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2019 M8 engine noise: Trying to get a straight answer

32K views 16 replies 8 participants last post by  JLR 
#1 ·
I am now on my 2nd 2019 Street Glide. The first, a 'Standard' with a 107 engine, was repurchased by HD due to an engine noise that was seemingly non-repairable. Dealer had the bike for over 40 days and HD couldn't tell the dealer 'what' or 'how' to fix the noise problem, so I simply enacted our State's Lemon Law and had HD replace the bike. In so doing, I moved from the Standard to the 'Special', which has the 114 M8 motor. Both bikes have remained 100% 'stock', as I purchased them for long-distance trips, and really have no need for additional power.......or 'noise'. So, in riding the first bike through the first 1000 miles, I noted a noise that I considered to be 'detonation'. I informed my selling dealer of the issue, and was told to continue to ride the bike to see if it went away. I then took a 2500 mile run on the bike and during this trip the noise continued. Upon my return, I took it back to my selling dealer where upon they claimed 'not' to hear anything. As this was a totally unsatisfactory answer, I took it to another more 'service reputable' dealer. They instantly heard the noise, but were unsure of 'exactly' just what it was. Long story short, they made some audio recordings of the noise while in the quiet of a 'dyno-room', and sent these recordings to the Motor Company for further review. Unfortunately, HD never did get back to them with an answer.......and after nearly a month and a half, I decided I simply didn't trust the bike........and requested HD replace it under the Lemon Law. They did! I now own the new bike. And.......while not nearly as severe as the last one, it too makes the same 'noise'. Let me try to describe it as best possible:

When riding at virtually any steady speed, the noise isn't there. ONLY when 'accelerating' does the noise present itself. Generally I will cruise the bike at about 2500 rpm in what ever gear suits the speed and terrain being traveled. I do NOT 'lug' my engines....EVER!! So, take that"you're not down shifting soon enough!" response OUT of this scenario. And, the noise itself is NOT present until crossing the 2500 rpm range. It enters as a sort of 'cackle' sound that begins at about 2600 to 2700 rpm, and essentially remains present up to about 3500, and then diminishes and is gone by about 4K. It is directly related to throttle pressure and 'load' as presented by the terrain and conditions. If you SLOWLY twist the throttle on flat or down hill road you can basically ride through the noise while accelerating. However, if you twist the throttle and expect to accelerate quickly, OR......if you're working your way up a steep incline.....the noise will be present. The 'level' of the noise is somewhat dependent on this load and throttle position. More load, more throttle.....more noise present.

In my experience, this type of condition is generally characterized by what in 'engineering terms' is referred to as 'pre detonation', or more commonly referred to as 'spark knock'. I would note that the M8 motor has 'detonation sensors' installed as part of the engine control system...... so clearly the issue was one that HD took seriously enough that the incorporated these sensors into both design and production. I'm quite sure they will claim that 'detonation' is NOT a problem with the M8 motor because of this. However, my experience is rather contrary in that regard. I will admit that this noise is not the same as what I've heard on other 'non-M8' motors when they clearly WERE pre detonating. I've had twin-cam motors that 'spark-knocked' like the devil......and further tuning resolved the issue. However, this M8 motor is running in bone-stock condition......and should (by all 'factory' claims) NOT have any spark knock problems under most any circumstances. For the record, I run ONLY either Shell premium grade fuel, or Sunoco Super Premium. I don't believe 'poor fuel quality' is a contributor to this, as I purchased fuel in 4 different States, and the problem remain consistent throughout the whole trip.

Anyway, my new 114 motor is showing signs of having the same condition....though not as clearly obvious and not as severe as the prior 107. Because the M8 is a substantially different motor than HD has produced in the past, I'm willing to be open to some other explanation for this problem OTHER than being pre detonation, or 'spark knock'. BUT....... I can't find anyone who has enough true technical knowledge to be able to even discuss the issue as related to the 4-valve motor and what effect that might have. Because the 4-valve head disperses air/fuel mixture differently, there are other possibilities that may exist. This motor DOES run at a higher compression ratio than past 'stock' HD motors..... and HD had to also install compression release mechanisms in order to get satisfactory 'starting' performance from the engine. It's a 'closed loop' EFI system......and with the included detonation sensors, you'd think that if running too lean or having a timing curve that was too far advanced was the problem, the motorcycle's ECU would be capable of self-correction. BUT...... if the oddness of this noise is a function of that 'self-correction' running right on the ragged edge of being 'un-corrected'....then maybe that's it!! My gut tells me.... IT IS! I just can't get a confirmation one way or another. And, like I mentioned, the Motor Company failed to respond to the dealer about the situation......and the lead tech there is simply bewildered.

Let me conclude this saga by saying that I know no one will be able to diagnose this thing via forum posts. And, if mine's doing it, then if others are doing it too, why is there not a litany of other complaints out there? My response to that is simply that 'most' guys would probably have already put slip-on exhausts and 'tuners' on the bike by now, as well as high-flow air intakes and perhaps other 'performance' stuff........so they're probably NOT 'listening' to the engine the way I do. But, I'd almost bet the farm that in 'stock' form, their bikes did it too. In any event, I'm now 2 for 2....and just looking for an answer. Any help or suggestions would be appreciated. I'll just end by saying that adding a tuner is a possibility AFTER the 2-year warranty expires. The new HD policy of voiding one's warranty if any evidence of an after-market tuner is installed is present is problem I don't want to get in to. So, bike is staying 'stock' for the time being.

Thanks the time in reading through all this!! Tom D.
 
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#2 ·
A phantom noise ? All 3 bikes ? No answer from the MoCo, no service rep checked the bike out at the dealer?
3rd Harley under the lemon law and no service rep ... c'mon man !
Let me just say this from experience, the fairing on touring models reflect a lotta engine sounds that aren't normally heard, they get amplified.
Hell stick your head under the hood on your car with the engine running, you'll hear shit you never heard when sitting inside the car ! Reciprocating engines make noise, it's inherent to the design !
 
#3 ·
Schmidty,

Damn poor response!! First, it was only ONE bike replaced under the Lemon Law! Second, there are only two bikes involved, the first that was replaced for the noise, and the second that also has the noise but to a lessor degree.

Clearly reciprocating internal combustion engines make noise. Some 'normal'.....some NOT! Ever hear a rod knock, piston slap, collapsed lifter? I'll give you the same...'c'mon man'.......

I was taught that if you didn't have something productive to say, best to keep your yap shut, otherwise you might just make an ass of yourself!

Thanks for the useless comment!!
 
#6 ·
I thought there were 3 bikes too.
 
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#7 ·
So, the very first line says: "I'm now on my 2nd 2019 Street Glide." Not sure how there can suddenly be a 3rd in there, but I know it's a lot of words....... but I don't think there's any mention of a 3rd bike!

My feelings don't get hurt Schmidty....... I just grow weary of useless commentary when trying to resolve a legitimate problem. I can understand if clarification is needed, or if I were to have made some kind of error in my write-up/description, or even if something just didn't add up. But to tell me that engines make noise......like I should accept that ANY noise they make is OK......and to imply that this is commonly accepted wisdom...... , nah! I'm going to call you out on that one.

This 'noise' is abnormal! I've been listening to engines on motorcycles for over 55 years, made my living in the automotive technical field, am a past ASE Certified Automotive 'Master Tech', and have wrenched on everything from chain saws and go kart motors to NASCAR and Formula 1 mills, as well as some 2-stroke High-Po stuff in the outboard field back in the day. I don't claim to be an 'expert'.......and I often yield to the current knowledge of others, particularly those with current training and experience on any given motor....like the Milwaukee 8! But, I ain't no dummy......and don't like to be treated like one! It's not about hurt feelings, it's about 'respect'....and people here in these forums need to show it... for everyone. That's what makes the Forums work.......otherwise they'd just be a bunch of dribble like you'd get at the local bar!!

End of Lecture......appology accepted in the spirit in which it was offered.......and back to the problem at hand.

Again, if anyone has any experience and knowledge on the subject, please chime in.
 
#8 ·
..... so I simply enacted our State's Lemon Law and had HD replace the bike.

and after nearly a month and a half, I decided I simply didn't trust the bike........and requested HD replace it under the Lemon Law. They did!
.
2 replacements would put you on your 3rd bike.

We don't have a reading comprehension problem, but you may have an explanation problem.

Sent from my SM-A102U using Tapatalk
 
#9 ·
here is where the confusion comes from


Discussion Starter • #1 7 hours ago

I am now on my 2nd 2019 Street Glide. The first, a 'Standard' with a 107 engine, was repurchased by HD due to an engine noise that was seemingly non-repairable. Dealer had the bike for over 40 days and HD couldn't tell the dealer 'what' or 'how' to fix the noise problem, so I simply enacted our State's Lemon Law and had HD replace the bike. In so doing, I moved from the Standard to the 'Special', which has the 114 M8 motor. Both bikes have remained 100% 'stock', as I purchased them for long-distance trips, and really have no need for additional power.......or 'noise'. So, in riding the first bike through the first 1000 miles, I noted a noise that I considered to be 'detonation'. I informed my selling dealer of the issue, and was told to continue to ride the bike to see if it went away. I then took a 2500 mile run on the bike and during this trip the noise continued. Upon my return, I took it back to my selling dealer where upon they claimed 'not' to hear anything. As this was a totally unsatisfactory answer, I took it to another more 'service reputable' dealer. They instantly heard the noise, but were unsure of 'exactly' just what it was. Long story short, they made some audio recordings of the noise while in the quiet of a 'dyno-room', and sent these recordings to the Motor Company for further review. Unfortunately, HD never did get back to them with an answer.......and after nearly a month and a half, I decided I simply didn't trust the bike........and requested HD replace it under the Lemon Law. They did! I now own the new bike. And.......while not nearly as severe as the last one, it too makes the same 'noise'. Let me try to describe it as best possible:

I read that as two swaps under the lemon law. I was wrong.
 
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#11 ·
This is EXACTLY what I mean by..... "trying to get a straight answer."

Lots of rhetoric........ no apparent 'meat' on the bone!!

If the explanation regarding 2 bikes / 3 bikes is unclear......sorry! But, I do have to point out how NO ONE has had one word about the symptom I've attempted to describe, or offer any kind of viable explanation.

So, again, 2 bikes, same symptom, first one (a 107) was worse than the second (a 114) which is what I now have. I'd love to have a discussion with someone who has some experience with the motor and might have some insight to the problem.


TSD
 
#12 ·
This is EXACTLY what I mean by..... "trying to get a straight answer."

Lots of rhetoric........ no apparent 'meat' on the bone!!

If the explanation regarding 2 bikes / 3 bikes is unclear......sorry! But, I do have to point out how NO ONE has had one word about the symptom I've attempted to describe, or offer any kind of viable explanation.

So, again, 2 bikes, same symptom, first one (a 107) was worse than the second (a 114) which is what I now have. I'd love to have a discussion with someone who has some experience with the motor and might have some insight to the problem.


TSD
Maybe if you weren't so long-winded and condescending, people might be more willing to attempt to help, but as you said, "I know no one will be able to diagnose this thing via forum posts". Also, really? Your initial post was 13 hours ago and you expected already to have a "straight answer"? There hasn't even been 10 total responses not counting your own.

And you seem already to be such an expert and know so much that you know it's "like detonation but not" and "it's not lifters or rod" etc, etc somewhere I read in there.

Come off it dude.

And for the record, I also thought there were three bikes. Actually my thought was: "wait, I thought he said this was the second bike... oh wait, I see, guy's repeating himself because he can't remember what he wrote in chapter one and he's on chapter fifty now".

After what I read so far, starting to think the problem is with your head.
 
#13 ·
Hmm, looking at your posts, you posted about the problem with the 107, got lots of responses, people tried to help.

Did you even try any of those suggestions with the previous one? Doesn't seem like it. Didn't even thank anyone for the suggestions.

So, do you actually want help or not? How are we supposed to know what this noise even could be without hearing it? Doesn't seem to be a common issue that I ever heard of, but you apparently had it back-to-back?

And you said the dealer hasn't heard back from the MoCo on the noise, how long did you wait for a response, one day?

Or are you just a troll?
 
#14 ·
Ya know, if you'd read the first post with any degree of understanding, you'd note that it said it was at the HD dealer for 6 weeks! That's how long I waited for a response from both the dealer and the Motor Company.

If I were a 'condescending' person........ I'd call someone a troll. I haven't done that. Have you?
 
#16 ·
Maybe the OP doesn't realize that all of us on the Forum actually work for MoCo and we're out to get him and his bike! When he enacts the Lemmon Law for the fourth time, maybe he should trade for the Livewire . . . Electric bike with a lot less moving parts to make noise. Rumor has it that the Livewire Exhaust is one of the loudest out there!!!
 
#17 ·
I really don't know why you banned him. He was treated with a lot of disrespect, answered back and got banned??
 
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