3.7 slight tick

[ericcarr2000]

Ok I recently had thought that I had a fresh lifter tick in my 3.7 mercruiser motor. I replaced all of the lifters with new ones and the tick can still be heard. The funny thing is you don't hear it when you first start the motor up or upon acceleration. Basically the only time you hear it is from idle to just above 1000 RPM's. Then that's when it seems to go away. The motor is a blueprinted 3.7 mercruiser that has only 100 hours on it. Is there anyone out there that can give some suggestion into this. I did a compression check on the cylinders and they all seem to be between 110 and 120 PSI.
Thanks

 

[nola mike]

Re: 3.7 slight tick

Did you ever check your push rod clearance?

 

[RogersJetboat454]

Re: 3.7 slight tick

What's your oil pressure at idle?

 

[stonyloam]

Re: 3.7 slight tick

If you checked the clearance, and it is OK then it might be a worn ball end on the push rod (according to the "book"). The fact that does not tick at startup or over 1000 RPM may indicate that the tick goes away with increased oil pressure. What oil are you running? How is your oil pressure? You might try Quicksilver 25-40 (recommended by Merc.). If it is just a mild tick and goes away, I probably wouldn't worry about it too much.

 

[ericcarr2000]

Re: 3.7 slight tick

I believe it was 60 psi at idle.

 

[ericcarr2000]

Re: 3.7 slight tick

I guess I'm gonna have to try to fabricate some sort of a lifter collapsing tool..

 

[Bt Doctur]

Re: 3.7 slight tick

Wondering if its the exaust shutters tapping on the exaust pipe.

 

[ericcarr2000]

Re: 3.7 slight tick

Hmmm....You know I never thought about that now..... Thanks for the input.....

Wondering if its the exaust shutters tapping on the exaust pipe.

 

[ericcarr2000]

Re: 3.7 slight tick

Any ideas on how to check the shutters, would I need to take the exhaust off?

 

[Bt Doctur]

Re: 3.7 slight tick

location B

 

[stonyloam]

Re: 3.7 slight tick

You should be able to loosen up those hose clamps, and work the rubber exhaust bellows off. Kind of a pain but doable.

 

[ericcarr2000]

Re: 3.7 slight tick

Where are these shutters located @, By A or B?

 

[Eric 3.7LX Alpha 1]

Re: 3.7 slight tick

Just below the lowest clamp on "B"

 

[ericcarr2000]

Re: 3.7 slight tick

Do you think I could use an automotive stethoscope at that location instead?

 

[artificialreef]

Re: 3.7 slight tick

Thats exactly what i did yesterday. I too have a ticking that i replaced a lifter and collapsed the rest to check rocker play. Dialed all the rockers in and still had the ticking. Used a stethascope and i was sure loud at the elbow bought a new flapper, oring and retention ring. and gasket for that square exhaust elbow at the top. I replaced my starboard shutter and found it easier to get to removing the elbow. Just an extra inexpensive gasket i think. I will go after it this long weekend and will let you know how i make out. My ticking is pretty loud. So loud it sounds like an engine problem but with the stethascope the bottom end and the heads were quiet. Only noise was coming from the elbow. Sure know how to change lifters and adjust the rockers now. If you finish before i do, please post and let us know how you made out. I had one rocker that was (the one lifter i changed) rusty and didnt look like oil was being pumped up through the rod so it wasnt in vain. Best of luck.

 

[ericcarr2000]

Re: 3.7 slight tick

Well, what im going to do is do a leak down test to be able to rule out any leaks internally caused by a bent valve or maybe even a worn valve spring, even though the motor only has 100 hours on it. Once I do that I will definitely let you know what I find out. I did try a quick listen at the shutter location and really couldn't tell what was going on. You know how noises travel, lol.

 

[artificialreef]

Re: 3.7 slight tick

The stethascope is like 5 bucks at HF. Leak down is not a bad idea but you got a brand new motor and a idk how old exhaust system. I was going to mention your flappers when you started saying you were going to replace all your lifters but at that point you were not listening to anyone. I only found 1 lifter questionable with my ticking. You appear very headstrong and determined and that is not a bad quality,but in this forum it is best to listen to what these gentleman/professionals tell you. 99% of the time these guys will be right. You need to take a step back and clear your head and consider the advice no matter how strongly you think the direction you want to go is correct. They gave up half way through your last post. Were the flappers changed when the motor was out? Thats not really a maintenance item but probing around with it may enlighten you. You do not know how bad the po abused the boat. Just be careful climbing around there with the motor running and dont get your hoohaa deskinned.

 

[artificialreef]

Re: 3.7 slight tick

probing around with it. It being the stethascope.

 

[artificialreef]

Re: 3.7 slight tick

I touched my bottom end with it, purring like a kitten. I touched my head with it same thing. Touched the exhaust elbow, ticking like a 35 year old jewish american princesses time clock.

 

[ericcarr2000]

Re: 3.7 slight tick

Lol, love the analogies....Its not that im not listening to anyone here. The reason Im probing around the motor is because I did contact the person that re-built the motor and they had suggested to me that I might have a bent valve or something going on with the cylinder walls. He had suggested that I do a leak down test to see if I did indeed have a leak. When I installed the motor in it I did NOT do anything with the flapper. I probably will just replace the flapper in the exhaust due to me not knowing how old the thing is. I will let you know....
Thanks