Posted a problem about my RDX a while back.

Turns out I had to take it back 3 times because the check emissions light kept coming back on. They first reset the sensor, then replaced the sensor, and then finally said that the entire electronic piece that reads the sensor had to be replaced. Needless to say, it has been a horrible experience considering the dealer has had it more days then I have since buying it.

I finally got it back yesterday, and my husband was testing it out to make sure everything worked ok after getting the replacement piece.

He had it in park and was revving the engine. At about 5 rpm, it makes a loud knocking noise from the engine.

Can anyone confirm that this happens with their vehicle too so that I know whether or not it is yet another problem? Is it supposed to make this noise?

It doesn't make this noise while actually driving it.

 

I assume you mean 5000 rpm. The first question (which I assume the dealer asked you) is are you using preimum fuel? Assuming you are and that this problem can be duplicated, I recommend you take the car back, show them this specific problem and ask them to fix the symptom you're seeing. Don't just drop the car off but ask to show the problem to a mechanic. If you're using preimum, you should not hear knocking under these conditions.

 

I think what might be happening is that the rev limiter (rpm limiter) is kicking in at 5000 rpm.

Because I've had so much trouble so far, I was wondering if anyone else's rev limiter kicks in at 5000 rpm or if this is truly something wrong with the car. Correct me if I'm wrong but usually a rev limiter in my mind is supposed to turn on in the red zone (7-8k rpm), not at a reasonable rpm like 5000.

 

The rev limiter in park or nuetral comes in at 5K. Is the tach going up and bouncing back down with a sound similar to the engine losing all power?

To really try it out, go on the highway, and go up to red line in second(assuming you've broken it in).

Mike

 

Yes, that's what happens when it's in park. Do you have a RDX that does that too? Is it a RDX specific thing or other vehicles as well?

 

Most if not all Honda/Acura's are rev limited in park. The NSX is even rev limited in gear until it is properly warmed up.

 

Not yet, but we have a TL.

Mike

 

A colleaue of mine bought a RDX after my suggestion (before I had all the many visits to the service department). I asked him to try it out on his car today, and he said it does the same exact thing.

Makes me feel better, but now I'm kind of paranoid about the car in general. To have your entire electrical system replaced never sounds good.

 

Its not the entire electrical system. A computer swap out is very simple, literally a few connectors and the mounting bolts.

In terms of bouncing off the rev limiter, you may not want to do that, its not a great idea to rev up an engine under no load.

Mike

 

why would you rev the car so high in P??

 

Because you can?

 

Which is why Honda limits it, so you can't

 

I was going to ask the same thing...

 

You are hearing a knocking (ping) sound from the engine? Are you using 91+ octane? anything less can cause knock/detonation.
5K limiter - thats what most Honda/Acuras have. Its normal.

What CEL code was being thrown? They replaced a wiring harness, a sensor, or the ECU?

 

OMG, you've had one problem! Not "so many"! If theres a problem with an O2 sensor, the first thing you do is reset the light, then you change the O2 sesnor (sits in the hot exhaust gas... a very hostile environment) then you change the ECU last.

They keep the car from revving past 5000 in park or neutral to keep someone from running it to redline and slamming it into "D".

For the fun of it, why not try to rev to redline in drive while the engine is stone cold. Report back.

 

Even with the rev limiter, don't do it. Its not good for the engine.

Mike