# Carbon build up on Valves? Prevention? Treatment? How often to change oil? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** integra, acura\ **Created:** [March 22, 2021, 8:04pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779 "2021-03-22T20:04:19Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![old\_mopar\_guy](https://avatars.discourse-cdn.com/v4/letter/o/6bbea6/32.png) [@old\_mopar\_guy](https://community.cartalk.com/u/old_mopar_guy)\ **Post date:** [March 23, 2021, 4:09pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/42 "2021-03-23T16:09:28Z")
Adopted, NOT adapted. ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 12:55am UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/43 "2021-03-24T00:55:38Z")
> [@VDCdriver](#): > > And if that advice turns out to be faulty, will “the Mobil guys” replace your engine w/o charge? It turns out that the Carbon build is on top of the valve an area where engine oil does not enter. So engine oil change interval had no effect on the Carbon build up. Pls correct me if I missed something! M/c used some instrument to inspect via spark plug hole - I am guessing. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [March 24, 2021, 1:07am UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/44 "2021-03-24T01:07:07Z")
> [@sciconf](#): > > It turns out that the Carbon build is on top of the valve an area where engine oil does not enter. The PCV system allows crankcase gasses which contain oil vapor to be reintroduced into the engine to be burned which comes in contact with the backside of the intake valves. This, along with the EGR gasses causes deposits to form on the valves. ![image](https://global.discourse-cdn.com/cartalk/original/3X/1/1/11a76fbec192bb35c1d3effa0ebdc0a2f4615743.jpeg) Tester ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [March 24, 2021, 1:09am UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/45 "2021-03-24T01:09:24Z")
> [@sciconf](#): > > M/c used some instrument to inspect via spark plug hole - I am guessing. M/C used a camera and light on a thin flexible probe (Docs call this an endoscope) into the intake to look at your valves. It is the intakes that usually have the problem. ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 3:00am UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/46 "2021-03-24T03:00:52Z")
Thank you @Tester So misfire could contribute to this? [https://www.howacarworks.com/basics/the-engine-how-power-is-created](https://www.howacarworks.com/basics/the-engine-how-power-is-created) ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [March 24, 2021, 12:32pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/47 "2021-03-24T12:32:39Z")
> [@sciconf](#): > > It turns out that the Carbon build is on top of the valve an area where engine oil does not enter. So engine oil change interval had no effect on the Carbon build up. After cleaning-out the PCV line and the PCV valve–and using Seafoam–you should make sure that you use only _Top Tier_ gas in the future. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [March 24, 2021, 2:17pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/48 "2021-03-24T14:17:40Z")
> [@sciconf](#): > > It turns out that the Carbon build is on top of the valve an area where engine oil does not enter Oil can get there if the valve stem seals are leaking. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [March 24, 2021, 2:39pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/49 "2021-03-24T14:39:27Z")
The valves in your cars will benefit from Top Tier gas, they aren’t direct injection. A bottle of Techron would also help with any valve deposits. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [March 24, 2021, 2:42pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/50 "2021-03-24T14:42:22Z")
> [@texases](#): > > The valves in your cars will benefit from Top Tier gas Just in case the OP doesn’t know which brands are Top-Tier certified, here is a link: > **[Fuel Stations - TOP TIER™](https://www.toptiergas.com/fuel-stations/)** > > TOP TIER™ Licensed Brands prominently display the TOP TIER™ logo on the pump, pump handle, canopy or in a station window. 👍 ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [March 24, 2021, 2:51pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/51 "2021-03-24T14:51:50Z")
I used Marvel Mystery Oil in my gasoline after my 1984 Chevy 2.0 engine started some preignition knock when accelerating. I thought carbon buildup may have been the cause. The problem went away and I kept using the MMO. Somewhere under 200,000 miles I had the head off and the machine shop guy remarked on how clean the innards were compared to many he saw. ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 3:11pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/52 "2021-03-24T15:11:58Z")
> [@texases](#): > > The valves in your cars will benefit from Top Tier gas, they aren’t direct injection. A bottle of Techron would also help with valve deposits. Thanks @texases - I have been using Costco gas for like 10yrs. I also like this additive [https://www.amazon.com/Red-Line-Complete-System-Cleaner/dp/B000CPI5Z0/ref=sr\_1\_4](https://www.amazon.com/Red-Line-Complete-System-Cleaner/dp/B000CPI5Z0/ref=sr_1_4) Seform is in my mind nowadays - might give it a try one day via manifold Update: **I do not know if the engine oil change interval is not good enough that PCV gets damaged and results in Carbon build up on valves?** ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 3:13pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/53 "2021-03-24T15:13:26Z")
> [@circuitsmith](#): > > Oil can get there if the valve stem seals are leaking. Then you will know from exhaust smoke and needing to top up engine oil - if I am not mistaken. ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 3:20pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/54 "2021-03-24T15:20:42Z")
> [@shanonia](#): > > I used Marvel Mystery Oil in my gasoline after my 1984 Chevy 2.0 engine started some preignition knock when accelerating. I thought carbon buildup may have been the cause. The problem went away and I kept using the MMO. Somewhere under 200,000 miles I had the head off and the machine shop guy remarked on how clean the innards were compared to many he saw. How often would you change engine oil, miles/months? On my car the oil filter is on the back of the engine - I used to do it myself and then started taking it to shop. With Full Syn, I was changing less freq - now this Carbon issue. ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [March 24, 2021, 4:12pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/55 "2021-03-24T16:12:40Z")
> [@sciconf](#): > > now this Carbon issue. Any symptoms of carbon buildup? How was it detected and where in the engine? My oil changes: probably close to whatever was in the owners manual. Every 6 months or 4-6,000 miles was common in the days of my 1984 Cavalier. ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [March 24, 2021, 6:16pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/56 "2021-03-24T18:16:31Z")
> [@sciconf](#): > > Another guy said that color gets dark because of the oil filter. ??? The color gets dark because the oil gets dirty. Did this other guy think someone is putting dye packets in the filter? > [@sciconf](#): > > Carbon build up - Valves If you have a direct injection engine, just resign yourself to getting/performing an induction cleaning every once in awhile. Unlike older designs, fuel no longer washes over the valves in DI engines, which means whatever lands on the valve stays there instead of being flushed away. And yes, seafoam is fine to use in the intake, and in the gas tank, and in the oil - though if you use it in the oil you should do it shortly before an oil change, because you don’t want it staying in the oil too long. ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 6:26pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/57 "2021-03-24T18:26:27Z")
> [@shadowfax](#): > > The color gets dark because the oil gets dirty. Did this other guy think someone is putting dye packets in the filter? So he was saying that the oil filter was not good enough to filter the dirt that oil color became dark. But even if the filter is good enough to filter the dirt away, as the oil go through the filter, it will inherit the dirt color right? @shanonia - the M/C used something like an Endoscope to inspect the valves via Spark plug hole. He said there is above average carbon on top of the valve. ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [March 24, 2021, 6:36pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/58 "2021-03-24T18:36:41Z")
“Not good enough” isn’t really the proper term. No filter will filter out everything. After all, if it filters out everything, it filters out the oil as well, and it’s called a cap. 😉 It filters out particles down to a given size. Anything smaller will pass through the filter. If the smaller thing that passes through the filter is not clear, then the oil will darken. It doesn’t mean the filter isn’t “good.” As for inheriting the dirt color, the oil already has the color from the particles suspended in it that don’t get filtered out. Anything it picks up by flowing past larger particles which are trapped in the filter would be indistinguishable from the stuff it’s already carrying. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [March 24, 2021, 6:40pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/59 "2021-03-24T18:40:56Z")
> [@sciconf](#): > > the M/C used something like an Endoscope to inspect the valves via Spark plug hole. He said there is above average carbon on top of the valve. Sounds like he tried to sell you an engine decarb treatment and he failed. Most people don’t care about the carbon in an old engine. ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [March 24, 2021, 7:01pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/60 "2021-03-24T19:01:28Z")
Good hunch. I don’t think OP has any carbon buildup problems at all. He hasn’t reported any symptoms. If the mechanic has diagnosed carbon as the source of a problem, we haven’t been told. If it were my car and I wanted to do something on my own, I would try MMO in the gas for quite a few tanks full. It’s supposed to soften the carbon deposits, which get expelled through the exhaust valves. That’s less dramatic than some “treatments” and possibly more thorough. But with no problem, it is not a solution — more like TLC that may or may not make a difference, ---
**Author:** ![sciconf](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sciconf](https://community.cartalk.com/u/sciconf)\ **Post date:** [March 24, 2021, 7:23pm UTC](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779/61 "2021-03-24T19:23:32Z")
> [@shanonia](#): > > If it were my car and I wanted to do something on my own, I would try MMO in the gas for quite a few tanks full. It’s supposed to soften the carbon deposits, which get expelled through the exhaust valves. What is MMO? [Previous page](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779.md?page=2) [Next page](https://community.cartalk.com/t/carbon-build-up-on-valves-prevention-treatment-how-often-to-change-oil/175779.md?page=4)