It's 3.slow that I'm having problem with. After it warms up it starts run to run very rough when driven. When I drive steady, for example @2000rpm on 4th gear it shakes very badly then I have to accelerate or let off the gas pedal. It idles smooth and starts perfectly (cold or warm), it doesn't smoke.

What could it be?

 

anyone?

 

Transmission problem? Broken motor mount? Could be a bunch of stuff. Give us a little more information to work with.

 

transmision - manual works perfectly, motor mounts are fine. This shaking is kind of stumbling, the motor chokes.

 

Sounds like something is happening to the air/fuel mixture. Is the iac clean, air filter clean?

iac= idle Air Control valve

Air filter, the top can be clean when you look at it, but if you pull it out, the bottom can be almost black with build up.

Just gusses from your info.

 

Hmmmm . .. . sounds a little like my 2.5 liter V6. Except that my 3VZE that's running on 5 cylinders (burnt exhaust valve - no compression) runs rough whether it's warm or cold. Mine runs rough up to about 2800 rpm and starts to smooth out. I'm guessing that the speed of the motor (all that heavy stuff spinning around fast) overwhelms the roughness of one cylinder not doing its share.

My truck goes in for its heart transplant on Friday! :bounce2:

 

Glina, do a compression test and let us know the results. A little more information would still be nice... we're all kind of grabbing at straws here. The 3.0 has a very common head gasket problem as Snorkeldepth is hinting at.

 

Head gasket was done 10000 miles ago. As I wrote, there is no smoke, only some white smoke at cold start but it is rather cold here where I live (-5C at night). After few minutes of driving it's not smoking at all even thought the engine is still cold. There is no milkshake in the oil pan, no exhaust gases in coolant. When it warms up it idles perfectly at 800-900 rpm, has no lost of power at all. Only when I drive at constant rpm 1500-2500 it's choking.

 

check your TPS

 

I'll do it on monday. I'm not good with electronic stuff so I have to visit a mechanic.

 

I did compresion test - perfect!
I did oil pressure test - perfect!
I've changed spark plugs (NGK) and air filter, checked TPS, VAF, high tension wires, ECM gives no codes.
It's not better, I would say it is even worse.
Please Help

 

Engine temp sensor? Fuel filter clogged? Fuel pressure?

Mike in AR

 

If temp sensor would be bad shouldn't it throw engine codes (there are none)?

Fuel pressure was checked and it's fine.

Stumbling and choking happens only when the engine is hot.

 

Egr valve? Check to see if it's working properly. It may be plugged.

Troy

 

Egr valve works fine. It was cleaned 2 months ago.
If engine temp sensor doesn't work properly would it turn CEL on?

There is another thing - it idles well 800-900 rpm, but when the engine is hot and I let itidle for some time (ex. red traffic light) idle becomes very rough and drops down to 400-500 rpm. Maybe it will help diagnosis.

 

I need help on this one.

 

bump

help!

 

Try the TPS. Anyone else want to chime in?

Troy

 

The TPS does affect idle, so that would be a good place to check.

Mike in AR

 

Thanks guys, but does engine temp affect TPS? As I wrote above, everything happens only when engine is hot. It starts well (hot or cold), but when it's hot it's choking and stumbling even when driven.