2009 pilot timing belt

My first time doing a belt on a Honda today and it didn't go well.

I thought I had the crank at tdc but when I took the covers off I said that what I thought was a 1 on the cam pulley was actually just a line, and it was set to #5. Actually, my boss, a long time Honda master tech pointed this out.

The belt was already off at this point, so wr left the crank where it was. At tdc and turned the cams over by hand until the marks lined up. They did not want to turn well but ended up going. My boss said he had never had some that we so hard to turn like that with no belt attached.

I start putting everything back together and do a hand turn on the crank and everything lined back up after going around.

I finish putting it together and start it and it runs like garbage, so I shut it down and left the the night.

What gives?

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Recheck timing marks if there all good do a compression test you may find 1 with very low compression.... if a piston was at TDC while cams were rotated (opening a valve into the top of a piston) it could bend the valve (which sounds like it could have been the difficult to turn spot. )

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For your reference (and anyone else reading this that may have just removed there timing belt without first lining up the timing marks )reinstall the belt with the cam as close as possible to the original position and rotate the crank to line up timing marks never rotate cam and crank independently on an interference fit engine.

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I was hoping that wasn't the case but didn't think you'd be able to bend a valve by hand?

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I'm not real sure as I've never tried but i think with enough leverage you may be able to

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Hey man, doing timing belts. Congratulations! Don't sweat this one - even the old guys get belts wrong sometimes. I watched a guy do a belt on a J35 just like yours, left the keyway out of the crank gear. :ohmy: He'd been wrenching longer than I'd been alive at that point.

You CAN bend a valve by hand that way, but you have to be trying. :lol: I think it would have been obvious while you were rolling the cams over.

A relative compression test would likely answer a lot of questions. Skipped timing will be evident, as will bent valves. If relative compression looks good, revisit your marks as Ben suggested.

If all is well with the timing, then start it up and let it run for a minute. Perhaps a couple of the intake valves got chunks of carbon on them while you were turning it over? Any damage to be done has already happened, so you don't have much to lose. :silly: You may be surprised when it straightens out and runs like a champ.

Don't sweat it, it is what it is. We learn the most through our mistakes.

Your boss being a Honda master should have never turned that motor without putting the belt back on as is. The J35 and J37 engines camshaft have this sweet spot where they'll snap forward very unexpectedly and violently, when rotating them individually. They have very minimum valve to piston clearance. Even with the decent size valve reliefs, the valves can easily bend. Take into account a motor which hasn't had a valve adjustment and the piston to valve clearance is reduced even further.

Working at Acura/Honda for a decade I have seen this happen to the best technicians. Worse thing is everything would be timed properly, but the cam gear was bumped by accident and the high tension valve springs would take the cam for a ride. Pistons never get hurt on those, just a few bent valves depending on your luck. Nothing you can't fix in 3-5 hours. Good luck to you.

I like the relative compression suggestion. Thankfully Honda gives you those nice little windows on the timing covers to check your marks.

I put heads on one that bent some valves over the summer (timing belt jumped and someone told the owner the symptoms pointed to a faulty oil pump) and accidentally turned it over by hand without the key in the crank sprocket :oops:
Got it back where it needed to be though.
It might be over kill, but I like to rotate the engine 4 times before putting the covers back on. I also check the marks with a straight edge or razor blade. It's easy to be a tooth off on the rear head and not exactly look like it.
Good luck brother, don't sweat it. All part of gaining experience.

For what it's worth, I've seen plenty of engine swaps start up and run like absolute garbage but eventually smooth out.

Relative compression is a great test but you have to pay real close attention to the amperage peaks as a 80psi cylinder won't look a lot different than a 160psi cylinder if it's completely dead it will be easily detectable . if you do a relative compression to it post the waveform so we can explain what your seeing . Also don't sweat it the old Honda master tech is the guy who should have known better ...heck you might even get to do your first head job now 2!

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Thanks guys. It turns out you can bend valves by hand! Yep, two cylinders have zero compression. Two different banks.

What makes this one extra awkward is that it was a side job that my boss told me to bring in because he wanted to help out. He feels like a goon now because he said they used to call him Mr. Timing Belt at the dealership he worked at.

The owner seems have taken it well. I'm going to fix it for him for, obviously, and replace his torque converter to make up for the boo boo.

Good thing I learn well from lessons!

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Ok, now I'm up for opinions on how to fix this.

1. Do I put a used engine in and do the torque converter while it's out?

2. Pull the heads and get the bad valves replaced at a machine shop? Pull the trans for the tq converter?

3. Pull the engine, then heads, get the valves fixed at a shop, do the tq converter while it's out?

Maybe replace the trans instead of the converter, with a used (hopefully good) unit.

The vehicle has 185k on it and the owner wants to keep it.

I can work on the car after hours or on a day off but I only have my one bay, so there may be some pushing in and out if it's not all done in one shot (unlikely at my working speed and I don't get two days off in a row). I do have a large area to work if I do have the engine out and work off the floor for head work while keeping my bay operational during working hours.

So keeping the price low on this and keeping in mind my working conditions, that makes the most sense?





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I like option 3 myself especially if the owner has taken care of the vehicle

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Or option 2 isn't bad way to go either but it's nice to be able to get to the back head out in the open instead of in the vehicle

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Ah sorry to hear that, sir. I guess these valves are more fragile than I thought. :blush: On the positive side, you're gonna be super familiar with these engines now!

I'm reasonably sure that pulling the trans means dropping the subframe, and that's where the load bearing mounts for the engine are. It also technically means an alignment afterward. IF the engine can come out the top, AND you can figure a way to brace the trans in the vehicle with the engine out, then #3 is the way to go. Keeping the subframe attached also means you'll be able to roll it around between days off.

As far as I know, I don't think there is enough room to pull the engine out the top. The way I have always replaced the engine is to drop the sub frame with the engine and trans still bolted to the subframe. And then separating them from each other leaving the trans on the sub frame.

Dropping just the trans means supporting the engine from above and removing the subframe.

Which ever way you decide to do it, I wish you the best of luck.

Ok, I've decided to lower the engine on a lift table and pull the heads off, then raise it back up to button up just enough to push it out again. I have off on Thursday so I'll start it after work tomorrow.

Part II question:

At 40-45mph, if you let off the gas and get back on, usually on a slight incline, there is a pretty harsh shudder. It usually happens until you let off the gas.

Original transmission fluid, as far as we know, with 185k on it.

Possible torque converter? I have no real experience diagnosing transmissions, but I'll have the engine out and if I can tell it's the tq converter, it will be right there!

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At 40 to 45 i doubt your in tcc lockup

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I'm not familiar with what that is.

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Too bad about the valves, that sucks. I was pulling for you to come out on top of that one.
Oh well, nothing to do but dig back in.

I would be scared of taking on the transmission issue to attone for the head job.

Those are notorious for bad transmissions, especially at that mileage.
For me, I would want a used transmission with a warranty instead of trying just a torque converter.

I would hate to see you have to drop the transmission, possibly for free, again all because a timing belt job went a little south.

I think I hear wedding bells...

BTW: we've got one of those long, low Home Depot carts at the shop. You can lower the nose of a front wheel drive car with no drive train into the cart and still push it around until the parts come in

You're right. I've decided to hold off on the transmission issue for now.

Starting bright and early tomorrow, or, as soon as guys start showing up to work to help me push it back in.

Tomorrow's long day goal is to get the motor down, heads off, and buttoned back up to push it again until the heads get back. Assuming that the valves are the only damage.

I'll post back tomorrow night with the results.

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