RPM drops when stopped then recovers
RPM drops when stopped then recovers
I had my 2005 checked a couple of weeks ago and then “winter” hit East Tennessee. I was driving home in traffic and when I stopped the idle went low enough to make the car shake before it recovered. It never stalled; however, I was sure that was about to. I try to drive the car weekly and it was raining when this happened. Any thoughts?
Join Date: Jul 2009
Location: Central South Carolina
Age: 69
Posts: 5,859
Received 388 Likes
on
335 Posts
Re: RPM drops when stopped then recovers
I had my 2005 checked a couple of weeks ago and then “winter” hit East Tennessee. I was driving home in traffic and when I stopped the idle went low enough to make the car shake before it recovered. It never stalled; however, I was sure that was about to. I try to drive the car weekly and it was raining when this happened. Any thoughts?
Yes, more information def needed. However as a start, open the hood and while the engine is running remove the oil filler cap. Let us know what happened.
.
Join Date: Nov 2020
Location: Hebron, Connecticut
Age: 63
Posts: 152
Likes: 0
Received 19 Likes
on
18 Posts
The following users liked this post:
Brian P (12-11-2022)
Re: RPM drops when stopped then recovers
I’m sorry for not responding, we had the grandkids this weekend. It happened to me while we were having lots of rain (humidity) and it was stop and go traffic. My wife says that it’s happened to her on sunny days. I had the car serviced less than a month ago for the standard things at 90K.
Join Date: Nov 2020
Location: Hebron, Connecticut
Age: 63
Posts: 152
Likes: 0
Received 19 Likes
on
18 Posts
Re: RPM drops when stopped then recovers
If the plugs, wires, and coils have never been changed within the 90K miles I would have this done as a preventative maintenance step. Replacing the RCM, cam position sensor, and crank position sensor are also good items to replace. The RCM is probably the most problematic control identified on this forum. Once the marginal cold soldered connections on the RCM pc board are repaired and relays replaced the reliability of this control is dramatically improved.
Join Date: Jun 2009
Location: Fort Worth, Texas
Age: 64
Posts: 13,469
Received 888 Likes
on
692 Posts
Re: RPM drops when stopped then recovers
I had my 2005 checked a couple of weeks ago and then “winter” hit East Tennessee. I was driving home in traffic and when I stopped the idle went low enough to make the car shake before it recovered. It never stalled; however, I was sure that was about to. I try to drive the car weekly and it was raining when this happened. Any thoughts?
Thought 2: A car with those miles should have plugs and plug wires replaced. My Graphite was doing odd stuff around 100,000 miles that didn't add up I put 12 plugs and wires in it (ordered from Rob at Needswings, not Autozone crap) and everything cleared up right away. "
Thought 2A: Do not waste time "diagnosing" a car that has not had regular maintenance done. Original plugs and wires at almost 100,000 are at/beyond their service life.
Thought 2B: I'd not replace coils right now. Im not of the mindset that coils go bad nearly as often or as soon as plugs and wires, but coils are something to keep in mind as you go thru this.
THought 3: You never clearly answered the question of how old your air filters are. While at it, keep in mind the seal at the MAF intake and airbox is known to get 'loosy-goosy", this break of the seal changes the volume of air/vacuum drawn by the engine. This also means that one MUST secure the airbox in place properly and completely, this has come up before on here.
Thought 4: Vacuum leak? To check for a leak, warm engine by driving the car for 1/2 hour or more. PLace in Park/neutral. Raise hood. Yank the oil cap off. If the engine does not change it's idle at all, you have a pretty bad leak. If the engine speeds and slows, shakes and kinda freaks out, you have no real vacuum leak to speak of. You see, yanking the cap off creates an instant, severe vacuum leak and the engine should freak out due to this. If it does not, there is already a vacuum leak or horrible intake problem.
You might grab a code reader and see if there are any codes or pending codes and post them here for us. All we need are codes in the format: P0xxx where the x's are numbers 0-9.
Last edited by pizzaguy; 12-12-2022 at 10:20 AM.
The following users liked this post:
Brian P (12-12-2022)
Re: RPM drops when stopped then recovers
A vacuum leak would show up consistently I would say.
As mentioned before you should look at the air filters, but you said you had a service just recently so that should not be a problem.
Think seriously about any diagnosis a garage gives you, good luck.
Join Date: Jun 2009
Location: Fort Worth, Texas
Age: 64
Posts: 13,469
Received 888 Likes
on
692 Posts
Re: RPM drops when stopped then recovers
I had my 2005 checked a couple of weeks ago and then “winter” hit East Tennessee. I was driving home in traffic and when I stopped the idle went low enough to make the car shake before it recovered. It never stalled; however, I was sure that was about to. I try to drive the car weekly and it was raining when this happened. Any thoughts?
It's weird in that it only will do it once, usually at my first intersection after the engine is warmed up. It won't do it again until it has a complete cool down and cold start.
I'm at 100K now, so I intend to do all the maintenance mentioned in this thread, so we'll see eventually if it goes away.
The following users liked this post:
Brian P (12-13-2022)
Thread
Thread Starter
Forum
Replies
Last Post
H LeMans
Engine, Exhaust, Transmission and Differential
1
10-28-2022 02:00 AM
BRappaport
Troubleshooting & Technical Questions & Modifications
2
06-12-2011 10:30 AM
CFbabe
Troubleshooting & Technical Questions & Modifications
27
11-01-2006 01:36 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)