Somewhat Lumpy Idle

[MacVay]

I have a new 05 V8 Limited and I find the idle a little lumpy. When the truck is in park, you can feel kicks here and there in the floor and steering wheel. The are light but annoying.

I am an anylitcal freak and would like to know what causes such events. I wonder if there is a slight missfire. I notice nothing under power.

How is your idle?

Cheers,

 

[Koz]

I was amazed at how low and smooth mine idles. Looks like 550 rpm and rock stable.

Koz

 

[DaveS]

At idle in park mine is very smooth - you have to look at the RPM gauge to tell its running sometimes. Held at the lights in drive it can sometimes feel a bit rough - I usually flick it into neutral if I am going to be waiting a while.

Is your experience when it is warmed up or from cold?

 

[MacVay]

Both,

I can fell a pronounced slight repetative shudder. I am wondering if it needs a valve adjustment as this can be the case. There is no CEL and it is minor but I can feel it.

I don't seem to notice it under hard acceleration.

My 02 Pathfinder was smooth as butter at idle.

I will mention it on it's first service but I doubt they will even try to look for it. It could run like crap and as long as the CEL isn't on they will not care. I hate issues like this because they will never do anything about it until it is major.

If I get crazy I may look at each plug and run a compression check.

Like I said, it is minor but I want my new truck running perfect.

Cheers

 

[Kanab]

Both,

I can fell a pronounced slight repetative shudder. I am wondering if it needs a valve adjustment as this can be the case. There is no CEL and it is minor but I can feel it.

I don't seem to notice it under hard acceleration.

My 02 Pathfinder was smooth as butter at idle.

I will mention it on it's first service but I doubt they will even try to look for it. It could run like crap and as long as the CEL isn't on they will not care. I hate issues like this because they will never do anything about it until it is major.

If I get crazy I may look at each plug and run a compression check.

Like I said, it is minor but I want my new truck running perfect.

Cheers

Let it run in and see if it smooths out. Give it 10K miles and a couple of oil and filter changes. It could be the gas or who knows what. I would not have the dealer mess with it or you mess with it. You might really screw something up.

 

[Oscarz]

My 03 V6 does the same thing and I tried to get the dealer to diagnose it a year ago, even to the extent of calling in the Field Service Tech.

They hooked up all the electronic gizmos etc., and found nothing wrong. As I sat in the vehicle and let him know every time I felt the "kick-shudder" , about 2-3 seconds apart (in park or neutral), he said nothing is registering on the device. Consequently, it doesn't point them in a particular direction to pinpoint a cause. At least that's the official answer.

You will probably notice the tach does not move when it happens. I think it's an internal imbalance that happens to cycle and repeat at idle (in park or neutral). When put in gear, it stops. Rev the motor even slightly, it stops. Turn on the A/C, it stops.

Idle just happens to be the "sweet spot" of the reasonating-cyclical-imbalance.

This is my theory anyway. If you find a cure, please post. Lots of V engines out there suffer from this annoying malady.

 

[MacVay]

I am a very anylitical and technical person, and I always wonder if this type of issue will cause a loss of performance.

With mine, I can feel a perfect beat to this shudder so one would assume that it is the unequal firing of one cylinder while under an idle condition. If this is the case, there is an issue with the combustion process in this cylinder. I affraid this will cause a performance issue in the end.

I'm sure it will be a waste of time taking to the dealer. I find you are better taking these matters into your own hands. I will do what I can to look at this problem. I will replace all of the plugs and make sure they are gapped correctly. If I get crazy I will do a compression check.

It is minor but annoying.

I hope that the resolution is simple.

Cheers,

 

[MicaBlue03]

vibration at idle

My '03 V6 used to vibrate just a little at idle once in a while. It was pretty mild and infrequent and I mostly ignored it. It seems to have gone away, probably after the first 2,000-3,000 miles.

MacVay, if you're interested in whatever data the engine computer has, there are accessories like the CarChip that keep track of things like RPM, throttle opening, misfires, etc. You can find more info at www.davisnet.com/drive/products/carchip_products.asp

These CarChips plug into your OBDII connector and have a data logging function.

Unfortunately I think the 2005 4Runners have changed the data protocol to CAN (controller area network) and may no longer be compatible with the CarChip products. Check out the compatibility list at the site above. Davis may be enhancing these products to be CAN compatible in the near future, but it would probably be wise to ask them.

Actually, I was surprised that Toyota would change the vehicle's network protocol from year to year, but that may be what has happened. I was going to buy a CarChip but I think I need to quiz them first.

 

[MicaBlue03]

Reply from the CarChip folks

Looks like CAN (for the '05 4Runners) will be supported in CarChips in a few months or so. No exact prediction.

 

[toyoboy]

The ecu on this vehicle is pretty safisticated (did i spell that right ) If it finds a misfire , your check engine light will light and code will be stored and inform you which cyclinder is misfiring. but you will need to determind what is the cause, fuel, ignition or mechanical. but in your case the problem may be too fast for the ecu see that there is a misfire. that is why your techs are having a problem finding it. so i would recommend switching gas company. if you are a regular to one station near your house, try another station, i like chevron. you can also remove your spark plug and compare each one, they should all look similar. same with your coil and wires. give those a try and tell me what you find.

 

[MacVay]

Toyoboy,

Amazingly, it was the gas! It is funny, I started to change where I fueled up when I received my 4Runner. Here in Canada, I used to go to Petro-Canada exclusively but I started going to Sunoco and this is where the problem was. I have filed up a few days ago with Petro-Canada gas and the problem is gone. The idle is now as smooth as butter.

Thanks for all your suggestions. I am just glad it has worked its way out because I know I would get no love from the Dealer.

Cheers,