This thread is for any discussions pertaining to the VTC actuator. Any new threads created will be locked and forum members will be pointed to this thread. Thanks for your cooperation!
Coastie05
Where are all the previous replies? How can anyone beneft if all the discussion has been deleted? The reason for the fluttering noise that occurs after startup is due to a weak spring in the locking plunger inside the variable valve timing camshaft sprocket. The problem is solved by replacing the weak spring with one that is new and slightly stronger.
I bought a spring selection from Handyman. Here is a link -
I have not yet replaced the spring but when I do I will compare the original to my selection and choose the one that fits without binding and provides slightly more pressure. Choose carefully because it is a fair amount of work to do it more than once. When I get around to it I will post some actual measurements of the original and replacement springs. This post has provided some incentive to quit procrastinating. We have a short road trip scheduled this week so maybe around mid July...........
I believe Banks99 was the one that steered me in the right direction. Thank you
Amazon.com: Handyman Springs SP 9722 Compression Spring, Spring Steel Construction, Nickel-Plated Finish, 0.028 GA x 7/32 In. x 1-3/8 In. (4 Pack) : Industrial & Scientific
Shop Amazon for Handyman Springs SP 9722 Compression Spring, Spring Steel Construction, Nickel-Plated Finish, 0.028 GA x 7/32 In. x 1-3/8 In. (4 Pack) and find millions of items, delivered faster than ever.
www.amazon.com
I have not yet replaced the spring but when I do I will compare the original to my selection and choose the one that fits without binding and provides slightly more pressure. Choose carefully because it is a fair amount of work to do it more than once. When I get around to it I will post some actual measurements of the original and replacement springs. This post has provided some incentive to quit procrastinating. We have a short road trip scheduled this week so maybe around mid July...........
I believe Banks99 was the one that steered me in the right direction. Thank you
Thank you for your post rls7201. I was wondering if it is necessary to remove the sprocket in order to change the spring. Your pictures show that it is not necessary. Good. I will be doing the replacemt spring soon and I will post a comment.
I changed the spring in my VTC sprocket a couple days ago. I used a stronger spring from Handyman kit SP-9722.
I cut off about two coils to make it the right length. It is stronger than the original but oil pressure can still release the pin. So far all is good. I do not expect to hear the noise again. Thanx to all who have contributed to this topic.
A couple additional notes............
No need to remove the entire sprocket or cam or timing chain. Just remove the five bolts on the VTC cover. The bolts require a five point torx bit. I purchased a selection for the job but the tool began to round off so I ended up using a small vise grip to break them loose. I replaced them with hex head bolts of the same length. Valve cover gasket and spark plug tube seals can be re-used if you are careful and use a light coat of oil or grease on them. The only part I replaced was the VTC lock spring.
I cut off about two coils to make it the right length. It is stronger than the original but oil pressure can still release the pin. So far all is good. I do not expect to hear the noise again. Thanx to all who have contributed to this topic.
A couple additional notes............
No need to remove the entire sprocket or cam or timing chain. Just remove the five bolts on the VTC cover. The bolts require a five point torx bit. I purchased a selection for the job but the tool began to round off so I ended up using a small vise grip to break them loose. I replaced them with hex head bolts of the same length. Valve cover gasket and spark plug tube seals can be re-used if you are careful and use a light coat of oil or grease on them. The only part I replaced was the VTC lock spring.
I have a tap and die set. I will confirm the bolt size and post it here later today
The valves are held closed by a strong spring. When a cam lobe pushes the rocker and the valve open the pressure on the chain rises and then as the lobe passes over top center the tension begins to drop and the lobe actually pushes the cam and the chain in the opposite
direction. If there is a slight amount of looseness or "play" the cam will turn slightly in the opposite direction. If you are turning it slowly by hand you can see this effect. Another factor that increases this effect is the variable valve timing sprocket. When there is no oil pressure the variable sprocket can move over a wide range if the locking pin is not engaged.
This locking pin in the variable valve timing spocket prevents the cam from turning forward or backward when there is no oil pressure when starting the engine. This is especially noticeable when the oil drains down out of the upper valve train after sitting all night. This is the reason we hear the dreaded loud rattle after an overnight startup. With no oil in the variable chambers the cam jumps backward and forward until oil pressure fills the chambers and
holds the cam in its correct timing position. This noise is intermittent depending whether or not the pin locked and how long it has been since the engine was stopped and also temperature and the position of the cam when it was stoppede
Also worth noting is that this "rattle" does not have any associated damage and the engine runs normally as soon as it develops oil pressure and the rattle stops.
Some people claim that turning the key to the on position and waiting for 10 or 15 seconds will prevent the noise when starting the engine. This will not help if the locking pin is not engaged and the oil in the VTC sprocket has drained out. The engine will need to run for a short time while oil under pressure fills the chambers in the VTC sprocket. This short time is when the noise is heard.
direction. If there is a slight amount of looseness or "play" the cam will turn slightly in the opposite direction. If you are turning it slowly by hand you can see this effect. Another factor that increases this effect is the variable valve timing sprocket. When there is no oil pressure the variable sprocket can move over a wide range if the locking pin is not engaged.
This locking pin in the variable valve timing spocket prevents the cam from turning forward or backward when there is no oil pressure when starting the engine. This is especially noticeable when the oil drains down out of the upper valve train after sitting all night. This is the reason we hear the dreaded loud rattle after an overnight startup. With no oil in the variable chambers the cam jumps backward and forward until oil pressure fills the chambers and
holds the cam in its correct timing position. This noise is intermittent depending whether or not the pin locked and how long it has been since the engine was stopped and also temperature and the position of the cam when it was stoppede
Also worth noting is that this "rattle" does not have any associated damage and the engine runs normally as soon as it develops oil pressure and the rattle stops.
Some people claim that turning the key to the on position and waiting for 10 or 15 seconds will prevent the noise when starting the engine. This will not help if the locking pin is not engaged and the oil in the VTC sprocket has drained out. The engine will need to run for a short time while oil under pressure fills the chambers in the VTC sprocket. This short time is when the noise is heard.
"vibratory shock loading on the timing chain and tensioner" ?
Maybe so but you are right it cannot be good.
Replace the locking pin spring with one slightly stronger as I described earlier in this thread. It has been a few months now and the problem has been eliminated.
Maybe so but you are right it cannot be good.
Replace the locking pin spring with one slightly stronger as I described earlier in this thread. It has been a few months now and the problem has been eliminated.
The VTC oil control valve is not a high failure item and even if it did fail oil under pressure would still be applied to one side of the pressure chambers in the VTC sprocket. I would guess that if the oil control valve failed a diagnostic code would be set because the intake cam position would not match the position commanded by the PCM. The dreaded "startup rattle" only occurs when the VTC locking pin is not engaged and the oil has drained out of the pressure chambers after sitting for a period such as overnight. The culprit is a weak locking pin spring.
Purchase the spring in this link:
You do not need to remove the VTC sprocket. Read through this thread for tips. YOUTUBE has a video that explains and demonstrates all the details. Search honda vtc actuator spring replacement
Amazon.com: Handyman Springs SP 9722 Compression Spring, Spring Steel Construction, Nickel-Plated Finish, 0.028 GA x 7/32 In. x 1-3/8 In. (4 Pack) : Industrial & Scientific
Amazon.com: Handyman Springs SP 9722 Compression Spring, Spring Steel Construction, Nickel-Plated Finish, 0.028 GA x 7/32 In. x 1-3/8 In. (4 Pack) : Industrial & Scientific
www.amazon.com
You do not need to remove the VTC sprocket. Read through this thread for tips. YOUTUBE has a video that explains and demonstrates all the details. Search honda vtc actuator spring replacement
I did not see your PM - sorry
The whole problem is the weak Honda spring. Changing oil viscosity may cause a temporary fix but the problem will return. The link below is for the Handyman spring which I used. It is stronger and longer. I had to cut off a couple coils to make the length right. I have not heard the rattle since I installed this spring about a year ago.
Look back through this thread and you will find installation tips. Search YouTube for "Honda VTC spring"
The whole problem is the weak Honda spring. Changing oil viscosity may cause a temporary fix but the problem will return. The link below is for the Handyman spring which I used. It is stronger and longer. I had to cut off a couple coils to make the length right. I have not heard the rattle since I installed this spring about a year ago.
Look back through this thread and you will find installation tips. Search YouTube for "Honda VTC spring"
Amazon.com: Handyman Springs SP 9722 Compression Spring, Spring Steel Construction, Nickel-Plated Finish, 0.028 GA x 7/32 In. x 1-3/8 In. (4 Pack) : Industrial & Scientific
Shop Amazon for Handyman Springs SP 9722 Compression Spring, Spring Steel Construction, Nickel-Plated Finish, 0.028 GA x 7/32 In. x 1-3/8 In. (4 Pack) and find millions of items, delivered faster than ever.
www.amazon.com
The sole purpose of the locking pin is to prevent the camshaft from jumping forward and backward when the oil has drained from the chambers after sitting for awhile.
The original spring does not have enough tension to engage the locking pin while the engine is starting up and developing oil pressure to fill the chambers and hold the cam at the correct timing location as controlled by the VCT solenoid.
Choose a stronger spring to engage the locking pin as soon as the starter begins to turn the engine.
All other parts should be OK. The weak spring is the culprit.
The original spring does not have enough tension to engage the locking pin while the engine is starting up and developing oil pressure to fill the chambers and hold the cam at the correct timing location as controlled by the VCT solenoid.
Choose a stronger spring to engage the locking pin as soon as the starter begins to turn the engine.
All other parts should be OK. The weak spring is the culprit.
See post #8, Deano-444 listed an Amazon site for the springs You can thank him for the home work. .
0.028 GA x 7/32 inch x 1-3/8 inch
Here is the link
Amazon
The problem IS solvable. I used the spring in the Amazon link above. The problem has been solved for more than a year and a half now.
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
