dandog96

Hey all. I'm a new member but an old lurker to these forums. Recently purchased a ES300 and have been facing a misfire type of issue. For the life of me I can't figure out what is causing it. Any help would be greaaaatly appreciated. It's a 97 with only 105k miles on it.

Here is an extreeemely thorough rundown of what I have done thus far:
Symptoms: Car runs rough with an occasional misfire code. Oil light also comes on. There is also a smell of gasoline from the exhaust. The code that was read came from cylinder 2.
-Inspected spark plugs. Looked to be new. Attempted to switch the place of the spark plugs on the front bank to see if this helped. It did not.
-Coil packs tested next. This was done by changing the place of the coil packs among each-other (cylinders 2, 4, and 6). The car continued to run rough. Then the coil packs of the front bank were sequentially taken out to double check which cylinder was misfiring / causing the rough engine operation. When the coil packs of cylinders 4 and 6 were lifted up (without disconnecting) the rpm's changed. However when the coil pack of cylinder 2 was lifted up the rpms did not change suggesting there was a problem within this cylinder.
-Next the injectors were tested. A stethoscope as used to listen to the sound of the injector when the engine was running. The injectors of cylinders 2, 4, and 6 all had proper opening and closing noises. Next we removed the injectors of the front bank, visually inspected them, connected a 9v battery to each to see if they were functional (open / closing noise). Injector 2 however looked a dirtier and more gunk filled than the rest. The injectors were cleaned with carb cleaner and then injector 2 was moved to cylinder 4 and injector 4 to 2 to see if the injector was the cause of the misfire. It was not. The car and cylinder 2 continued to run rough.
-The fuel pressure was tested. This was done by slightly loosening the bolt going into the front fuel rail as the car as running. A strong spray came out.

So far the coil packs, spark plugs, injectors, and fuel pressure don't seem to be the causes of the problem.

Important:
The MAF sensor was cleaned with carb cleaner. Antifreeze is present on the inner sides of banks 1 and 2 (crystallized). This suggests that the engine may have previously overheated. The gaskets look pretty new (very clean and visible looking at the head). The wires going from the front coil packs to the rear spark plugs are new. A small piece of tubing prior to the intake manifold was replaced because it had a small hole. Compression was tested on the front bank cylinders. The values were taken once when the engine was cold and once when it was slightly warmed. When cold the values were around 135 and identical for the cylinders 2, 4, and 6. When (slightly) warm the values were around 165.
The oil light is worrisome. The oil itself appears to have been changed recently as it is clean and there is a good level present.


Thanks everyone!

JetsonES

Maybe the oil pressure sensor is going bad.

fortitude

The oil light coming on - I believe there are two indicator lights - oil level indicator & oil pressure indicator light. Which one is coming on in your car?
Can you determine the COP for cylinder 2 is actually sending energy to spark plug? I read you rotated COPs so the coil itself is functioning, but could it be the signal before the coil for cylinder 2?
The mis fire code - does this happen immediately when car is started or it occurs later when the car warms up?
Does the engine oil smell like raw fuel?

dandog96

Thanks guys for the prompt replies. It is the oil pressure light. The misfire starts as soon as the car is started. The spark plug on cylinder 2 is definitely getting energy as the portion of the coil pack going inside arched against the body of the head as it was being taken out. I'm kinda stumped:/

fortitude

If the existing oil in the car was from the previous owner, I recommend changing the oil and filter ASAP. If that has no impact on oil pressure light, then aim your focus on that first. If the engine is starving for oil while you are diagnosing the mis fire issue, that could lead to a very expensive fix.

INNOUTFAN

Had a similar issue without the oil pressure light. After checking all of the items you tested, and thinking I had a bad injector it was a rear spark plug wire from the coil pack on the front cylinder. As you know these are almost impossible to get to without removing the plenum. Replaced all three rear cylinder wires and plugs while I was at it. Runs great again. Good luck

dandog96

Thanks for the advice. However, those wires are new, as are the plugs in the rear bank...
On a different note, I can not tell if the oil smells like raw fuel. Doesn't seem to.

mooseboy84

I would still say you have a fuel injector going bad. You say you switched it around, but did you clear the code?

Having had a few fuel injectors go out, I know the car will start having a very low rumble detonation before a CEL will come on. Also, smell of gas in the exhaust means its too rich somehow, which could be a leaking fuel injector. If you pulled the fuel injectors, sometimes you have to replace ALL the o rings on the side of the rail you pulled, because they moving the old injectors can make the old rubber crack and start to leak etc.

As far as the oil light, driving with oil light on is a bad thing, the engine will be starved for oil and then go bad within seconds if the flow gets too restricted. This happened to me on a car, not an es300, but it can and will happen with any internal combustion engine. Once your bearings are gone you need a new engine.

OR, it could be...

I am not sure what year vvti came, 97 or 99, but if your car is VVT-I (should say on valve cover) this could also potentially be causing the oil light. Variable valve timing adjust the timing of the camshafts with the oil pressure. Obviously if oil pressure is low, it will mess up the cam timing and will cause the car to run rough.


Also look at the oil cap and look into the valve cover and see if you see sludge. If youre up to it, you may want to pull that front valve cover and see if the engine has any sludge build up in it.

Before you do all that, you need to check oil pressure first. Borrow or buy a guage and test it, It should be over 40psi at idle.


What you could do for a cheap test of about $20, get an el cheapo walmart filter, and buy 20w-50 oil. This is very thick oil and will raise the pressure, see if the oil light goes away and if the engine runs better.

fortitude

I found in a previous posting a link to the FSM
https://www.clublexus.com/forums/es-...-fsm-tsbs.html

when you follow the link for the FSM in the above post it will open a table of content page. 1997 Lexus specific link is located at the bottom of the page.
Once unzipped, go to Diagnostics PDF. Large document with 584 pages. Go to page 56. Shows diagnosis mapping for misfire.

fortitude

In that same zip file go to Sequential Fuel Injection pdf - that document discusses fuel injectors and fuel pressure

mmatheny

Also those engines are famous for plugged oil channels - there was even a TSB that came out, and my '01 ES had the engine rebuilt at the dealer before I bought it because of that issue. I ALWAYS run oil flush in the engine for 5 minutes before I change the oil. Also, get some Marvel Mystery Oil and put it in the oil - they say to replace a qt. of oil with a qt. of it. It will keep those oil channels clear.

dandog96

Lot of helpful advice. Been busy lately and hadn't had the chance to reply. Went to the Lexus dealership and got a service history on the car. The last record said that the customer (previous owner) said that they were getting a misfire code, took it to another shop that replaced front 3 coil packs and spark plugs, the misfire persisted. The car was then given to a Lexus tech who verified the codes, found the oil pressure light, removed the front valve cover, and found cam bearing caps melted on bank 1 head and alot of metal debris on the engine.

Is it even worth putting more effort into this engine at this point? Also, I was wondering one thing. I do not have any contact with the previous owner but my mechanic told me that the engine that is currently inside the car appears to come from a junk yard. This does appear to be the case as it does have writing on it that looks like the type seen at a junk yard.

The car itself is in great shape. Literally like new. If i were to get a replacement engine, would just the non-vvti engines be compatible? Or can I put in a newer 1mzfe?

mooseboy84

I do not believe vvti and non vvti engines are compatible, because the ecu reads inputs to adjust the timing from the oil pressure. Used engines are too cheap to put money into that burned up engine. Unless its something that can easily be bolted on (which its not) then the price cant justify any type of work. And with cam bearings melted you would probably need new heads and machine work. which would cost more than the value of the car.

I would look for an engine from an importer or wrecker. I have seen 1mzfe for as low as $600 in my area (most are 800-1k), and if you find an engine that is under 150k I would just go for that and buy from a place that has at least a 90 day warrant and low restocking fee. Search on craigslist in your area and also car-parts. com for engines.

dandog96

So I had a mechanic remove the valve cover gasket and just take a look at the inside of the tap part of the engine. This is what we found. I would rather fix this engine if there is any hope for it than replace it... By the looks of the attached pictures, do you guys think there is any hope that it can be cleaned or something and that it will run. Like maybe doing a kerosene flush?

I know it is a little far out but I don't think that I have much to lose.

Zacharias

I'm a noob so my advice is of a general nature, based on my own experience on the rebuild work vs. used motor decision see-saw, on other marques. I have taken both routes in the past and my advice is....


Get a used motor. But look around for a reputable supplier, even if that includes going to one out of town. By reputable I mean one with a meaningful guarantee, that deals in at least a semi-professional way.

Even reputable suppliers sometimes sell a bum engine, it happens, and when it does you want to have a reliable and known company to go back on if it the used motor has to be replaced. Your local Bob the Wrecker likely won't pay for any exchange labour... and not even have another engine to give you.


There are even some (or were, maybe this has changed with time) whose guarantee includes the labour charges for the second change, if the original engine they supplied is no good. Also some sell this as "insurance" for a couple of hundred extra, IIRC that extends the engine warranty to a year or even two.



Just another $0.02.