Awesome thread and thanks for all the pics. I'm glad to see you're in AZ too.

 

Hi, I've not checked the spark plugs. I did replace them ~15k miles ago. It's possible I didn't fully seat the spark plug tube seals. I don't really like the 2 piece design. Looks like I have a list of things to check, fun fun. Thanks for the suggestion.

 

Oil leaks can pop up in 15k but probably not to the level of all those cylinders affected. It's also unlikely that a vacuum leak would only affect some cylinders, it would be all. What does seem possible is that injectors need cleaning, more than a fuel treatment. My '13 460 has both direct and efi. Your car, being an '08 may very well need pro type cleaning.

 

Yes she is!!

She is now misfiring when cold. After a few seconds the engine smooths out and runs fine with no misfires. It did finally throw a code for cylinder 5 misfire.

After sitting overnight I pulled the spark plugs out of cylinders 4 and 2. They were the easiest to access. The plugs look fine. I borescoped the top of the pistons. The first 3 pictures are piston number 4. The last 3 pictures are piston number 2. There appears to be a puddle of fluid on both pistons. The pictures when viewed on my borescope are slightly clearer. Both pistons had similar carbon build up and fluid puddles on them.

Is the fluid puddle is normal?

I'm assuming the pistons were very high on their stroke which limited my ability to get a good overall picture. Any guesses if that is oil or fuel? Looks like oil to me but fuel mixed with the carbon buildup would probably look the same.
I ordered a pcv and 5 vacuum hoses. Hopefully it's the pcv flooding the intake with oil. If not too difficult I may try to swap #5 injector with #1 while I have it apart.

My theory.. most of the oil is leaking past the piston rings after the car sits for 12+ hours. Then it sometimes starts with no misfires.

Or since the spark plugs look clean is it more likely a bunch of fuel injectors went bad? What's your guess?

 

Oops. It's either oil or you have injectors that are a-pissing. Possible oil source is PCV system. Check intake manifold for oil (unscrew the tb and look inside).
And sure, rings are a possibility, esp. if wrong oil was used for a prolonged period. There's some specialized chems to try freeing up rings. But 'puddles'? Not rings. It comes from top side, bro. Rule of thumb is 'gravity. stuff leaks down, not up'.
You can also have worn valve sleeves and/or seals. High vacuum will suck oil from heads into cyls. This is non-repairable (heads replacement) basically.
Clean plugs? Not oil probably. Oil in cyl will produce caked plugs. Gas won't - gas washes things pretty good (looking at your pistons).
Injectors. If you're lucky it's one of the uppers (low pressure). If you're not - one or more of HP ones. Those are a bugger to replace properly (and you need a particular color coded one).

 

Those old lines and pcv valves catch up quick when they're older!

 

Thanks guys. I'll start with the pcv and hoses. If there is no change I'll order new port injectors. She is parked for now.

I wonder if the set of 8 Chinese port injectors for $100 on ebay are any good? I should probably lower my deductible incase the car catches on fire with them lol.

These pictures below are NOT my pistons. I copied them from ebay listings. If you compare the "B" on the ebay piston to the B on my piston it helps visualize the borescope pictures. The big half moon shape on my piston had me confused as to what I was looking at.








This is my piston.

 

Too many posts warning about Chinese parts that don't perform to specs. Electronic injectors fall under that warning.

 

Clean spots on piston head could be internal coolant leak. If you do have injector issues, it can cause cylinder wall scoring. Does the oil smell like gas?

 

Chinese port injectors? Are you sane?

 

No the oil smells totally normal. I changed it a few weeks ago. About half a quart of used oil ended up on my garage floor, smelled normal.

 

I was mistaken they are only $65. 9 sets have been sold, 9 auction specials lol https://www.ebay.com/itm/314061163317

I see a listing for new oem injectors for $400. I'll likely go the oem route but I do feel this cars days are numbered. My gut tells me the piston skirts / cylinder walls have been damaged either by coolant, fuel, or oil. Maybe all 3. Tomorrow, I may pull a spark plug out of my 460 to borescope a piston for comparison.

Currently cylinder 5 in my 600 has around 50-60 misfires during the first 10 seconds, then runs fine. I may end up installing new injectors the same time as the pcv to save some time.

 

Another boat to the boneyard. I parked beside a black 2008 600hL at the airport parking lot. It looked to have been a ultra luxury package. Naturally I crawled all over it and began to notice the worn badges and weathered emblems along with missing side mirror glass and yellowed headlights. It seemed like it had been abandoned there.

Reading all the threads popping up constantly about the same issues that seem to be hitting every single car, what's happening to miket's and the laundry list of issues my own is facing, it's no surprise many are just deciding to walk away from these luxury experiments.

Parts are expensive and hard to get, fuel only keeps going up, and a 2023 camry hybrid is just as loaded with technology if not more, and is similarly quiet all for a fraction of the upkeep.

​​​​​Sometimes I wonder if it's just not worth the headache. Even more so if it was a hybrid going bad.
​​​​​​

 

I don't know why I didn't think of this yesterday. This morning I dipped my borescope in the puddle of oil on top of the piston. It's the consistency of a thick oil. It didn't smell like gas.

Here are a few more pics for your viewing pleasure. First few are my 460 piston with 193k miles.


460


460


460


460. This car does burn a bit of oil .5 to 1 quart every 5000 miles.



460 spark plug with 20k miles. This plug gap is much wider than my 600. I'm not sure which is normal.



600 spark plug hole. I dipped my borescope in that puddle.



I attempted to get a sample from the area on the left.



This is my borescope oil sample. Best description... a sticky oil.

 

Those plugs are gone. Top electrode gone.
Ok, if it's oil - PCV first to check. Check intake for oil puddle.
How does your engine sounds? Any clatter?