Valve Stem Carbon Build-up from Oil in DI Engines
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Originally Posted by jbutch
Low saps euro oils like Mobil 1 ESP or Pennzoil euro both have MB 229.51 certs which has a Noack of less than 10% (IIRC) would be my go to oils in GDI engines.
I feel the same. Driven also has a nice 0w20. DI20 - Driven 0w20 is based on mPAO technology. Noack is 10% and the HTHS is 2.88 and the TEOST is 15.2. Sulfated Ash content of the DI oils is .722
Low saps euro oils like Mobil 1 ESP or Pennzoil euro both have MB 229.51 certs which has a Noack of less than 10% (IIRC) would be my go to oils in GDI engines.
I feel the same. Driven also has a nice 0w20. DI20 - Driven 0w20 is based on mPAO technology. Noack is 10% and the HTHS is 2.88 and the TEOST is 15.2. Sulfated Ash content of the DI oils is .722
Originally Posted by Mad_Hatter
Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???
Compression stroke, notably for Atkinsonized engines---which generally aren't DI.
Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???
Compression stroke, notably for Atkinsonized engines---which generally aren't DI.
Originally Posted by paoester
This will make you want to use a low saps oil!
First advice: if a total stranger walks up and says: "I'm a race car driver, where are you parked?," you don't take him to your car.!
2nd advice: don't expect $25, or even $40 worth of oil to clear up GTDI mess. (Note to self: don't expect $75 worth of oil to, either...or $120 with tax for 6qts)
Now, where can I get one of those fabulous toys (the fluoroscope???)
This will make you want to use a low saps oil!
First advice: if a total stranger walks up and says: "I'm a race car driver, where are you parked?," you don't take him to your car.!
2nd advice: don't expect $25, or even $40 worth of oil to clear up GTDI mess. (Note to self: don't expect $75 worth of oil to, either...or $120 with tax for 6qts)
Now, where can I get one of those fabulous toys (the fluoroscope???)
Last edited:
Originally Posted by CR94
Originally Posted by Mad_Hatter
Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???
Compression stroke, notably for Atkinsonized engines---which generally aren't DI.
How are you compressing air if the intake valve is opened during this stroke? Do you have or know of where I can read up on it.. I'm just having trouble visualizing it.
Nevermind.. found it. Tx.
Originally Posted by Mad_Hatter
Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???
Compression stroke, notably for Atkinsonized engines---which generally aren't DI.
How are you compressing air if the intake valve is opened during this stroke? Do you have or know of where I can read up on it.. I'm just having trouble visualizing it.
Nevermind.. found it. Tx.
Last edited:
Originally Posted by Mad_Hatter
Originally Posted by CR94
Originally Posted by Mad_Hatter
Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???
Compression stroke, notably for Atkinsonized engines---which generally aren't DI.
How are you compressing air if the intake valve is opened during this stroke? Do you have or know of where I can read up on it.. I'm just having trouble visualizing it.
Nevermind.. found it. Tx.
The original explanation i heard for this was valve overlap and that doesn't appear to be it at all but rather the valve is being held open for a slightly longer period carrying over into the compression stroke. Interesting..so in theory the valve could see some fuel spray but is it enough to make a noticeable difference with respect to carbon buildup? Just seems like an inefficient means. And as you pointed out, these engines seem to be PI hybrids to begin with.
Originally Posted by CR94
Originally Posted by Mad_Hatter
Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???
Compression stroke, notably for Atkinsonized engines---which generally aren't DI.
How are you compressing air if the intake valve is opened during this stroke? Do you have or know of where I can read up on it.. I'm just having trouble visualizing it.
Nevermind.. found it. Tx.
The original explanation i heard for this was valve overlap and that doesn't appear to be it at all but rather the valve is being held open for a slightly longer period carrying over into the compression stroke. Interesting..so in theory the valve could see some fuel spray but is it enough to make a noticeable difference with respect to carbon buildup? Just seems like an inefficient means. And as you pointed out, these engines seem to be PI hybrids to begin with.
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https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
Originally Posted by BucDan
https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
That would work fine. Gumout makes a similar product but I've got nothing against CRC, they mfg solid products.
Fwiw, there are YouTube videos if this is your first time.. it's not rocket science but I suppose you (not you per se) could eff it up somehow (hydrolock maybe??). I have my son work the throttle while I introduce the spray.
Btw.. welcome!
https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
That would work fine. Gumout makes a similar product but I've got nothing against CRC, they mfg solid products.
Fwiw, there are YouTube videos if this is your first time.. it's not rocket science but I suppose you (not you per se) could eff it up somehow (hydrolock maybe??). I have my son work the throttle while I introduce the spray.
Btw.. welcome!
Last edited:
Originally Posted by Mad_Hatter
Originally Posted by BucDan
https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
That would work fine. Gumout makes a similar product but I've got nothing against CRC, they mfg solid products.
Fwiw, there are YouTube videos if this is your first time.. it's not rocket science but I suppose you (not you per se) could eff it up somehow (hydrolock maybe??). I have my son work the throttle while I introduce the spray.
Btw.. welcome!
Thank you for the welcome. Lurking and lurking for a few years, but saw this thread and just HAD TO ask you guys what you all thought about the CRC product.
Originally Posted by BucDan
https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
That would work fine. Gumout makes a similar product but I've got nothing against CRC, they mfg solid products.
Fwiw, there are YouTube videos if this is your first time.. it's not rocket science but I suppose you (not you per se) could eff it up somehow (hydrolock maybe??). I have my son work the throttle while I introduce the spray.
Btw.. welcome!
Thank you for the welcome. Lurking and lurking for a few years, but saw this thread and just HAD TO ask you guys what you all thought about the CRC product.
Originally Posted by gathermewool
...... variable valve timing now being common on both intake and exhaust valves. I don't know how it would work, exactly, but there's got to be a way to allow some of the DI fuel to be forced back into the intake just enough to provide at least some minimal level of cleaning. Does this make sense? Is this already a real thing?
Great conversation, btw. I'm enjoying reading the comments!
Real thing, yes it is already being done, as an implementation of the Atkinson Cycle for more MPG, via late intake valve closing. It burps some fuel-air mixture back up into the intake during the compression stroke. Problem is, it's not a high speed flow to really clean the intake valve stems, but at least keeps them sorta wet, which could maybe(?) loosen carbon on the intake valve stems. Lots of engines do Atkinson part time or full time these days.
VW, in all their wisdom, implemented something effectively similar to Atkinson with their "Budack" cycle EA888 2.0L turbo, which is early intake valve closing. Like Atkinson, It still makes a reduced partial charge so that the combustion stroke has less molecules to explode and more expansion. Notice Budack doesn't wash the intake valves though like Atkinson manages to do.
Adding insult to injury, the Euro version of the EA888 uses dual port+DI injectors, ours only DI. Bummer.
...... variable valve timing now being common on both intake and exhaust valves. I don't know how it would work, exactly, but there's got to be a way to allow some of the DI fuel to be forced back into the intake just enough to provide at least some minimal level of cleaning. Does this make sense? Is this already a real thing?
Great conversation, btw. I'm enjoying reading the comments!
Real thing, yes it is already being done, as an implementation of the Atkinson Cycle for more MPG, via late intake valve closing. It burps some fuel-air mixture back up into the intake during the compression stroke. Problem is, it's not a high speed flow to really clean the intake valve stems, but at least keeps them sorta wet, which could maybe(?) loosen carbon on the intake valve stems. Lots of engines do Atkinson part time or full time these days.
VW, in all their wisdom, implemented something effectively similar to Atkinson with their "Budack" cycle EA888 2.0L turbo, which is early intake valve closing. Like Atkinson, It still makes a reduced partial charge so that the combustion stroke has less molecules to explode and more expansion. Notice Budack doesn't wash the intake valves though like Atkinson manages to do.
Adding insult to injury, the Euro version of the EA888 uses dual port+DI injectors, ours only DI. Bummer.
Originally Posted by BucDan
https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
I use this once a year as a preventive maintenance on my FXT.
It can't hurt and I'm sure it helps.
https://www.amazon.com/CRC-05319-Intake-Valve-Cleaner/dp/B00PHNQKR2/ref=sr_1_1?crid=MQELQHKY1ZH7&dchild=1&keywords=crc+gdi+ivd+intake+valve+%26+turbo+cleaner&qid=1576012104&sprefix=crc+gdi%2Caps%2C208&sr=8-1
Would this work? Or just snake oil? Since walnut blasting is a lot of labor and expensive. Apparently you spray in directly into the intake on a warmed up car holding 2500 RPM then letting it heat soak for an hour and then you go drive.
I use this once a year as a preventive maintenance on my FXT.
It can't hurt and I'm sure it helps.
Originally Posted by buster
Originally Posted by jbutch
Low saps euro oils like Mobil 1 ESP or Pennzoil euro both have MB 229.51 certs which has a Noack of less than 10% (IIRC) would be my go to oils in GDI engines.
I feel the same. Driven also has a nice 0w20. DI20 - Driven 0w20 is based on mPAO technology. Noack is 10% and the HTHS is 2.88 and the TEOST is 15.2. Sulfated Ash content of the DI oils is .722
My TGDI seems to like HTHS of 3.5 and and up, but for a 0w20, the oil you are suggesting seems great.
Originally Posted by jbutch
Low saps euro oils like Mobil 1 ESP or Pennzoil euro both have MB 229.51 certs which has a Noack of less than 10% (IIRC) would be my go to oils in GDI engines.
I feel the same. Driven also has a nice 0w20. DI20 - Driven 0w20 is based on mPAO technology. Noack is 10% and the HTHS is 2.88 and the TEOST is 15.2. Sulfated Ash content of the DI oils is .722
My TGDI seems to like HTHS of 3.5 and and up, but for a 0w20, the oil you are suggesting seems great.
Originally Posted by BucDan
HAD TO ask you guys what you all thought about the CRC product.
I can't see how it would work on caked-up valve stem deposits like we saw on the Valvoline video. Walnut blasting is expensive like you mentioned. Also, if you did start chunking off the carbon pieces, they would get near the rings, which can't be good. Walnut pieces are vacuum sucked out after the blasting.
CRC claims only 23% is removed. https://www.youtube.com/watch?v=JfDfNuKlD7U for a good summary video on what is done to the intake with CRC or the other ones too.
Originally Posted by jbutch
I use this once a year as a preventive maintenance on my FXT. It can't hurt and I'm sure it helps.
I say every 30,000 miles in any DI engine. Then maybe it won't cake on big-time, needing hard removal (walnut blasting). The CRC can get off some light carbon, or at least fight it well enough.
HAD TO ask you guys what you all thought about the CRC product.
I can't see how it would work on caked-up valve stem deposits like we saw on the Valvoline video. Walnut blasting is expensive like you mentioned. Also, if you did start chunking off the carbon pieces, they would get near the rings, which can't be good. Walnut pieces are vacuum sucked out after the blasting.
CRC claims only 23% is removed. https://www.youtube.com/watch?v=JfDfNuKlD7U for a good summary video on what is done to the intake with CRC or the other ones too.
Originally Posted by jbutch
I use this once a year as a preventive maintenance on my FXT. It can't hurt and I'm sure it helps.
I say every 30,000 miles in any DI engine. Then maybe it won't cake on big-time, needing hard removal (walnut blasting). The CRC can get off some light carbon, or at least fight it well enough.
so what would one use on the dreaded OD prone honda 1.5t (tdi)??
Originally Posted by earthbound
so what would one use on the dreaded OD prone honda 1.5t (tdi)??
The CRC or Gumout intake spray like discussed above, best as periodic preventive (cheap & easy). Fuel dilution doesn't affect the intake valve deposit issue.
so what would one use on the dreaded OD prone honda 1.5t (tdi)??
The CRC or Gumout intake spray like discussed above, best as periodic preventive (cheap & easy). Fuel dilution doesn't affect the intake valve deposit issue.
Originally Posted by paoester
Originally Posted by earthbound
so what would one use on the dreaded OD prone honda 1.5t (tdi)??
The CRC or Gumout intake spray like discussed above, best as periodic preventive (cheap & easy). Fuel dilution doesn't affect the intake valve deposit issue.
At 9:22 on this video, you can see the before and after of CRC on a bad case of IVB and it really does seems like it works.
Originally Posted by earthbound
so what would one use on the dreaded OD prone honda 1.5t (tdi)??
The CRC or Gumout intake spray like discussed above, best as periodic preventive (cheap & easy). Fuel dilution doesn't affect the intake valve deposit issue.
At 9:22 on this video, you can see the before and after of CRC on a bad case of IVB and it really does seems like it works.
You're not going to get carbon off a valve with any cleaning products you see in stores, best to blast it off and not waste your time/money.
Here's an example; I sprayed an entire can directly on a carbon coked valve. Directly on it (crc intake and throttle body cleaner).
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/12/full-84574-39058-c54ab6ac_eaec_4a9c_8601_e6ccf862b8ba.jpeg "[Linked Image]")
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/12/full-84574-39059-1f17aae1_61ba_45ad_8176_c97e11680653.jpeg "[Linked Image]")
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/12/full-84574-39060-d01c7d3a_779c_4d9d_b43e_bdae70ea0f54.jpeg "[Linked Image]")
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/12/full-84574-39061-b98ec9f1_09ba_42bb_8cad_4cc7b8b06c20.jpeg "[Linked Image]")
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/12/full-84574-39062-e82fa6b7_33ee_4427_9609_e78856fe6185.jpeg "[Linked Image]")
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/12/full-84574-39063-3b08a6cb_24ad_4c89_b90e_53bcd5b9aebb.jpeg "[Linked Image]")
Entire can. Then I socked the valve for four hours in CRV engine cleaner. I agitated the valve in the solution back and forth every half hour. Then I took the valve out and heated the face with a propane torch. Let the heat sink in, then put it back in the solution for another hour. Took it out, sprayed a can of brake clean directly on the valve.
The result? Not much. I'm not saying it did nothing, but it did very little.
Here's an example; I sprayed an entire can directly on a carbon coked valve. Directly on it (crc intake and throttle body cleaner).
Entire can. Then I socked the valve for four hours in CRV engine cleaner. I agitated the valve in the solution back and forth every half hour. Then I took the valve out and heated the face with a propane torch. Let the heat sink in, then put it back in the solution for another hour. Took it out, sprayed a can of brake clean directly on the valve.
The result? Not much. I'm not saying it did nothing, but it did very little.
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