ticking noise

[ericcarr2000]

Ok, as some of you may realize, I have been trying to track down this mysterious ticking noise coming from somewhere in the valve train I assume. I took the lifters out to drain the oil out of them to be able to collapse them so I can check the clearance per the manual for the 3.7 mercruiser. After I checked the clearances of all valve stems, everything seemed to be within tolerance. After checking the clearances I started the motor up and let it run for a bit, this was with the lifters NOT being primed with oil. As soon as I started it up, some of the lifters quieted down...There is still some ticking noise coming from it. I guess my question is this, im going to try to do leak down test to be able to rule out a bent valve, but the only cylinder I can have both valves closed on are cylinder #1, the other 3 I cant seem to get closed at the same time. I assume this because in the manual you torque down the intake and exhaust valves at the same time while at TDC on the compression stroke on cylinder #1, all other cylinders vary. Did I screw up when I started it with the lifters not primed, or was I ok for doing this?
Give me your guys thoughts.
Oh yeah the motor is a blueprinted 3.7 mercruiser with 110 hours on her. I did replace the lifters about a month or so ago with new ones because I started to notice a slight ticking noise then. It didn't get real noticeable till after I took the lifters out to be able to bleed the oil out of them then re-install them to be able to check the clearances. As soon as I started it up, some of the ticking is still there. All rocker arm nuts are torqued down to 24 ft. lbs....

 

[ericcarr2000]

Re: ticking noise

Wait a minute, I just thought about something. If I take the darn rocker arms off, shouldn't I be able to do my leak down test then, seeing how all valves will be closed at this time?

 

[alldodge]

Re: ticking noise

the only cylinder I can have both valves closed on are cylinder #1, the other 3 I cant seem to get closed at the same time. I assume this because in the manual you torque down the intake and exhaust valves at the same time while at TDC on the compression stroke on cylinder #1, all other cylinders vary. Did I screw up when I started it with the lifters not primed, or was I ok for doing this?

I'm no 3.7L guru but I have never heard of torquing all valves down at the same time while number 1 is at TDC. You have some valves open. closed and others in between. When a valve is closed the Hydraulic lifter is turned down until resistance is felt or the valve and rocker just touches, then it is turned in 1/2 to 1 full turn, no more. Turning all the valves in equally will cause some valves to be open when they should be closed because the valve can go no lower.

If I take the darn rocker arms off, shouldn't I be able to do my leak down test then, seeing how all valves will be closed at this time?

Yes but the above has got me scratching my head real hard

Just looked up the engine and it seems that adjust them at once could possiably work, still kind of wonder why it needs to be done at no 1.

That being said, you should still be able to rotate the crank to fire TDC on each cylinder

 

[Another retired guy]

Re: ticking noise

Wait a minute, I just thought about something. If I take the darn rocker arms off, shouldn't I be able to do my leak down test then, seeing how all valves will be closed at this time?

If you're looking for an answer then yes, removing the rockers will close all valves. But this shouldn't be necessary - each cylinder must have a point at which both valves are closed - if not, that cylinder will have zero compression something is definitely wrong
Can you do a compression test?

 

[bonzoscott]

Re: ticking noise

New lifters and running dry may be smoked cam causing your ticking. Motor should prime them pretty soon, but not sure of the back ground on the motor. PSI good?

 

[tank1949]

Re: ticking noise

New lifters and running dry may be smoked cam causing your ticking. Motor should prime them pretty soon, but not sure of the back ground on the motor. PSI good?

Not to be disrespectful, but you may have exhause leak? Been there! Or, if motor had carb throat open, small amount of trash like piece of leaf or gasket may have sucked in and valve keep slapping. Ben there! Or, if you have mechanical fuel pump, cam action may be slapping. Or, manually adjust valves and see if it goes away. Been there too!

 

[ericcarr2000]

Re: ticking noise

As far as the motor goes, it is a blueprinted one which I purchased from tide water machine a few years ago. It now has 110 hours on her. The oil PSI is around 65-70 when first started then drops to around 25 after it has been run at WOT for a bit..

New lifters and running dry may be smoked cam causing your ticking. Motor should prime them pretty soon, but not sure of the back ground on the motor. PSI good?

 

[ericcarr2000]

Re: ticking noise

Not to be disrespectful, but you may have exhause leak? Been there! Or, if motor had carb throat open, small amount of trash like piece of leaf or gasket may have sucked in and valve keep slapping. Ben there! Or, if you have mechanical fuel pump, cam action may be slapping. Or, manually adjust valves and see if it goes away. Been there too!

I know its not an exhaust leak. The ticking I have now has become since I tried to check the clearance between the valve stem and the rocker arm.

 

[ericcarr2000]

Re: ticking noise

The motor starts just fine, just the ticking noise. Could I possibly slowly tighten down the rocker arm nuts till the ticking goes away maybe? As I stated before I checked the clearances between the valve stem and the rocker arm and everything seems to be within specs. Im thinking that I didn't quite torque them nuts down all the way.
Give me your thoughts on this one. I know these 3.7's are their own character, but maybe just maybe a little bit of the old school technology could help out here....

 

[stonyloam]

Re: ticking noise

Could I possibly slowly tighten down the rocker arm nuts till the ticking goes away maybe? ...

You can not! 1: It shouldn't make any difference 2: you could wind up overtightning the nut on the rocker stud. Torque to 20 ft lb (in the proper sequence as per the manual) and leave it alone.

 

[ericcarr2000]

Re: ticking noise

Well then I guess Ill give it another try when it pertains to torqueing down the rocker arm nuts. The thing is at TDC on the compression stroke right before the intake or the exhaust valve closes?

 

[stonyloam]

Re: ticking noise

You need to torque the rocker arm bolts in sequence with each of the valves closed. At TDC compression: Torque #1 intake and exhaust, #2 i,#3 e,#4 i. Turn the engine 360 degrees and torque #2 e, #3 i, #4 e.

 

[ericcarr2000]

Re: ticking noise

I understand that, but, when is the thing at TDC on the compression stroke, is there a way to tell?

 

[ericcarr2000]

Re: ticking noise

Ok, I just got back from looking at it yet again. I did notice that before I even tried to turn it over that the lifters, pretty much all of them, were still a tad bit soft. I could take my finger and push down on the rocker arm and be able to compress the lifters a bit. So at this point I took out all of the lifters and im soaking them in a vat of oil this time to be able to "prime" them and hope for the best....

 

[alldodge]

Re: ticking noise

I understand that, but, when is the thing at TDC on the compression stroke, is there a way to tell?

Yes, Firing order is 1-3-4-2. At TDC on No 1 both Intake and Exhaust are closed so long as your not 180 off, and rockers are loose.
Next rotate engine 180 degrees intake valve 3 should close durning rotation, rockers are loose.
Next rotate engine 180 degrees intake valve 4 should close durning rotation, rockers are loose.
Next rotate engine 180 degrees intake valve 2 should close durning rotation, rockers are loose.

Ok, I just got back from looking at it yet again. I did notice that before I even tried to turn it over that the lifters, pretty much all of them, were still a tad bit soft. I could take my finger and push down on the rocker arm and be able to compress the lifters a bit. So at this point I took out all of the lifters and im soaking them in a vat of oil this time to be able to "prime" them and hope for the best....

Soaking lifters is fine, I usually do that my self. With the ticking continuely returning are you sure the lifters bores are not worn? If the block holes are worn were the lifters go sufficient pressure will not be able to be developed to fill the lifters completely.

 

[ericcarr2000]

Re: ticking noise

Im pretty sure the lifter bores aren't worn. When I had it all put back together before, I could take my hand, when the erngine was at TDC on the compression stroke, and compress a few of the lifters a tad bit. So I am to this point of letting them soak in oil overnight and try to bench bleed them before I put them back in. As I stated before the lifters are only a month or so old..

Yes, Firing order is 1-3-4-2. At TDC on No 1 both Intake and Exhaust are closed so long as your not 180 off, and rockers are loose.
Next rotate engine 180 degrees intake valve 3 should close durning rotation, rockers are loose.
Next rotate engine 180 degrees intake valve 4 should close durning rotation, rockers are loose.
Next rotate engine 180 degrees intake valve 2 should close durning rotation, rockers are loose.



Soaking lifters is fine, I usually do that my self. With the ticking continuely returning are you sure the lifters bores are not worn? If the block holes are worn were the lifters go sufficient pressure will not be able to be developed to fill the lifters completely.

 

[ericcarr2000]

Re: ticking noise

Now as far as bench bleeding them, after I pull them out of the oil, is there anything else I need to do to them before I put them back in the lifter bores like using my hands and trying to pump the lifters up and down ?

 

[stonyloam]

Re: ticking noise

At TDC both #1 rocker arms will be loose.

 

[ericcarr2000]

Re: ticking noise

Hi Stony, Ok, but as far as the lifter being able to be pushed down by my bare hands goes, im sure that shouldn't be able to be done though right? Also, if they are loose, wont they have some sort of noise to them then?

At TDC both #1 rocker arms will be loose.

 

[stonyloam]

Re: ticking noise

I am not sure how much pressure it would take. Yes, seems like if the pushrods are at the short end of the tolerance they could make a little noise. Heck mine tick all the time, as long as the oil pressure is there, oil is coming through the pushrods to the head and the engine is running well I just don't worry about it.