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Discussion Starter #1
after getting a new head put on a month or so ago, i've been noticing a loud tick coming from the engine. i take it to a mechanic and he put a sthescope to the valve cover and told me the sound was coming from the front. He said that it was most likely coming from the timing chain area and that i should have him look at the chain and everything else under the valve cover. i said that i would just take it off myself and look at it because i didn't feel like paying him $60 to have him take my valve cover off. he pointed out that i should check the chain, tensioner and the guides to see if they were loose.
chain seems to be really tight. he told me that i can tell if the guides were bad if they were loose and i could wobble them around. they also seemed tight. how do i check the tensioner? also, is there anything else i should be looking out for that can be making the ticking noise?
 

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Discussion Starter #2
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in the 2nd picture, if you look at what i think is the chain tensioner, it has a small latch on it. i don't know if you can see it from the pics because they are a little blurry (shitty camera phone), but it isn't hooked onto anything and it looks like its suppose to be. don't really know
 

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Discussion Starter #3
anybody?
 

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Don't mind some of the guys on this sight they are a little too judgmental.Two things to check.(1) check valve clearance.(2) If the tech that removed your head did not put the two bolts to hold the exhaust cam gear tension before removing the cam,that will make a loud ticking noise that sounds like a bad lifter. :D
 

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LavosTRD said:
diagnosing a tick over the internet is like diagnosing a rash over the phone....
You must like to hear yourself talk? Lonely?

On topic: A bad lifter is a possibility. Have you ever had the engine head off prior to this?
 

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Discussion Starter #8
GDOG57 said:
Don't mind some of the guys on this sight they are a little too judgmental.Two things to check.(1) check valve clearance.(2) If the tech that removed your head did not put the two bolts to hold the exhaust cam gear tension before removing the cam,that will make a loud ticking noise that sounds like a bad lifter. :D
how exactly would i know if the mechanic didn't do that?
 

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Discussion Starter #9
hk'dontoys said:
may not help much, but my 01 d/c has a noticable fuel injector tick.
definitely not an injector. the noise is coming from the front near where the timing chain is. thanks for your input though.
 

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Discussion Starter #10
tderose said:
You must like to hear yourself talk? Lonely?

On topic: A bad lifter is a possibility. Have you ever had the engine head off prior to this?
the owner of my truck before me had a valve job done at 118,000 miles and i'm assuming they had to take the head off to do that. other than that, the head has only been taken off that time and just recently at 169,000 miles due to a cracked head and a burnt valve in the #4 cylinder.
is there anyway of telling if it had a bad lifter? the noise is started to get annoying. starting to sound like metal on metal grinding, but the chain and guides seem to be really tight...
 

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4XTACO99 said:
the owner of my truck before me had a valve job done at 118,000 miles and i'm assuming they had to take the head off to do that. other than that, the head has only been taken off that time and just recently at 169,000 miles due to a cracked head and a burnt valve in the #4 cylinder.
is there anyway of telling if it had a bad lifter? the noise is started to get annoying. starting to sound like metal on metal grinding, but the chain and guides seem to be really tight...
Is it safe to say that the cracked head and burnt valve were caused from overheating?
 

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Discussion Starter #12
tderose said:
Is it safe to say that the cracked head and burnt valve were caused from overheating?
i've owned my tacoma since may 2005. bought it with 128,xxx miles on the clock. it's never overheated since i've owned it. i can't say the same for the last owner because i don't know, and i don't personally know the person who sold it to me. the crack in the head wasn't even that bad. it was a hair line crack probably a little smaller than a millimeter in length. the mechanic at the machine shop said that i didn't even need a new head because the crack was in a spot that wouldn't affect anything. i decided to buy a new one just to be on the safe side. so in the 42,000 miles i've owned my truck, it hasn't overheated. i've never even driven it where the temp. gauge moved, other than when the truck was warming up from a cold start.
 

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That lever on the tensioner/slack adjuster is supposed to be like that. Toyota uses a ratcheting slack adjuster. The ratchet prevents the slack adjuster from going slack when the engine is shut off and the oil pressure is lost. Oil pressure pushes the piston in the slack adjuster out and as the chain stretches it moves further out. The ratchet prevents it from going back in on shut down. This prevents that chain slapping noise on start up. This is a very good design and it works well.

The noise you are hearing is most likely a valve out of adjustment. While you have the cam cover off, check the lash on all the valves and see if they are in spec or not. If not, adjust the ones that are not.

The guy that made the comment about the failing to install the service bolt to lock the exhaust timing gear sub gear is a valid and very probable problem.

The sub gear is spring loaded and it is to prevent gear slack in the gear teeth. Also because a slanted gear cut is used to reduce noise, as the cam lobes engauge and disengauge from the valve followers, that load and unloads the cam. If the spring tension is not properly set in the sub gear this will cause an osilating end trust to the exhaust cam. It will slam into one side of the thrust bearing and then to the other like a pile driver and will make one hell of a noise like a hammer hitting the head.

You can use the stethiscope on the head near the thrust bearing and you should be able to hear it very clearly. The thrust bearing should be in the bearing cap that is the larger of all of them. In that picture it looks like the front most one.

Another problem if the service bolt was not installed prior to cam removal is that it will cause the subgear to be out of time. If the sub gear has timing marks on it and if those were used to set the cam timing, the cam can be way out of proper timing.
 

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yea what gadget said. I would guess its the timing chain. My engine makes a loud ticking noise under accel. I think i can go another 100k before i change the chain.

either that you or need valve adjustment but i hear that it doesnt really go out of spec too often.
 

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Gadget said:
That lever on the tensioner/slack adjuster is supposed to be like that. Toyota uses a ratcheting slack adjuster. The ratchet prevents the slack adjuster from going slack when the engine is shut off and the oil pressure is lost. Oil pressure pushes the piston in the slack adjuster out and as the chain stretches it moves further out. The ratchet prevents it from going back in on shut down. This prevents that chain slapping noise on start up. This is a very good design and it works well.

The noise you are hearing is most likely a valve out of adjustment. While you have the cam cover off, check the lash on all the valves and see if they are in spec or not. If not, adjust the ones that are not.

The guy that made the comment about the failing to install the service bolt to lock the exhaust timing gear sub gear is a valid and very probable problem.

The sub gear is spring loaded and it is to prevent gear slack in the gear teeth. Also because a slanted gear cut is used to reduce noise, as the cam lobes engauge and disengauge from the valve followers, that load and unloads the cam. If the spring tension is not properly set in the sub gear this will cause an osilating end trust to the exhaust cam. It will slam into one side of the thrust bearing and then to the other like a pile driver and will make one hell of a noise like a hammer hitting the head.

You can use the stethiscope on the head near the thrust bearing and you should be able to hear it very clearly. The thrust bearing should be in the bearing cap that is the larger of all of them. In that picture it looks like the front most one.

Another problem if the service bolt was not installed prior to cam removal is that it will cause the subgear to be out of time. If the sub gear has timing marks on it and if those were used to set the cam timing, the cam can be way out of proper timing.
Thanks Gadget for explaining that much better than me! :D
 

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4XTACO99 said:
Just for the hellofit, have you ruled out the exhaust manifold leak that causes a tick on acceleration which is common to every 4cyl toyota ive ever been in?
 

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Discussion Starter #17
VF'N8 said:
Just for the hellofit, have you ruled out the exhaust manifold leak that causes a tick on acceleration which is common to every 4cyl toyota ive ever been in?
I replaced the exhaust manifold with a header (as you can see in the first pic). The tick, which is starting to turn into a "knock/grinding" noise is in no way related to an exhaust leak. thanks alot for contributing to this though.
the only thing i can think of is what gadget said and that it may be time to just swap out the timing chain(even though its still tight) while driving it yesterday, i noticed it was turning into a kind of a "grinding" noise. like metal on metal.
is there anyway to check the lower part of the chain without having to pull the motor or take everything off? thanks everyone for all the help on this. really appreciate it.
 

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Did you have your valves adjusted ? The latch on the chain tensioner is just to hold the tensioner open during installation, its not supposed to be hooked up. my truck made this sound when the valves needed adjusted. make sure that mechanic didnt mismatch any of your valve shims during the installation of your head, they all are not the same thickness.
 
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