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In regards to the valve spring recall - I reviewed my maintenance history that I got from Lexus and this was done in Oct 2010.
On the weekend I pulled the air surge tank off of the intake manifold and discovered that the gasket was damaged. I replaced the gasket and put everything back together. From here the P0300 and P0303 codes went away, but unfortunately the P0305 code still came back. Since the misfire had migrated to another cylinder the seal seemed like a likely cause, but unfortunately did not get rid of my original problem
From here I swapped the fuel injectors between cylinder 5 and 6 - the misfire didn't follow.
Tonight I plan on doing a compression test and will use a test light on the fuel injector 5 harness to see if it is getting power.
Despite the fact that the misfire didn't follow I still think it is a fuel injector issue, not a compression issue because of the differences in the condition of the fuel injectors.... if you look below, fuel injector 5 is a silvery color - the gunk on it is a mixture of oil and carbon. While the other five fuel injectors are gold in color.
Not sure how I can help because I'm honestly not all the car savy when it comes to something like this but I had something similar happen to mine.
So I got a cylinder 1 misfire code and went to go get it checked. I took it to a Toyota dealership (closest Lexus is 3 hours away). They told me it was the ignition coil so they replaced that and the spark plug. Picked up my car and a day later, I got the misfire again.
Took it back to Toyota and they said it may be a leaking fuel injector. Cost was too expensive so I went ahead and took it to Lexus to get it under waranty. Lexus called me a couple of days later saying Toyota had misdiagnosed it. Service advisor said they were going to have to replace that piston. Wish I could elaborate more on what they did but it was a lot to take so i don't remember exactly what was done other than that.
My service advisor told me this was actually a fairly common problem but not to a point where a recall was necessary. There was actually another car there with the same problem. This was a 26 hour labor job would it not have been under waranty.
She did say from what I recall that Lexus extended the waranty for this (for people with expired waranty i am assuming) problem until August of this year.
Like I said not sure if this relates to your problem but it could be something worth looking into.
I would really be surprised to find out you have a compression issue at 135k. Hopefully the injector is the culprit, as that would be much easier and less expensive! Keep us posted and best of luck!
Tested the injector harness with a noid light and it showed that the harness is getting power and firing fine. I then did a compression test - all cylinders show 160 psi, except for cylinder 5 which showed 90. Squirted some oil in cylinder 5 and retested it. The psi dropped to 80... So it appears to be a top-end issue.
I have begun pulling off the valve cover and working my way to the head so I can investigate further. I suspect it's a burnt valve.
Anyone have any suggestions when pulling the head? Anything to look for? Or a workshop manual? (I know about TIS already)
Wow, getting more in-depth by the minute! You're heading into un-charted territory really with removing a head. Not much I can ad here other than to be careful and methodical with your process. Document along with the way if you can.
Oh, have you removed the valve cover to look for any odd wear on the cam lobes or anything on that #5 cylinder?
Wow, getting more in-depth by the minute! You're heading into un-charted territory really with removing a head. Not much I can ad here other than to be careful and methodical with your process. Document along with the way if you can.
Oh, have you removed the valve cover to look for any odd wear on the cam lobes or anything on that #5 cylinder?
Yeah, it sounds like I'm a little more hands on then most CL members.
I did a quick inspection of the cams and they look good. I'll be able to look at them better once they're on the bench.
Looks like the water pump might have to come off to access the forward most head bolts and make it easier to get to the head... So I guess that's my next step.
Yeah, you can say that! LOL! I can just say I'm glad I've not had a need to get that in-depth into my motor yet.
If you can, post a larger and closer pic of the valvetrain above cyl #5.
If you helps you out any, you can simply unbolt the entire front radiator core support to access the engine bay. Hope you don't need to do it, but it can be helpful if necessary.
I've been a bit busy, but here's my most recent update...
Let me start off by saying that this task is one that I would NOT recommend for most CL members or even general DIY'ers...it was interesting, but the end is near and my car is about a week off from being back to herself (if not better).
This is a general listing of what I have done to get to the head:
- removed all of the fuel rails, intake, valve covers, exhaust manifold
- set the engine to TDC and marked the cams and chains
- removed the cams. While I was slacking off the timing chain to remove the cams I noticed that one of my timing chain guides had a broken seat between the guide and the tensioner - I suspect this is from the Lexus tech who did the valve spring recall...so that needs replacing
- removed the cam surround
- removed the head bolts in sequence and *gently* removed the head with some choice words and a little blood
(note that I did not removed the front timing chain cover, but I decided to replace the water pump since I'm in there)
- Inspected cylinder heads and walls (they were all good)
Once all of this was done I took the head to the machine shop. They called back shortly after to tell me that the valve seals are all perfect at 18 psi. From here I gave them the go ahead to take apart the whole head...I refused to accept that this wasn't the issue. Several hours of worrying that I did all this work for nothing, the machine shop finally called me back. Both intake valves on cylinder 5 had severely worn valve guides (to quote the shop, "razor sharp") and worn valve stems. Currently they're replacing the valve stems, guides, and seals and I should have the head back Wednesday.
For all of the work on the head I've been quoted between $500-600. In addition, I've ordered a top end seal kit from Lexus for $568, which will help me replace all of the seals I've had to open up in this process.
At the end of the day, we're not really sure what caused the part failure but I'm glad we've at least figured it all out.
I've also got some pictures of the internals of the engine that I'll try and post later for anyone who is interested.
I've been a bit busy, but here's my most recent update...
Let me start off by saying that this task is one that I would NOT recommend for most CL members or even general DIY'ers...it was interesting, but the end is near and my car is about a week off from being back to herself (if not better).
This is a general listing of what I have done to get to the head:
- removed all of the fuel rails, intake, valve covers, exhaust manifold
- set the engine to TDC and marked the cams and chains
- removed the cams. While I was slacking off the timing chain to remove the cams I noticed that one of my timing chain guides had a broken seat between the guide and the tensioner - I suspect this is from the Lexus tech who did the valve spring recall...so that needs replacing
- removed the cam surround
- removed the head bolts in sequence and *gently* removed the head with some choice words and a little blood
(note that I did not removed the front timing chain cover, but I decided to replace the water pump since I'm in there)
- Inspected cylinder heads and walls (they were all good)
Once all of this was done I took the head to the machine shop. They called back shortly after to tell me that the valve seals are all perfect at 18 psi. From here I gave them the go ahead to take apart the whole head...I refused to accept that this wasn't the issue. Several hours of worrying that I did all this work for nothing, the machine shop finally called me back. Both intake valves on cylinder 5 had severely worn valve guides (to quote the shop, "razor sharp") and worn valve stems. Currently they're replacing the valve stems, guides, and seals and I should have the head back Wednesday.
For all of the work on the head I've been quoted between $500-600. In addition, I've ordered a top end seal kit from Lexus for $568, which will help me replace all of the seals I've had to open up in this process.
At the end of the day, we're not really sure what caused the part failure but I'm glad we've at least figured it all out.
I've also got some pictures of the internals of the engine that I'll try and post later for anyone who is interested.
Kudos to you! Glad you were able to diagnose it properly. I'm not sure the dealer would have been as successful....
Kudos to you! Glad you were able to diagnose it properly. I'm not sure the dealer would have been as successful....
Yeah, I had the same thought. The dealer would have done a cylinder leak down test and it would have given a false reading. So I'm glad I went with my hunch...
Sorry to bring up a super old post but what was the outcome? Just purchased an 08’ 350 and I’m getting the same code. Exact same symptoms. Doesn’t sound like I’m going to like the answer...
06-25-15, 01:59 PM
