Engine flush

greybrick

New Member
I've been looking around for some engine flush options for awhile to keep varnish buildup to a minimum and reading the pro's and con's of various off the shelf products but was mainly seeing negative comments on most of those. I happened to read something about an old school mechanics trick of using ATF as a prechange engine oil flush, ie: pull out a quart of engine oil, put in a quart of AFT, idle the engine for about a 1/2 hour, and then drop the oil, so decided to give it a try. I usually check the engine oil fairly soon after an oil change and have been kind of disappointed with the PF VQ40 as the oil usually looks almost the same color as before changing even after a day or two use. I did the ATF recipe yesterday and pulled the dipstick today after doing about 200 miles and got a good surprise.

I've tried several different types of engine flushes in the past on other vehicles but with this one all I can say is WOW, looks cleaner than when I bought the truck...have others heard of this or used ATF as an engine flush. About the only problem I'm having now is I can't see the oil on the stick anymore because it's too clean, but now I'm thinking it works so good there might be some kind of a downside.

YMMV

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eglaisi

New Member
I think 30min is a bit excessive for letting it idle, I'd say 10min would do the job. ATF is less viscous than engine oil so therefore breaks down faster than engine oil.

You could also use something like Mobil-1 0w30 synthetic since it has a high detergent agent. Just do the same; drain your old oil; put in the 0w30; let it idle; drain it; filter change; new oil.
 

greybrick

New Member
eglaisi said:
You could also use something like Mobil-1 0w30 synthetic since it has a high detergent agent.
Poly-Alpha-Olefin "PAO" based Mobil-1 oil in an engine that you want to respect in the morning? Haha. :smt002

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mdawg4x4

Administrator
The many gaskets and seals would be my concern. They react differently to different oils. I knew somebody years ago that said break fluid was good. He would use it when his lifters would start tapping. then go back with clean oil. I never did care for chemistry, but I would be careful.
 

greybrick

New Member
mdawg4x4 said:
The many gaskets and seals would be my concern. They react differently to different oils. I knew somebody years ago that said break fluid was good. He would use it when his lifters would start tapping. then go back with clean oil. I never did care for chemistry, but I would be careful.
Here's the opinion of a track racer that I respect a lot who also runs a Stillen SC 4.0L but in a PF;

http://www.thenissanpath.com/viewtopic.php?t=812

If he says ATF is good for an engine flush then I sleep OK. :smt002

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mdawg4x4

Administrator
Sounds good if he has experience with it. I worked as a design engineer in the fork lift industry, and we put a lot of time into choosing seal properties for our hydraulic systems.
 

greybrick

New Member
mdawg4x4 said:
Sounds good if he has experience with it. I worked as a design engineer in the fork lift industry, and we put a lot of time into choosing seal properties for our hydraulic systems.
Too Cool ! So what's your opinion on controling varnish, sludge or carbon build up in VQ40 engines or do you see that as a long term problem and do you think that users should address this before it gets out of hand or just do the regular oil changes as prescribed by Nissan and trust the rest to god? Thanks.

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mdawg4x4

Administrator
I have never given that much thought as far as the oil goes. When I was a kid, I learned of the gunky build up of some oils. I have always used high quality oils and changed every 3000 miles. And have only kept two vehicles for over 100,000 miles.

The fuel system has been more of a concern for varnish, especially with fuel injection. There are many fuel injector cleaners on the market. A mechanic friend of mine said if it came in a plastic bottle, it wasn't strong enough to do any good.
 

greybrick

New Member
mdawg4x4 said:
I have never given that much thought as far as the oil goes. When I was a kid, I learned of the gunky build up of some oils. I have always used high quality oils and changed every 3000 miles. And have only kept two vehicles for over 100,000 miles.

The fuel system has been more of a concern for varnish, especially with fuel injection. There are many fuel injector cleaners on the market. A mechanic friend of mine said if it came in a plastic bottle, it wasn't strong enough to do any good.
Thanks MD, I'm not really up to speed on optimum VQ40 engine lubrication either. That being said I think we could all do better to keep internal varnish/soot/carbon sidewall buildups to a minimum and to provide engine lube oil with a minimum amount of carried contaminants to the internal engine lube ports and lines imo.

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mdawg4x4

Administrator
I have been considering switching to Mobile 1. With a synthetic, there should be less contaminates to deal with. I still have problems using a filter for more than 3000 miles. And 3000 miles on a synthetic would get expensive.
 

greybrick

New Member
mdawg4x4 said:
I have been considering switching to Mobile 1. With a synthetic, there should be less contaminates to deal with. I still have problems using a filter for more than 3000 miles. And 3000 miles on a synthetic would get expensive.
Have a look at Motul offerings for top end ester based oils, 0w-30 E-Tech Lite is what many are using. :smt001

Just the reduced cold start friction will pay for the price difference of some others, oil good to -75 C. :smt004

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mdawg4x4

Administrator
greybrick said:
mdawg4x4 said:
I have been considering switching to Mobile 1. With a synthetic, there should be less contaminates to deal with. I still have problems using a filter for more than 3000 miles. And 3000 miles on a synthetic would get expensive.
Have a look at Motul offerings for top end ester based oils, 0w-30 E-Tech Lite is what many are using. :smt001

Just the reduced cold start friction will pay for the price difference of some others, oil good to -75 C. :smt004

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BRRR. I hope I never see -75 C.
 

BRUTAL

New Member
I HAVE USED ATF FOR YEARS WHEN NEEDED, ITS VERY HIGHLY DETERGENT. MORE SO THAN ENGINE OIL AS HYDRAULIC SYSTEMS CANNOT TOLERATE ANY CRUD IN THE OIL. ON MY VEHICLE THAT I HAVE OWNED SINCE NEW OR THAT HAVE BEEN WELL CARED FOR WITH FREQUENT OIL CHANGES ITS NOT NEEDED AS THE ENGINE STAYS CLEAN. I go 3k with conventional oil and 5k on synthetics. put atf in couple 100 beforehand then change oil. On fuel systems, cleaner in a bottle is pretty useless as just about all grade fuels have detergents to clean system. The problem is not with the fuel but more the oil that comes from the crankcase and put into the air intake system in front of the throttle body. I clean the throttle body with a tooth brush a cleaner once a year, and would recommend a fuel filter replacement at 60k along with a system and intake flush using BG products that run the engine on cleaner alone and a fine mist wand that goes into the air intake in front of the throttle body to clean oil residue from the intake tracks and the ports and valves where the fuel injector cleaner wont get cause it doesn't spray there and only hits a portion of the intake valves. yes you have to see a shop or someone with a kit to do this, going rate should be $100-200 includes the cleaner. I understand others have used that foam stuff with good results but I only relayed info I know of personally
 

eglaisi

New Member
greybrick, what do you use for oil, just out of curiosity. I picked up 12L (about 13 quarts) of Royal Purple 5w30 for $60. They say it gives better fuel economy, less pollutants, and a tiny bit more power, so we'll give it a shot and see if it's true.
 

greybrick

New Member
eglaisi said:
greybrick, what do you use for oil, just out of curiosity. I picked up 12L (about 13 quarts) of Royal Purple 5w30 for $60. They say it gives better fuel economy, less pollutants, and a tiny bit more power, so we'll give it a shot and see if it's true.
Hey Eglaisi, I think as a group V ester based oil RP is a great choice, I've seen studies that show horsepower gains using esters as they have the lowest fiction coefficients of oil based lubricants. First change after the Nissan factory fill I put in Castrol Syntec 5w30, but whether the CS oil was degrading quickly or just cleaning up carbon and sludge from the factory fill, the oil was black in about a week so I stopped using it and went to an ester which generally stands up to heat better and has a better low temp pour point than most, this one good to -75F.

One of the local dealerships offers Motul products at cost plus $15 for the change so I've been using Motul 8100 E-tech Lite 0W30, but RP was a close second choice. Here's the Motul site to look around in, the oil properties are at the bottom of each page and depending on which oil they are labeled as 100% synthetic. I've also been using Motul Gear 300 75W90 in the diffs which also give some efficiency improvement, and are also good to about -75F. When I get to that point I'll stay with the Nissan Matic J for the transmission and Matic D for the transfer box though, as I don't want to take a chance of screwed up warranty on those.

http://www.motul-canada.com/main.htm

As an aside at about a week and about 1500 kms after doing the transmission fluid engine crankcase flush I still can't see the oil on this dipstick, it's staying clear as water.

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