Preventing sludge/varnish with Honda J35A7 VCM enabled engines.

[Bill7]

Bill- I got an '08 VCMII equipped engine with 108k. I do 5k oc, service that PCV valve frequently. Runs great, super smooth, strong runner and get 30+ mpg running high speed on interstates. No oil consumption, no varnish or sludge observed, or any mechanical issues so far. Just normal maintenance. I estimate about 75% highway miles, where VCM is heavily engaged

But for $95, just install a VCM disabler on your rig and stop worrying...

Thanks Wilbur for sharing your vehicles history. Yes for the VCM II 2008+ years, 5k seems ok.
The 2005-2007 with VCM I get extreme high temperatures on the front cylinder heads.
I've been reading a lot of old posts on BITOG about similar questions like mine.

Seems like the recommendation on 2005-2007 with VCM enabled is to do 3k-4k OCI with synthetic (or risk sludge/varnish), or 5k OCI if VCM is muzzled. I went to the EPA's US Government's fuel efficiency website, and for a 4,000 mile with VCM enabled, I would save about $60 in gasoline for every 4,000 miles travelled, as oppossed to having the lower trim level without the VCM.

So keeping VCM enabled saves me $15 in less gasoline used at today's prices for my town for every 1000 miles driven.
This would save $1500 for every 100,000 miles driven.
Not that much $, but still significant savings if you do the 4k mile/6 month OCI with a very low priced Dexos 1 Gen 3 full synthetic 5W-30 oil (not 5W-20) and avoid the sludge / varnish.

 

[The Critic]

and avoid the sludge / varnish.

You have probably repeated this statement hundreds of times. Have you removed the valve covers for a valve adjustment? You might be surprised to find that your front bank is already full of sludge and varnish; it is quite common for VCM engines from that era.

 

[Sequoiasoon]

If you travelled the same route in the same conditions all the time you might be able to test that manually. I'd be very suspect that the government website would be accurate to that amount. Gas prices change daily. Your chasing a $$ amount instead of a measurable MPG amount or oil change time. If you went 6k/8month you could even save more and STILL be under the maintenance minder. Future effects unknown.

I spent 2x the amount on gas then I did a couple years ago and for a while almost 4x. I didn't change any habits and my mpg's that I track manually really didn't change, just the $$.

Some people can distinguish (or at least say they can) the difference in .5psi in the right rear vs. left rear on their highway drives. That would also impact things. You could always try some hyper mileage techniques.

Everything is a trade off. I go for safety for my family, comfort, hopefully longevity. Lot's of things you can save money on you just need to decide where. I worked with a guy that saved the wet paper towels he used at work and would let them dry and bring them home, seriously!

In one of my cars I changed my clutch, put in new struts and timing belt and got T-boned and totaled 1 month later. Don't drive yourself nuts. You KNOW it gets hot because of the VCM. You could confirm issues if you pulled cover. If you have to pay someone it will cost you 20 oil changes worth of $$, that's 10 years.

 

[Bill7]

You have probably repeated this statement hundreds of times. Have you removed the valve covers for a valve adjustment? You might be surprised to find that your front bank is already full of sludge and varnish; it is quite common for VCM engines from that era.

Sorry about that, I meant to say no new sludge/varnish - it's worth it to be able to just freeze the existing sludge/varnish at it's current level, without it ever increasing.

I've stocked up on engine flushes, I have 20 bottles (combination of LiquiMoly, STP super concentrated, and BG EPR 109). I'm doing an engine flush at each 4k OCI for the next 5 oil changes for each of the 4 vehicles = 20 bottles total. Then after that I'll add the 1 quart HPL EC 30 + 3.5 quarts regular full synthetic and run that for a few 4k OCI's. Slowly but surely getting these Honda J35A7 engines cleaned up and ready for another 150k miles (if that is possible).

Dave from HPL had told me that HPL EC 30 and PCMO can clean varnish slowly, perhaps noticable cleaning after 12 months.
He said to help with the varnish removal, it helps to have extreme heat. These J35A7's are good at producing extreme heat on the front cylinder heads, which is where the varnish usually is in these engines, so just what the doctor ordered - to use that high heat for HPL to clean off the varnish.

 

[maintenanceMan]

I have an 07 Odyssey at 210,000 miles now and I have tracked fuel economy for over 100,000 miles. I also have a vcm muzzler and have tracked the differences. At no time, was it worth more than 1 mpg. The biggest single thing to increase fuel economy I ever saw was in a simple cleaning of the MAF. Got almost 2.5 mpg out of that. Still only up to a 24 average but that generation is not all that aero.

 

[thunderous1335]

Sorry about that, I meant to say no new sludge/varnish - it's worth it to be able to just freeze the existing sludge/varnish at it's current level, without it ever increasing.

I've stocked up on engine flushes, I have 20 bottles (combination of LiquiMoly, STP super concentrated, and BG EPR 109). I'm doing an engine flush at each 4k OCI for the next 5 oil changes for each of the 4 vehicles = 20 bottles total. Then after that I'll add the 1 quart HPL EC 30 + 3.5 quarts regular full synthetic and run that for a few 4k OCI's. Slowly but surely getting these Honda J35A7 engines cleaned up and ready for another 150k miles (if that is possible).

Dave from HPL had told me that HPL EC 30 and PCMO can clean varnish slowly, perhaps noticable cleaning after 12 months.
He said to help with the varnish removal, it helps to have extreme heat. These J35A7's are good at producing extreme heat on the front cylinder heads, which is where the varnish usually is in these engines, so just what the doctor ordered - to use that high heat for HPL to clean off the varnish.

Why do you continue to waste people's time discussing this matter? The money you save on gas will go towards being spent on HPL cleaner, which wouldn't be needed in the first place if you would shut down VCM

 

[nicholas]

Sorry about that, I meant to say no new sludge/varnish - it's worth it to be able to just freeze the existing sludge/varnish at it's current level, without it ever increasing.

I've stocked up on engine flushes, I have 20 bottles (combination of LiquiMoly, STP super concentrated, and BG EPR 109). I'm doing an engine flush at each 4k OCI for the next 5 oil changes for each of the 4 vehicles = 20 bottles total. Then after that I'll add the 1 quart HPL EC 30 + 3.5 quarts regular full synthetic and run that for a few 4k OCI's. Slowly but surely getting these Honda J35A7 engines cleaned up and ready for another 150k miles (if that is possible).

Dave from HPL had told me that HPL EC 30 and PCMO can clean varnish slowly, perhaps noticable cleaning after 12 months.
He said to help with the varnish removal, it helps to have extreme heat. These J35A7's are good at producing extreme heat on the front cylinder heads, which is where the varnish usually is in these engines, so just what the doctor ordered - to use that high heat for HPL to clean off the varnish.

Great plan

 

[The Critic]

Why do you continue to waste people's time discussing this matter? The money you save on gas will go towards being spent on HPL cleaner, which wouldn't be needed in the first place if you would shut down VCM

He likes to think that folks are listening…

 

[zfasts03]

looks like like Honda revised the PCV valve with a new part number, maybe that will improve things.

 

[dumkid]

I'd muzzle it. One less dash light, 3 more cylinders, no more problem.