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Cold start rattle on k20a2 motor

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#41 ·
in my case the timing chain was changed, hybrid racing tensioner was put in, cams were swapped to stock cams only the aftermarket valve train was left. no sign of wear on the guides at all. and noise is still there. im pretty convinced now that it has to do with the vtc mechanism not getting enough oil pressure to lubricate therefor it is causing chain slap. however no skipping of the teeth are apparent. do i learn to live with it or do i need to change my valvetrain setup ? :hammer:
 
#46 ·
Dont really wanna bump a old thread but has there been any other info on this subject. My car has been doing the same thing just wondering where to really start. Seems like ppl replace tensioners and it still does it. So whats the real cause of this problem?
 
#47 ·
Jdm2ltrcpe said:
Dont really wanna bump a old thread but has there been any other info on this subject. My car has been doing the same thing just wondering where to really start. Seems like ppl replace tensioners and it still does it. So whats the real cause of this problem?
Click to expand...
I'm with Jdm2ltrcpe for bumping an old thread. I don't drive my EF8 swap all that often (once every two weeks) but get this noise on each cold startup. It's like several random clunking noises of a varied intensity and noise level. Usually goes away after a few seconds but its not nice on the ears when its happening!

If anyone was some firm results on this issue then shout out as it seems there were/are a few people having this issue!
 
#48 ·
Found this on Blueprints Facebook page.

A friend of mine forwarded a new/ newer Honda TSB that I think BP fans might like to read.

Title: Always replace engine chains and sprockets together

Applies to... All engine models with chain driven camshafts and oil pump.
This information is intended as a reminder for technicians who have had limited exposure to repairing engines with chain driven camshafts and/ or oil pump.

Condition… Worn, noisy, or loose timing chain
Replacement may be necessary as periodic engine maintenance, or with other engine repairs. Timing chain replacement is not be scheduled maintenance item with a specific time or distance interval.

Cause… Chain and sprocket wear
The effect of wear on the pivoting components of a drive chain is to gradually increase the spacing between its rollers and links, causing the chain to loosen and become longer - the chain does not actually "stretch".

Chain wear leads to wear on the drive and driven sprockets to which it mates because the sprocket tooth spacing cannot change to match the increase in spacing between the worn chain rollers. The chain "grinds" a wear pattern into the drive side of the sprocket teeth and this is what will cause rapid wear and damage to a new chain if installed on used sprockets.

Repair… Replace chains and sprockets together
Although this is not stated in the service manual repair procedures for timing chain and oil pump chain replacement, it has been normal convention to replace these parts together since the early beginnings of chain and sprocket drive systems, regardless of application.

When replacing and engines timing chain, always also replace the camshaft sprocket or sprockets (including VTC actuator type), crankshaft sprocket, oil pump chain, oil pump drive sprocket and oil pump chain tension, timing chain guides and timing chain tensioner. These parts wear together as a system, especially the sprocket teeth and chain rollers. Reusing worn sprockets with a new chain will result in shortened lifespan of the new chain.

Note: The oil pan and oil pump/balance or shaft cassette must be removed to replace the oil pump chain and crankshaft sprocket.

Engine oil and chain life
As proper lubrication is essential to chain, sprocket and guide durability, it is imperative that required engine oil change and oil level maintenance be performed to ensure longevity. Oil that is deteriorated, contaminated and contains suspended abrasive particles will not properly protected timing chain system components, increasing the rate of wear and shortening lifespan.

When the engine oil level is low, normal contamination must be absorbed by a lesser volume of oil, this results in higher concentration of contamination and rapid deterioration of oil performance. The engine oil cooling capacity is also compromised when the level is low, further promoting lack of lubrication and ware
Click to expand...
 
#49 ·
I think this is a case by case maintenance thing. A lot of people insist the OE chain shouldnt need to be changed. But this depends on cam/valvetrain and abuse level. I say the same for cam gear replacement. If you know the history of the parts, and the maintenance/use history of the engine, then a visual inspection of the gears should reveal their needs.

For those that rev the piss out of their k's with big bumpsticks, stiff springs, and stiff modded/aftermarket tensioners... expect to replace the chain/TCT more frequently than NEVER.
 
#50 ·
I just installed a new tensioner and chain. Before I strated it up for the first time i primed the oil system. I did not get a rattle. This morning I started the car and it rattled. When I got to work I got an old push button start and wired it into the ign switch. When I get in the car now I push the button for a few seconds and the engine turns over and builds some oil pressure and it does not rattle when started. I know this is not a fix but it keeps it from rattling when started after sitting for a while.
 
#51 ·
... Now I am going to bump this thread... my set-up starting doing this rattle BS also. So hard to tell exactly where it is coming from since it only happens for 1-2 seconds, only on the first start of the day. I decided to pull the whole motor out last weekend.

I bench tested the starter... it makes no rattle sounds at all

No metal shavings in the oil... so i doubt it is bearing related

Took off the chain and removed the cams. I did the VTC Actuator test in the honda manual... the locking pin works perfectly fine. If it were a failing VTC actuator, wouldnt this test diagnose a problem here????

My motor only has ~7K on it, and the chain was brand new when i first started it up, along with the tensioner. No major signs of wear on the tensioner, not fully extended, teeth still in good shape. I replaced the tensioner with the Hybrid Racing tensioner anyways.

Chain guides don't have any damage or signs of "slapping" chain.

Turns over smooth by hand...

Anyway now I need to re-install the motor to see if its gone. Really frustrated because I didn't find anything abnormal.

Has anyone found anything more definitive on this? If I read through all of the posts, I can't really tell for sure what fixes this problem even though so many people have had it! Help!
 
#53 ·
Ba82Ep3 said:
What engine? I know the thread specifies k20a2... but.

Also... are you using the newer/longer top chain guide (over the cam gears)?
Click to expand...
I'm running a K20a2. I know people mentioned chain stretch but the chain is essentially new only like 6-7K on it. I wasn't aware of a longer top chain guide though, I'm probably using the older one. Is this a culprit?

I re-used all of the guides when I rebuilt the motor...
 
#54 ·
gsr916 said:
I'm running a K20a2. I know people mentioned chain stretch but the chain is essentially new only like 6-7K on it. I wasn't aware of a longer top chain guide though, I'm probably using the older one. Is this a culprit?

I re-used all of the guides when I rebuilt the motor...
Click to expand...
The upper chain guide on the k20z3 is longer... and a direct fit. I only ask because i havent had this issue on the new engine im running as of yet, and im using the k20z3 upper guide. Its like a $15 part. I just didnt know if it was a coincidence or not...
 
#56 ·
Well... I am still working on this problem. Over the last week I completely removed my motor and went through it.

1) No metal shavings in oil, so fairly confident it is not bearings.
2) Installed Hybrid Racing tensioner
3) Removed Intake cam to check the VTC. I did the VTC actuator test that is in the service manual and it worked fine. It was in the locked position when i pulled the cam out. Using air pressure was able to unlock it then it re-locked as it should.
4) No abnormal wear on the chain guides
5) Confirmed it is not the starter making the sound. First by removing the flywheel cover and shining a light up inside there while my brother started the car. The starter fully disengaged after starting even though the sound remained. Also I wired up the starter on my workbench including the solenoid and ran it with no abnormal sounds.
6) Re-adjusted all valves to spec and double/tripple checked.
7) After i put my motor back in and got it all together, I kept the injector clips off and cranked it for about 5-6 seconds to circulate oil to the engine. I didn't hear the sound. But after I started it, it made the sound longer than I had heard before (probably 3-4 seconds this time). I'm attributing it to not cranking it long enough, especially since I had drained every bit of oil out of this thing as it was on the stand.

I think everyone is aware of the service bulletin put out by Honda for the VTC on accords. I was not aware until this last friday that there is the same service bulletin put out for 2009 TSX (10-024). I got a soft copy of this from the acura dealer and can email it to anyone that is interested... it has the full repair procedure for the VTC actuator.

No matter who i talk to, including several very experienced people in the Honda game, mechanics and multiple Acura dealers, no one has reported any experience with the VTC actuator actually failing on an RSX (strange?). Isn't the TSX head almost the same as a K20a2?

The bad thing is taking off that VTC actuator is a pain in the ASS!!!! Especially by your self, and it is very easy to damage the cam journal when doing so if you are not careful. Putting it back on is just as difficult, especially keeping it in the unlocked position as you torque the thing to 83 ft lb.

The good news (if it is the VTC actuator), I don't see how it can cause internal engine damage. I took apart the actuator on a set of spare cams I have just to make sense of it all. The only thing that can really go defective is that the pin doesn't lock back into it's slot. Worst case the cams are bouncing back and forth between 0-50degrees advance for the first few seconds after start-up. Especially in my case, since I have low compression pistons (9.8:1), there is no interference with valves even at the max cam advance. Which would explain why my shit still runs great after making this heinous sound.

I'm going to try starting it up again in the morning to see if maybe it is gone with this Hybrid RAcing tensioner since the start-up today was essentially a dry start. If not, I'm ordering the VTC actuator tomorrow and will keep everyone posted on results.

Two more lil bits of info:
1) Check this video out: http://www.youtube.com/watch?v=JLk8iX3L9o4
2) So far I haven't seen any bulletins for the 08+ Civic SI. But I checked with Honda and the VTC part number is 14310-RBC-003 even for a 2002-2004 RSX-S. So it's the same actuator for civic si... You can also confirm this from acuraautomotiveparts.org on the exploded view.
 
#57 · (Edited)
The VTC actuator... for clarification... is the intake cam gear? If so... there are differences between PNF (or maybe it was PND) and RBC internal designs... albeit minimal. I have pix and can find to compare if you like.

Did you ever find a TQ spec for the 4 bolts that hold the VTC assembly together?

TQing to spec isnt hard if you have help... use a wrench on the cam to hold its position while you tighten or loosen the bolt.
 
#59 · (Edited)
as mentioned^^ video guy talks about using a impact and i did so i'm getting all the following symptoms as mentioned in video.

so gonna pull out pin and add used one that hadn't been hit with impact...


didnt want to repost to to situation but honestly after doing install no gear grind noise on head at all..but this was after install still waiting for tomorrows crank..

ohhhhh yeah and to report pin was bent there was more meat on one side of pin that holds gear in place..


hope it works used k24 pin on k20 cam gear :scared:



update:


well guys it still made the noise 2 times insead of knocking all the time for 1-3 seconds.. maybe the pin i used was bad...gonna see if it gets better or worse..







:hmmm:
 
#60 ·
My new actuator is coming in on Thursday after xmas... I'm going to take the cam out completely and install it into an empty K24 head I have... I think it will be easier to prevent damage to the cam journals this way. Then use impact to take that b**** off and i'll install the new one using a torque wrench in the unlocked position.

When i installed my current actuator i didn't do it in the "unlocked" position, so it seems like I could have damaged it I guess.
 
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