4,000 mile oil change interval (with Synthetic) from now on.

VolvoZ - very interesting photo of Honda Odyssey 3.5 Liter VCM engine with valve covers off. Front bank of 3 cylinders brownish, back bank silver colored under valve cover with your photo. My mechanic mentioned mine looked sludgy under front valve cover - maybe it was similar to yours.

Now that one of my priorities is a really clean inside of the engine, I might use Liqu-Moli engine flush a few more times with each 4k PUP oil change. It's actually fun to strive to have the cleanest inside of the engine in town (even if it costs a few more bucks in maintenance).

Not sure if the analogy of sludge in a car engine = cholesterol in human arteries is a good analogy, but nice in either case for the deposits to be minimized or completely removed.
 
VolvoZ - very interesting photo of Honda Odyssey 3.5 Liter VCM engine with valve covers off. Front bank of 3 cylinders brownish, back bank silver colored under valve cover with your photo. My mechanic mentioned mine looked sludgy under front valve cover - maybe it was similar to yours.

Now that one of my priorities is a really clean inside of the engine, I might use Liqu-Moli engine flush a few more times with each 4k PUP oil change. It's actually fun to strive to have the cleanest inside of the engine in town (even if it costs a few more bucks in maintenance).

Not sure if the analogy of sludge in a car engine = cholesterol in human arteries is a good analogy, but nice in either case for the deposits to be minimized or completely removed.
You didn't answer my question before, how is that product working for you to remove varnish or contamination?
 
I can recall one of my first cars. A used Chevelle with a 307cui engine. When I got it there was a valve cover leaking.
The owner bragged and bragged about using "only Quaker State 10w40" oil all his life. Well I don't have a clue what
his oci was but when I pulled that valve cover ! I had to look twice. I thought I was seeing some new kind of hi tech
engine.... Everything seemed to be coated in what looked like plastic! It was gunk! I replaced the cover , changed the
oil and went right down to a used car lot and traded that one for a used truck.
 
F32C37C1-730D-44F4-9FEF-866A009A5D46.jpeg

This is a peek inside the valve cover of an engine that has had only 10,000 mile oil changes. Some of those changes were several years apart.

I’m not seeing the sludge…

But then, it got the manufacturer specified oil (MB 229.5), and the manufacturer recommended change interval.

I’m going to stick with 10,000 miles.
 
View attachment 76346
This is a peek inside the valve cover of an engine that has had only 10,000 mile oil changes. Some of those changes were several years apart.

I’m not seeing the sludge…

But then, it got the manufacturer specified oil (MB 229.5), and the manufacturer recommended change interval.

I’m going to stick with 10,000 mil Beautiful.

View attachment 76346
This is a peek inside the valve cover of an engine that has had only 10,000 mile oil changes. Some of those changes were several years apart.

I’m not seeing the sludge…

But then, it got the manufacturer specified oil (MB 229.5), and the manufacturer recommended change interval.

I’m going to stick with 10,000 miles.
Looks almost brand new to me...... Beautiful.
 
Bill7: That 4K OCI should work well. But wondering what your driving patterns are like and what your prior OCI and OLM % remaining were before this new oil change regimen. Photo is of my 06 Odyssey 3.5 VCM engine with 155K miles. Has had regular synthetic oil changes since the beginning. Just replaced PCV valve on it over the weekend. Note how the hotter front bank gets varnished much more than the rear bank which does not run as often due to VCM.

View attachment 76234
VCM muzzler ftw!
 
Service intervals are just one part of the sludge equation, and assuming you're using an oil that meets or exceeds the spec, it's not a big factor either. Consider these:
engine design (known sludger?)
engine age/condition
oil capacity
driving style
short trips (or not)
all systems working properly (PCV, other emissions stuff)
what tiger862 stated in post 31
 
Since some have suggested that a view under the valve cover is not definitive, and that sludge might be hiding elsewhere, I offer a view of the same engine with the oil pan removed.

Remember, dealer serviced at 10,000 miles, often several years between oil changes, according to the CarFax.

B5B3041C-5AA0-4903-84CA-71CA3C59B729.jpeg
 
We have many engines in our family doing well with OCI's over 4,000 miles (6400km) and with conventional to boot.

If you are concerned reassure your fears with evidence... Buy a cheap LED lit boroscope camera from Amazon and stick it down the oil filler tube and in the drain plug of the oil pan and have a look.

You can also back it up by some cheap UOA's to confirm with wear metal trending for the wear part of it.

What you will save in oil changes and time will more than pay for the above and help you sleep at night!
 
  • Like
Reactions: FZ1
I can recall one of my first cars. A used Chevelle with a 307cui engine. When I got it there was a valve cover leaking.
The owner bragged and bragged about using "only Quaker State 10w40" oil all his life. Well I don't have a clue what
his oci was but when I pulled that valve cover ! I had to look twice. I thought I was seeing some new kind of hi tech
engine.... Everything seemed to be coated in what looked like plastic! It was gunk! I replaced the cover , changed the
oil and went right down to a used car lot and traded that one for a used truck.


Quaker State had their problems during that era.
 
I'm only saying this: If you love your car, treat it well.
I have a Honda Odyssey which some mechanics criticize as having a problematic transmission.
From reading the forums, some people say they do a drain/fill of their transmission fluid annually, which is much more frequent than
the owner's manual says to do it. They say it makes their transmissions last from 200k to 300k.
A transmission failure can cost $3k to $4k.
My mechanic charges me $40 labor and I give him the 3 quarts of genuine Honda ATF for the annual drain and fill.
Many people would say I'm wasting my money, but I feel good about the over maintenance. It can't hurt and might well save me $3k to 4k.

I'm am a very frugal person, but sometimes saving money in short term can be catastrophic in the long term.
My wife has a 2010 civic, 235k miles on it. I do oil changes myself, around 7500 miles (which I think I would cut back to 5k if I could start over). Minor repairs here and there, typical maintenance. Car has been outstanding in my book. I drain/fill the transmission fluid every 20-30k miles. Done it since new. Transmission on the car is amazing. People need to use some common sense. Dealer charges $170 for transmission fluid, if you do it every 40k, that would be once every 2 years. Pennies a day. Then there are those who want to be good world citizens and hug trees and conserve resources, so they push fluid changes. The worse thing for the environment is for you to not get the car to 300k miles before it ends up getting crushed. I suppose the majority of the people out there follow what the manual says. I think a little skepticism here is warranted. The auto manufacturers don't want their cars lasting 300-500k miles. They don't care that you reduce life span by going 10k between oil changes. Mainly because the general public thinks 100k on a car is alot. 10k interval will get you to 100k miles. And those 10k miles are ideal miles. In my case, most of my driving during the week is short trips (8 miles). Even with this, my accord is at 107k now, burns oil (but it did from day one). But, I want 300-400k, I doubt 10k interval will get me there. Maybe it would, but I'm going to 5k now on the accord.
 
VolvoZ - very interesting photo of Honda Odyssey 3.5 Liter VCM engine with valve covers off. Front bank of 3 cylinders brownish, back bank silver colored under valve cover with your photo. My mechanic mentioned mine looked sludgy under front valve cover - maybe it was similar to yours.

Now that one of my priorities is a really clean inside of the engine, I might use Liqu-Moli engine flush a few more times with each 4k PUP oil change. It's actually fun to strive to have the cleanest inside of the engine in town (even if it costs a few more bucks in maintenance).

Not sure if the analogy of sludge in a car engine = cholesterol in human arteries is a good analogy, but nice in either case for the deposits to be minimized or completely removed.
Below are photos of oil filler area on the 3.5. The varnish level seen in the oil filler cap area is fairly representative of the rest of the valve train area under the cover. The only exception was that the PCV valve was kind of cruddy…and that was replaced recently.

8B72183D-AA5D-4955-96C9-31CEF98B54C0.jpeg24B9D4EE-4702-4EF4-B7DF-A8426437362B.jpeg
 
It comes down to whether the engine is known for being the sludge motor or not. If your engine is known for having a sludge problem with extended OCI's then yes change sooner. If the vehicle used mostly in stop and go, low speed driving conditions then I'd suggest shorter OCI's.

If you're spending a lot of time on the highway then I don't see a problem with 7500-10,000 OCI's. I've never seen a sludge engine that was used mostly on the highway, varnish yes, sludge no. Most cars I've seen with sludge are short trip vehicles that never really get the oil warmed up to full operating temperature.
 
I bought the Camry during Covid, and, with some notable exceptions, have been doing a lot of short trip driving. A typical day puts on between 4 and 12 miles, and that's always broken up into two or three trips ... point A, park for a while, Point B, park for a while, home.

I'm on about a 6-month OCI which is about 3,500 - 3,750 miles. I use a quality oil and filter, and while I know that some will consider what I do a "Bitog Money Flush," I consider it reasonable considering the driving that's done and that I want to keep this car a long time and minimize as much as possible expensive repairs.

The car's running great, uses no oil to speak of, gets decent mileage, and I hope to keep it that way. I don't consider what I'm doing a waste of money, I consider it an investment in longevity. If the car gives up the ghost sooner rather than later, it won't be because I neglected it.
 
I just wanted to share my "Zero-Sludge" strategy for oil changes going forward.
I'll be changing my oil every 4,000 miles with PUP Synthetic (5 quart jug from Walmart) from now on, and changing my PCV valve every 30,000 miles.
I started the regiment with an engine flush (Liqui Moly) to clean out the engine first.

I think oil testing labs that are telling people with 10k oil change intervals that their oil is still good for another X thousand miles, are missing the point.
The amount of sludge in your engine is proportional to how many miles you go between oil changes.
Sludge is that gooey black thick formation all over the inside of your engine which clogs oil passageways and causes lower oil pressure which can really
harm an engine over the long term.

I read so many posts on BITOG about people that are so proud that they are going 7500, 10000, 12000, 15000 OCI's and testing labs saying their oil is still good.
The focus should not be on how long you can go without an oil change, but instead how clean is the inside of your engine.

Think about it this way. If you were going to buy a used car, would you prefer the previous owner did 3k to 4k oil changes, or 15k oil changes.

Bill
So do you know what you're talking about? Is this posted just to make you feel better about doing short OCIs?
 
Can’t help but think of Tig doing 10k OCI’s on M1 for several decades …
Has changed valve cover gasket’s and pristine underneath

I do 5k-10k depending on vehicle and circumstances

4K on PUP ?

4K on PUP ?
0593F3E1-9BBF-4590-98F4-F2798D756DF1.jpeg
 
Last edited:
Nothing I read here has made me change what I've been doing for the last 50 years . If it ain't broke ........
 
We have many engines in our family doing well with OCI's over 4,000 miles (6400km) and with conventional to boot.

If you are concerned reassure your fears with evidence... Buy a cheap LED lit boroscope camera from Amazon and stick it down the oil filler tube and in the drain plug of the oil pan and have a look.

You can also back it up by some cheap UOA's to confirm with wear metal trending for the wear part of it.

What you will save in oil changes and time will more than pay for the above and help you sleep at night!

Quaker State had their problems during that

Nothing I read here has made me change what I've been doing for the last 50 years . If it ain't broke ........
LMAO... A older guy used to say at work... "well. that aint the way we been a doin it!" Oh, he also said "don't go a kickin that sleepin dog boys!"
 
My wife has a 2010 civic, 235k miles on it. I do oil changes myself, around 7500 miles (which I think I would cut back to 5k if I could start over). Minor repairs here and there, typical maintenance. Car has been outstanding in my book. I drain/fill the transmission fluid every 20-30k miles. Done it since new. Transmission on the car is amazing. People need to use some common sense. Dealer charges $170 for transmission fluid, if you do it every 40k, that would be once every 2 years. Pennies a day. Then there are those who want to be good world citizens and hug trees and conserve resources, so they push fluid changes. The worse thing for the environment is for you to not get the car to 300k miles before it ends up getting crushed. I suppose the majority of the people out there follow what the manual says. I think a little skepticism here is warranted. The auto manufacturers don't want their cars lasting 300-500k miles. They don't care that you reduce life span by going 10k between oil changes. Mainly because the general public thinks 100k on a car is alot. 10k interval will get you to 100k miles. And those 10k miles are ideal miles. In my case, most of my driving during the week is short trips (8 miles). Even with this, my accord is at 107k now, burns oil (but it did from day one). But, I want 300-400k, I doubt 10k interval will get me there. Maybe it would, but I'm going to 5k now on the accord.
Of course not one shred of evidence that any of that is true, in fact plenty of evidence in this thread that it is not.

One size does not fit all. This entire discussion is completely dependent upon specific engines and operating conditions. Do you have any evidence that your engine has an issue with the prior OCI?
 
Back
Top