Advice for top end disaster

[2Sheds_Jackson]

Hello everybody - I'm a noob to the forum - been lurking for a while and used some advice I found here. I had hoped my first post to be one where I brazenly showed off my awesome handiwork...but instead I've got a real mess on my hands.

I think I know what I need to do to fix it -but i need advice to find the smartest way to go about doing the repair. Some history-

I did a timing belt replacement/water pump job on my '93 Accord LX (150k indicated) and got all that done per the procedures found here (TDC etc). I didn't have any real issues and everything was aligned. To me, the reassembled new timing belt seemed to lack tension - the springs didn't hold it very tight, but this being my first one, I didn't know what to expect. At the same time I replaced the o-rings on the plug holes since they were leaking oil pretty badly. Everything was torqued down per the manual. Or so I thought.

I turned the motor over several times by hand - there was no binding or unhappy noises, the alignment marks would still line up, so I completed the reassembly. I started it up, and it fired right away and went to high idle (it's cold here) - ran fine & sounded great as it warmed up. When it came off high idle, the idle started to bounce. I attributed this to the fact that I hadn't burped the coolant system yet. I did that, and it didn't improve - as it got warmer over the next 3-4 minutes, the idle dropped again, this time so low that it would stall.

It would start right back up - but I had to keep my foot in it around 1k rpm so it would run..and it sounded fine. Suddenly, it just shut off. I attempted to restart - it wouldn't catch at all.

Upon investigating, I found it had no spark. I ohmed out the coil and according to the book it was out of spec, so I shotgunned it. Tried again, still no spark. At this point I was convinced I was barking up the wrong tree so I removed the valve cover to inspect - and was stunned to see that the cam sprocket had sheared off the end of the cam. After a change of pants, I took a closer look - I don't know if I under or over torqued it - but the sprocket is sheared right off, with the bolt still in place. There's no other damage visible at this level of disassembly.

My question is- what's the smartest course of action to get it back on the road (besides, you know, just not screwing up in the first place)? I'm thinking that I should install a salvage cam & do a compression check - or would that be a waste of time & I should just get a salvage head and be done with it? Or just put the car out back and make it a giant birdfeeder? That's a viable option.

[Ralphie]

Wow, this is THE best rookie post ever. I used rookie, because you are clearly not a noob.

Just the fact that you read on here, read a manual, and attmpted to do the work without asking us to do a video conference and hold your hand, is awesome!

Don't get that a lot around here.

But i'd keep your head up. All it was is a simple mistake, sounds like you pretty much nailed the work, and it might not have even been something you did, who knows!

In any case, I have no real advice except it will depend on how much work you want to do, will guide what path you take.

Someone with more knowledge will surley come in here and chime in at some point.

Good luck and thanks for the well written post!

P.S. - don't use it as a birdfeeder. LOL.

[oyajicool]

If it was mine, I would get another cylinder head assembly from JY. It will be quick turn around getting back on the road.

You may have bent a valve(s) with the one you have due to attempting to start with cam gear broken.

[2Sheds_Jackson]

Thanks for the kind words - my ego is definitely bruised. I plan to lie like a bastard to my wife & daughter (it was to be her college ride)...something like "it needs a new Yamato valve, and that has to come from the factory at Mt Fuji".

I've looked at a few places selling remanufactured heads - but I haven't heard of JY (there's the noob part)...my google-fu is weak, what's the actual name of that place?

[af_1132]

I think you mean Pick n' Pull. If you don't have it yet, get the Row52 app for your mobile device. It helps you locate a particular make/model at nearby junkyards.

When you started describing the bouncing idle, I immediately thought a vacuum line to either the FITV or IACV was loose, unhooked, or the IACV was not hooked up properly to the harness. My friend's 3SFE Camry motor would stall after the car got to operating temp, and we couldn't figure it out until he found that the IACV was not hooked back up (we did a hg job on it).

That doesn't seem to explain why there is no spark, though.

Would you mind showing us some pictures of the head and the front of the engine with the covers removed? We need to find out what caused low levels of tension. Also, do you remember the torque specs you used for the bolts involved?

[oyajicool]

JY is for junkyards.

[2Sheds_Jackson]

Due to all the throwing of things and ranting in the front yard I haven't had the time to get the bottom cover off yet - I'll do that tonight. But here's what I have so far.











For torque figures I used the specs out of hte Haynes manual;
camshaft bolt 27ft / 324in
crank 159ft / 1908in
balance shaft + timing tensioners 33ft / 396in

...although I think I must have under-torqued the cam sprocket bolt...I was able to un-thread it with my fingers. It was the first one I did & maybe I mis-read my fancy new wrench.

[ahdiofreak]

Sheet. Looks like you'll need another camshaft.

[PakaloloHonda]

OOOoMG! I've never seen anything like this! Wow! Hope you get it sorted out ..
Damnn, How much would a completely re-built head cost?
I dunno if I'd do the JY part .. wouldn't you still have to have the head machined?

And welcome to the forum .. that was a well written OP.
Keep us updated, specially with photos .. we like photos .. G'luck!

[oyajicool]

I thought the cam gear was busted for some reason. It was the shaft. WOW.

[af_1132]

Can you tell us what timing belt kit you purchased? Are the stock valves and valve springs in the head?

I am also wondering if timing must have gotten way off somehow, like the belt jumped a considerable amount of teeth. If it was off enough, then one set of either intake or exhaust values could have opened while a piston was approaching top dead center, causing a collision that could have resulted in something that catastrophic. I know that is far fetched, but I can't think of another reason for that much torque to be generated from the cam to the cam gear.

Do you have a breaker bar and a 14mm impact socket? If so, would you mind taking off the head and getting a look (pictures) at the valves and top surfaces of the pistons?

[johnl]

I doubt you've done anything wrong (unless you over-tightened the sprocket bolt). Unless it's a trick of the light in the photos, looking at the broken faces of the camshaft I can see light and darker coloured areas. To me that looks like there was possibly a crack in the metal that has been there for a while.

The darker colour is (possibly) staining caused by either oxidation (occurring slowly over time) or dark coloured particles embedded in the rough surface of the crack (carried there in the oil, again over some period of time). The lighter coloured areas would be a new break, occurring suddenly due to the weakening affect of the existing crack.

A crack that might cause such a breakage could either be due to a manufacturing fault, or substantially over-tightening the sprocket bolt (not necessarily recently). It's at least plausible that the uncracked area may have held on for a long time if left undisturbed (or failed at any time), but if the sprocket was removed and then refitted then the re-torqueing may have stressed it beyond the level at which it had previously been stressed(?), which might account for total failure not long after re-torqueing the bolt(?).

That's my best guess. My next guess is that you now have bent valves (unless you're extremely lucky). If so then the path of least resistance and cost is likely to be a replacement second hand head. With a SH head I'd dismantle it and very lightly lap the valves with a fine paste, check the valve stem to guide clearance, and fit new guide seals.

[dj_ender]

I would replace the cam, then perform a leak down test. Way easier, and cheaper, than ripping the head off.

Also, get a real manual. That Haynes is garbage, you want a Helms. They usually run $50. www.Helminc.com

[oyajicool]

If you want to perform leak down test on this engine for the purpose of finding bent valve, you don't need to replace camshaft.

Loosen all of adjusters so all valves would seat.

Then, do the leak down test.


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Come to think of it, you don't need the gauge set for leak down test in this case. Install one spark plug at a time and rotate crankshaft. You should feel pressure building up as you turn if that cylinder does not have bent valve. And, if you don't feel it, then you know what needs to be done.

[2Sheds_Jackson]

If you want to perform leak down test on this engine for the purpose of finding bent valve, you don't need to replace camshaft.

Loosen all of adjusters so all valves would seat.

Then, do the leak down test.


-------------------------------

Come to think of it, you don't need the gauge set for leak down test in this case. Install one spark plug at a time and rotate crankshaft. You should feel pressure building up as you turn if that cylinder does not have bent valve. And, if you don't feel it, then you know what needs to be done.

This seems like a good first step. I really don't want to get into removing the head unless it's required - my confidence is pretty badly shaken and I don't want to risk screwing up something else. If the valves test ok, at least I'll know that I don't need to replace anything up there beyond the cam.

I still need to get the bottom cover off and take a look at the tensioners etc.