iceblast

Hello,
I have a 2007 ES 350 with 41K miles (67K Km), and I feel like the engine is quite laggy/ losing the 'pep' it once had. Is there any maintenance items I should be looking at? (especially coming out of a winter season).

I am thinking fuel rail line cleaning, spark plugs, air filter, etc. Not sure where to start. I have been told there is no serviceable fuel filter...

Strangely, I have also noticed when I fill my gas tank, there seems to be better pressure in the fuel system and the car runs with what feels like 20 HP more. This lead me to believe I have some issues with the engine as I have experienced this on some older cars I have owned, but wouldn't expect this here.

Any suggestions? Thanks!

garsarno

I would look at the spark plugs and air filter to replace. Also, gas is cold from the ground and when it is in your car, you receive a minimum power boost because of the coldness. Drag racers used to (or still do) run a chiller called cooled can to chill the gas before it hits the engine, hence giving a power shot of cold gas to the engine.

iceblast

Air filter will be easy...
How should I test the plugs? I don't have a torque wrench and don't really want to start monkeying around with them.

I think the service manual said to change the plugs at 119K miles (192K Km), so why would mine be so gummed up so quickly?

oldgrump

Does this car get a "good high speed run" on an expressway once in a while? If not, and you have no engine check light on (or flashing) and no warning messages, then fill the tank with a brand name premium gas (preferably one that has no ethanol......Shell here on the coast has 91 octane with no ethanol, not sure about Ont.), check that the engine oil level is at or near the Full mark and that the coolant level is between the Full and Low marks........then take the car for about a one hour drive on an expressway and give it a "good run" including a few "kickdowns" to get the RPM over 3000 or so for a few seconds each time. Has there been a consistant decrease in fuel mileage that has gone along with the perceived performance issue? Has the hot idle RPM changed or is there any noticeable shaking or vibration? It is highly unlikely that the spark plugs themselves are the problem.

iceblast

I take the highway all the time, although not more than 20 mins at a time...
I run 91 octane from various retailers... no ethanol.
Engine oil level fine. Coolant level fine.

I notice when I start the car the RPM is in the 1-1.5 K range for 1 or 2 minutes then down to 700 RPM. Probably normal.

Should do some kickdowns to clear it out... Haven't been too stringent on my mileage lately, should start testing that too...

jbalian

The transmission on our cars learn the way we drive and adapt to that so maybe you've been taking it a bit to easy on her during the rough winter season and it still didnt have time to re-adapt to your new driving style... Try driving it on sports mode and see if there's still a lag!

oldgrump

This car has relatively low mileage and other than your "laggy" comment everything else you describe about the car seems to be normal. If this is really bugging you it might be time to bite the bullet......a knowledgeable person (like a dealer's lead tech) with a scantool that reads sensor/live data and that has access to the shop manual specification values/troubleshooting charts etc. could prove one way or the other if the engine fuel delivery and emissions control sytem is operating as it should be. In the meantime.......I doubt that it's an issue but go ahead and replace the air filter if it's not been changed in a lot of kms. It's not a K&N by any chance? I doubt that the in tank fuel filter is the problem either. Has there been any obvious change in the transmission shifting? Any "hissing" air sound? Intake duct between the air filter housing and the throttle body connected properly?

LexBob2

Not a bad idea about taking it to a professional. You could also consider a Toyota dealership and it might save you a few dollars. The 3.5 V6 is the same engine used in a wide variety of Toyota models.

iceblast

Good suggestion with the scanning tool...

The filter is OEM. I will probably replace it with an OEM one too.
No hissing sounds (i.e. air leaks).

When I say 'lag' I just mean, there is a half second pause between foot to the accelerator, to the RPM's moving responsively, I find that to be sluggish, but it may be normal for these cars. I just want to make sure I have covered all maintenance points, otherwise it may be the car is just simply aging. I haven't driven many other 350's.

I test drove an 09 maxima prior to buying this one, and that thing was responsive!! Maybe a more sport oriented car, and slightly newer as to why I noticed this difference.

Macklin

That is a classic characteristic of the '07s. There were many threads about it back in the day. And it is my top complaint about my so far reliable '07.

Knock, knock, knock...

mlacomb

I drove a maxima for a week in Chicago, is a sporty setup a compared to our luxury cruisers we have.

LexBob2

Good catch. If you do a Search here, there is a lot of information on the drive by wire throttle which was new in the '07's. I had a 2010 after my '07 and the throttle response was smoother in the later model.

oldgrump

Throttle "tip-in" (the throttle plate's sensitivity to the driver's input) can vary somewhat from car model to car model. The sensitivity (the rate of travel, and the amount of travel when the gas pedal is moved) on some cars is adjustable (i.e. more "sensitive" in Sport mode for example), or it may be adjustable with an ECM "update". A few years ago a new model year Infiniti G35 got some owner compaints ("it's jerking my passengers" kinda thing) because of an overly aggressive throttle tip-in, which I believe Infiniti addressed with an update. But as far as our cars go a scantool can verify if the throttle is responding correctly to the throttle pedal position sensor (particularly as the OP seems to indicate a change in his car). My 2011 sure doesn't have any throttle lag.

iceblast

Boo ... I've come to accept that the ES 350 isn't that sporty, despite its looks lol. Oh well.

I'm not sure i wan't it that responsive after all. I mean the car does have power.

UPDATE: I swapped out the air filter with another OEM one and the old one was decently dirty and all puffy. I think I have gained about 5-15 HP, and the car does seem to go more aggressively when I give her. I'm content with where I am at so far.

I'm planning on dropping the car off at the dealer for an alignment, and I plan on loaning a newer year ES to compare.

jcat_350

You didn't gain 5-15hp by swapping an air filter.

67k miles you should be looking at spark plugs to ensure they don't need replacement. Running a quality fuel system cleaner (techron, Lucas) should also be on the list. Maybe even clean the throttle body while you're at it. I feel as though a failing throttle position sensor would cause MUCH more issue than you're describing.

Another idea is to reset the ECU, then go out and drive the hell out of the car. That'll reset the self-learning feature that has softened your throttle response.