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knocking/rattle noise from cold/cool engine

36K views 51 replies 20 participants last post by  moe1953 
#1 ·
I started hearing this knocking noise from the engine about a year ago on a cold/cool motor and it is getting louder and taking longer to quiet down(engine needs to be hot before it goes away) if i very lightly accelerate(maybe1/8th throttle) in 1,2,3 0r 4th gear from 1600-2300rpms. it sounds like like a diesel engine. after 15 min of driving it quiets down enough where i cant hear it . any thoughts? i was thinking piston slap.:confused: yes i run premium fuel and change my oil ever 3750 miles .
 
#2 ·
Guesses - hope it isn't piston slap, cuz if it is that bad, the engine is toast.
With you running premium, my first guess is that the timing is off. Also, an easy check is to take off the air filter, see if that clears it up. Doubtful, but it is a freebie! Timing check, if you have the tools you already know how. If not, get it into your friendly local mech. Knocking is REALLY hard on an engine!
 
#3 ·
My new/leftover 2009 used to do this too the first several cold starts, but it is getting better. I was under the impression that the lifters just needed time to fill/pressurize with oil. Of course, my bike sat unsold on the dealer's floor for some three years without being run much, if at all.

If it is a dry lifter noise, the only reasons I can think of to explain it getting worse would be if the oil passages are getting clogged or the oil pump is wearing out.

Have you tried some Sea Foam or similar product in the oil just before an oil change in order to clean out any sludge or deposits?

However, since you seem to change oil quite regularly, you shouldn't have any major sludge or deposits.

Is it possible that your oil viscosity is too thick for the climate?

I've read complaints of similar Knocking sounds on cold start-ups, but so far, I am not aware of anyone having it actually diagnosed as "piston slap".
 
#4 · (Edited)
it's definitely not lifter noise...thats more of a ticking sound....this is a deeper toned noise and only does it around 2000 rpms. i run mobil 1 10w40 synthetic....and its NOT at startup cold or cool motor 1800-2300 rpms under very light accereration. the motor is quiet above and below those rpms and it has to be under a load....wont do it free revving
 
#9 ·
Engine knock cold accelerating!



I've had this problem for the past 18 months on my 2010. Asked dealer twice , once when it just started about 1300 klms and was told nothing to worry about, common for big bore motors till warms up as long as long as it goes away, probably primary gear backlash till expansion happens - told to keep an eye on it if it gets worse. typical dealer answer. Anyway warranty just about up and 20,000 klms later still there and not accepting that excuse they told me they're going to replace the crank drive chain possibly hitting cover till tightens up, no adjustment and tensioner stationery. This after talking to MAKAW. Hasn't been done yet chain B/O surprise surprise !! Anyway will let u know if it fixes problem.
 
#11 ·
I have an appointment on the 20th and told the dealer they will keep the bike till it's fixed...all winter if necessary. i have the gtpp for 3 more years so it is all free:) it does kinda sound like spark knock and i hear it from under the gas tank and close to the faring
 
#12 ·
and the spark knock theory would apply more under a large load or more throttle?? i am barely cracking the throttle to do this ... barely enough to accelerate
 
#13 ·
well my old school kaw technician said the noise was valvetrain noise and told me to take out the mobil 1 synthetic and put in the stock kaw 10w40 conventional oil .... doing it tonight.... i hope he's right
 
#15 ·
My '11 Vaquero does it too Doc. Only happens when the motor is cold and is worse when ambient temps are below 60f. It usually stops within 1-2 miles at any rpm (most noticeable when accelerating from dead stop) or when the temp gauge gets past 1/4.

I've tried letting it idle for 2-4 minutes before pulling off and it doesn't seem to matter. Sound is most noticeable from the right side cover at the throttle body and sure sounds like valve train to me.. Never does it after it's warmed up even if it sits for an hour. It's also not very noticeable if the ambient temps are 60f plus at first start up. Almost sounds sounds like the lifters aren't pumping up right away.

Good luck. I'd be interested to hear if they find anything.
 
#16 ·
Engine knock still !!

Well just got her back from shop and after replacing primary chain and guides . NO change what so ever, still knocks under load all gears when cold and doesn't matter if she's left to warm up and i do use 10w40 dino oil not syn. I put an extra 2yrs gtpp on her because can't aford to dump her just yet for a Victory cross country! :drool:
 
#18 · (Edited)
my tech has been working on kawasaki bikes for 20+ years and claims to have had 10-12 v-twins do this and the oil quieted down the valve train....worth a try before majoe engine teardown
 
#19 ·
hey doc I do a engine oil analisis on my freightliner engine every oil change 20000 miles at that miles oil is still good just dirty i could go longer if wanted


I also done it on the trans and diff.


It tell you the kind and % of of metals found, fuel in oil, coolantin oil, if found in oil and other inportant things

I pay about 30 dollars at truck stops in my area

you may find in the internet
 
#20 ·
I would not worry about the knock. My Nomad does the same thing. I bought a new Corvette in 1995 that does the same thing when the temperature is below 70 degrees. I still ,own, and it still does it.
 
#21 ·
Sounds like your "old-school" technician needs to go back to school for some refresher courses
Actually the "old school" tech is right. Synthetic oil is not the do all, save all, fix all oil for everything..... and not everything likes it. I run both, just depends on what in.... I do not run synthetic in all my scoots. I have semi syn Castroil 20-50 in my Voyager, and will probably go back to regular Castroil 20-50 next time.

I ran regular Castroil in a Venture with over 240k miles on it when I traded it in and the valves were checked every 75k miles and I never had to adjust them. They never go to the point it was needed. On plain old 20-50 oil. It never had a engine rattle either.
 
#29 ·
Sounds like you may need to go back to school, too.

Weight for weight, certification for certification, grade for grade, synthetics are superior to conventional oils in all applications---period. To maintain differently is a matter of opinion or ignorance, but far removed from fact.
 
#22 ·
I love these stories with high mileage. A buddy of mine has a 1500 goldwing (and an 1800 gw). He bought the 1500 with 12k miles on it. Last I checked, it was over 260k. That mileage was in about 8 years. It did two Ironbutt competitions as well as many other rides.

As for the knock, mine Vaquero did it at the dealership when I bought, and does it everyday. Am I concerned? A little, yes. I thought mine was the only one doing it. Sounds like several others are having it. The dealer said it was just the way these bikes run. No, I didn't believe that, but not a lot I could do about it.
 
#23 ·
I also had this knocking issue with my Vaq. After installing the BIG 3 and re-mapping with advance in idle timing the bike no longer knocks.The Vaq has a 0 degree advance at idle (which will cause this knock) so they can run it a little leaner than normal.
 
#24 ·
My 2004 Roadstar had the "Mother of All KNOCKS", but only when warm. It rattled like a Cummins Diesel when starting off in first. I had to put straight drag pipes on it to partially mask the KNOCK so that I was able to sell the bike. The Roadstar KNOCK, which affected upwards of 10% of production was not Piston Slap, but was supposed to be the result of excessive play in the generator shaft, which hammered and reverberated against the engine casing.

Compared to that, the minor knocking (lower case intended!) that I get occasionally with my VN1700 is acceptable as a minor irritation ;)
 
#25 ·
My VN1700 motor makes the same sounds when it's under 50F and cold at start up. I just let it run for about 3-5 minutes. After which time, sufficient oil pressure and head temperature has occurred. Ever since allowing for the additional warm up time after a cold start. I no longer hear the valve train rattle. Using Amsoil 10w40 MCF. There have been zero lubrication issues with either the VN1700 with 16K or ZG1400 with 17k miles.
 
#26 ·
I have an 05 Vstar 1100 Silverado with 85k miles on it. It does have a little bit of journal knock I think or piston slap or whatever knock. It's not ricky ticky enough to be valve lifters, and it only does it at certain RPM too.

But it runs fine. Unless it gets a lot worse I won't worry about it.... its the bike that visiting family drives....
 
#28 ·
Everyone in my family drives scoots. Wife, daughters, son in law, sister, sisters husband (ex motor cop too), brother (retired USAF), wife's sister and brother in law, nephew, and friends, when they were alive my dad and mother. For 42 years of marriage, most everyone in our circles ride motorcycles.

I have two 1100 silverados, a majesty, and two 650 yamaha customs, and two mopeds for company to ride. BUT right now they are all in Texas. Don't ask how I ended up with it, but I also have my oldest daughters 1100 silverado ( I love those scoots) here in NV as she moved to Texas too and did not have room for it in the truck. (because she did not listen to daddy. But she is 35 and does not have to I guess) Only thing wrong with it is no windshield. It is is Texas... she forgot to leave it. I do not like riding without a windshield.

Even when I was working, I could go a couple months and never get in a car. Still that way. But it is getting winter time here in NV quickly. Supposed to get first snow tomorrow.

My oldest daughter takes my Voyager to work most days in Corsicana as she is staying in the house until we "finally" move there in March. She and her friend ride all the others there to keep them charged up and gassed. I have already registered most of them in Texas. LOT CHEAPER than Nevada. The Voyager last July here in Nevada one year old would have been $328 in Texas when I registered it, $45.

I will be there the end of next week for 3 weeks, (taking the next to last load of stuff down, the third 26 foot uhaul and 12 ft trailer load) and hopefully the weather will be good enough to ride the three places I want to go while there.
 
#30 ·
Is the idle set correctly? My 900 does that if the idle gets too low. It was ultra low one day (must have bumped the knob or something). The 'high idle' when cold masked it, but once I got it warmed up and came to a stop I realized it was idling really low. Knocked like crazy and knocked when I pulled out of the light. Resetting the idle to 1000 +/- 50 RPM's, where it's supposed to be, fixed that.

On gadgets page he talks about that (as linked earlier), and also claims that to be a likely cause of cold engine knock. He blames extra vibration and jarring from the low RPM's on the clutch basket.
 
#31 · (Edited)
Weight for weight, certification for certification, grade for grade, synthetics are superior to conventional oils in all applications---period. To maintain differently is a matter of opinion or ignorance, but far removed from fact.
Whatever... I am sure syn oil is slick and all that good stuff... has all kind of certificates, guaranteed not to wrinkle, tinkle, rub, rust, bust, collect dust, or slide down hill in a rain storm, however...

I was in a seminar in 2002 talking face to face with three engineers from Chrysler who designs their engines. They told the 100 or so of us there that there is NO REASON to waste your money on synthetic oil, mass produced engines are not designed to take advantage of it, the tolerances are not all that critical as in performance engines, and you can go from syn to standard oil back and forth all you want. And none of them see a need nor do they use syn oil. (I admit at that time anyway, who knows what they do now)

They made a living designing engines.... So I guess they are dumb asses too.... Hmmmmmmm.....

I have no performance engines in anything I own including my Voyager.

They said the key to engine life is regular oil change no matter what you use. I know people that go 6000 to 8000 miles between oil changes because they say you can using syn oil...

Your mileage may vary..... just saying.....

Engine oil....
Car tires.....
Batteries.....
Oil change intervals....

Bring out the BEST discussions.... you gotta love it....
 
#32 ·
They told the 100 or so of us there that there is NO REASON to waste your money on synthetic oil, mass produced engines are not designed to take advantage of it...none of them see a need nor do they use syn oil. (I admit at that time anyway, who knows what they do now)
So, in other words, they told you that, even ten years ago, it was their professional opinion that synthetic oils were superior to conventional oils? Got it. Sounds like they were, indeed, a pretty well-informed group.

Back to the original post. Any mechanic, "old-school" or otherwise, who tells you that the way to solve a persistent engine knock is by replacing a synthetic oil with a similarly graded conventional one is not much of a mechanic. I mean, if you really want to quiet things down (however briefly) let's just load the crankcase up with some 90W gear oil. Imagine how quiet things will be for a minute or two!

Obviously, the way to correct an engine knock is to identify the true cause of the knock and fix what's wrong, and what's wrong is not the fact that someone may have chosen to use a synthetic oil.
 
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