Caddy

Hey all need some advice here. I maintain all my cars myself, the RDX is the wife's. Her old pilot had 238k when we traded it that I did all the work on myself, my benz has 190k on it currently.

We bought it last year with 100k on it, been a good car other then shortly after we bought it the MAF took a dump, dealer replaced gratis which was nice.

It has always had a rough idle. At a red light for example the RPM will dip and you will get a very slight shake, then it recovers fine, at anything above idle it seems fine.

Well we were heading out the other night and I was cruising about 30mph in traffic, let off the gas to get in the left lane to turn and the truck cuts off completely. I guess it fell to idle RPM and bounced to low and couldn't recover.

Brought her to a stop, put in park, started back up just fine and been driving fine since.

SO. RDX people. What do you all think, IACV? I have no codes, the A25 service minder just popped up like a day before this happened but that is an oil change, air filter, and coolant.

Caddy

After reading some more I see people have a problem similar and guys are attributing it to the alternator. Not sure on that one, I have never seen any flickering of lights, dash, etc, never a warning light for charging. I am going to connect my obd reader and use the torque app to watch my battery levels while driving for the next few days to try to rule this out.

it literally went from driving to dead black cluster and not running instantly.

also, air filter, this was changed when the dealer replaced the maf, apparently the air box gasket wasn't seated and fouled the maf so they replaced the whole shebang.

Caddy

anyone home? was only able to test on a short trip last night but my voltage graph was steady the whole time, of course I couldn't get it to rough idle either though...

DRR98

How long was the filter bypassed? How dirty was the environment driven in while the filter was bypassed?

If the air filter was bypassed long enough to cause the MAF to fail, you have to ask yourself what else got contaminated with unfiltered air.



Let me think, maybe...intake, turbo, inter-cooler...throttle body...piston rings...oil...

Caddy

That's helpful. I have no idea how long the gasket on the filter housing was leaking. The maf died about a month after i bought it. The filter wasn't bypassed per se but according to the dealer it was leaking....but that's what they said, which I don't really trust.

Nonetheless, short of tearing down the complete engine for inspection, I'd like to clean the iacv, and keep a scanner on it till I find a culprit.

I was just asking if anyone else had seen an issue like this or had better ideas.

Caddy

after having a scanner on it for a bit i see that during regular driving my voltage will drop randomly from about 14v to 12.5v for 10 seconds or so at a time.

i wasnt able to stop and idle during these drops but i suspect i have a bad alternator. will followup

gche_99

Thought I pass this along...
I have a 2007 base RDX and I too had an idle rpm drop issue with no CEL. With about 160k km, it was time for changing the plugs. After changing the plugs and cleaning the throttle body, the issue persisted. Next was a new air filter. Previously, I had only cleaned the air filter, since it didn't look too bad. After I removed the air box screws, I finally found the issue. The air intake tube was splited on the bottom. I swore I had checked this previously, but somehow this was missed. After some duct tape and test runs and stops, the rpm sudden idle drop was gone and throttle response was back to normal. So, guys check your air intake tube.

rsxdude

Thanks for the response! So if I am having these problems, just get an intake. Got it. Justification woo!

bchizzle

Just brought my 2007 RDX Carbon Tech Pkg w 115K miles to the shop for the same rough idle/stalling issues.

They discovered a rip in the air intake tube and recommended I change the plugs as well.

rsxdude & gche_99 - did replacing the intake tube resolve your issues? Can you confirm the part #?

Thanks!

rsxdude

I never got an intake but have changed the plugs. Previous owner had it serviced and they stuck autolite plugs in it. Two were gapped pretty bad and two were normal. I stuck NGK plugs in and it's been good ever since. Only issue I have is a knocking noise on the suspension and a stutter when I turn the a/c off. I replaced the struts and end links when I acquired the vehicle so I'm looking at strut mounts next.