Hoping someone can chime in! About a month ago I noticed a light sort of growling sound after accelerating, usually within a minute or two of starting up the car (2013 Honda CR-V, ~150K miles). After a couple weeks it got worse and became a pretty regular grating/growling sort of noise when I’d accelerate. It has seemed less noticeable at highway speeds but otherwise became consistent when driving (not going away after the first couple minutes).
After a couple attempts to figure it out a local mechanic who’s done other work on the car told me I needed a valve adjustment, that that was the problem, and he did the work. But after doing it we talked and he basically told me (I’m trying to summarize):
He is certain this is the issue, and post-repair the valves are now aligned. But he also said it had been loose for so long the lobes on the cam shaft were worn, and so while this shouldn’t be a problem for the engine, I would keep hearing the rattle because the cams are worn. He emphasized that when it “hits the wear spot under load, it will rattle.”
That’s my jotted notes / recollection of what he said. I’ve done work on my car myself but not serious engine work, this sort of thing I have to look at a diagram to make any sense of.
Anyway, the rattling/growling/whatever is definitely still there, not a pleasant noise when accelerating. Does his explanation sound plausible? I like this mechanic, as I say his shop has done a couple repairs on this car. But I don’t have a terribly long history with him and wondering if I need another opinion. The car has like ~150K miles, it feels fine when I drive it, but this noise is not great.
EDIT: “Rattling” isn’t the right noise, it’s more of a grating growl.
It’s possible that this noise could be the result of a bent heat shield on the exhaust system. Even though you trust your mechanic, I think that you need a second opinion from a different guy.
The noise from a damaged heat shield can be annoying, but it’s not dangerous. However, you need to rule-out the worn cam as the source of the problem, as well as other possibilities.
Thanks. Yeah a heat shield crossed my mind. But I recall from dealing with this once before (and confirmed via YouTube), wouldn’t that be more of a rattling noise?
(And yeah, I am in touch with another mechanic. I’ve got to drive a couple hundred miles this weekend though, so hoping things are OK until next week.)
Did mechanic use term “aligned” for valves? No one aligns valves. As valve seats wear, the valves sink into head and clearance is less. So, a Honda with worn valves is not looser, It is tighter. And makes less noise. Valve clearance is adjusted. It is not aligned.
Eh I’m going off my notes/memory so I don’t know. He said this was a valve adjustment, that I know. And he said there were worn lobes on the cam shaft and, if I understand it right, the friction on those worn spots is causing the rattle.
I think it might be a good idea to rent a vehicle for this weekend trip . It could make it but getting broke down away from home on a weekend might be more expensive.
Whoops! Yeah preciseness of language with car issues can be tricky but yes, “rattling” probably wasn’t the right word to use. More of a growl. Though I don’t know this definitely rules out the heat shield.
Just to rule something out: It’s not the transmission, right? My son has an issue with his truck where it rattles in certain gears and at certain speeds.
Actually it is impossible to rule anything out with this vehicle right now. A second opinion is needed here . Maybe WS will post what the problem was .
Yeah, nothing’s really ruled out. Hopefully have more info later this week. Transmission issue did occur to me as well. These CR-V models seem prone to a “judder” problem at low-ish speeds sometimes. When I bought this car (about two years ago, with 120K miles on it) this was quite noticeable. A different mechanic flushed the fluid and installed some kind of filter that had worked out well on another car with a similar problem, and that made the juddering more or less disappear.
I mention this as I have actually noticed it again a few times recently and have wondered if there’s a connection.
Just to re-phrase and clarify, the mechanic said it was from worn cam lobes. Seems to me that would affect engine performance but I’ll wait for some of the experts here to tell how to ■■■■, the symptoms, and cost to replace. I suggest extended oil changes could wear a cam prematurely. Never had one wear myself.
Car has been well-maintained. I bought it from a guy at 120K miles and it had all the service records, I’ve maintained it reliably since.
All this said… here’s an update. The mechanic who did the work took another look after I talked to him about the persistent noise. He definitely said the lobes were worn on the cams. However, he also told me there was I guess a separate issue, of something being out of whack with the shims. If I understood him right, he said these were really worn and he swapped them out and adjusted things.
All I can say is, I’ve driven less than 50 miles since but the engine sounds great. Noise is gone; we’ll see how it goes as I continue to drive it.
For future reference, and because I’m going to be paying attention to this, does this make sense to folks? Is he talking about the valve shims? Better yet, anyone care to explain to me in a basic way what they think is/was happening? The mechanic didn’t charge me for the additional work and is in my experience a good guy, but I’m not thrilled by the idea that there was some careless error or oversight.
