nech

Hi Guys.

First time posting here.
I've got a 2006 IS 350.
Getting close to 100,000 miles on it now.
I've got a little problem.

It seems that the engine rev will go super high. like to 3500 RPM
during low speeds, and I won't get an power out of it.
Problem seems to be worse when the engine is cold.

Any tips or pointers would be greatly appreciated
Thanks!

Edit with more details:

This is the pattern I'm observing.

If I'm just going normally, not pressing on the gas hard or anything,
I will shift from gear 1 to 2 at around 3000+ rpm
and shift from 2 to 3 at around 3000 rpm .
and 3 to 4 at 2500 rpm.

But not alot of thrust even though the engine is going at 3000+ rpm.
I recall by my faulty memory that I can get to 40mph with out even breaking the
2000rpm mark before. This seems to be no longer the case.

After the engine warms up a bit, the revs aren't as high when going from 1-2 , 2-3 but still
over 2500 rpm.

The check engine light is not on.

snaggle

Sounds like a clutch problem to me. Very similar problem happened to one of my buddies cars. His clutch needed to be replaced.

Did this happen all of a sudden after you drove your card hard or something like that?

nech

Thanks for the quick reply!

I think it got worse slowly and slowly till the point now that I can tell its not something
in my head and its a real issue.

I dunno much about cars. But I drive an automatic. Can I still have "clutch" problems? ("Torque converter" problems, as wikipedia has taught me just now)

Is there a way I can narrow it down and confirm that its a transmission problem?

B16da9

iTrader: (7)

He owns a 350, which is automatic so no clutch.


nech, you're problem could be something as simple as a broken vacuum line or a bad MAF sensor.

I say pop off your engine cover and look at the vacuum hoses to see if any are off or cracked. Also just maybe since our manifolds are plastic it developed a crack.

You also have the possibility that a manifold gasket is leaking causing your symptoms. The way you can test that is buy some carb cleaner and start spraying the manifold around the areas where the two half’s meet and where the manifold meets the head. If the idle surges when you spray an area then you've found the source of your leak.
One other question, does your car have the check engine light on?

nech

Hi B16da9,

Thanks for the reply!
No, the check engine light is not on.
I'll do some research into the steps you've suggested and come back with the results.

I've also updated the original post with more info.

B16da9

iTrader: (7)

Just read your updated post, just to rule out the engine. Does it idle smoothly while the transmission is in “park”. If so does the engine rev without a problem when you tap the gas without any signs of hesitation?

nech

Hi B16da9,

When in Park, the engine doesn't rev. Unless its super cold day. Then the rev will be higher in P than in D gear1. I believe this to be normal behavour.

When I step on the gas peddle, I believe the engine rev has no noticible delay. I'll keep an eye out on that. But the amount of thrust I get doesn't match the corresponding rev that I'm getting.

I did some more googling here and there.
So this is a complete noob hypothesis, but could this be a spark plug issue?
What would be an easy way to tell if its the spark plugs that are failing me?

Thanks again for the reply!

B16da9

iTrader: (7)

I have a feeling that you're having transmission issues. Sounds to me the transmission is slipping which is a sign of the internal clutches going bad.

nech

Oh man, that sounds expensive.
I'm sorta leaning against a transmission issue?
I figured it'll be more of a transmission issue if I'm losing power when it switches gears?
Cause if I keep it in gear 1 or keep it in gear 2 for example,
it still seems like i'm not getting much power.
does that train of thought seem to be on the right track ?

anthrax144

If you haven't changed the spark plugs at 100k miles, it is possible that could be causing some problems. Even if it's not the problem, you should probably change them out. It's no more than a two hour job, just follow this DIY: https://www.clublexus.com/forums/is-...g-service.html.

Gville350

iTrader: (10)

Have you been the only owner of this car? Can you detail what has been done to the car? Have you looked up the service history of your car on Lexus.com via your via #?

GS4_Fiend

iTrader: (22)

Try cleaning the TB and MAF sensor.

Pnthrzrule

Original Poster...good luck with your issue. If you can...please let us know when you get it fixed! We would love to know the root cause of the problem.

fewslowcar

Definitely sounds like a transmission issue. Most likely slipping clutches in the auto transmission.