noisy valves

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Joined
Oct 5, 2007
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Ancho, NM
I just completely desmogged my 60. It runs beautifully and quiet, until it warms up. Then all the valves get really noisy, mainly at idle and certain engine speeds. It's not like knock it sounds more like the valves are rattling. Is this normal? Or are my valves too loose and need to be adjusted? Any help would be great, thanks
 
Like was said go through them....might be time for a valve adjustment. If you do not have a FSM there was a writeup in tech links here on mud.
 
This started just after the de-smog?

One thing the EGR does is to LOWER the combustion temps to reduce nitrous oxide. High temps can also cause pre-ignition which sounds like rattling. Engine might be running lean. Make sure you don't have a vacuum leak. Try some high octane gas just to see if it gets better or goes away. Reduce timing.
 
Maybe you just lost the insulative effect of thirteen miles of rubber tubing and you can hear your engine for the first time.:) Some people have have told me I'm crazy for doing this, but I always set my valve lash on a warm engine to .005 intake and .007 exhaust which is tighter than what Toyota specifies. It was quieter and ran better.
 
Maybe you just lost the insulative effect of thirteen miles of rubber tubing and you can hear your engine for the first time.:) Some people have have told me I'm crazy for doing this, but I always set my valve lash on a warm engine to .005 intake and .007 exhaust which is tighter than what Toyota specifies. It was quieter and ran better.
:eek:
 
Maybe you just lost the insulative effect of thirteen miles of rubber tubing and you can hear your engine for the first time.:) Some people have have told me I'm crazy for doing this, but I always set my valve lash on a warm engine to .005 intake and .007 exhaust which is tighter than what Toyota specifies. It was quieter and ran better.
yea, i have thought about that, as far as the hoses go. That is why I was wandering if it was normal, it sounds a lot like a diesel, with rattly valves. Your not worried about burning up an exhaust valve by setting the tolerances too tight?
 
This started just after the de-smog?

One thing the EGR does is to LOWER the combustion temps to reduce nitrous oxide. High temps can also cause pre-ignition which sounds like rattling. Engine might be running lean. Make sure you don't have a vacuum leak. Try some high octane gas just to see if it gets better or goes away. Reduce timing.
lol..I was trying to form this into words last night.....but I had to many drinks..
Good advice:cheers:
 
yea, i have thought about that, as far as the hoses go. That is why I was wandering if it was normal, it sounds a lot like a diesel, with rattly valves. Your not worried about burning up an exhaust valve by setting the tolerances too tight?

The only way I can conceive of burning a vale is that it doesn't seat at all, meaning less than 0 tolerance, or a mixture that is grossly off. Most Japanese engines with mechanical lifters (except Toyotas) run something like .003 to .008. Having owned a bunch of different things over the years I always felt like the stock specs were a bit on the loose/noisy side. I had an FJ40 years ago and the FJ60 that I currently have, I ran them both this way, never had any issues. I could feel the difference though. If you remove .010 from your lifter clearance, you gained .010 of valve lift and a small amount of duration. Anyway, this isn't mechanical gospel, just what worked for me.
 
I've been told that the time the valve stays in contact with the seat is important in order to aid in cooling the valve and especially with exhaust valves. A tighter valve lash will keep the valve off the seat longer and indeed make it open more but may make it run hotter. I suppose the difference in the valve adjustrment you are talking about in these old school big iron engines may not have much of an ill-effect.
 
I've been told that the time the valve stays in contact with the seat is important in order to aid in cooling the valve and especially with exhaust valves. A tighter valve lash will keep the valve off the seat longer and indeed make it open more but may make it run hotter. I suppose the difference in the valve adjustrment you are talking about in these old school big iron engines may not have much of an ill-effect.

You're right, when you consider that a healthy V8 will hold the valve open 20 to 30 degrees longer than these little tractors, it really won't make any difference. Any perfomance cam would do the same.
 

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