I understand Auto-Rx is the best way to clean inside a gasoline engine (maybe a diesel too), but for those who don't want to go through the Auto-Rx regime (or are scared about stories of leaking or smoking during treatment, that later goes away), what else could one do?

I don't think these 5 minute engine flush products are really any good. I have heard that certain kinds of synthetic oil help clean an engine, but believe that synthetic oils are mostly better at not dirtying an already clean engine.

Finally, I heard running a dual rated gas/diesel oil such as SL/CF-4 would really clean up a gasoline engine because of the higher detergents needed for diesels. So I am seriously thinking about running a SL/CF-4 for about 2000-3000 miles to clean up my engine a bit (see signature below). It has 110,000 miles and a fair amount of deposits showing in the valve train as seen throught the oil filler hole.

Anybody have experience in this area?

I honestly don't have a problem with engine flushes - unless they use harsh solvents which may deteriorate seals/gaskets.
The only reason you'd have problems with smoking/leaking is when the engine wear has been fairly substantial, and the only thing hiding it is the gum and varnish sealing your rings etc... So old **** box engines I wouldn't reccommend.
There's no problems running a diesel engine oil in your passenger vehicle. In fact the overtreat of ep/antiwear/anti corrosive etc and the fact that higher detergency will have your engine crystal clean within five changes is nothing but a plus. I know alot of mechanics who run diesel oil standard in petrol engine servicing.

The reason it isn't so popular - it costs more!



By the way a synthetic won't help clean your engine but should reduce the breakdown of the oil which causes sludging etc...

You could try using a high grade with a high detergent capacity and using it like you mentioned for a while and than drain it again. But check carefully if your engine does not have any restrictions with high synthetic grades regarding the materials used in gaskets and sealings.

I'm not familiar with the AutoRX product you mentioned, but overhere (Europe) there are various additives which you can mix with your fuel and/or oil which also clean your engine.

The best way to get rid of it is to drain regulary and always change your filters (air and oil) when doing this.

Astrixstar confirms much of my thoughts. I do think the quick flushes are more of a last resort. I did one once and the lifters were noisy for several minutes after the fresh oil was put in.

Eazy E: I think the high detergent oil is the way to go. Guess there always is risk of cleaning off the seals and then they leak. But I can follow up with Maxlife which has seal conditioner.

Auto-Rx is highly regarded on the bobistheoilguy site. There are other, similar products. As for engine cleaning additives, Rislone Engine Treatment and Marvel Mystery Oil come to mind, but I think they are a longer term version of the 5-minute flush. Too bad I can't buy a 15 oz bottle of detergent to add to my oil that would beef it up to diesel detergent levels. Anyway, easy enough to use the SL/CF-4 oil next go around.

I did regular drains every 3000 miles and used Rislone on my last truck. Did not keep the engine from getting deposits. But, it still runs great (I know the owner) at over 200,000 miles. I am extending my oil change intervals with used oil analysis to 4000-5000 miles.

Thanks

Thanks to you too! I've got very little knowledge on the situation(s) and products on the American market and this way I'm learning a lot!
That's what I like about this forum, the diversity in nationalities and their 'local' problems which aren't that 'local' after all

greetz and until next time!

eAzY E: Here is someting interesting. Because of the different motor oil standards between N. America and Europe the oils are quite different. Check out the Valvoline Maxlife. In Europe it is a semi-synthetic blend and has different parameter values for viscosity, flash point, etc. And Europe has 10w40 and 15w40 whereas USA has 5w30, 10w30, 10w40, and 20w50, but not 15w40 which I would like and why I am running Valvoline Durablend 15w40 this summer. However, the weird thing is the Maxlife 10w40 gives me higher idle oil pressure than the Durablend 15w40. It should be the same. I think the Maxlife is better.

They probably use a different blender.
In Europe you have even different blenders per country/company which is making quality levels of products also very difficult.

I guess each company has a different strategy on each continent. But that's understandable if you consider the climates, the people and cultures.

Fortunately, there's the internet which enables us to inform eachother!

Well, as you probably know from bobistheoilguy, Nuetra is sort of the poor man's autoRX...

The autoRX is the best way to quiet lifters and clean out an amazing amount of junk. I don't believe in the 15 minute fixes, or (as many mechanicas here believe - filling the engine with kerosene or diesel fuel and running it a few minutes) Diesel/Gasoline oil is fine for both, and I use Delo in my gasoline and diesel engines. The detergents/dispersants (Delo uses 3300 ppm of calcium) will clean up the sludge of a poorly kept engine to a normal level, but will not take out the varnish in the lifters or all of the crud from the covers and pan. The autoRX treatment cleaned up my 88 BMW 325ic so much that I continue to think the engine is off.

Good point on the 15W40's. I'm using Delvac 1300S with AutoRx currently to get the best of both worlds!

(I picked Delvac on price, about $1/gal less than Delo locally)

1) I wonder if one can get a calcium additive to boost the calcium in a regular oil?

2) For a clean engine I heard that synthetic oils are good at keeping them clean. But would that apply to a group III "synthetic"?

TallPaul,

Try running LC and FP through your engine consistently.

I have used Auto RX and feel it is a great product, but if you run LC and FP (lube control / fuel power) you should not need to run Auto-RX

@TallPaul

quote:

---

However, the weird thing is the Maxlife 10w40 gives me higher idle oil pressure than the Durablend 15w40.

---

Look at the oil temperature and the VI of both oils, higher VI is better in hot idling condition. Besides, the SAE J300 Spec does have a certain allowed range of kinematic viscosity @100°C which may have an influence on your observed oil prssure, too.

Callisa, Actually I think the idle difference in oil pressure between the two would be statistically insignificant (1-2 psi). Interesting, the 15w40 does seem to hold 2000 rpm pressure better under hard use vs the 10w40. Again maybe not statistically significant as is only a couple psi.

BTW folks. I forgot about this thread. Am now 900 miles into my first Auto Rx treatment.

is it true that putting diesel fuel into the crankcase of a gasoline engine will clean the sludge and deposits? and If it is true, how much diesel should be added and should it be done during an oil change?

Don't know where you heard that, but "do not" put diesel fuel inside your gasoline engine and "do not" put diesel fuel in the gasoline tank.

There are additives that might help clean a dirty engine but diesel fuel is not one of them.

I'd imagine diesel fuel (or something VERY similar) is the primary ingredient in most of those quick crankcase flush products.

Probably the basis for what DallasTrooper heard, and practiced more often than you might imagine.

But I wouldn't recommend it.

How about using a good HDEO which with its inherent high detergency would do a good cleaning job. I have done this in many high mileage gasoline engine and the results have been very good so far.

quote:

Originally posted by DallasTrooper:
is it true that putting diesel fuel into the crankcase of a gasoline engine will clean the sludge and deposits? and If it is true, how much diesel should be added and should it be done during an oil change?

Most quick flushes are more than just diesel and none that I know of actually recommend you driving with the stuff in the crankcase. I've seen flushes help evacuate the engine of oil and that can be a good thing...but not really clean varnish. Neither have I seen HDEO clean varnish - not that multiple quick OCI's with HDEO won't help some engines - it will, but none of these will make an engine or more importantly the ring lands clear and clean.

I have seen quite a few gasoline high milegage cars with neglected engienes whose compression improved greatly with HDEO use.