isoenksen

The car suddenly started running rough (1998 ES300).

The symptoms are:
* Runs fairly smooth in idle
* Slight bit of vibration when sitting still and put into gear.
* A noticeable amount of vibration when driving
* With the Over Drive (OD) engaged at between 40 and 45 mph the car shifts into OD (moving normal down the street) and shakes frantically until higher RPMs are reached around 2000 rpm.
* With the OD disengaged the vehicle shows a steady amount of vibration (misfires) throughout driving and no frantic vibrations.
* When driving fast and high RPMs the vehicle appears to run progressively worse.
* I disconnected the battery over night and drove very calmly to work (no more the 2 to 2 1/2 x1000RPM with no Check Engine Light (CEL) and seemed to run noticeably smoother..
* When leaving work, I drove normal and the CEL came back on repeated to shaking around 40/45 MPH drive roughly..

* The automotive told me it was several misfires...no duh.

These are the repairs I have made:
* Replaced the spark plugs
* Replaced the spark plug cables
* Replaced the coil packs
* Cleaned out the Throttle body
* Cleaned out the upper intake manifold
* Cleaned out the lower intake manifold
* Cleaned the oil sensor
* Checked all the hoses
* Checked all fuses
* Unplugged and re-plugged every connector

I read many comments about these allusive Oil Control Values (OCV)
Did they skip putting the OCVs into the 1998 ES300 model?
A real picture would be extremely helpful if anyone has one that shows the OCVs 'Specifically' for a 1998 ES300 because I have looked Everywhere short of pulling the engine for them.

Please advise with you r opinion of the problem.

PuReChaos

What was the exact CEL code that was thrown? That might help others in diagnosing your problem.

As for the OCV, I can't find any documentation about there being one in the 1998 model. Doesn't mean there isn't any, just wasn't able to locate any for you. Hopefully someone with a 3ES will be able to confirm or deny the existence of one.

tomf

The oil control valve, also known as the variable timing solenoid, is part of the VVt-i system. The 1998 ES300 does not have VVt-i. 1999 was the first year for VVt-i on the ES300.

You do not have an oil control valve

310V6

What are the DTC's you pulled out?

isoenksen

Thank you everyone for replying.
I was becoming mentally unstable trying to find those OCVs. Thank God I wasn't going crazy.
I will go get a new reading on my DTCs/CELs codes in my next reply.
Too late tonight.

Again, thank you for the replies...ESPECIALLY learning that the 1998 Lexus ES300 do NOT have OCVs.. lol :-)

isoenksen

Sorry for the delay.

The automotive gave me 2 old and 2 new DTCs:

Old went from 3 to 1
* P0300:Misfire
* P0304: Cylinder 4

New are
* P0171: Too Lean
* P0125: Low Coolant

I apologize that I did not mention this previously because it may have helped you.
After all the repairs, cleaning and checks the engine ran wonderful and purred like a new car. I was ecstatic then after a short while I accelerated the engine around 2000 rpm still with a the new engine purr, then I finally revved it several times to 3 and 4000 rpm. The purr became misfires and the shaking as I first described and still exist.

With these new codes, I'm now beginning to wonder if excess gunk from all the cleaning went into the cylinder to gunk or fowl plug in #4. I did buy all OEM parts and read that I should Not gap the plugs. Was that a mistake?

When I initially pulled the plugs they had a brown burn and not a tan. I contributed that to the gunk I found in the throttle body and intake manifolds. I will be removing plugs 2,4 and 6 to inspect for gunk from the cleaning. Could the original brown burn been from the gas being too lean?

The lean gas and low coolant are new codes. I am about to replace the coolant and oil + filter.

Do you see any correlation or combination of the new CEL codes that may point to a common denominator?
Is adjusting the lean of the gas a difficult procedure?

Please advise which direction(s) you would suggest I take.

Thank you Very much!

tomf

Normally when I see P0171 I think faulty AF/O2 sensor or dirty/defective MAF. But since your symptoms appeared after cleaning the throttle body, I'd try cleaning the throttle body again and the MAF before doing anything else. If you removed the manifolds to clean them, did you replace the gaskets? Is it possible the gaskets are not sealing correctly?

O2 sensors are notorious for failing on the 1mz-fe engine, especially if you are over 100K miles. Taking an optimistic view, replacing the O2 sensor could be viewed as preventive maintenance even if it is not the cause of your problem.

P0171 points to a bank 1 problem but the P0304 points to a bank 2 problem. It seems doubtful that a bad bank 1 O2 sensor is causing misfires on bank 2. But I could be wrong.

Your year ES300 requires an AF sensor for a California emissions car or just an O2 sensor for a non-CA car. Go to the Denso website to figure out what sensor you need.

Another possibility would be a bad fuel injector. You could swap fuel injectors (#4 and another one) to see if the misfire changes cylinders. (I'd try this before replacing the O2 sensor)

Adjusting the lean is done automatically. The ECM is getting bad data from somewhere causing it to adjust the lean incorrectly. You do not manually adjust the lean.

isoenksen

Thank you for the reply.

Before reading your post I was wondering if the single #4 misfiring was from gunk in the cylinder left from the cleaning so I exchanged #4 with #6.
#4 was dark but had signs of firing a little.
#1 and #6 were tan and firing well.

After exchanging #4 and #6 the misfiring was still there so I drove to the automotive and got new readings. I did forget to remove the battery and reset the codes before I went so I won't have a clear reading until tomorrow. For now I got an interesting reading.

P0300
P0301
P0303
P0304
P0125
P0171

Where in the world did 301 and 303 come from. My thought is to remove all the plug for inspection and cleaning. The plugs are OEM so should I re-gap them?
I agree with the idea of changing out the O2 sensor which I will save for last.
I will swap fuel injector #1 and #4 and check to see if the misfire moves.
I had not cleaned the MAF so that is also on the list for tomorrow.

I know these reading are unclear because I didn't reset the DTC/CEL but with the 301 and 303 showing up does that give you thoughts of other possible problems?

I will let you know the results of your suggestions tomorrow.
Thank you for taking the time to help with this, I greatly appreciate it.

isoenksen

I did everything you suggested and things got even better. Thank you!!

The misfire continued and I shuffled all the scenarios between plug, valves, coils, fuel injectors, O2 sensors, WAF, Throttle body....just everything.

Each time I made a change I would reset the CEL, drive until the CEL came back on and then went to the automotive and got a new reading.

It was the fuel injector on #4. Some how I had put #4 injector back into the same hole during my last cleaning so #4 continued to have errors. Today I removed the 2,4,6 injectors just to test them again. I shuffled them back in to find that the #4 misfire was now #2 misfire.

I'll have the injector tomorrow morning and let you know.

isoenksen

First, many thanks to the experts on the Club Lexus.

I replaced the Fuel injector and the car runs great. I'll never understand why the car purred after the in-depth cleaning but I'm not going to try and figure that out.

For those who may follow these threads, If ever you find the need to replace a Fuel Injector it is well worth the time and effort to clean the Throttle Body, Upper Intake manifold, Lower Intake Manifold.

I feel certain that if I had been able to quickly locate the problem to being a fuel injector than I probably would not have gone through the dis-assembly and cleaning. But because I did the ES300 purrs like a new baby.

If I knew how to U-Tube I'd like to have taken a video of 'How I replaced the Spark Plugs and Cables' without having to undo or remove any other parts. Quite simple.

THANK YOU again 'tomf' and 'PuReChaos' at CLUB LEXUS !!!!!!