Athebeast

Hello Everyone! I've come to this forum to seek assistance for a 1998 Lexus ES300 I have. The car has a clean title and previously had one owner (older lady) and had only 70K miles on it when I purchased it a year ago (original everything). I've done my regular maintenance and even had the timing belt and water pump professionally replaced! I've put 15k miles on it since purchase and had no issues whatsoever up until recently, when things went south so so fast (and not just cause I'm from Louisiana). SO to the issue, I was driving one day normally until I noticed a slight shudder in the engine when i hit a certain speed (around 55mph) and I thought it was just low on oil or something so i checked the oil and that was fine. Eventually a check engine light was thrown and i checked it to be a Cylinder 4 misfire. Now i come to remove the spark plug and ignition coil to see that they're both halfway gone!!!!!!!!! MY SPARK PLUG LITERALLY BLEW UP!!!! So anyways i had to rethread the inside of the cylinder and went ahead and replaced all 6 spark plugs and coils which solved the issue.... for 4 days!! And then random cylinders, including 4, have been misfiring!! Also, it has suddenly begun to burn oil at a very rapid pace and the exhaust smoke is so thick and white! And help would be greatly appreciated as I've invested so much into this car and didnt even do anything wrong yet so much is going wrong! Thanks for any help!!!! Attached are images of the spark plug and coil.

Richardsr

Just a wild guess, but maybe your timing belt was installed incorrectly(?).

Athebeast

I highly doubt it as the mechanic who did the repair is highly experienced and has over 15 years of experience working on Lexuses. Also, the issue appeared quite some time after that replacement. And lol screw guessing I've been guessing this whole time I've had enough of that!

Richardsr

What codes are you pulling?

daredeil95

something bad happened; looks like something caused the spark plug to break in the cylinder/electrode fell off or a critter crawled into the air cleaner and made into the manifold/cylinder with some nuts or something crazy. IDK Looks like when plug broke it pushed the spark plug electrode up in the cylinder, broke ceramic and pushed electrode through the rubber coil boot and ground/sparked against the head or engine cover and you have that burnt mess. If it's smoking that bad then you need to pull the head and do a inspection but, if you're paying a mechanic, it will probably be much cheaper to just change the motor. Plenty of used motors online with decent mileage for about $600 bucks or could be as simple as headgaskets at this point, a good mechanic can pressure test at minimum costs and go from there....update post when you find out more information. good luck

Ace20Six

Wow um ok, so after seeing a blown to pieces spark plug I would have instantly went to pulling the cylinder head. Make sure cylinders in the block aren’t scared or look for damaged valve.

Richardsr

I didn’t see the conventional wisdom prepping the head and throwing another plug in there myself, but I’m not a “mechanic” by trade but I knew something catastrophic happened and that’s why I suggested TB problem.

So I started reading up on why coils fail (and explode) and found that extremely worn plugs, old wiring, moisture and cheap gas or the combination of any of them are in the running for causes. And of course when one coil, wire, plug goes bad... the rest of them start showing codes as well, hence the need to clear out the First Code and then proceed.

If the first cylinder showed the damage it did, the prudent thing to do would be to pull the head and at least look for damage to the piston, valves or cylinder wall first. A coil will try and deliver higher output voltage to compensate for higher resistance to spark output caused by moisture, a bad plug, worn wiring to the point of failure or in this case, an explosion. Maybe the old plug couldn’t take the extremely high voltages and the plug exploded at the same time and blew the lower end of the plug into the cylinder/piston head in a molten explosion.

But, I’m not a mechanic and these are “wild guesses”.

LeX2K

I've only seen this happen for two reasons 1) engine was severely over heated 2) cheap spark plugs

The valves cannot hit the pistons for any reason unless a connecting rod breaks.

Athebeast

I'm thinking of loaning a tool from Oreily's or autozone and just doing a compression test myself. I heard if i change the motor i risk the transmission going out since it was used to a different motor. Thanks.

Athebeast

I did put 87 gas when my brother always put 89 so maybe that did it. I didn't think that putting 87 as opposed to 89 could cause a spark plug to explode.

Richardsr

I never said cheap gas did it. BTW, the owner's manual in the 02 ES says to "select premium unleaded gasoline with an Octane Rating of 91 or higher for optimum engine performance. However, if such premium cannot be obtained, you may temporarily use unleaded gasoline with and Octane Rating as low as 87.” I would venture to say your 1998 owner’s manual says the same.

BTW, I run 91 - 93 octane all the time to help reduce engine problems. 87 octane for an engine with 10.5 to 1 compression ration is asking a bit much no matter what computer program is used to run it.

80es300

98 ES300 manual says: Select Octane rating 87 or higher.
I have always used 87 and so don't think that is the issue. Do you know if the spark plugs were original? If not, you may want to check when changed and what brand.

Coldax

Are you sure you used the correct replacement plugs?
And the coils? Just cause they are 'new' does not mean one or more are not bad out of the box.

Richardsr

The 2001 ES300 and Prior Owners Manual States:
Quote:
Select Octane Rating 87 (Research Octane Number 91) or
higher. For improved vehicle performance, the use of
premium unleaded gasoline with an Octane Rating 91
(Research Octane Number 96) or higher is recommended.

The last line clearly states that they recommend 91 or higher.

In 2002 (still the same engine) they changed the wording, and made it even more clear to use 91, and to only temporarily use 87.
Quote:
Select premium unleaded gasoline with an Octane Rating
of 91 (Research Octane Number 96) or higher for optimum
engine performance. However, if such premium type
cannot be obtained, you may temporarily use unleaded
gasoline with an Octane Rating as low as 87 (Research
Octane Number 91)..

Octane Rating is an issue just as much as using substandard parts is an issue. You can get by on 87, but for improved or optimum performance use what Lexus recommends. And we debate knock-off parts vs Toyota/Denso parts here too for the same reason.

Knock Sensors allow for cheap gas by advancing the ignition to it’s maximum so it can be used.

daredeil95

Autozone also has a radiator/cooling system pressure tester which could also be used to check the headgaskets for coolant leaking into the cylinders....especially if your getting white smoke that could be coolant if not oil. As far as changing motors and having issues with transmissions not working is not the case in your situation. Another motor will bolt right up to your trans with no issues. Good Luck