From: Michael on
A friend said her '00 or '01 Lexus (6-cyl.) occasionally gradually
loses power on the highway. While pressing the accelerator with
constant pressure, speedometer will slowly lose speed.

What could cause this?

From: ransley on
On Oct 29, 2:42 pm, Michael <mrdarr...(a)gmail.com> wrote:
> A friend said her '00 or '01 Lexus (6-cyl.) occasionally gradually
> loses power on the highway.  While pressing the accelerator with
> constant pressure, speedometer will slowly lose speed.
>
> What could cause this?

Alot of things can cause it, mine was a bad transmission.
From: john on
Did the engine RPM gradually increase as in a transmission flare? Does
the engine rev fine in idle?

Among the causes I would suspect the transmission as well. 00-01 could
be using one of the two transmissions. One is the more reliable Aisin
A541 series, the other is the clunker Aisin U140 series. Check one of
the stickers near the door (?), it should tell you.

When was the transmission fluid and strainer last changed? I'd check
the ATF condition and level, and then consider dropping the pan,
change out the strainer/gasket, and maybe refill with a high mileage
ATF, like Valvoline Max. This fluid is compatible with Dexron III or T-
IV (Mobil-3309).



On Oct 29, 11:42 am, Michael <mrdarr...(a)gmail.com> wrote:
> A friend said her '00 or '01 Lexus (6-cyl.) occasionally gradually
> loses power on the highway.  While pressing the accelerator with
> constant pressure, speedometer will slowly lose speed.
>
> What could cause this?

From: Michael on
On Nov 1, 8:54 am, john <johngd...(a)hotmail.com> wrote:
> Did the engine RPM gradually increase as in a transmission flare? Does
> the engine rev fine in idle?
>
> Among the causes I would suspect the transmission as well. 00-01 could
> be using one of the two transmissions. One is the more reliable Aisin
> A541 series, the other is the clunker Aisin U140 series. Check one of
> the stickers near the door (?), it should tell you.
>
> When was the transmission fluid and strainer last changed? I'd check
> the ATF condition and level, and then consider dropping the pan,
> change out the strainer/gasket, and maybe refill with a high mileage
> ATF, like Valvoline Max. This fluid is compatible with Dexron III or T-
> IV (Mobil-3309).
>
> On Oct 29, 11:42 am, Michael <mrdarr...(a)gmail.com> wrote:
>
> > A friend said her '00 or '01 Lexus (6-cyl.) occasionally gradually
> > loses power on the highway.  While pressing the accelerator with
> > constant pressure, speedometer will slowly lose speed.
>
> > What could cause this?


Ok, interesting... I'll tell her to change the trans fluid.

She said her husband put in some oil additive and that improved things
a bit. So I suspected engine sludge, and recommended 5W-30 synthetic
oil next change...

Michael