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I don't know how to upload a video or would.

Start car it sounds good and strong.

About a min in while parked the rpm is at 1000 idle..

Then it starts to go from 1k rpm to 1,100 rpm

It does this steady for a couple minutes then it goes..

From 1k to 1,000 rpm dips down to about 900 ... that is maybe a second to do that then stays like that consistently..

Should I be worried

I don't know how to upload a video or would. Start car it sounds good and strong. About a min in while parked the rpm is at 1000 idle.. Then it starts to go from 1k rpm to 1,100 rpm It does this steady for a couple minutes then it goes.. From 1k to 1,000 rpm dips down to about 900 ... that is maybe a second to do that then stays like that consistently.. Should I be worried

(post is archived)

[–] • 3 pts

sounds like a vacuum leak some where on the intake manifold. Not usually critical but a bitch to find.

[–] • 0 pt

Mam I was feeling really good about your comment until...

A bitch to find
[–] • 1 pt

A can of carb cleaner will help find said leak.

[–] • 0 pt

not really. Get a can of spray carb cleaner and with the motor running spray some along both sided of the intake manifold and if the rpm's increase you found the vacuum leak. CAUTION the carb cleaner is highly flammable so stay away from very hot or open flames. Since it is a used engine it is likely the intake manifold bolts got loose during pulling. The intakes are also plastic so may be a crack. Need anymore help just let me know,

WWG1WGA

[–] • 0 pt

use WD40 then dont have to worry about flammability/

[–] • 2 pts (edited )

Unlike some have said don't start with shit like ignition components. You said it was running smooth and a 2012. This could be perfectly normal operation. It's called a high idle and used to help get the catalytic converters fired up.

The only thing you need to do is hook up a scan tool. You can get bluetooth ones for $20. There may be history/pending/current codes even with the MIL off. If you don't do this first you're wasting your time and money.

If you have a vacuum leak it might not have a P0171 or P0174 code yet. So then you look at Long Term Fuel Trims for both banks. They should stabilize at 0% +/- 10%. If they are >+10% you likely have a vacuum leak causing a idle hunt.

That or your throttle body is dirty/not adapted. Clean your throttle body and clear codes even if their aren't any, turn key off for ten seconds, turn key on and do not touch anything for ten seconds, fully depress accelerator a couple times, start engine and let idle for a minute or 2. Take on a drive and see if any codes pop up.

Do not just start replacing shit.

[–] • 1 pt

Try a vacuum test. If the needle bounces around, it could be a broken valve spring. Worth checking.

[–] [deleted] • 0 pt

In cold weather my car does the same thing, it is normal if it has been sitting for a while also. Acura btw.

[–] • 0 pt

Sounds like the auto choke turning on and off exactly like it should.

Does it drive fine under load?

[–] • 0 pt

It was salvage title. I'm scared to drive it 30 miles to the shop.. gonna have it towed and hope it is something minor

[–] • 1 pt

Haha, dont be a bitch. Put it to the floor and see what happens.

It sounds like it's running exactly like it should from what you say.

Much cheaper to start with new plugs, wires, and distributor cap than bringing it to a shop.

First time I replaced those things I was 13. Easiest shit to change on a car you just buy. Change the oil and oil filter of course as well.

[–] [deleted] • 0 pt

It's gonna have plugs on coil for sure, a little more pricey than a cap, rotor and some wires. More so if it's a hemi and has the double plugs

[–] • 0 pt

Idle air control valve maybe

[–] • 1 pt

I hope so it was salvage title I am hoping it is something minor.

[–] • 0 pt

That valve doesn't exist on your car(newer). It's all done with small throttle plate and valve timing adjustments.

[–] • 0 pt

It sounds familiar to an issue an old friend's prelude had. It will run and everything, but the idle rpm would oscillate up and down rather rapidly. Now, there's probably a big difference between how honda and dodge make it work, but there aren't too many different ways to control the throttle at idle. I'd look for the throttle position sensor on the intake manifold and see if there are any other sensors around the throttle valve. I don't have much experience with this model, but that is how I would start. It doesn't sound like anything big, I hope I'm right.

[–] • 0 pt

Hope it was cheap

[–] • 1 pt

10,300.. gonna put about 5k in.. a used one similar in perfect condition is about 26k.. I'm hoping to get out at around 20k drive it till I get the price I want. Worse case I keep it.

[–] • 0 pt

I've always regretted selling cars I really liked and put work into

[–] • 0 pt

this sounds right up your alley

[–] [deleted] • 0 pt

What motor does it have?

[–] • 1 pt

Srt8.. hemi the 470 hp one

2012 392

[–] [deleted] • 0 pt (edited )

Nice. The good thing about the Hemis is there's a huge community around them. I'd search youtube and forums.

I have a 5.7, should be similar. Your idle is definitely high, mine settles in around mid to high 600s. Get some carb, brake, throttlebody cleaner, whatever. spray it around the intake manifold. If you get a surge, you found(one of) your leak(s). Don't be too liberal with the shit though, there could be a vaccuum leak in a hose nearby. Or it could be your IAC valve or throttle body maybe isn't zero'd.

Mine hesitates to start sometimes, it's new to me and the previous owner was running nos, EGR delete, no air filter. Tons of hack shit. So I was going to go over the IAC valve and throttle body and see if anything is fucked up. I'll let you know if I find anything about the 6.1 IAC

[–] • 0 pt

Almost certainly a vacuum line

[–] • 0 pt

,70% chance dirty Maf