Hello everyone,

Thanks in advance for reading this and helping me out and apologies in advance for it being a long one.

I have a 2005 Acura TL with ~220k KMs on it. I don’t know when the timing belt was replaced last, so I figured it was due. I did a timing belt on a 2000 Honda Civic so I figured I would try it on the TL.

Before taking the old belt off, I made markings on the belt and the cam sprockets and crankshaft.

I also wanted to replace the cam seals but couldn’t get the bolt off the sprocket, *** I did have it move a bit, like 10-15% at most, but always reset back to TDC before trying again (mostly cylinders 4/5/6 side (so bank 2) as it was closer/easiest to attempt on). ***

I also replaced the water pump, tensioner pulley and tensioner and the idler pulley (was all part of the kit).

On the reinstall, I copied the markings from the old belt onto the new belt and made sure it all lined up with the markings on the sprockets/crankshaft.

I turned the engine by hand SEVERAL times, probably close to 20-30 (paranoid) and it felt fine, could feel the compression build up but nothing was ever binding. Each time I would review the timing, everything was where it needed to be.

In addition to the timing belt kit, I’ve also replaced the serpentine belt/tensioner, all spark plugs, oil, and coolant (all before starting the engine).

When I first started the engine, 1-2 seconds in, it started ticking loudly (video 1) (ran it for about 4 seconds?).

I took everything back off and re-checked all of the timings and everything looked good from my perspective. I once again turned the engine by hand and again, everything was okay from my perspective.

2nd attempt at starting the engine, the same loud ticking noise (ran it for maybe 8 seconds).

I’ve taken everything off again and took out cylinder 1 coil and spark plug and put an extension in there and confirmed that when the timing on the sprocket/crankshaft was at TDC, the extension was all the way up. As soon as I moved off TDC, it started to go down.

One thing I noticed is that the tension when turning the engine by hand was good for cylinders 1/2/3 and was okay for 6 and mild for 4 but almost non-existent for 5. Going through 5 it feels like there is no fighting it at all.

I did confirm when the sprocket reads 4 and 5, cylinders 4 and 5 are at TDC.

Since I did the oil, I figured I will let it run for a bit to see if the noise gets better. 3rd attempt, I ran it for about a minute and although it got a bit better, the noise is very much there (couldn't upload the video here so link: ).

The loud ticking sounds like it’s coming from cylinders 4/5/6 (bank 2).


I have a compression tester kit coming so I will test the compression of cylinders 4/5/6 shortly, but it seems like the valves are bent or somehow the timing is off.

I’ve seen people say it might be off 1 tooth, which is possible, but I don’t know which way I should be going and if I do, then it seems like the lines won’t be where they need to be.

Anything you guys could think of that could help diagnose what might be the problem?

Thank you!



Spark plug replacements: DENSO 4702 (NGK was out of stock at the time)
Timing belt kit: https://www.rockauto.com/en/moreinfo...pt=5759&jsn=21 (it is a Gates...)


bank 2 cam

bank 1 cam

crankshaft

 

May need a valve adjustment, timing marks look good to me

 

Belt valve(s), timing off by a tooth, or poor compression and she would be running VERY rough, which it doesn't sound like. And all your timing marks look dead-on.

Sounds just like some noisy valves like on every other J-series. I'm gonna guess that your compression test is going to come back fine and you just need to do a valve adjustment (merely a coincidence that it started happening after your timing belt job)

 

Your timing looks good. A few years back, I had a similar but softer knocking. In my case it was the tensioner (serpentine)

What timing belt kit did you use and where did you buy the kit? (lots of fakes on Amazon and Ebay).

Where did you buy the serpentine belt tensioner?


I used one of these scopes to narrow down my noise.

 

Thank you all for your inputs!
I did the compression test and Cylinder 5 is 0. I tried a couple of times, going from 4 to 5.
Cylinder 4 was up to 150 the first time and 175 the second. I did not test 6 since it feels good when cranking the engine by hand. I also tested 1 by hand and the pressure was going up and it also feels good when turning by hand.
@redbeard1 , I ran the engine without the serpentine belt and it was still making the noise. Both of the kits (timing and serpentine) are Gates from RockAuto.
I couldn't believe it so I actually did Cylinder 5 the 3rd time and still 0.

So what happened with Cylinder 5...? Does 0 compression on just 1 cylinder mean bent valves on that cylinder? Is it possible for it to be at 0 without a proper valve adjustment?
I hope it's not the piston?
What would you guys recommend as next steps?
Thanks again in advance!

 

If you are getting 0 from 5 then it seems that is most likely the problem. I don't think you can get 0 from an engine needing a valve adjustment and, even if you could, you would have had the issue before the timing belt change. There was a poster in the timing belt DIY that also had 0 from 5. I think he bent valves and needed to get some work done to fix that. I'll see if I can get you the link.

 

The poster wasn't sure what went wrong but he bent two exhaust valves on 5. A closer reading may give you some ideas. From what I skimmed, he wasn't sure what caused the problem. Good luck.


https://acurazine.com/forums/3g-tl-2.../#post15669272

 

Yeah, you may have a bent valve in #5.

 

Alrighty, all good! Thank you!
More experience here we come!
I think when I was trying to get that bank 2 cam bolt off, moving it 10/15%, I must've bent the exhaust valves.
Actually, I checked and when Cylinder 1 is at TDC, so is Cylinder 5, probably on the exhaust stroke (makes sense why that other person bent their exhaust valves).
I was... stupid enough to try and take that bolt off without the belt on so, paid the price!
Will be pulling the head off in a little here and reviewing the damages. Sounds like another RockAuto order is in my future!
I will be MIA for a bit while I get this worked on but will come back here to provide an update!

Thanks again everyone!

 

Took a bit to take everything off, parts to arrive, and back together but we are "back in business"!

As expected, the exhaust valves for Cylinder 5 were bent. I replaced them, the head gasket, engine bolts, and all gaskets except for the intake (I re-used these... they were about a year old... maybe a bad call on my part). I also did the valve adjustments for bank 2.

The car starts up fine, and it sounds good, no loud ticking like it was before. The idle is very smooth, and it starts up well.

However, when I attempt to rev it, even ever so slightly (idle at 1100, rev to 1200-1300), it wants to die. RPM drops significantly to about 300-400, but then does come back to life. Revving to 2k, same thing, as soon as I let go of the pedal, RPM drops to 300-400 and it barely makes it back up to idle RPM.

I've double-checked things and everything is plugged in. I haven't cleaned the TB and did re-use the previous engine air filter (wasn't that dirty). I also still need to bleed the coolant system.

No CEL, unfortunately.

My thinking is that since the idle is very smooth, I don't think it is timing-related? Similar to the pictures above, the timing marks were the same this time around. Similar to last time, I turned the engine over by hand and it felt good. Before starting the car, I did do a compression check on Cylinder 5 and it held compression.

I'm hoping it's a vacuum leak/TB related since it only "wants to die" when I push the pedal, or potentially fuel-related. Unfortunately, my OBD2 scanner isn't fancy enough to read live data so I can't tell what the engine is doing unless it throws CEL.

Any help or thoughts would be appreciated. Thank you in advance! <3

 

Have you attempted the idle learn procedure below?
If not, it may help to disconnect the battery first, for a few minutes, reconnect & then try the below.

 

Your poor car. Sounds like you need a mechanic and shouldn't have touched anything.

 

Lots of gaskets came off to fix the engine. My thoughts are also a vacuum leak. Especially if you didn't use OEM gaskets purchased from dealer. Lots of fake, inferior quality parts out there.

There are some DIY methods to check for vacuum leaks, but I don't feel comfortable listing them as some can cause fire. Best of luck.

 

If the guy was able to get his heads off and back on and the engine running, he's beat most of the "mechanic's" out there that get paid for a living. I know a few that won't even go near a timing belt but will do trans and engine swaps all day long.

 

@zeta thanks for the recommendation! I... kind of did this!

I had to go on a trip so I left the car as it was. When I got back and started testing things again, it performed better. I've decided to test my luck and took it on a drive and after a bit of driving around, everything is working as expected! The RPM after revving stabilizes at ~900/1k, where it was before.
The drive was super smooth. I haven't sent it yet but I would say she is back in order!

Thank you @redbeard1 for your thoughts on this as well! I thought it might've been a vacuum leak as well, especially after re-using the intake gaskets. I've used FelPro for all intake/TB gaskets. They're not OEM but I believe these are decent quality replacements.

@GasMonkey I didn't come here looking for sympathy, I wanted to share my experience and get thoughts from other people who may have experienced the same thing or dealt with something similar. I was well aware of the consequences of what might happen.

Just wanted to say thanks again to everyone who has participated in this journey and hopefully, this serves as some help to anyone who decides to take this job on in the future!