Sudden rocker/valve noice
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
Sudden rocker/valve noice
Hi,
My car has been running great for couple of days after a top end rebuild. But this morning when I started the engine there was very loud valvetrain noise. It varied with rpm. I let the car run for 15 seconds and then turned it off. After some thinking and checking the oil level which was ok. I fired it up again and after about 5 sec the noise went away and the engine sounds normal again.
It sounded like the valves were not adjusted at all.
I did install Crane Gold 1.6 RR's and grinded the drib tabs almost flat. I can't hear or feel any contact under the valve covers.
Any suggestions?
ToniH
Ps. a tip: EGR heat shield is there for a reason, I burned 2 ignition wires yesterday as mine is missing :rolleyes:
My car has been running great for couple of days after a top end rebuild. But this morning when I started the engine there was very loud valvetrain noise. It varied with rpm. I let the car run for 15 seconds and then turned it off. After some thinking and checking the oil level which was ok. I fired it up again and after about 5 sec the noise went away and the engine sounds normal again.
It sounded like the valves were not adjusted at all.
I did install Crane Gold 1.6 RR's and grinded the drib tabs almost flat. I can't hear or feel any contact under the valve covers.
Any suggestions?
ToniH
Ps. a tip: EGR heat shield is there for a reason, I burned 2 ignition wires yesterday as mine is missing :rolleyes:
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Sudden rocker/valve noice (ToniH)
It sounds like it wasn't getting oil. If it happens again check the pressure.
BTW, I just installed a new GM EGR tube with integral heat shield. You're right gotta keep those right side wires cool.
BTW, I just installed a new GM EGR tube with integral heat shield. You're right gotta keep those right side wires cool.
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
Re: Sudden rocker/valve noice (ToniH)
Additional info:
We took the valvecovers off today and readjusted the rockers just to be sure. The car has run very nicely all day but if possible it runs even better after the readjustment. Very smooth.
Lets see what it sounds tomorrow morning when I start her up again. Hope I don't hear that noise again!
I've heard that a main bearing problems might sound very much like valvetrain noise. How do I know which one is it?
Any other possibilities?
Thanks,
ToniH
We took the valvecovers off today and readjusted the rockers just to be sure. The car has run very nicely all day but if possible it runs even better after the readjustment. Very smooth.
Lets see what it sounds tomorrow morning when I start her up again. Hope I don't hear that noise again!
I've heard that a main bearing problems might sound very much like valvetrain noise. How do I know which one is it?
Any other possibilities?
Thanks,
ToniH
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Sudden rocker/valve noice (ToniH)
I just installed new seals and so had to adjust the valves, again. I have two references; one states zero lash plus 1/2T, the other zero lash plus 3/4T. So I split the difference. I may have been a little off on zero lash because on startup there was a little lifter noise that smoothed right out.
In your case it's possible that some lifters were adjusted to the edge and so got noisy that time after oil had drained down.
I've heard on the Forum that a spun bearing noise is not RPM dependent whereas your noise went with RPM. So I wouldn't worry about that possibility.
You might consider getting an oil/filter change if it's been a while.
In your case it's possible that some lifters were adjusted to the edge and so got noisy that time after oil had drained down.
I've heard on the Forum that a spun bearing noise is not RPM dependent whereas your noise went with RPM. So I wouldn't worry about that possibility.
You might consider getting an oil/filter change if it's been a while.
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
Re: Sudden rocker/valve noice (65Z01)
My factory shop manual states 1 full turn after zero lash. If I remember it right Crane installation sheet said 3/4-1 turn. We did adjust them to 1 full turn.
Oh, yes I forgot to mention: there was no contact marks inside the valve covers or on the rockers.
I sure hope you are right about the bearing noise not being rpm dependent. After all this work it would really be a big disappointment if I had to start all over again and do the bottom end too.
My Mobil 1 Rally Formula oils only have 200 miles on them. Before that I ran cheapo Esso oil for 30 minutes and flushed the engine and put the Mobil and a filter in.
We only have about 3 months of summer in Finland when it is warm and nice to drive a sports car and I would not like to waste it repairing things. Winters are for that activity.
Thanks for your replies.
ToniH
BTW. other summer activities: crashed with a 250cc go kart couple of hours ago. went out in a sweeping fast corner accelerating at about 60mph. It happened so fast I had no time to react. The seat broke and now my butt hurts - ouch I can hardly sit on my Recaro office seat ;)
Oh, yes I forgot to mention: there was no contact marks inside the valve covers or on the rockers.
I sure hope you are right about the bearing noise not being rpm dependent. After all this work it would really be a big disappointment if I had to start all over again and do the bottom end too.
My Mobil 1 Rally Formula oils only have 200 miles on them. Before that I ran cheapo Esso oil for 30 minutes and flushed the engine and put the Mobil and a filter in.
We only have about 3 months of summer in Finland when it is warm and nice to drive a sports car and I would not like to waste it repairing things. Winters are for that activity.
Thanks for your replies.
ToniH
BTW. other summer activities: crashed with a 250cc go kart couple of hours ago. went out in a sweeping fast corner accelerating at about 60mph. It happened so fast I had no time to react. The seat broke and now my butt hurts - ouch I can hardly sit on my Recaro office seat ;)
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
Re: (scorp508)
Yes, I did realise that. I just mentioned that because it was different from the sources 65Z01 mentioned. We installed the rockers reading the Crane instruction sheet.
Toni
[Modified by ToniH, 10:14 PM 5/23/2002]
Toni
[Modified by ToniH, 10:14 PM 5/23/2002]
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