Engine developed "chirping" sound from stbd side exhaust
 

Finally got a chance to get out on the water this weekend - yes, pretty sad that it is the end of July before I finally splashed it, but life (work) has been busy and the river and many local lakes have been screwed up from all the rain. I had just replaced the fuel system and impeller, and since I didn't really have a chance to water test it at home, I went pretty easy on it this weekend. Another reason is that it seems to have developed a weird "chirp" that seems to be coming from the exhaust on the starboard side of the engine. It seems to be in time with the exhaust pulse, and it only seems to be evident at idle.

This sound was not apparent when I ran it last year, or least I don't recall hearing it. I did have some fuel delivery issues last year, and my fear now is that I could have done something to "hurt" the engine. Wondering if I could have an exhaust valve or head gasket going away. Have not run a compression check or leakdown on that bank yet. Replaced header gaskets this spring, and did not see any obvious visible damage (i.e. tuliping) to the exhaust valves.

Any ideas?

I would start with a compression and leak down test. I recently traced a chirp sound to a bad roller lifter. Ended up replacing cam, lifters, rockers, etc just to make sure everything was 100%.

Good luck!

Wow, hope not! Strange that it would make that sound rather than the usual tick. Were you lofting the lifter on the cam lobe? I'm running Morel hyd lifters in this one with Manton pushrods and Scorpion lifters. I get the usual lifter noise that is associated with the Morels when the oil is cold, but it goes away when the oil warms up.

I guess you could almost describe this sound as a squeak in addition to a chirp. I have heard similar sounds coming from the headers on race cars. Maybe I need to try to get a video of the sound.

Valve guide

Valve guide doing what - leaking, seizing?

Exhaust leaks can make strange noises as well.

My bet is the exhaust tips. The metal flapper in my Corsa tips will make the sound you are describing from time to time....I read others that have had the same sound.

bud,maybe you have a bird nest in the pipe.chirp chirp.

Lounge, that is a valid suggestion, but I have the big Corsa tips with the baffles and the salisbury flaps on the ends. They don't have the internal baffles that swivel and clank.

I guess I'm just going to have to do some investigating. I'll start with a compression check on the starboard bank, followed by a leakdown.

After you ran it at higher rpm on the water for a while, did it still make the noise later in the day when you idle down, or did it go away.

A slight tight spot in the guide which only makes a little screach/chirp at idle when the valve is opening and closing slowly. What do you have bronze guides and inconels with PC seals?

you hear it under hatch or outside the exhaust behind boat?

My chirping noise turned out to be the same as Turbo's. You didn't say what engine that you had but mine was a 1997 500HP. One of the roller lifters failed due to the roller 'skidding' on the cam. The roller and pin eventually wore down until the 'ears' of the lifter were scraping on the cam (hence the chirping noise). I had to replace all of the lifters and cam as it scarfed up the lobe that it was riding on. I had heard that this was a common problem with this vintage of HP's especially if you use synthetic oil as it is 'too slippery' for the surface finish on the cam lobes to make the rollers spin 100% of the time. When I checked the other engine, one of the lifters was beginning to do the same thing but I caught it before it damaged that cam. Needless to say, I no longer run synthetic oil in these engines....

Wouldnt that be a pretty significant reduction in power. Did you notice the power loss?

I get this on my motor when engine speed drops below idle a bit when the IAC motor doesn't respond fast enough. I think it is just the tips and flappers as well. Goes away as soon as revs return.

your lifter did not break because the oil was to slick,it failed because the valve springs were weak and the lifter was not being kept in contact with the cam lobe.lots of people using synthetic oil with roller lifters without any problems.do you really think it is posible to have oil that is to slick?

My thoughts also, I love tech posts lol

Yes, it consistently makes the noise at idle. Pretty much goes away at anything above 1000 RPM's

Is the noise heard under hatch or out the back of the boat?

Both, I'm pretty sure. You can definitely hear it with the hatch down, and I think you hear it out the exhaust in back of the boat. Kind of reminds me of the "crickets" you hear from some of the high HP drag cars at the starting line.

Big issue is that I don't remember hearing it last year. If it was something like the tips making the sound, I would have remembered it from then.

Wouldn't a lifter going away produce a lot of metal in the oil filter? We cut the filter open last year at the end of the season and there were not any significant debris.

Jim, they are AFR 265's, so whatever kind of guide and seal they run. They probably do have a bronze liner in them, and yes, inconel exhaust valves.

Pretty much gonna say it's the more aggressive cam chirping that you hear, and probably not an issue at all.... Or metal flappers in tips on exhaust... Mine has little birdys chirping also, same ans many buddy's boats with more cam in them... The drier the exhaust the more you will hear it, most boats with wetter exhaust it gets drowned out...

You typically only hear this on very high compression, big cam, well tuned exhaust race cars. Most EVeryone believes it's just some exhaust port / pipe noise. These camshafts open the exhaust very, very early.

You can also get simialr noise from exhaust leaks. Especially very small ones that aren't big enough to let out exhaust noise, but enough where air/exhaust forced thru it 'squeeks' instead of whistles.

Any baffle or etc falling apart can do this.

Air moving past/around objects can make noise. Chirps and sqeeks and whistles are the most common.

However, metal on metal can squeek / chirp too...obviously.

So...if your concerned, you need to diagnose on your issue. HArd for any of us to tell you what it is....we'll just have suggestions where too look.

if this is a brand new noise I would take the time to pull the intake manifold off and have a look I was convinced that my tripping was coming from outside the motor coupler may be a gimbal bearing but after pulling the intake it was obvious that I had a roller starting to go south.

Spark plugs all tight?

I was able to catch mine early enough that we were able to replace the cam lifters springs and rockers without doing any other damage. No metal in the oil either.

Mine at idle no issues... Is this what you hear?

http://www.youtube.com/attribution_link?a=yFLhHHqKOXs&u=/watch%3Fv%3DHrOnCf1AMt4%26feature%3Dem-share_video_user

I appreciate all the replies! I am going to have to investigate this a little more thoroughly. RT930turbo has me a bit spooked - I would hate to wipe out an expensive cam and lifters on something like this. I'm going to run it on the hose and get a good close look at it, maybe even take a little video, listen around with a stethoscope, etc. Probably run a quick compression check at the minimum. If still not satisfied I'll pull the intake and have a look.

Full Force, come to think of it I was having some impeller issues, so probably not as much water was exiting the exhaust. I had smoked an impeller last year on the hose (did not overheat), and put in an aftermarket one that is not building goo water pressure. I was running between 5 - 7 PSI even at 3000 RPM over the weekend. Oil temp stayed at around 190* and water temp was around 150*, so no harm done, but it should be a lot higher than that. At idle it was barely reading on the gauge, although I could still see water coming out the exhaust.

Force, it does sound a lot like that - but I can hear it with the hatch down, and it definitely seems to be coming from the starboard side. Can you hear yours under the hatch, or just in back of the boat?

Both, big cams will do that...

Don't need a lot of water on hose at idle, I really think it's a normal sound with new power you didn't have before...I could be wrong but don't think so..

Hard to diagnose these over the web. Good luck, and let us know what you find!

Mine sounded like a tensioner squeak.

my boat has the same noise.afr 265 heads.stock 454 mag short block.bob mandera cam.scorpion rockers.had morel roller lifters now has johnson roller lifters.stainless marine exhaust.didnt do it until i upgraded the engine.went so far as to pull the head back off mine found nothing.has been doing it for going on 3 seasons.if you guys figure it out let me know.haha

RT, mine doesn't really sound like a squeak so much. More like a ping or a chirp. Sounds a lot like Force's video. I just don't remember it being that prevalent last year, if I heard it at all. Part of my worries are the fact that I had fuel delivery issues at the end of last season and did not get my anticipated top speed on the one full throttle run I made all season. I'm afraid I leaned it out and possibly damaged something, hence my paranoia about any new sounds. :eek:

You guys are correct - impossible to diagnose via keyboards, as much fun as it is to conjecture. I definitely appreciate all the suggestions on things to check. Hopefully I can get it on the hose this afternoon.

It sure makes it even more fun to have the wife asking me "what's wrong with the boat this time?" every time I have the hatch up on it. I guess the next time she buys another pair of black shoes I'll have to ask her "what's wrong with the other 57 pairs of black shoes you have?" I'll probably have to go out and swipe an engine out of someone's Suburban if this thing goes south again. ;)

Why did you switch to the Johnson lifters? Were you having problems with the Morels? Your setup is virtually identical to mine, with the exception of a stroker crank.

That is exactly what I have with mine. I do have a pretty aggressive cam and 10.6:1 CR with semi-dry exhaust.

had a cam/lifter failure that was my mistake.went back to bob mandera for the exact same parts becuase my previous set up had exceeded my expectations.bob recommended the johnsons so i went with them.they both seem to be fine.havent made a full throttle pass on the motor yet.it does have some issues i didnt have before but i cant tell you if its related or not.

What do plugs look like? I didn't hit my speeds expected either but no issues with engines wrong powerband... I bet the noise is cams and no issues...