Is It An Issue With My 99 Es300 Engine?

[Avneesh]

I've recently got my first Lexus, the 1999 ES300.

While everything looks good in the car, I felt a slight drag in the engine while accelerating on high speed (nearly 60). I mean when I start the car...it accelerate and picks up fast with engine RPM reaching 4-5 mark but when after driving for 20-30 minutes, I try to accelerate, even a deep push on the paddle doesn't take the rpm high and engine accelerate slowly (unlike a V6 engine ). engine heat mark is normal all the time and is not overheated.

Could that be a problem with the filter or throttle ? need advice as I'm new to this. Also need to know whether gas (regular unleaded or premium) makes a difference... Car is having 101K mileage and timing belt was changed on 85K. latest oil change was done 2 weeks back.

Regards

Avneesh

[sur4dude]

I've recently got my first Lexus, the 1999 ES300.

While everything looks good in the car, I felt a slight drag in the engine while accelerating on high speed (nearly 60). I mean when I start the car...it accelerate and picks up fast with engine RPM reaching 4-5 mark but when after driving for 20-30 minutes, I try to accelerate, even a deep push on the paddle doesn't take the rpm high and engine accelerate slowly (unlike a V6 engine ). engine heat mark is normal all the time and is not overheated.

Could that be a problem with the filter or throttle ? need advice as I'm new to this. Also need to know whether gas (regular unleaded or premium) makes a difference... Car is having 101K mileage and timing belt was changed on 85K. latest oil change was done 2 weeks back.

Regards

Avneesh

A couple of things: check trans oil, replace if neccesary. Don't know if it has been serviced. Double check motor oil level (just in case). As for gas I've always used premium. Manual recommends 91 octane or above for "improved performance"

[Toysrme]

I find it unlikely to be filter problem. Air filters don't do anything very measureable either way.

Fuel filters on any modern Toyota are rarely, if ever a problem. Who knows. Anything can happen!

It could be running hot... The gauge just tells you a rough guide as to what the temperature of the coolant exiting the lower intake manifold is. Not the temperature of the coolant at various places inside the engine where it could be overheating & cooling back down later on before it exits.

At any rate... Start by resetting the ECU & drive it like you stole it for awhile a good half hour.

After that, I would run around town until it's having problems & then do a compression / leak-down test to see how the valves/rings are doing when they're hot.

Clean the MAF wire, throttlebody etc.

Check/replace the plugs. (I recommend NGK 5553's on that engine)

While you're definately not confused about the issue & it sounds like there really is a problem. Understand what a "deep push" on the throttle pedal means to the engine. If you're not atleast 75-80% wide open throttle, most ECU's are lallygagging with the fuel trying to keep gas mileage up, so it aint exactly gonna take off like a rocket. ;)

That being said, check/replace the main o2 sensors also. If the A/F ratio is getting off when hot, it'll decrease power.

Like sur4dude said. You may want to flush the transmission fluid out, or atleast do several drain & fills. That'll change all the transmission & differential fluid out. Either way, preventative maintenece.

[abrarcool]

Its normal try to test drive another car of same make and year to verify just go to a dealer like u want to buy it and test drive it ull know the difference if any u could try maybe 2 or 3 if u have the time make sure its 99 though