This doesnt sound good.

[artificialreef]

Hello folks. I have been chasing this ticking forever now. 1983 mercruiser 3.7/470. I have replaced a lifter that looked like it wasnt pumping up. I checked all the rockers to be within spec. Had to change a few push rods and did them correctly by compressing the lifter and using the feeler guauge, then used the oversized rod. I thought maybe a cooked flapper, and went after that. Looked brand new but replaced anyhow since i had the new one in hand. I used a stethascope around the whole motor. Quiet on the bottom and top ends. The closest i could find the noise was on the exhaust elbow that housed the flapper. I am at my wits end. Good compression at 140-150lbs. Doesnt run hot. Oil clear. Good oil pressure. Any of you pro's recognize the sound? Thank you for your advice. Video at link below
470_zpsc42f00db.mp4 Video by artificialreef | Photobucket

 

[Don S]

Re: This doesnt sound good.

When I get an engine with a complaint of a clicking sound, I get my mechanics stethoscope out and pinpoint as close as possible as to where the click is coming from. Once the location is pinpointed, I can then make an educated guess as to what may be causing the click, and what to do next.

 

[Volphin]

Re: This doesnt sound good.

I think it sounds like an exhaust gasket leaking or a crack in the exhaust manifold. That's pretty loud!
Are all the plugs wires seated? Coil wire seated? I've heard popping like that from electrical arcing, but i don't think it would be that loud...

 

[dozerII]

Re: This doesnt sound good.

I agree with Volphin, sounds like an exhaust leak, use a piece of 3/8" fuel line as a stethoscope, put one end up to your ear and use the other end to trace along the manifold gasket with the other end, as well as all other exhaust gaskets.

 

[81 Checkmate]

Re: This doesnt sound good.

I know nothing about the 470 motor.....but from the video it sounds like an exhaust leak puffing

 

[wrestling coach]

Re: This doesnt sound good.

Exhaust leak.

Dennis

 

[Eric 3.7LX Alpha 1]

Re: This doesnt sound good.

I am going with the others.... I feel it's an exhaust leak.

Maybe between the exhaust manifold and the head? Did you ever pull the head off?

 

[Don S]

Re: This doesnt sound good.

This is why I said in my first reply that you have to determine exactly where the sound is coming from, and we can't do that with a microphone and video. The human ear can detect direction but not from a video.

If you can't pinpoint where the problem is, you sure aren't going to fix it.

 

[artificialreef]

Re: This doesnt sound good.

Yes, i understand about the stethascope. I was in there before my post probing around with my stethascope. I am having trouble locating the noise. Just wanted to know if others here thought it sounded familiar. Thankfully it is not coming from the head or the bottom end. I will focus more on the exhaust because if you notice in the vid it is louder on the exhaust side. To answer the question no i have not had the head off. Dont want to mess with it because it runs cool and has good compression. I will go back in and probe some more around the exhaust manny. Thank you all for your opinions, because that is promising. As long as the head is not cracked at the exhaust port should be no biggy. Im going back in.

 

[stonyloam]

Re: This doesnt sound good.

I can tell you exactly what that is (maybe) the iron casting plug on the back side of the head has rusted out and exhaust from #4 is blowing out.
#11 here: http://www.mercruiserparts.com/Show...bnbr=130&bdesc=CYLINDER+HEAD+AND+ROCKER+COVER Hold your hand behind the head when running and you can feel it blowing out. Clean out the remnants of the old plug and drive the new one in.

 

[artificialreef]

Re: This doesnt sound good.

Did you see the room i have in that engine compartment. I dont see how i can drive anything into that head back there. I did read a post earlier that mentioned that and felt back there and didnt feel anything cancerouse. But i didnt do it with the engine running. When you say drive the new one in. What does that mean? Is it like a freeze plug because i may have a chance at that. Stony do you have 3.7 tatooed on you anywhere because you are awesome with these.

 

[Eric 3.7LX Alpha 1]

Re: This doesnt sound good.

Did you see the room i have in that engine compartment. I dont see how i can drive anything into that head back there. I did read a post earlier that mentioned that and felt back there and didnt feel anything cancerouse. But i didnt do it with the engine running. When you say drive the new one in. What does that mean? Is it like a freeze plug because i may have a chance at that. Stony do you have 3.7 tatooed on you anywhere because you are awesome with these.

He may.... but he can't post the picture here cause it will get deleted by the mods before you can say "Alpha One"!!

 

[artificialreef]

Re: This doesnt sound good.

And that would make sense because the closest i got with the noise was near the elbow. Which was at the back of the head. I will try the stethascope at the very back of the head tomorrow. Stony is that a freeze plug or a threaded plug? Please see no room in the stern of the head. Thank you in advance 3.7 brother.

 

[wrestling coach]

Re: This doesnt sound good.

Did you see the room i have in that engine compartment. I dont see how i can drive anything into that head back there. I did read a post earlier that mentioned that and felt back there and didnt feel anything cancerouse. But i didnt do it with the engine running. When you say drive the new one in. What does that mean? Is it like a freeze plug because i may have a chance at that. Stony do you have 3.7 tatooed on you anywhere because you are awesome with these.

Get a mirror and a good strong flashlight and direct the light off the mirror and onto the back of the motor as you observe through the mirror.

Dennis

 

[stonyloam]

Re: This doesnt sound good.

It IS a "freeze (casting) plug", Just a little one. Yeah it looks pretty tight in there. You should be able to feel around back there and locate it. If you can you should be able to wedge a screwdriver in the hole and lever the old plug out. You might be able to hold the new one in place with some duct tape and drive it in somehow, just so it is flush with the surface of the head. The plug is dished like a bottle top so you should be able to tap it in with something flat over it. The other alternative might be to use something like high heat epoxy and a small metal disc (maybe a penny or nickel) and epoxy it over the hole. JB makes a high heat epoxy that goes to at least 400F, that should do it. Good luck. Let us know how it works out.

 

[stonyloam]

Re: This doesnt sound good.

Got a manual #8? Look at page 6-B-3 Exhaust system. Port side of the head (next to the "OK" in the photo). There she is, should not be too difficult to get to.

Mercruser says they are discontinued, but your local ford dealer should have them ask for "thermactor port, cap plugs for 460 heads"

 

[ericcarr2000]

Re: This doesnt sound good.

It sure sounds like an exhaust leak to me also. I have been trying to track down my own ticking noise although im pretty sure mine is internal.....Did a leak down test on her and was not pleased to hear air coming from somewhere, the problem with mine is I really cant seem to pinpoint where the air is coming from just that theres an internal air leak from somewhere. Anywho, check on that plug on the back of the head, sure sounds like that's where it is to me...

 

[britisher]

Re: This doesnt sound good.

An out of the box suggestion here. I'm an avid watcher of Wheeler Dealers on Velocity. Ed China, the grease monkey was dealing with a blowing noise from a car they were fixing. To pinpoint the leak on the manifold, he used a piece of tissue paper and held it round the manifold from place to place. When he got to the leak, the gas escape blew the tissue paper, so he knew where the leak was. Just a suggestion.

 

[wrestling coach]

Re: This doesnt sound good.

An out of the box suggestion here. I'm an avid watcher of Wheeler Dealers on Velocity. Ed China, the grease monkey was dealing with a blowing noise from a car they were fixing. To pinpoint the leak on the manifold, he used a piece of tissue paper and held it round the manifold from place to place. When he got to the leak, the gas escape blew the tissue paper, so he knew where the leak was. Just a suggestion.

Great suggestion!!

Dennis

 

[artificialreef]

OK folks i am sitting down, please give me the bad news

OK folks i am sitting down, please give me the bad news

OK folks, i have been chasing this ticking on my 1983 3.7/470 for quite a while and i have found it. I attached some thumbnails and it is where the screwdriver is pointing. It is a half circle shaped opening on the front of the head. I looked at the schematics and there doesnt appear to be any type of plug that goes in there. Does that mean my head rusted out/blew a hole and i need a new/replacement head? Really hate to have to buy$$$ and install a head but if thats what you pros say i have to do. Oh well. At least i know how to adjust the lash now. Thanks all for all your help with this.