lexslexus

Hi everyone. I'm back again with yet another problem on my LS430 (a well maintained 1 owner '02 with 163,xxx miles). I've had it for a little over a month. For the most part, it's been just as reliable and perfect as you'd expect from an LS.

However, I'm starting to have problem after problem with the engine since I had the Toyota dealership replace my PCV valve, hoses, and grommets a few weeks ago because the hose was brittle and caused misfiring when it rained.

After I replaced that, it was fine for about a week and a half. Then last week, it started vibrating hard out of nowhere along with the CEL and VSC off lights plus the Check VSC message. Got the code read and was told that my #7 ignition coil was the only thing wrong. I replaced the #7 ignition coil and the car drove better than ever until this afternoon.

I let my mother borrow my car. She called and said it was driving beautifully and then, out of nowhere, it started vibrating and the CEL came on. Then the CEL started flashing so I had her pull it over and shut off the car. When I got there, the engine seemed perfectly fine like you'd expect from any LS. Decided to drive to the Auto Zone that was 30 seconds away to get the codes read. On that short drive, the vibration wasn't as strong but the engine felt weaker and there was a faint burning smell.

An employee who's a fellow Lexus enthusiast told me that I had a misfire on cylinders 2,4,6, and 8. Nothing else wrong other than that. He said I could make it back safely on the 2 minute drive home but I'm not taking my chances and I'm currently awaiting a tow truck.

At this point, I'm starting to seriously regret trading in my LS400. For the last few weeks, I keep being told, "That's your only problem. Nothing else is wrong." Yet, new engine problems keep popping up. Will getting a tune up solve my problems or is my engine screwed and I should just trade into another LS430 or 460?

BMW7_LS430

If ignition coil was bad on #7 then odds are that the other coils are not far behind.
I had misfires on another vehicles recently. It was only on cylinder #1 (from V6) but I replaced all spark plug boots and no check engine light again, touch wood. You might try that. I did it myself with parts from RockAuto therefore it was very cheap fix. Not sure if it will fix the issue but worth a try if it is not too expensive.

LS430inDE.

Sounds really strange that all the even numbered cylinders are now misfiring according to the scanner. I seriously doubt ALL the even numbered plugs went bad or the coils are all bad, or a combo of each, ALL at the same time!? I don't believe that. I do believe that something common to all those even numbered cylinders has got to be wrong. I believe all the even numbered cylinders are the passenger side of the engine block. The #7 coil you replaced was the closest to the firewall (aka rear of the engine) on the driver's side. Besides the fuel rail, what else is common to all those cylinders? Could the Toyota dealership have screwed something up? Possibly.

I've heard of the oil control valves doing really funny things to the engine's smoothness and power, but I usually read a code is thrown related to the oil control valve.

Perhaps you can plead ignorance and use some God given talents, and go back to the Toyota dealership and tell them ever since they worked on your car, it hasn't been running smoothly? I don't think a 'tuneup' is going to solve your issue, unless, when you pull all the plugs on the passenger side, they are covered in oil from a leaking gasket? Hmm, might be worth it to see if you can pull a plug boot or 2, and see if there's any oil at the bottom of the boot? That would be an easy check for you, since you already know how to replace the cop/boot!

You were very WISE to instruct Mom to shut off the engine asap when the CEL was flashing!!!

Pull off a couple of the passenger side plug boots and see if the bottoms are dry or if they appear like a dipstick for the engine block and are covered in oil.

mykvr6

do a quick check of all your electrical connectors and make sure none are broken and possibly not making a good connection. I say this because when I worked on my LS with similar mileage I had to replace quite a few connectors because they cracked and broke when I was removing them. I had to replace an injector connector, my MAF connector, a VSC connector, a cam position sensor, throttle position sensor etc. They're brittle and just broke using normal pressure to remove them. I went through and replaced all the ones I broke while doing to valve cover gaskets, pcv, pcv grommet, pcv vacuum hose, an air intake vacuum hose, spark plugs and cleaning the throttle body. Mine runs great, idles smooth. I just mention it because those connectors on mine were all so brittle and there are quite a few connectors that can cause issues if they arent positively locked in.

Daspyda

iTrader: (1)

So, if you will trade, you will lose a TON more money than if you just fixed what's happening.

Firstly, the dealer will give you wholesale, and then deduct for the issues, anyway...

lexslexus

Thanks for your replies everyone. I had my car towed to the Toyota dealership. They're looking at it right now and will let me know what's going on. I have a good relationship with them but my intuition says that they screwed something up when the tech changed everything related to the PCV valve. I never had a problem before that.

I also agree that it's really strange for all the even numbered cylinders to be misfiring. It feels no different than when #7 went bad. Maybe something is going on with the fuel rail? I did notice that any issue I'm having becomes most apparent after I've filled up.

I found some paperwork from last summer showing that the previous owner had codes for the OCV, misfire on 2 even numbered cylinders, timing belt may have skipped or jumped a tooth, and a VVT-I sensor went bad. Seems like he had those issues fixed and went ahead and replaced all the spark plug tubes/seals as well.

Johnhav430

Maybe have an indie look at it? I "once" got a misfire on my BMW where the SES lit up, but went away after a restart. The code was stored and I erased it, and it never came back. I dunno but am skeptical about coil packs myself, it would seem to be a widespread issue if so (like 1999 Maximas vs. 1998, the former did have coil pack issues). However, if they were touched, of course, could be just human error where something was partially disconnected or not put back snugly? I don't think the mileage is high so maybe no need to think about getting rid of the car....good luck.

LS430inDE.

I'd love to know if when you pulled a COP/boot, if the bottom portion was covered in oil.

My theory (for now) is a bad gasket allowing oil to form in all your spark plug wells/threads, and causing misfires on all the even side cylinders.

How is he on oil? When you check via dipstick, are you ever showing low oil level?

Gronemus

Highly unlikely about the oil in the spark plug wells. She already posted that the seals were replaced last year.

I'm thinking that there is an issue somewhere in the cabling for the injectors. Probably a bad ground. I wonder if the tech that did the work last summer might have exposed some wire in one of the harnesses when he was working on the OCV.

I also found this thread concerning a V-6 Lexus suffering from the same problem. Unfortunately there was no resolution posted but what the technician said at the end might give some clues...

From that thread: It is also very important to know whether or not you ever had any VVT I malfunction codes set with these cylinder misfire codes or any lean condition codes set with these malfunction misfire codes. It is just unusual to have one entire bank misfiring with no other correlation codes.

rkw77080

Be sure to ask for all the DTC (Diagnostic Trouble Code) the Toyota dealer pulled from your vehicle, and what they did to address them.

lexslexus

Hey everyone. Just heard back from the Toyo dealer. The service advisor told me that the master mechanic did a thorough inspection of my car and found that I have several codes for misfires because my OCV is stuck open and it's messing with the timing. So, it sounds like either a new OCV went bad or my assumption that the old one never got fixed was wrong.

LS430inDE.

That's good news that we now know what the CAUSE of the misfiring is. Now, the other half is knowing how (much) it will be to fix the OCV! Whatever price they throw at you, I'd try to knock off some $$ from it! You can always buy the part(s) yourself and hand it over to them to save some buck$! Keep us informed!

lexslexus

He said it would be either $300 or $340 to fix it (can't remember which). Seems like it's $100 higher than I think it should be. I've got a 10% off coupon. I'll try to find the best deal on parts but I'll end up with whatever will get me back on the road fastest.

campisi

.... what's an OCV?

lexslexus

Oil control valve/VVTi solenoid