'00 Avalon Shudders at Idle in Drive

[IamJon]

Hello,

When I am in drive from a stop (automatic transmission) and ease off of the brakes (no throttle) the car shutters as it moves forward until I completely let off the brakes and let the car freely build up speed (still no throttle applied). It is the same feelling you would get with warped rotors but the brake pedal is not pulsating and there is no pulsating in the brake pedal when brakes are applied at any speed. The shuddering/pulsating also occurs when stopping when car approaches 0 mph.

Any suggestions as I don't trust any mechanics unless I have a clue first.

Thanks in advance!

[fourwheeler]

I'd check the wheel bearings or to see if a brake caliper is not releasing as it should.

If you have access to a jack and jack stands, lift the car up just enough to get the wheel off of the ground. Grab each tire at 6 and 12 and try to move the by pushing on one side and pulling on the other. If there is any wiggle, suspect a wheel bearing. Also, spin the tire by hand to see if it moves freely. Any grinding, suspect wheel bearings. Also, pay attention to how the rotor spins, does it hit at only one point as it spins around. Are the brakes releasing? The wheel should be fairly easy to turn by hand. Repeat for the other 3 wheels.

This should help if you find a problem on what to tell a mechanic and to make you feel like you aren't being ripped off.

[IamJon]

Thanks so much for the advice. I haven't had a chance to check out how well the wheels spin yet but earlier today I saw the check (engine) light flash a couple of times. I checked for codes and saw a pending P0305 "cylinder 5 misfire". Now the typical set of lights (check, vsc, vsc off) is lit and P0305 is now set. I purchased spark plugs for the last tune-up/emissins test but didn't put them in yet. I am going to put in the new plugs first and see if it fixes the problem. I will update this thread with my findings

[IamJon]

Spark plug #5 had a rather large gap. I smashed it down a little and cylinder 5 misfires went away and did not come back after code was cleared. I changed 4 of the 6 spark plugs (2 look like I need to pop off the intake manifold to replace, thanks toyota). The car runs a little smoother but the pulsating still exists and is synchronous with engine RPM.

One thing to note is that the exhaust damper fell off a couple of months ago. Is it possible this tuned mass is to eliminate this issue? Has anyone experienced any changes in their car's behavior (vibrations/sound) after this thing (damper) falls off or after changing the exhaust components to aftermarket ones, thus eliminating the damper altogether?

Still yet to check the rotors/wheel bearings.

[thattoheath]

Check out the spring mounts . There is a TSB on these mounts on this generation. I had the problem at 35000 miles and the local service manager told me that "they all do this" I didnt belive him and got them to replac the springs under warranty but 500 miles later it came bck. I am now at 85000 and it still shudders like a binding noise at low speed, specially when reversing or truning, into or out of the edge of a drive way on full lock. This apparently is the spring settling into the spring mounts under this torque and my local dealer says no matter how much these mounts are tightened this generation still does it. It drove my wife crazy so I am stuck driving this car but the good news is that it has got no worse over 50000 miles. Braking does help while at low speed as presumably the torque is changed on these spring mounts /brackets .Anyone else know anything about this front end binding shuddering noise at low speeds ,when the suspension flexes coming backwards down a drive at the road interphase???

[aznstylez]

Originally Posted by thattoheath

Check out the spring mounts . There is a TSB on these mounts on this generation. I had the problem at 35000 miles and the local service manager told me that "they all do this" I didnt belive him and got them to replac the springs under warranty but 500 miles later it came bck. I am now at 85000 and it still shudders like a binding noise at low speed, specially when reversing or truning, into or out of the edge of a drive way on full lock. This apparently is the spring settling into the spring mounts under this torque and my local dealer says no matter how much these mounts are tightened this generation still does it. It drove my wife crazy so I am stuck driving this car but the good news is that it has got no worse over 50000 miles. Braking does help while at low speed as presumably the torque is changed on these spring mounts /brackets .Anyone else know anything about this front end binding shuddering noise at low speeds ,when the suspension flexes coming backwards down a drive at the road interphase???

You might want to check your engine mounts and sway bar bushings up in the front.

[aznstylez]

Originally Posted by IamJon

Spark plug #5 had a rather large gap. I smashed it down a little and cylinder 5 misfires went away and did not come back after code was cleared. I changed 4 of the 6 spark plugs (2 look like I need to pop off the intake manifold to replace, thanks toyota). The car runs a little smoother but the pulsating still exists and is synchronous with engine RPM.

One thing to note is that the exhaust damper fell off a couple of months ago. Is it possible this tuned mass is to eliminate this issue? Has anyone experienced any changes in their car's behavior (vibrations/sound) after this thing (damper) falls off or after changing the exhaust components to aftermarket ones, thus eliminating the damper altogether?

Still yet to check the rotors/wheel bearings.

Why only changed 4 spark plugs? And what kind of spark plugs did you use? NGK or Denso? I once put in Bosch Plus 4 Platinum in my 01' Avalon, 2 weeks later the car started shuddering at low speed while at the light. It was misfiring. I changed to NGK and and everything was all good afterwards.

[nosretep]

You don't need to remove the intake plenum to change the plugs. I also thought i'd need to do that when I first looked at the back cylinders, but there is room to disconnect the wires to the coils, remove the coils and with a combination of the proper length extensions and a universal joint to remove and replace all plugs on the back cylinders.

[IamJon]

New Plugs are NGK IFR6T11.

I replaced the PCV valve (was sludged) and PCV hose (was cracked). The car runs well cold and idles well cold. I will get around to changing the other rear plugs as I get a chance. Cleaned the MAF with CRC MAF cleaner.

When the car runs for a good while and heats up it starts to idle rough and sets the P0305. Last freeze frame indicated:

Control Module
$10 ISO 9141-2
View Freeze Frame
DTCFRZF P0305
FUELSYS1 CL
FUELSYS2 CL
LOAD_PCT(%) 22.7
ETC(°C) 185
SHRTFT1(%) 0.0
LONGFT1(%) 0.8
SHRTFT2(%) -0.8
LONGFT2(%) 10.2
RPM(/min) 633
VSS(km/h) 0
IAT(°C) 77

What is curious is that the longfueltrim for bank 1 is always 10% less than bank 2. If bank 2 is 0, bank 1 is -10. If bank 2 is 5, bank 1 is -5.

I also checked the following:
Fuel pressure at injector rails - OK
IAC passes TE1-E1 jumper test (idle raises to 1000rpm for ~5 sec)
Cylinder 5 compression 145PSI
Cylinder 6 compression 170PSI

Note: Does not appear to "idle up" when A/C is engaged but passes the jumper test. Compressor cycling causes idle to dip.

Any advice would be appreciated

[IamJon]

Well, since no one has chimmed in, I have tried a few more things.

1. Cleaned the IAC.
2. Rechecked the compression on cylinder #5.

dry ~140PSI
wet ~180PSI (3 sqirts of SAE 30 down the plug hole)

Car still runs poory at warm idle. Looks like some stuck rings.

There is no resistance specification published for the motor on the IAC used in the 2000 Avalon (specification is NA). I am under the assumption the DLC 1 test is the defacto method used to determine the IAC operation/function.
Is this true?
Can anyone verify this? (take resistance measurements on a known good IAC on a 2000 Avalon XLS and post them. I will then follow up with mine)

[ChiTDI]

Jon - You seem well versed around an engine. Is this car new to you, and/or do you know the service history? I ask because they are known sludge producers, and specific cylinder diagnosis is sometimes complicated by overall engine condition. The new PCV and plug should start the slow process of buildup removal in #5 if there is any. I'd check the coil on that cylinder too.
The IAC motors/valves are historically an issue with these engines too. Mine failed without giving a CEL or code. Food for thought. Failed on the electronic side so no cleaning would have helped.
Good luck and thank you for posting the freeze frame results. That doesn't show up here too often.

[IamJon]

Chi, I have had the car for 7 years. I had it serviced by others up until now. I got lax with the oil changes. Used only dino oil. It is the wifes car so it sits and idles for long periods of time to warm up in the winter. I am in part at fault for the problem but never encountered an engine that was so sludge prone before. I swapped coils #5 and #6 and the misfires on #5 persisted. It is possible more of the cylinders in bank 1 may have low compression but have yet to check. I understand some of the IAC problems and have not excluded it as a culpret. The IAC does pass the onboard diagnostic that is triggered by jumping TE1 to E1 in the DLC 1 connector (raises the idle to ~1000RPM for ~5 sec). I see that this IAC (2000 Avalon) is not the same as the 2000 Camry V6 IAC just by compairing part numbers at an aftermarket supplier. This IAC motor/coil may have other circuitry in the housing that makes a simple resistance measurement not possible. I just don't want to buy an IAC, install it, and find out that is not the root cause.

Thanks for your reply.

[maun]

My two cents on your shuddering problem:
Your numbers on the compression between 5 and 6. The theory is the compression should be within 20% of each other and these numbers are on the edge of 20%. And your number on the bank 2 longterm ratio of !0%. ARe the 5 & 6 cylinders on the bank 2 side? If they are then these two sets of numbers may have something to do with the shuddering. One side of the longterm correction should not be too much different than the other side. I think you need a spark test and test of the fuel injection. A quick and dirty method of the fuel injection test is put a long screw drive on the injectors and listen for any difference between injectors with the engine on. I am assuming that you do not have stethoscope. To test the spark you need a noid light that attaches to the ignition to see if there is spark up. There is also a way to test the spark by not using the light, but if you do not know the method, the computer will be affected.

hope this helps,
Norman

[IamJon]

Updates:
I have tried a couple of piston soaks on cylinder 5 with little improvement in how it runs. I will have to do a compression test to see if the compression is any better.

I got around to replacing the spark plugs on cylinders 1 and 3. The most difficult part was removing the cylinder 3 ignition coil connector.

The IAC is not a simple motor for this vehicle. As such, a simple resistance measurement cannot be done. I observed the IAC control waveform with an oscilloscope and replicated it with waveform generator. I was able to "twiddle" the idle speed by changing the duty cycle of the waveform. I suspect my IAC functions as it is supposed to.

It runs a little better with the additional new spark plugs.
It gets around 30MPG on the highway.
At highway speeds, the fuel trims (bank 1 and bank 2) are the same. I didn't get a chance to evaluate the trims after a bunch of around town stop and go driving.

Maun,
I don't have a stethoscope. I tried listening to the injectors with a long screwdriver and they all sounded the same.
Cylinder 5 is in bank 1 and cylinder 6 is in bank 2.
I don't have noids but I have tried removing the ignition coil connectors and this made the engine run worse. This created fault codes for each ignition coil in the computer.
I decided to swap all of the ignition coils between bank 1 and bank 2. If either was problematic from bank 1 they should now cause a problem in bank 2.

I removed each of the OCVs. There were no filters and there were small chunks of carbon blocking some of the holes. I cleaned them as well as I could and tested them to make sure they worked.

My next thing to try is to swap the A/F ratio sensors if the cables will allow. I doubt they are the problem but it may be worth a try.

No MILs since I changed the other two spark plugs but it's only been 2 days. Sometimes it takes a couple of days for the faults to occur.

I am running out of time and options. The vehicle tag expires the end of this month and cannot be renewed without passing an emissions test.

[ChiTDI]

Careful when swapping the A/F sensors. There is history of them stripping and you getting the pleasure of installing new exhaust manifolds.
Are you getting any codes? Do you think you'll fail the emissions as is?