Ethan's Thread.

[REDWINTERZ]

See, I am just as confused at how timing error = bad ring. WTF??

I would check for a cracked piston. I don't know if oil would temporarily fix a cracked piston like it does bad rings but it's worth a check, right?

Keep us updated!

On a side note, I am now SCARED s*** of doing my timing belt.

[JustinGB]

Timing belt is a pretty precise and detailed job, however, if you have someone who's done it before succesfully, triple check everything you do and just take your time, you'll be fine.

I did my own timing belt for the first time this year, so far so good, 8k miles, zdayz road trip, several track days.

[REDWINTERZ]

Timing belt is a pretty precise and detailed job, however, if you have someone who's done it before succesfully, triple check everything you do and just take your time, you'll be fine.

I did my own timing belt for the first time this year, so far so good, 8k miles, zdayz road trip, several track days.

Not to threadjack, but what parts should I replace while I'm there to prevent catastrophe?

[Z-owned]

Timing belt is a pretty precise and detailed job, however, if you have someone who's done it before succesfully, triple check everything you do and just take your time, you'll be fine.

I did my own timing belt for the first time this year, so far so good, 8k miles, zdayz road trip, several track days.

Not to threadjack, but what parts should I replace while I'm there to prevent catastrophe?

Replace all the idler pulley's as well as upgrade the idler studs to the heavy duty ones (studs aren't needed but recommended) Pretty much as far as maint. goes the 120k kit's do a pretty good job of covering everything you need. You can upgrade things well you are in there but that becomes more personal as far as what is worth it to you. I did a ud pulley and od waterpump pulley for example when I had to pull the stock ones off anyway. nismo thermostat, upgraded coolent hoses, pulley's, cam sprockets, stronger tbelt etc are all possible upgrades. I have about 10k on the car since mine and zero issues, just gotta make sure to check everything.

[raremotive]

^ I agree idler stud... RB motors are susceptible to this kind of failure too. That's why I asked Ethan to check it.

[es.biggs]

I think I might just swap another NA engine in while I rebuild this one...I have TT heads laying around here, and I can get some pistons from a friend. Maybe this will turn into another TT swap. This blows...does everyone agree that it's gotta be a piston ring though? Are there any other possibilities?

[BigTDogg (MA)]

Not to threadjack, but what parts should I replace while I'm there to prevent catastrophe?

The Ramey Z heavy duty idler studs are cheap insurance.

Other than that, just take your time, check your belt tension and torques on bolts and you'll be fine.

It's not a difficult job, just requires patience and attention to detail.

Ethan's case is one of s*** luck I'm afraid.

Ethan, how your ring land busted is beyond me. Have you checked all your injectors for impedance? Is it possible you ran super lean in that cylinder causing detonation?

[es.biggs]

I haven't checked my injectors, but they were replaced 10,000 miles ago, just before I bought the car (have dealership papers)

I'm stumped as well...

When oil is put through the spark plug hole...it goes on the piston (and the tops of it's rings) so it would help the seal between the rings and cylinder wall. Compression going up during this part of the test would indicate bad rings, or even a cracked piston, correct?

BUT what if the oil is splashed up onto the valves? There could be a bent valve that doesn't quite seal up all the way and the oil helps it seal. Is this even possible?

I just find it RIDICULOUSLY hard to believe I had my rings or my ring land is busted. I mean, 91,000 miles is still practically breaking this thing in. It's been meticulously maintained too. I don't know. Prayin to God for some help getting this car fixed...

I appreciate everything you guys

edit-I'm going to try and get a leakdown tester tomorrow from someone at work. Hopefully I can use that with the small compressor I have at home...I think it's 110 PSI max, and it's not very big. But I can use that to figure out where the leak is coming from; intake, exhaust valves, or the piston.

Has anybody ever leakdown tested? I watched someone do it before, but I never did it. I know you get the piston at TDC and inject the air and use the gauge to see how much leaks out. I will be using it more for the sounds though - listening to the throttle body will tell if it is intake valves, listening to the exhaust will tell if it's exhaust valves, and listening to the oil cap hole (or dipstick tube) will tell if it's rings.

That's what I know. Does anybody know how much air pressure you can use? I need to use as little as I can while still being effective (damn small compressor :/) Anyways, thanks a lot guys for all the help!!!

[es.biggs]

So put my air compressor to my bad cylinder - using the spark plug fitting from my compression tester and a tire inflator gauge from sears, with a cutoff valve to keep air from flowing back out through the air lines. I could hear air escaping from the exhaust, and it sounded like some was going through the crankcase.

I've never done this before so I'm not sure if the noise through the crankcase was normal or not.

There is definitely some exhaust valve leakage going on though. I don't know what to think about the piston/rings.

Air is leaking from this cylinder so fast that I can't even build any pressure in it. I'm applying 125 psi and it's not even holding anything.

I also found a NA motor, said compression is supposed to be about 170 in all 6 cylinders, from a wrecked 2+2 that was owned by an older guy. A seemingly trustworthy member of 3ZC is parting the car out (he knew the guy from his local Z club) and wants $800 for it. He said the 120k was done right before the car was rear ended. The reason I say this guy seems trustworthy is because he has a trader rating of 76 over there (I think that means he has bought/sold 76 items) Does this seem like a decent deal?

I still can't decide if I want to do a motor swap or put new heads on. With the condition of the piston in question, I'm leaning towards a whole swap. It's a little more though What would you guys do?

[REDWINTERZ]

If you don't have time to fiddle with it (like I do), then I would go with the swap. However, if you have the time, a rebuild will yield you much better results in the end. It just depends on how much time you have. Sounds to me like the swap is the better fix at the moment.

[es.biggs]

I just pressurized and checked another cylinder (a good one) to see what kind of sounds it made, and the crankcase sound was the same as with the bad cylinder. So I have come to a conclusion that the problem lies in the valvetrain, so now I am probably just going to put my extra pair of heads on and hope for the best.

I will start taking it apart tomorrow. I've been putting it off because I wanted to drive it to my friend's garage to work on it there, but he/we have to clean the garage out first. I called around and found a place that will rent me a tow dolly for just $25 so now I don't have to run it until its all done

I need to put together a list of items I will need....

First on that list will be a head gasket. I can't go with OEM because the heads we shaved a good bit - .028"

I will need something thicker than the OEM gasket. I could get an MLS gasket, but the price and power handling capability of MLS is a little overkill for a mostly stock NA. Are there any alternatives for a thicker head gasket? Or what about shims? The guy at the machine shop said I could do that as well.

LMK what you guys think

Thanks, Ethan

[es.biggs]

Update time...

I decided to keep the heads I have now and get my valves cut, stem seals replaced, surface machined, and inspected for wear and stuff by a very reputable machine shop I found by word of mouth - for $170 per head. Doesn't sound too bad right?

Anyways, today I finally towed the car to a garage I will be borrowing for a few weeks to fix everything (a nice garage too ) and I had to remove the facsia just so we could get the thing on the dolly lol, but it makes things easier to work on anyways.

My brother and I got the timing covers off and counted teeth - it jumped one tooth - after checking and double and triple checking, I counted 58 (rather than 59) between the left side exhaust sprocket and the crank sprocket :/ it's what I expected though. We then started to remove the exhaust to get ready for transmission removal and I found something that is REALLY bothering me.

my left side exhaust is COATED with oil on the inside. This makes me nervous about the rings or the piston...how else could oil end up there? Unless it is dripping down from the bent exhaust valve(s)....I really hope that is a likely possibility. What does anyone else think this means? I ran the car for roughly 10 minutes to warm it up for a compression test after the breakdown occured. I also did a wet compression test where I poured probably 2 teaspoons of oil into a cylinder on this side of the engine. I thought valve stem seals keep that from happening. Could this be the cause though? Tell me somethin good haha

Also, I forgot to look before I left tonight, I am planning on pulling the engine out; do these come with places to sling the motor from the factory or do I have to buy the Ramey Z Engine Sling to get it out? I can't find a solid answer on this and I've been searching a good bit.

Thanks everybody, any advice is mooooore than welcome.

EDIT - I recounted later after I got the belt off (I marked it before removal) and the teeth were right on.

[REDWINTERZ]

I don't know if it's the correct way, but mine has chains that form an "X" over the upper intake manifold, and attached by a bolt on each side, which are in the holes for the exhaust manifold. If that makes sense. LOL

[es.biggs]

Not sure if anyone reads this thread anymore but if you're out there wanna help me put together my list?

So far:

Clutch
Clutch pivot ball
might get the rebuild kit for my RPS flywheel
Throw out bearing
Bronze shifter bushings
Rear transmission seal
Nismo transmission mount
Rear main seal
Both idler pulleys (doing it right this time)
RameyZ idler studs
Crank sprocket
Coolant bypass hoses (I ripped my brand new ones in a fit of anger when my water pipes wouldn't come back off
EGR delete kit
AIV delete plugs
PCV valves
PCV hoses
Head bolts (ouch)
Gasket kit (OUCH)
Exhaust valve cover gasket half moon looking things in the back of the heads (forgot what they are called)

I also will install my ES diff bushings that I've had laying around.

Does anything else come to mind from you guys? Should I do the knock sensors while I have the motor out?

+$350 for the head job (grind/replace valves, new stem seals, resurfacing) this is not a cheap project! If anybody has parts they want to donate or sell for small sums of money I can live with that lol

Thanks!

[Z-owned]

should do a pcv hose re-route well your at it. Also make your own egr delete kit, just need to cut two metal plates to fit the area under the plenum, (I made a gasket out of some paper like gasket material that comes in rolls to seal it off with on mine that I made) also can find the vacuum hose end plug's for a couple bucks at a parts store. I also suggest the 3 piece rear main seal kit rather than just the rear main itself.

[es.biggs]

pcv re-route...is that just new hoses? or actually moving where the hoses go and stuff...

I think the other two gaskets for the rear main should come with a kit...the upper oil pan upper rear main housing gaskets right?

[Z-owned]

Some places don't come with the other gaskets when you get the rear main, but yes those are the other's that you want. the pcv re-route re directs the hose's, z's have a tendency when pushed hard to smoke out the exhaust caused by oil getting in the pcv hoses and getting burned off. Not really a issue but more an annoyance.

[es.biggs]

Ah I see. I will def look into that, thanks.

Question for you...I am quite embarrassed to admit, I broke the tab that holds the stopper bolt on the tensioner, while I was trying to remove it I screwed it in too fast I guess. I knew it was supposed to be slow but I didn't know it was supposed to be THAT slow, (1/8 turn every 10-15 seconds? jeez lol)

Anyways, I am thinking about using a pry bar to get it off and then using a clamp to reset it back to 4mm...then I need to somehow hold it while I reinstall it...Do you think a big zip tie would hold it until I reinstall, then I could cut it?

[Z-owned]

Are you talking about the bolt you loosen on the auto tensioner to add tension once the belt is on? Here is what the write up on tt.net said about if it broke not sure if that's what you used or not. As for a zip tie as long as it's a decent sized one I would think you should be fine.

"If the retaining bolt is tightened too quickly, the casting on the tensioner will break. If it does, it's not a deal breaker. Just maintain tension on the belt and pry the backside of it instead of using the retaining bolt to retract the pulley. Loosen the two bolts and nut on the auto-tensioner, re adjust the position of the tensioner, tighten the bolts and nut again."

[es.biggs]

Thanks, I remembered reading that but I wasn't sure where I could find it again and I couldn't remember what it said lol.

Hopefully I can find a meaty zip-tie and use it for what it was never designed for lol

[es.biggs]

transmission is out! MAAAAAAN did it feel good to wheel that thing out from under the car

[AchilleZ32]

^ I'll be by to pick that up in a few nights lol.

[es.biggs]

Haha keep dreaming. The guy who is letting me use his garage has a friend, we call him Mr. Winchester

lol just kiddin bud

[es.biggs]

quick update...

thanks to my buddy ric for being super helpful and lending a hand wherever needed...







I'm fred flinstone here...

[es.biggs]

Heads are off, pics later tonite or tomorrow sometime. Planning on stripping them and dropping them off at the machine shop tmrw.

I looked at the pistons and thank god, they are look great. There is more carbon buildup on the top of the cylinder with the bad compression, but it looks like it fell off the valves when the piston and the valves crashed. The intake valves over that piston look all cracked up, I can't tell if they are bent but there was def some contact. The black carbon buildup on all of the other valves looks smooth, and the buildup on the valves in the bad cylinder looks cracked like tree roots or something.

Pics will be up soon, you will see what I mean! Thanks for all the support guys, nobody's been replying lately and it don't bother me but all the help early on helped me a lot! I still have a long way to go, and as always, I'll keep updates comin!

[es.biggs]

Heads are done...machine shop didn't find any bent valves. WTF?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?

I have no idea where to go or what to do now. I have a limited amount of funds and time and looks like both are out the window right now. There are a lot of things that have stressed me out in my life but this is towards the top of the list.

[JustinGB]

have you looked at a possible spun bearing or bad piston ring?

[es.biggs]

Haven't disassembled the block yet. I guess I'm doing that tonite. Is a spun bearing a possibility?

Anyways, bottom end rebuild should be what:

hot tank and measure everything - will let machine shop do that if possible
hone (and bore cylinders if necessary)
main and rod bearings
piston rings
oil pump (would it be completely foolish to save $170 and re-use mine with 90k on it?)
wrist pin bushings
freeze plugs

do the main and/or rod bolts need replacement after removal?

[JustinGB]

yes a spun bearing will show low compression and bad piston ring would mess with compression too i believe

[es.biggs]

Ok that's good to know, thanks.

I got the oil pan off and looked at things. didn't find any metal chunks or shavings anywhere. I did find scratches on the crankshaft (I think they are called the counter-weights) but I'm not sure if they are supposed to be like that or not. The scratches are very uniform, and on every counter weight. The rod caps also each have on scratch on them...it might have been a mark though to make sure they were installed in the correct position. Each cap has the same exact scratch on it, in the same spot.

Here are some pics; let me know if this seems normal please

Scratches on the counterweights


I've only seen a few crankshafts, but I don't ever remember seeing scratches like that on any of them. I thought they are supposed to be smooth...

Something else I found that looks like it shouldn't be there


Tonight wasn't very productive...I got distracted and ran into a few setbacks...the guy who is lending me his garage space, air compressor, tools, etc is a very interesting guy. We got to talking about his 67 Ford pickup and how he pulled the motor out of it in about an hour back when he was young. Then he told me about when he was in mechanics school back in the day, every day he would go in an hour early to his transmission class and he'd tear apart and put back together a turbo 400 transmission until he got so fast at it that he could do it all in 10 minutes. Haha man I wish they still made cars like that today.