99 Es300 Hesitation And Poor Fuel Mileage

[denn77]

Hi people, I recently got a 99 es300 and I have problems with it:( Fuel mileage was really bad when I first got it, around 15 mpg and now after a couple of techron bottles, new ngk iridium plugs, cleaned MAF sensor and change pcv valve, I'm up to 18 mpg.

This is 60% city driving. The car has 87k miles. Oh, the maf sensor cleaning made a significant improvement with acceleration. But it is sluggish in the morning. It gets better after it warms up, but still even after it's warm its sometimes sluggish. After reading several posts, I was thinking of changing out both o2 sensors. I test drove several other es300 all 1998 models and they were all quicker than the one I have. What else can I do?

[jweiss]

I had similar problems with my used 2000. I disconnected the battery for a short while so that the computer setting for transmission reverted to factoty setting. If you have the intelligent tranny, it may have morphed to driving habits of previous driver(s). It worked wonders for me.

[camlex]

Hello,

Which year they started intelligent tranny(Smart).

Thanks,

[denn77]

Actually, I've tried disconnecting the battery for several hours to try to get things reset already and it didn't help. :(

[Beer Dave]

If you aren't getting a check engine light, you might want to look into a Motorvac service. Do a search on the forums for more details.

[IlyaIlya]

I think 18 mpg is fine,

I m getting 14-17 in city/highway, but i think its because its NYC and we got ethylene in 87 octane,

I ll try cleaning the pvc/replacing it,

HOW did you cleam maf?

if i do motorvac would i need to clean maf/replace pvc

thanx

[denn77]

Cleaning the MAF was really easy. I just pulled it out of the air intake tube and sprayed electrical component cleaner on the red sensor needle. One side of the needle was clearly dirty. Afterwards I remounted it and thats it. This did make the acceleration smoother. I'm still having the sluggish acceleration problems though.

Will the motorvac clean out the injectors too? Are there any side effects to worry about with the motorvac procedure?

[ford212.809]

I hate to here about your "poor" mileage. I consistantly receive

25-27 m.p.g. with my ES with 122,000 miles. I have done nothing

to the car to speak of to deserve the great mileage. B)

[Beer Dave]

Cleaning the MAF was really easy.  I just pulled it out of the air intake tube and sprayed electrical component cleaner on the red sensor needle.  One side of the needle was clearly dirty.  Afterwards I remounted it and thats it.  This did make the acceleration smoother.  I'm still having the sluggish acceleration problems though. 

Will the motorvac clean out the injectors too?  Are there any side effects to worry about with the motorvac procedure?

←

I haven't done a motorvac on my car, however as I was researching the problems I was having the symptoms were pointing in that direction. Turns out I had a faulty coil on one of my plugs. I recommend you read the forums and search for motorvac service. From what I have seen this is a common issue for people with hesitation and idling problems. My understanding is the motorvac service cleans out the throttle body and associated components, but I don't believe it does anything to the injectors. Based upon other posts in the forum it appears that shops that offer this service charge $100-$120.

Good luck.

[Lexusfreak]

Hi people, I recently got a 99 es300 and I have problems with it:(  Fuel mileage was really bad when I first got it, around 15 mpg and now after a couple of techron bottles, new ngk iridium plugs, cleaned MAF sensor and change pcv valve, I'm up to 18 mpg. 

This is 60% city driving.  The car has 87k miles.  Oh, the maf sensor cleaning made a significant improvement with acceleration.  But it is sluggish in the morning. It gets better after it warms up, but still even after it's warm its sometimes sluggish.  After reading several posts, I was thinking of changing out both o2 sensors.  I test drove several other es300 all 1998 models and they were all quicker than the one I have.  What else can I do?

←

From your description, you have done a 'partial major tune up'. I would change the fuel filter, air filter, have the throttle body cleaned & adjust your tire pressure (assuming this has not been done).

Perhaps a couple of tanks of premium fuel wouldn't hurt either. B)

[IlyaIlya]

FORD: there is no way you will be getting that fuel milage here in nyc in city/highway driving

[ford212.809]

I do not doubt that at all, friend. THAT is why I live in the hills of

Tennessee. ;)

Like I said in another post, I don't know why I get the great mileage,

I try to drive the speed limit at all times. Maybe that is why.... B)

[SKperformance]

motor vac funs through the fuel system from the fuel lines.

so it does clean the injectors.

The throttle body is cleaned manually by the tech doing the service with a can.

Motorvac is the best way to improve gas mialge easily.

Btw you never mention clean the intake /throttle body which is also a problem for cold drivability issues.

[denn77]

You guys have been a lot of help. As I make changes to my car, I'll report any improvements.

Thanks! :) javascript:emoticon(':)')

smilie

[denn77]

I think I have another clue to my problem. It sounds weird but usually after I fill up the gas tank, the car runs faster. I always use Shell or Chevron 87 octane. I've had many cars and never have I seen something like this.

I made an appt with my local lexus dealer for an engine diagnostic for this Wednesday and then over this last weekend I filled up the tank. Now the car runs great, no hesitation.

When I do have the hesitation problems, one of the symptoms is surging I think its called. I would accelerate and as the rpms climb to around 3k I'd feel this sudden burst of power, which is not right.

Thats all I have for now.

[melhadri]

I also experienced bad gas mileage and hesitation. The hesitation drove me crazy until I stopped at the local Advance Auto and purchased me a can of SEA FOAM. Dang, this stuff really works...its a beast.

[KWV]

I also experienced bad gas mileage and hesitation. The hesitation drove me crazy until I stopped at the local Advance Auto and purchased me a can of SEA FOAM. Dang, this stuff really works...its a beast.

←

I have also been experiencing the "really" bad gas mileage hesitation problem. Have cleaned the EGR valve, throttle body, etc - everything except the motorvac.

What is SEA FOAM and how do you use it?

[melhadri]

SEAFOAM works just like fuel injector cleaner. Pop it in your gas tank and thats it. Not sure what it contains but many say that it's used to clean EGR's and other Emission components. Only cost $5/bottle. I apply 1 bottle to the gas tank every oil change.

[denn77]

What is involved in cleaning the EGR valve on a 99 es300? Where is the EGR valve located to begin with?

[steviej]

I started to have hints of surging and the mileage dropped 1-2 mpg.

Solution for me was a new set of plugs.

steviej

[denn77]

Well I finally took my car to the local Lexus dealer to get an engine diagnostic to find out why my car hesitates on acceleration sometimes. Of course, they found nothing and sent me on my way. They didn't charge me for the diag which is cool but I'm still left with this problem.

I want to try cleaning the egr valve to begin with. Can I get some help on doing this? I can't seem to find the egr valve either.

thanks,

denn77

[melhadri]

Take a look at this post: http://us.lexusownersclub.com/forums/index...showtopic=21075

I dont think the 99 ES300's have an EGR valve.

Definitely try the SEAFOAM ($5) and also consider a motorvac service ($80-$100).

[andrecat112]

on the back of the can of seafoam it says you can add it to the crankcase. has anyone tried doing that? any bad effects in doing so?

[Toysrme]

Seafoam kicks the *BLEEP* out of everything else you'll find. Yet costs $5 a can.

It's a top notch fuel cleaner (Better than auto-rx)

I use it in my oil, and transmission. (Add half a can) (Trans-tune is the inverse formula of engine seafoam) It does exactly what it's suppose to do. It dissolves sludge buildups, and eventually starts stripping the baked on varnish.

Change the oil and add then recommended amount. DO NOT SHORT CHANGE IT. Leave it in until the next scheduled change (Same with trans-tune). They don't do much if they don't have the time in the enigne to do so...

The most typical use is pouring 1/3-1/2 of a can in the intake through a vacuum tube to clean the heads, valves, and combustion chamber of carbon build-up.

Crank the engine and have someone rev it to 2000rpm. Pull a vacuum hose off (I like the front valve breather isntead of the brake booster line. The FVB get's better distrobution. The brake booster distributes most of the fluid to the front bank) and insert a funnel. Pour out 1/3-1/2 of the can & immediatly cut the ignition. Put the hose back on.

Let the engine sit 10 min. Crank the engine & let it idle for 5 min.

You will get the most ebarrasingly glorious smoke cloud ever!!! Seriously... You can fill a two-three bocks with THICK smoke. (Sometimes black, sometimes white, older cans will sometimes be light blue - hence the name)

One it's idled for 5 min, drive it until it stops smoking, and be sure to get on the gas while you're driving around to help burn it out.

When it stops smoking you're done.

When adding to the fuel system, wait until you are near empty, and dump in a full can before you fill up.