.4 camry, tc, rav4) motor but whatever. Not sure what I'll be doing with these....

I need one so that I can stare at it every night while falling asleep!

Rear wheel drive conversion anyone?

Would you be ashamed of me if I said "OH OH ME ME!"?

[Chiadog]

Hopefully its just a broken rod bearing cap and the crank is unmarred.

[shaeet]

Unsure of the mileage on the spare motors. The guy i got them from said they are "low mileage take outs" and estimates theyhave 10-30k. He is taking care of his oldest sons estate whom had a business buying/selling engines from a jdm importer on the west coast.

[Chiadog]

Twenty-some years back, my brother bought a used Toyota engine from an importer on the West coast. He was told it had 50K miles on it because Japanese regulations required engines be replaced at 50K for emission reasons. Truth?, Urban Legend?, I don't know.

[DopeVibeGT]

Twenty-some years back, my brother bought a used Toyota engine from an importer on the West coast. He was told it had 50K miles on it because Japanese regulations required engines be replaced at 50K for emission reasons. Truth?, Urban Legend?, I don't know.

I also heard this. No idea if it's true or not.

[JohnO]

Got the head off & not sure what to make of the damage. It looks like the piston impacted the plug shearing off the ground electrode which then marred up the piston & head. What could've caused this? bent rod? Spun bearing? the engine didn't knock at all so I'm not sure.

Maybe a connecting rod that was just about to break?

[shaeet]

UPDATE TIME:

Took the rod & piston out and I'm pretty sure its a spun bearing. take a look at the bearings & let me know what you think:

#2 rodcap off & immediately noticed the scorch marks:


Bearing & endcap removed:


Rod & bearing up close:


Top of cylinder had debris but none seemed to go below the first ring, should be reuseable i think:


Cylinder wall has some light scratches on the grey coating, not sure if that means i'm screwed or not. The other cylinders had NO marks at all:


90 degree turned angle of cylinder wall:


Removed the #3 rodcap to see if the bearing looked different & it looks very similar, scorch marks & scoring on the ends:


So questions:
Are these tell-tale signs of a spun bearing? The scorching is caused by a lack of lubricant & it getting too hot?

Is the rod/endcap salvageable to reuse. I can't feel anything with my fingernail when i run it over. Also the crank looks fantastic & the bearings show no real signs of wear at all on that end

Are the cylinder wall scratches a big deal? Again i ran my fingernail over them and it feels silky smooth. No scoring was done just a few scratches here & there especially towards the top of the stroke.

[Chiadog]

Are the tabs intact on the bearings? Can't spin a bearing without shearing off / flattening the tabs.
Could the engine have been previously rebuilt to repair spin bearing / overheated journal?
I don't see any cause here for piston interference, Foreign object got into combustion chamber? Or a destroyed main bearing allowing crank to flex and piston to contact spark plug?
This is a good who-dun-it! or what-dun-it.

[shaeet]

Are the tabs intact on the bearings? Can't spin a bearing without shearing off / flattening the tabs.
Could the engine have been previously rebuilt to repair spin bearing / overheated journal?
I don't see any cause here for piston interference, Foreign object got into combustion chamber? Or a destroyed main bearing allowing crank to flex and piston to contact spark plug?
This is a good who-dun-it! or what-dun-it.

Yea they aren't spun..i didn't know what that scorching on the backside of the bearing was but someone told me they look perfect.

My only guess at this point is the plug was old & the electrode busted off when I was revving high. Perhaps from advanced timing/running lean or the cylinder running too hot.

if you look at the pic of the plug, it looks corroded towards the base & looks like it heated up too much.

[Rayven01]

My only guess at this point is the plug was old & the electrode busted off when I was revving high. Perhaps from advanced timing/running lean or the cylinder running too hot.

if you look at the pic of the plug, it looks corroded towards the base & looks like it heated up too much.

I would buy that except for that thread damage on the plug. If the only thing knocking around in there was the tiny electrode it seems pretty unlikely it could cause that much force on the plug to break the threads.

[joatmon]

on my first vibe (1ZZ) , at about 209K miles, I replaced my rod bearings to cure what was developing into a loud constant knock. It's hard to tell from your pics, but I'm pretty sure my bearings looked a lot worse than yours, (see attached pic) and I had no plug impact. Guess its possible that yours might still be smooth but too thin. I assume you would have mentioned if one of your rod caps wasn't bolted on tight. I thought for sure you'd have obviously wasted bearings there, not sure what else to recommend you look for. If only one cylinder was affected, do you see any difference between the piston travel height in that cylinder compared to the three that didn't have plug damage? Can you feel any play in the vertical travel of that piston?

Did you look in the front end of the cat converter pipe to see if there were any objects that might have been chewed up and spit out into the exhaust? The catalyst grid is right at the engine end of the pipe, if anything got spit out of the engine it would probably be right there waiting to be found. (I know, quite unlikely)

the problem with rebuilding an engine is the constant "Might as well replace it while you're in there". One individual part might not cost much, but they add up quickly. Still, I'd probably replace them anyway while you're in there