Ethan's Thread.

[es.biggs]

Well I finished my timing belt late this afternoon. Started her up and I thought a valve was ticking at first so I was freaked out, but I let it idle for a few minutes and it was gone. Must have been a lifter giving me a hard time for not starting the car in a few days

Everything was going great, and I drove it around a little. No leaks, no noises, no power loss. I was off the chain

....until 15 miles later.

I was pulling away from a stoplight and at about 3500 in 3rd gear (semi-spirited I guess ) and just as I was about to clutch in to shift, I heard and felt a bang from my engine or drivetrain, and the car sputtered a lot, and eventually it died. I coasted to a stop after trying once to gas it and keep it moving. It shook a lot when I pushed the throttle in so I stopped that. The car shut off while I was in neutral pulling off of the highway.

I tried to start it several times, and it won't fire up. It seems to be shaking a lot more than normal when it turns over; I can feel it and it kinda reminds me of riding in a helicopter haha. Anyhow, I sat and pondered ways to get my car home with chains and one of my buddies pickups...but that wasn't gonna happen so I called the local tow guy. Thankfully I only had to go about 2 miles to my house.

I am suspecting the timing belt slipped. I checked and double checked the tension on the belt before reassembly, but I must have done it wrong. Compression test will be done in the next few days. I am not looking forward to the results.

So here we are, it's 1.00am and I have to open at work tomorrow. Here's a recap of tonight, for the books.






If my engine is toast, I don't know what I'm going to do. Money isn't exactly abundant right now. Maybe buy an 80s civic to beat around in...during a TT swap???

Haha I might be dreaming. Who knows. I'll keep this thread updated

[JustinGB]

did you put the timing belt all right? did all the hash marks line up? did you count teeth between sprockets? how did you check the tension on the belt? Sorry but it really sounds like the motors toast.

[Z-owned]

Curious how you checked the tension as well, does sound like the belt slipped.

[tg]

could have been lots of things :\ the idler stud looks like a prime candidate.

[AchilleZ32]

It seems like everytime someone does this themselves, something goes catastrophically wrong. Dude this sucks, it appears my days are numbered =(

[es.biggs]

Checked the tension by measuring the gap on the tensioner - it was between 3.8 and 4.3 the whole time I rotated the crank...the marks lined up fine and I turned the motor over like 10 times back and forth before buttoning it up.

I didn't have the tool to measure deflection but it felt just like the old belt, maybe a little tighter. I measured it with my finger and a measuring tape (just to give me a rough idea) and it was within spec - I think it was 6-8mm? Don't remember. Maybe that's where I coulda shoulda woulda

I didn't count the teeth, and when I was sittin on the side of the road that came to my mind

I think I might get a cheap Tacoma (oxymoron...) and hold on to the Z til I can TT swap it. I think it's gonna be retired for a while though.

[Z-owned]

tg could be right as well, especially if the belt was to tight.

[es.biggs]

Time will tell. Wonder if I can peek into the upper covers without removing everything again.

[raremotive]

Hmm sorry to hear. Fingers crossed for you.

[ztommyx]

damn. sorry to hear that...

[tg]

Time will tell. Wonder if I can peek into the upper covers without removing everything again.

Well, at least you've taken it off once before

My personal thoughts on the matter are that Z's like their owners to know about their inner workings, and breaking down is the best way to get you to do so. Once you've build a Z up from the bare short block they usually stop doing that. (unless it still thinks you need to get to know it better, in which case you probably didn't spend enough time in there).

[Chattzx]

man that really blows in sorry to hear about that. Reason #1 why I don't do such important things like t-belts on my own I let my trusted mechanic do those things

[Ace2cool]

Time will tell. Wonder if I can peek into the upper covers without removing everything again.

Well, at least you've taken it off once before

My personal thoughts on the matter are that Z's like their owners to know about their inner workings, and breaking down is the best way to get you to do so. Once you've build a Z up from the bare short block they usually stop doing that. (unless it still thinks you need to get to know it better, in which case you probably didn't spend enough time in there).

I honestly think you may be on to something there. My z's have been really good to me for the most part, but when I got the 2+2, I spent about 3 hours a night with my head buried in the service manual for about 2 months.

[BigTDogg (MA)]

I'm guessing, as others have, that the belt has slipped, or a tensioner stud broke.

But all hope is not lost.

Doing my own TB on my old Z I forgot to tighten the PS pump pivot bolt. It stayed right in the path of the pulley. I didn't notice this, so I started the car anyway. Wouldn't start. Swapped PTUs, checked fuel, spark etc etc. Eventually found the bolt and said figgity f***. Tightened it and checked the timing belt. The shock from the pulley not moving (and possible under tensioning of the belt) had made the TB jump 7 teeth. We reset the belt to the proper position and buttoned it back up

I thought for sure the car wouldn't start, but it fired right up. Went home and checked compression. #1 was at 91 PSI, with all the others at 135-145. Car still made 330RWTQ at 11psi boost.

My case may not be as bad as yours, because I wasn't actually driving when it happened.

Definitely take the covers off and look in there to see what's going on. It doesn't sound pretty, but you might be surprised as well.

[NissanFairladyZ32]

See if your Crank Angle Senor didint come loose, that would not let the car start

same thing happend to me

[es.biggs]

Today at work I was talking to my buddies and they were all telling me about how bad this car needs an LS1 now that my motor is probably toast lol

I had pretty much given up most if not all hope, and when my gf brought me home today I asked her to try and start the car. I had the oil cap open and I was going to check to see if that intake cam directly below it was turning when the starter was engaging. I figured if the idler snapped, the belt would be pretty ineffective and the cams wouldn't be turning over, correct?

WELLLLL much to my suprise, the car started right up, and I freaked. I was expecting some nasty noises to develop....nope. It sounded pretty smooth. It was cold from sitting all day (97 degrees though lol) so it sounded like a cold engine, but there were no obvious ticking, knocking, tapping, etc. I let it run for about a minute, and then revved the engine slowly to 3000 rpm to see if I could feel a misfire or anything. Felt a little hesitant and it definitely sounded different than what I was used to (especially the exhaust), but that may be just because it was cold and I was over-analyzing everything. I shut it off immediately after that and haven't touched it since.

This is good news...I think??? I'm still going to get around to a compression test tomorrow morning, hopefully.

I lost the metal clip for my CAS - that does seem to be a very integral piece for holding the CAS connector to the harness...how did I forget about that!?!?!?!? Man oh man, if that's all this is, I'm going to be thrilled.

Where can I get one of those clips for my CAS?

And if it isn't the CAS, what does this narrow it down to? The cams are spinning, so the belt is still tensioned. Because we have interference engines, a slip of the timing belt would result in valvetrain damage, correct? I don't hear any taps, but I will need to run the engine longer to verify this. I am nervous to do that because I don't know how safe it is to run the thing! I guess from the amount of times I turned it over trying to start, and the minute or two it ran today, any damage is already done right?

Anyways, enlighten me?
All thoughts and comments are welcome

[serg-z32]

wow... thats awesome dude. lol, i can only imagine ur face being freaked and surprised. but thats good the Z started up..

[JustinGB]

Maybe you just have a bad injector? Just do the compression test, try get a boost leak test done and check your codes

[es.biggs]

Injectors are less than a year old, and I has no boost

I'll check my ecu codes, guess it's as good a time as any to learn how to do it now!

[es.biggs]

Got a 55, so no ecu codes. Checked the CAS connector...it's held in there pretty good by the bundle of wires right next to it. I tried to push it on a little more and it was already sitting flush against the CAS, and I couldn't get it to move any closer.

I dunno. I guess I'm just gonna wait to start it again until I get the compression test results.

ohhhh the stress.

[REDWINTERZ]

I just picked up a 1991 (well, that's what year he said it was) motor today. If there are any little miscellaneous parts you need, LET ME KNOW. My motor will not be up and running anytime soon, so if you need anything feel free to hit me up. Glad to hear she's ok for now

[raremotive]

Looks like crossing my fingers helped out!

Get her fixed!

[es.biggs]

Thanks fellas

[es.biggs]

COMPRESSION TEST RESULTS

179------------175
189------------62
193------------164

Not sure how I get 193 in one of them, I don't know if this is the most accurate tester in the world, but no doubt the 62 is a problem.

I need a beater, and a lot of cash

[raremotive]

Did you drop a bolt down the plenum? Or your timing was thrown off?

I suppose we will be seeing/hearing about a tear down and how the damage is. I can just hope the valve was messed up and you just need to send the head in the shop to get it fixed. But as a worse case, replacing the head.

[BigTDogg (MA)]

COMPRESSION TEST RESULTS

179------------175
189------------62
193------------164

Not sure how I get 193 in one of them, I don't know if this is the most accurate tester in the world, but no doubt the 62 is a problem.

I need a beater, and a lot of cash

Congrats on getting it started, now about those numbers.

I'd check the timing belt, counting teeth between marks. If the belt slipped, then you need to reset it and find out why it slipped. Did you use a new tensioner?

However, the low compression cylinder doesn't mean the car isn't driveable, just means you're not getting optimum power. It'd be safe to drive it home or to where you'll be doing head work (assuming a bent valve). Pour a teaspoon or so of oil into the spark plug hole on # 3 or # 4 (the 62 cylinder) and see if that raises the number. If so, it's your rings, if not, it's your valves causing the issue.

[es.biggs]

I used a new tensioner. I could have sworn it was right; it was always very close to 4 mm, never moved more than maybe .3 mm when I turned the crank around. I didn't get a chance to do a wet compression test; I had to go to work as SOON as I posted up those results haha. Is it going to be reliable to test it again when it's cold? I might just check it dry first, then compare it to the wet results. That's all we need anyways right, just to see if the oil makes much difference?

I'll tear into it again soon, I have to build a small work area in my back yard. Maybe use a canopy/tent type thing (like what they use for shade at cookouts, etc.) for shade, and lay a tarp on the ground and drape tarps on the side to keep my parts safe from the weather and dirt. I have no garage :/ It's either that or spend ANOTHER $100 I don't have on a storage space.

I'm trying to stay optimistic. Spoke with my gf tonight and she is really encouraging and understanding that I'm gonna need a lot of time and money for this - I need to be back on the road soon before this year of college starts (my last, thank God)

Has anybody on here ever done a head swap? I need all the help I can get, I don't even know where to start. I might try to get a more seasoned Z32 guy from around here to help me out this time. I can't afford another repeat

[raremotive]

Check your tensioner/idle bolt/studs as well when you take it apart. The bolt/stud itself could be the culprit as well.

Cold or hot... all cylinders should be consistent to each other... the hotter the more accurate the reading is...

[es.biggs]

Oh lord...if I left that bolt loose I'm going to tattoo D.A. on my forehead...

How likely is it that, if in fact I did bend my valves, the piston is damaged? Like I know there will probably be a couple scratches on top (maybe more I won't know til I pull the heads), but can it crack the skirt? I just want to know if I should be concerned about it...but I really don't want to go into full rebuild mode :/ it's only got 91,000 miles on it.

edit - I forgot to mention, during the compression test, I would hear a really loud pop every once in a while. Like, so loud that it kinda made me jump once or twice. It sounded similar to a little rubber suction cup being quickly removed from something it was stuck to. Seemed to be louder near the 62 cylinder. Symptom of a bent valve?

[es.biggs]

So I did a compression test on the 62 cylinder again. It was about 60-65 dry, then it went up to 180 when I put a teaspoon-ish of oil in the spark plug tube. Thats a sure as hell sign the rings are bad right?

I can't even think of any way to relate timing belt to piston ring failure. The only thing I can guess is the piston could be cracked from colliding with a valve; but the wet compression result still wouldn't be so high if a valve was bent...

Maybe it's just my luck to do a major preventative maintenance, only to have something this random/devastating to happen the same day I finish it.

Any thoughts?
Thanks