Engine Performance Problems

[chilphil]

I'm becoming a regular.....

Guys, I changed the front and rear valve cover gaskets, timing belt, and plugs (NGK) about 2 weeks ago. I have noticed that the car does not have the same horsepower as it had prior to the work. Also, the engine sounds louder than it did prior, almost as if it is straining as I accelerate and then getting louder in the 2500 to 3000RPM range. Once up to speed the "strain" seems to subside. My gas mileage doesn't seem to be suffering at all after 2 tanks. What could be the cause of this?

Also, if someone can elaborate on this issue as well it would be much appreciated:

When checking the motor oil levels on my car, the dip stick always reads oil half way up the stick (not half way up the fill line - half way up the whole stick). It doesn't matter if the engine is cold or hot. What does this mean? How can I determine if my engine has correct oil levels?

Thanks

[SKperformance]

DID you do the work yourself?

Sounds like the timing belt is not correctly installed and needs to realigned a degree or 2.

You have to wipe the stick once you pull it out then reinsert it to read the oil otherwise it will be coated from the pump.

[chilphil]

No, I didn't do the work myself. I'll talk to my mechanic on Friday. Could there be any other causes for the lack of performance?

Sorry that I didn't articulate myself well enough in my first note. When I stated that oil is half way up the dip stick, that is after wiping off the dip stick every time it is pulled. I am not judging the dip stick on the initial pull.

thanks

[SKperformance]

Ahh not problem.

You need to check the oil first thing of the day before you start the car otherwise it will always coat the stick and be hard to read.

SOme cars are harder than others. But none can be read while the engine is running.

[94LexusES]

Check the oil when the engine is warm. Oil expands when it's hot and contracts when it's cold; different temperatures will give you different readings. Obviously don't check it when its running.

[backwoods lex]

I would definitely not drive the car if there is a possibility that the crankcase is overfilled with oil. Did you get it changed somewhere or do it yourself?

[Toysrme]

You can drive around with 6-7 quarts without a thought. The pan<s> themselves holds around about a gallon. (More for 1mz-fe's on the larger dual pan.).

Three immediately bad things can happen when you have way too much oil:

1) The rotating assembly slaps into more & more oil (Not really a problem, but will decrease power from growing resistance - don't confuse this with your power loss. Different issue)

2) Eventually you'll fill the entire crankcase & no longer have oil circulation as oil has no where to drain.

3) Fluids are incompressible. Piston going down = blowded up

But it takes alot of oil to do that stuff! Not something that would be apparant if it was just over filled.

A quart, or two, maybe three over isn't going to hurt anything. It's just wasted money.

I would bet the cam timing too, or a timing/vacuum problem.

Minor cam timing changes shift the powerband around. One/two teeth either way on either the cam sprocket, or intermesh gear won't change timing too bad. (7.5* for the intermesh gears+any change to the distributor if it's the rear intake cam)

Three teeth & someone that drives the car regularly would feel the change. Anything more than three & you get into running progressively worse.

Intake cam opening VS overlap also makes a huge differance in the sound of the engine.

I agree with sk. I think the first job is to check & re-check the cam timing.

[monarch]

The ES300 owners manual says ANY amount of oil about the Full mark on the dipstick is too much. The manual further states: "Avoid overfilling or THE ENGINE COULD BE DAMAGED."The owners manual also says the oil level should be checked a few minutes after a fully warmed up engine has been shut off.

[Toysrme]

Brandon doesn't really give a *BLEEP* when the oil pans themselves will obviously hold well over a gallon of oil.

So long as the oil pick-up isn't sucking air, and you don't double fill the thing with 10 quarts of oil. Anything in between is ok.

[chilphil]

My mechanic is opening up the timing compartment today in order to inspect the belt and its positioning. He said that he had done many Lexus and Camry's before and that if the belt gets placed on wrong that the engine light comes on. My check engine light hasn't come on, though. He then drove the car and said "yeah, I think it is off a notch or two." Hopefully he'll get it corrected today. I'll post back by next week to let you guys know if it did the trick. Thanks for the feedback.....

[chilphil]

Timing Belt was fine....mechanic did not tighten a hose clamp from the throttle body after doing the initial work... car runs fine now....

thanks

[Toysrme]

Va-va-va Vacuum leak!

Glad it worked out to the best!

[chilphil]

back on topic:

long story as to why I haven't gotten back to this one since April but I'll spare you all the details. This is in regards to the performance issue and not the oil fill level...thanks SK for the nugget about checking when car is cool...made all the difference.

Basically, my car is still having intermittent performance issues. Intermittent meaning that sometimes the car runs and accelerates like a champ. Easy, fluid, comfortable....like the lexus should. But sometimes.....

Problem descriptions:

Feel - sometimes I'll feel a slight vibration in the gas pedal (emphasize slight - for lack of a better description, it feels like a little cell phone vibrating on the bottom of my foot while accelerating). When running well and accelerating easily, my RPM's will get up to about 2500 and then the car shifts. However, when the car is in its lack of performance mode, the RPMS will shift at roughly 2700 to 3000 RPMs. I can also discerably feel that I have to press the gas pedal down further to get the same amount of output.

Sound -I am having a tough time figuring out how to describe the engine tone in writing but it gets considerably louder upon acceleration - I want to use the term grind but feel as if might be too harsh to describe the sound - I'm drawing a blank (note that when I say acceleration, I do not only mean off of the starting block. the acceleration symptoms occur at any point in time that I take my foot off of the accelerator and then back on again).

Power - It feels as if I am running on 5 cylinders about 75% of the time. That is the best way for me to explain it.

Gas mileage affects - I used to get roughly 330 miles per every 3/4 of a tank (I fill up at 1/4 of a tank). I now get somewhere between 290 and 310 miles per tank. These figures are using Regular Unleaded always.

I am tempted to get a 2nd opinion on the settings of the timing belt but wanted to know if any of you had any suggestions that I could do myself?

Thanks

[SKperformance]

Still sounds like timing , also could be a dirty throttle body not helping.

[Toysrme]

Still in agreement. Timing's off somewhere.

BTW while I normally wouldn't address something so old, nor against somene that can't rebut themself...

An Mr2 with a 1mz-fe v6 swap almost blew up in the last month driving on the track. The stock amount of oil wasn't enough to pick-up in the corners once the oil was heated & pumping. So basically... Now everyone with a v6 that races their motor needs to run 5 1/2 quarts instead of 4 1/2 quarts LoL! Soooo... Toyota was wrong again. :) Hope ya still lurking monarch!

[chilphil]

Hey guys, thanks for all of the advice thus far.

I am still having the same issue and have confirmed via a 2nd mechanic that the timing is set correctly.

I am bringing the car back to my main mechanic next week to do a thorough investigation of anything that can possibly rob the car of power. Also, the car has developed a slight hesitation, upon acceleration, over the past couple of weeks.

My question to you all, is what can I tell my mechanic to check in order to make it sound like I know what I am talking about and in order to hold him accountable for checking everything? I want the thing fixed and have been dragging my heels on this issue for too long.

I was thinking Dist. cap, ignition timing (again), o2 sensor, plug wires and some others that I see spoken of in different threads but I either do not know what the accronym means or do not know what their function is:

MAF?

ERG? EGR Valve?

any other suggestions would be greatly appreciated....

[anthonyiez]

Still in agreement. Timing's off somewhere.

BTW while I normally wouldn't address something so old, nor against somene that can't rebut themself...

An Mr2 with a 1mz-fe v6 swap almost blew up in the last month driving on the track. The stock amount of oil wasn't enough to pick-up in the corners once the oil was heated & pumping. So basically... Now everyone with a v6 that races their motor needs to run 5 1/2 quarts instead of 4 1/2 quarts LoL! Soooo... Toyota was wrong again. :) Hope ya still lurking monarch!

i put 5 1/2 quarts in all toyota 3.0/3.3 engines

[justin97]

Still in agreement. Timing's off somewhere.

BTW while I normally wouldn't address something so old, nor against somene that can't rebut themself...

An Mr2 with a 1mz-fe v6 swap almost blew up in the last month driving on the track. The stock amount of oil wasn't enough to pick-up in the corners once the oil was heated & pumping. So basically... Now everyone with a v6 that races their motor needs to run 5 1/2 quarts instead of 4 1/2 quarts LoL! Soooo... Toyota was wrong again. :) Hope ya still lurking monarch!

i put 5 1/2 quarts in all toyota 3.0/3.3 engines

me too it says it is full then hell my 3rz take 5.5 quarts.

[anthonyiez]

what i really prefrer to do is 5 quarts oil and a can of bg moa additive.