'07 V6 - engine shaking on highway under load

[Agent WD-40]

I'm having a perplexing problem. I have a 2007 Camry SE V6 with 75k miles and from time to time the engine really starts shaking under load on the highway. It seems to come and go so it is hard to figure out exactly what is causing it. It seems to happen after the vehicle has been driven 30+ minutes on the highway though.

It is an RPM dependent shake or vibration (shakes more at higher RPMs). It feels like a really out of balance wheel, but the more you accelerate or if you go up a hill it gets worse. If you let your foot off the gas or drop out of cruise control it smooths out. It will stop after a few minutes though and return to normal.

Anybody else experienced this? I cannot tell if it is a transmission or engine problem. I'm guessing engine because it will do this in any gear on the highway. It has been happening the last 2 months or so. There is no check engine light. I haven't plugged a scan tool in to check for codes yet though.

[gdanaher]

I'd take a hard look at the upper engine mount for starters. You can pull that one and examine it off the car. It might be a lower mount, but the top one seems to suffer from engine torque more so it often is the first to go.

[Agent WD-40]

Originally Posted by gdanaher

I'd take a hard look at the upper engine mount for starters. You can pull that one and examine it off the car. It might be a lower mount, but the top one seems to suffer from engine torque more so it often is the first to go.

What exactly should I be looking when I get it off?

I might be a little dense or perhaps am not aware of how these behave as they fail, but if the mount was going bad wouldn't the engine vibrate all the time rather than a vibration that comes and goes?

[JohnGD]

Does the vibration go away when you shift into neutral at highway speeds (on a safe stretch of the road of course)? Even if maintaining the same vibrating rpms I would suspect things will smooth out when you shift into neutral. Just be very careful not to shift into R or P, while moving.

At the rpm where the vibration happens, does the engine vibrate if you rev it in the driveway to those rpms? Use parking brake and exercise all precaution.

If no to both the above then my guess is not with the engine but probably with the transmission or the drive axles.

When was the last time the transmission filter and ATF were changed? It's good that you haven't experienced other problems with the U660E transmission. The clunker primarily is known to flare.

Originally Posted by Agent WD-40

I'm having a perplexing problem. I have a 2007 Camry SE V6 with 75k miles and from time to time the engine really starts shaking under load on the highway. It seems to come and go so it is hard to figure out exactly what is causing it. It seems to happen after the vehicle has been driven 30+ minutes on the highway though.

It is an RPM dependent shake or vibration (shakes more at higher RPMs). It feels like a really out of balance wheel, but the more you accelerate or if you go up a hill it gets worse. If you let your foot off the gas or drop out of cruise control it smooths out. It will stop after a few minutes though and return to normal.

Anybody else experienced this? I cannot tell if it is a transmission or engine problem. I'm guessing engine because it will do this in any gear on the highway. It has been happening the last 2 months or so. There is no check engine light. I haven't plugged a scan tool in to check for codes yet though.

[Agent WD-40]

Originally Posted by JohnGD

Does the vibration go away when you shift into neutral at highway speeds (on a safe stretch of the road of course)?

At the rpm where the vibration happens, does the engine vibrate if you rev it? For example, put it in neutral on the highway and rev the engine to the higher rpms where you experienced the vibration. Just be very careful not to shift into R or P, etc. Exercise precaution.

If no to both the above then my guess is not with the engine but probably with the transmission or the drive axles.

When was the last time the transmission filter and ATF were changed?

I cannot recall if I tried putting it in neutral. I have tried putting it in a different gear at the same speed and the vibration will get stronger. It definitely varies with RPM, not speed.

The vibration is most noticeable with a load on the engine. Say 70 MPH, about 2k RPM and driving up a slight hill on the freeway. If I let off the gas in that situation the vibration will subside. When this happened yesterday I put it in "S" mode and shifted to 4th and the vibration grew stronger and faster (while holding the same speed or just a slight acceleration).

Because of that this is why I think it is engine, but I could be wrong.

I have never changed the ATF or the trans filter. I was told it was a lifetime type fluid and changing it wasn't necessary when I got it looked at. They also said the fluid looked clean. This was probably at 65k miles.

[BlackCamSe]

Sounds like a misfire to me. But if it were misfireing it would throw a MIL and cut spark/fuel to the affected cylinders

[JohnGD]

I'd try shifting it into neutral and see if you maintain the same rpm (the rpm will try to spike up as you shift into neutral, so don't redline it). If the vibration goes away in neutral and at the same problematic rpms, then my guess is that it's most likely not the engine.

But BlackCamSE is right, it could be misfires too. I'd think OBD-II can easily pick up the misfires and light the MIL on the dash. See if Autozone or your local parts store can pull any hidden codes free. and this is already a persistent problem, not a random, intermittent thing.

As far as the lifetime ATF fill. Dealer's "lifetime" is sometimes quite different from an owner's car "lifetime". But if the problem is narrowed down to the transmission, then that may be something you'd want to do. IMO newer U-series Aisin transmissions aren't that great.

Originally Posted by Agent WD-40

I cannot recall if I tried putting it in neutral. I have tried putting it in a different gear at the same speed and the vibration will get stronger. It definitely varies with RPM, not speed.

The vibration is most noticeable with a load on the engine. Say 70 MPH, about 2k RPM and driving up a slight hill on the freeway. If I let off the gas in that situation the vibration will subside. When this happened yesterday I put it in "S" mode and shifted to 4th and the vibration grew stronger and faster (while holding the same speed or just a slight acceleration).

Because of that this is why I think it is engine, but I could be wrong.

I have never changed the ATF or the trans filter. I was told it was a lifetime type fluid and changing it wasn't necessary when I got it looked at. They also said the fluid looked clean. This was probably at 65k miles.

[gdanaher]

Originally Posted by Agent WD-40

What exactly should I be looking when I get it off?

I might be a little dense or perhaps am not aware of how these behave as they fail, but if the mount was going bad wouldn't the engine vibrate all the time rather than a vibration that comes and goes?

The engine mount allows for a little engine movement and the connections should be pretty rigid. If anything less than this, or if the thing falls apart when you pull it out, then it is shot.

[Agent WD-40]

Originally Posted by gdanaher

The engine mount allows for a little engine movement and the connections should be pretty rigid. If anything less than this, or if the thing falls apart when you pull it out, then it is shot.

Cool. I'll look at that.

[11LE]

Misfire would also mean loss of power. Do you run into this when the vibrations start?

[Agent WD-40]

Originally Posted by JohnGD

I'd try shifting it into neutral and see if you maintain the same rpm (the rpm will try to spike up as you shift into neutral, so don't redline it). If the vibration goes away in neutral and at the same problematic rpms, then my guess is that it's most likely not the engine.

But BlackCamSE is right, it could be misfires too. I'd think OBD-II can easily pick up the misfires and light the MIL on the dash. See if Autozone or your local parts store can pull any hidden codes free. and this is already a persistent problem, not a random, intermittent thing.

As far as the lifetime ATF fill. Dealer's "lifetime" is sometimes quite different from an owner's car "lifetime". But if the problem is narrowed down to the transmission, then that may be something you'd want to do. IMO newer U-series Aisin transmissions aren't that great.

I have access to a scan tool at work so I'll see if there are any codes that aren't throwing a MIL. I actually think I might have the dealer service tool at work too. I'm sure the generic tool will read the codes as well as the dealer one, but I guess I'll have to see if there are any other diagnostic functions with the dealer tool.

I thought it might be misfires but I never saw any MIL. I'm assuming even if I had water in my tank from bad gas I would see a MIL go on for misfires. I'm running some HEET through my current tank of gas right now to see if this will help. I'm not holding my breath.

I have lost a bit of faith in the MIL though. About 2 months ago we had to tow the car into the dealer because the engine was shaking pretty bad when I started the car. It sounded pretty bad (loud knocking sound) from outside of the vehicle and was beginning to have a burning smell. The dealer saw the problem and did a fuel injector clean and the problem went away. I wasn't convinced the dealer got the diagnosis correct; they said it was bad gas but didn't flush the tank or change the fuel filter. It just got better after the $250 fuel injector cleaning. The shaking on the highway started after this so I'm not sure if this is related at all.

When I took the car to the dealer for the above problem, I also noticed that my coolant overflow bottle was empty (the top of the radiator was full though). The dealer topped the coolant off and it has dropped since they refilled it about 2 months ago. It is close to the low line on the tank. It was filled to midway before. I don't notice any coolant in the oil though so I'm guessing it isn't a head gasket. Again, I'm not sure that this is even related though.

[Agent WD-40]

Originally Posted by 11LE

Misfire would also mean loss of power. Do you run into this when the vibrations start?

No, I haven't noticed any loss in power when the vibrations start.

[workerant]

Misfire is a common issue with V6 '07. Mine happen at around +60K miles. Out of warrantied so I had to pay it out of pocket. I have a feeling yours is misfire too. But mine started to happen when it's at a redlight. It just shivers for a sec. error coded too.

[Agent WD-40]

Originally Posted by workerant

Misfire is a common issue with V6 '07. Mine happen at around +60K miles. Out of warrantied so I had to pay it out of pocket. I have a feeling yours is misfire too. But mine started to happen when it's at a redlight. It just shivers for a sec. error coded too.

I have the 100k mile extended warranty so hopefully I will be OK. Did you get a MIL on the dash or just a code? What was replaced?

I need to check the car with a scan tool this week.

[workerant]

Light on the dash turned on, that's when I had it checked out... I did a stupid thing and cleared the code. No more clearing code for me... but than no more Camry for me too.