Concerned about new sound coming from engine
 

A couple weeks ago my engine started to sound different. It's hard to describe, but the sound makes me imagine one of the apex seals is loose or damaged because when I first start the engine up when it's cold there's a consistent ticking noise. The rhythm of the ticking change as the revs change. When I finally start to drive and I accelerate, the noise changes to a "ssssssss", like maybe the extra combustion pressure from the acceleration pushes the seal against the chamber harder. Eventually the sound goes away once I've driven for a while.

I could be way off but can anybody offer some speculation about what the problem is?

I have a new noise that is more of a vacum leak type. It comes and goes, and does also sound like it could be a ticking at different rpm's. It did show itself at the dealer during an oil change, and even the service mgr, who really knows his stuff, could not track it down. The sound appears to be coming from the passenger side of the engine, towards the rear.

Could be a thousand things including a leaking exhaust manifold gasket. A stethescope (or hose in your ear) used to walk around the engine can help narrow down from which part of the engine the sound is coming from. Best of luck.

RxGr8,
If it were a piston engine, I'd say you were describing the sound of an engine with not enough oil. Don't know what that translates to on a rotary. I'd have it checked out anyway, I don't like funny engine noises.
--Dave.

I have the same exact sound. I noticed it at 4500 miles. It is not the noise that you hear when idiling with the clutch disengaged, but different. I have also noticed that it changes in variation to RPMs as well. I think it is a slight exhaust leak emitting from the catilytic converter flanges on the engine side. I wonder what could cause this, bad cat?

Re: Concerned about new sound coming from engine
 

If one of the apex seals had let go, you would know.. It would sound like a lose bolt in the engine. AS for the noise... It would be hard to tell you what it is without more info. Try the stethoscope method.

Me too I just discovered it yestereday its only when the car is cold.

It sort of sounds like tik tik tik tik tik, but the car is warm it dont do it no more. I dont remember if that was there or not theres no engine light but maybe if I check it up with the dealer it might be more helpfl.

The ticking noise may be the injectors, they tick when cold in many other cars, may be the same for the RX8 as well. The vacuum leak you discribe is probably the electrically driven smog pump. It is located on the passenger side, just behind the shock tower.

Mine ticks all the time and varies with the RPMs. I was thinking it was a sticky belt so i tried some belt dressing, but it only made the sound worse. I'll bring it to my dealer's attention on my next service (and then they'll tell me they can't recreate the sound and give me the car back still ticking..argh).

I have an AT RX8 and I noticed the same some when I first start the car but it goes away after the car warms up. I have no idea what it is caused from!

How weird- I noticed something like this the other day- but I don't know if it's normal and I just couldn't hear it before because I always have the stereo up, or if it's really something new. The car isn't acting funny, though, and it just had it's 15k checkup a week ago.

I don't know what the sound is, but I would bet it isn't your any of the apex seals. Ticking has been related to fuel delivery in the experiences I have had, so injectors sounds like a good bet. Have it checked and please let us know.

My engine just started to make a simulor sound. But when it is warm it makes a high pitch wistle (kind of like your ears ringing but a little lower) and the idle is a little ruff. I wonder if it is the same problem.

so what the hell is it

RXGr8

Thanks for making this thread. I've been trying to figure out how to describe the noise I've noticed for some time. I have the same situation at a cold start. The "ticking" noise will eventually go away when the car is warm. Sometimes I notice it before I shut the car off. I wasn't sure if it was something normal since I used to start my car with the doors closed and the radio on. Now I start my car with the doors open just to see if I get the noise. I want to know what it is because it doesn't sound natural to me. Please let me know if you come up with any findings. I'm gonna have it checked on my next visit. Lets hope its nothing serious.

timely thread, I first heard this two days ago as well. Only when cold.

My car is in the shop for this and other reasons. I will report what they find.

I'm guessing that it's some sort of exhaust leak. Could be injectors, but I highly doubt it given the low mileage. Also, several have indicated that the sound goes away or changes once the car is warmed up, which indicates a small exhaust leak to me. We'll see. Let us know the final verdict!

I listened some more today and am having a very hard time figuring out where it comes from. Its mostly noticeable when the car has been cold for a long time (like when I first start it in the morning). Unfortunately its hard to show the dealership what your talking about since the car will be warmed up by the time you drive it there. I have on occasion noticed the sound after the car has been warmed up and during driving. We need a RX-Detective. Anybody out there have any clues?

Idler Pulley? I used an engine stethoscope to try and locate the noise, but of course it doesn't make the noise when I have the scope around. On a recent long highway trip the ticking was really loud when I stopped for gas. I was expecting something to fall off the car at any minute...never did of course.

Even so I checked the sound of the alternator, water pump, AC compressor, engine in general...all smooth and quiet. Yes, the engine was running..... The Idler pulley (tension pulley is likely a more correct name for this unti) for the drive belt....well that damn thing would knock you ears off it was so loud. Not a ticking noise, just damn loud.

I don't really think it is the pulley, but I'm hoping to hear the tick again soon so I can track it down with the scope. Will let you know what I find.

ok, heres another one. i noticed what sounded like the front input shaft whirring when the clutch was disengaged. it was very prominent and two very knowledgable car people (my dad and one of his friends) were there and verified it. after about five minutes of engaging/disengaging it went away.

Hey Kellybrf,

I was wondering what you dad and friend thought it was? So far on this thread it is believed to be an injector or exhaust leak. Did they feel it was the same thing?.

Heard the ticking noise for the first time on my car today when I started it.. Please let us know what your dealer found.

front impact shaft bearing, but mine was a different noise. it was a definate whirring, no clicking involved

I've noticed a ticking lately too. I haven't really paid much attention but it does seem like it happens before it warms up.