2007 Accord 2.4L - Valvetrain Pictures

[The_Eric]

Originally Posted By: Merkava_4
Not clean enough for me; too much varnish.


And what is it hurting? Nothing. Who cares if there is a bit of varnish? The car will run to 300K+ looking a lot worse.










Originally Posted By: zeng
Originally Posted By: The Critic
Vehicle had 102k - prior oil change history (up until the 98k mark) was every 4-5k using Mobil or Pennzoil conventional 5w-20. The cover was removed because I did a valve adjustment on the engine.




1 )Looks like to me the 5W-20 minerals had caused permanent damage to the :

a )All single cam-lobes (inlet?) of all 4 cylinders, and

b )the 2 cam-lobes (exhaust?) of Cylinder No 2.

The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had overheated to a

very high local temperatures as witnessed by gold yellowish stains then progressively to light

blue burning marks , further overheated to dark blue/grey dark colored marks.


Originally Posted By: The Critic
The engine consumes approximately 1 quart of oil every 5,000 miles.




2 )I interprete it as likely caused by (1) above and stucked piston rings . However the oil

leaks could also be other reasons like mal-functioning valve seals etc.




The wear patterns are normal. If half as much damage as you are thinking had occurred, then valve clearance would be off by a mile, not a few thousandths of an inch.

 

[hattaresguy]

Run the top engine on mobil 1 for 30k miles and it bet it looks closer to the bottom one. Good synthetics always leave a spotless inside.

Having said that the mild discoloration is just cosmetic, the OP's engine will happily go to the junk yard suffering no issues from it.

 

[Phishin]

Originally Posted By: Merkava_4
Here's another Honda engine after having Mobil 1 since day 1 . . .

I want to see some cam lobe pics!! ....to see if they look the same as the OP's

 

[Brybo86]

Originally Posted By: Phishin
Originally Posted By: Merkava_4
Here's another Honda engine after having Mobil 1 since day 1 . . .

I want to see some cam lobe pics!! ....to see if they look the same as the OP's


I agree pics of the same engine part would be easier to compare

 

[alcyon]

i sense a storm brewing....

 

[zeng]

Originally Posted By: The Critic
Originally Posted By: tomcat27
Very cool! We're any valves out of spec?


All of the intake valves were a bit loose and some of the exhaust valves were a bit tight. I set the intake valves to a "tight" 0.009" and the exhaust valves to 0.0012".


Hi Critic , exhaust clearance should 0.012" right ?

Btw before valve adjustment , how much residual clearances in intake and exhaust to be precise ?

What symptoms/behaviour of this car that drives you to open up its valve cover , obvious loss of engine power?

 

[The_Eric]

Originally Posted By: Phishin


I want to see some cam lobe pics!! ....to see if they look the same as the OP's


That would be irrelevant. They are from different engine families.

 

[MobilinHyundia]

http://s1375.photobucket.com/user/mirageless/media/2009Sonataengine-150000kms_zps93e6b176.jpg.html

Im going 15000 miles OCI!!!
5000miles on oil is a waste of resources.

 

[Danh]

Originally Posted By: MobilinHyundia
http://s1375.photobucket.com/user/mirageless/media/2009Sonataengine-150000kms_zps93e6b176.jpg.html

Im going 15000 miles OCI!!!
5000miles on oil is a waste of resources.


Meh. Even if used oil was used for nothing (it is used or all kinds of stuff), in your example you could achieve the same resource saving by driving maybe 50 miles less over the 15,000 mile interval. 15k could be a good interval I guess, but the reasons for extending should really be cost and convenience. And the resource implications of car that meets an early end aren't insignificant...

 

[camrydriver111]

Originally Posted By: zeng

1 )Looks like to me the 5W-20 minerals had caused permanent damage to the :

a )All single cam-lobes (inlet?) of all 4 cylinders, and

b )the 2 cam-lobes (exhaust?) of Cylinder No 2.

The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had overheated to a

very high local temperatures as witnessed by gold yellowish stains then progressively to light

blue burning marks , further overheated to dark blue/grey dark colored marks.


Is the engine really damaged?

 

[bubbatime]

Originally Posted By: zeng
What symptoms/behaviour of this car that drives you to open up its valve cover , obvious loss of engine power?

His owners manual tells him to open it up, as it is recommended maintenance at 100K miles.

 

[oliveoil]

That is a nice clean engine with harmless varnish. Go 15k with M1 and don't look back. Take another photo at 200k valve adjust.

 

[zuluplus30]

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2948204&page=all
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3542429/all/Acura_TSX_K24_-_Rotella,_PU_Eu

Just a few other users who have valve train pics of their K24s using exclusively synthetics. They all have wear mark patterns on the cam lobes exactly like the OP. As somebody else mentioned, its from the roller followers. Every K20/24 i've ever seen with the valve cover off looked the same.

 

[The_Eric]

Originally Posted By: camrydriver111
Originally Posted By: zeng

1 )Looks like to me the 5W-20 minerals had caused permanent damage to the :

a )All single cam-lobes (inlet?) of all 4 cylinders, and

b )the 2 cam-lobes (exhaust?) of Cylinder No 2.

The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had overheated to a

very high local temperatures as witnessed by gold yellowish stains then progressively to light

blue burning marks , further overheated to dark blue/grey dark colored marks.


Is the engine really damaged?


No.

 

[KrisZ]

Originally Posted By: zeng
1 )Looks like to me the 5W-20 minerals had caused permanent damage to the :

a )All single cam-lobes (inlet?) of all 4 cylinders, and

b )the 2 cam-lobes (exhaust?) of Cylinder No 2.



blue burning marks , further overheated to dark blue/grey dark colored marks.

2 )I interprete it as likely caused by (1) above and stucked piston rings . However the oil The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had overheated to a

very high local temperatures as witnessed by gold yellowish stains then progressively to light

leaks could also be other reasons like mal-functioning valve seals etc.

3 )From your description in bold , those are after-effects of excessively high local component

surface temperatures probably caused by (1) above.

4 )Very-very dark used drain oils means very-very good for the engine health , I believe, as

higher amounts of combustion contaminants had been removed from the system.

It indicates 4K synthetic Mobil 1 EP 0w-20 works harder and more effective in removing

contaminants/sludge from engine component surfaces than a 5K mineral oils.

5 )minor shades of light sludge/heavy varnish ,despite use of (high-detergent ?) full synthetics

Mobil 1 EP 0w-20 for 4K miles, can still be found around most of the bolt heads of the 10 cam

bearing caps on both DOHC camshafts.

Just my 2 cents.

Wow, and you can tell all of the above just by looking at the low res, low quality picture?
"Looks like to me the 5W-20 minerals had caused permanent damage" - really?

"The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had overheated to a very high local temperatures as witnessed by gold yellowish stains then progressively to light" - I though, and it's been confirmed through my experience, that overheated metals, especially the hardened ones, would turn blue-ish when overheated?

IDK, but for now my [censored] meter is pegged.

 

[Merkava_4]

Originally Posted By: Char Baby
That engine looks great with Mobil 1

How many total miles are on the engine?


I'm told the pictures were taken during a period somewhere between 105,000 and 110,000 miles.

 

[zeng]

Originally Posted By: camrydriver111
Is the engine really damaged?


Cam lobes.

It's the cam-lobes that has discolored with light bluish and dark blackish color , which are

further hardened at the discolored areas , in relation to non-discolored areas of the cams.

 

[zeng]

Originally Posted By: KrisZ
- I though, and it's been confirmed through my experience, that overheated metals, especially the hardened ones, would turn blue-ish when overheated?



Absolutely agree with you , KrisZ .

The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had

overheated to a very high local temperatures as witnessed by gold yellowish stains then

progressively to light blue burning marks , further overheated to dark blue/grey dark

colored marks.

 

[aquariuscsm]

Originally Posted By: zeng

- I though, and it's been confirmed through my experience, that overheated metals, especially the hardened ones, would turn blue-ish when overheated?



Absolutely agree with you , KrisZ .

Quote:
The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had

overheated to a very high local temperatures as witnessed by gold yellowish stains then

progressively to light blue burning marks , further overheated to dark blue/grey dark

colored marks.

Would a thicker oil have prevented this?

 

[KrisZ]

Originally Posted By: zeng
Originally Posted By: KrisZ
- I though, and it's been confirmed through my experience, that overheated metals, especially the hardened ones, would turn blue-ish when overheated?



Absolutely agree with you , KrisZ .

Quote:
The 6 cam-lobes has very clear and wide rubbing marks around the lobes that had

overheated to a very high local temperatures as witnessed by gold yellowish stains then

progressively to light blue burning marks , further overheated to dark blue/grey dark

colored marks.

I simply think you are reading way too much from those pretty low quality pictures. To truly assess the wear you have to inspect them in flesh and I'm sure if these lobes looked off, Critic would pick it up.

Here is a picture of my now sold 2003 Focus and below my Mazda 3. They do look like they have overheating marks and look almost scored. But it is simply the light reflecting off of the lobes. Trust me, they are smooth and I cannot feel any ridge with my fingers.
The marks of that Accord look normal to any cam over bucket or over roller follower design I've seen. These marks are usually much more pronounced with varnish buildup simply because the area where the lobe or roller touches the bucket does not have any varnish and looks much brighter then the portion that does not touch anything and is discoloured by varnish.

That Accord does not have overheated cams.