how does ARX increase compression?

[fpracha]

jmac,
thanks for comments and positive input. uptill now regularly serviced the car at Driving pattern is mostly short trips of 4~10 miles one way several times daily. So really not driving in upper rpm range.
- Do you think the toyota oil is the culprit ?
Now i'm thinking of changing to LE8800 after reading some reviews about how monolec protects.
- Are you saying the oil is mostly burning with fuel via air intake hose ? If yes then how to stop this ???

 

[ltslimjim]

Originally Posted By: fpracha
jmac,
thanks for comments and positive input. uptill now regularly serviced the car at Driving pattern is mostly short trips of 4~10 miles one way several times daily. So really not driving in upper rpm range.
- Do you think the toyota oil is the culprit ?
Now i'm thinking of changing to LE8800 after reading some reviews about how monolec protects.
- Are you saying the oil is mostly burning with fuel via air intake hose ? If yes then how to stop this ???


Some people rig a catch-can on the PCV system if it indeed is allowing excessive amounts of oil by. Lot of DIY write ups on this online. I don't have time to find them right now, but if you were to rig something up it could help you see how much oil is really coming through that location, then you can get a more accurate idea of where the rest of the loss is resulting from.

 

[jmac]

Originally Posted By: fpracha
jmac,
thanks for comments and positive input. uptill now regularly serviced the car at Driving pattern is mostly short trips of 4~10 miles one way several times daily. So really not driving in upper rpm range.
- Do you think the toyota oil is the culprit ?
Now i'm thinking of changing to LE8800 after reading some reviews about how monolec protects.
- Are you saying the oil is mostly burning with fuel via air intake hose ? If yes then how to stop this ???


Hi fp,

I don't know anything about the toyota oils, but providing you are actually getting the correct diesel rated oil installed at the dealership and not the bulk 5w30 out of the tank it should be ok. Anyway easy things first. Check your air filter, if it looks at all dirty, change it. A restricted air intake in any diesel can create high oil consumption as the engine will try to suck air anywhere it can including through that pcv tube to the crankcase. Change the pcv valve at the same time.

Quick way to check for excessive blowby, with engine running remove the oil fill cap on valve cover and put your hand covering the hole. You should be able to feel the pulses of air coming in conjunction w/ the pistons on their powerstroke down travel. Some pressure pulse is normal. If it feels very strong then it is a sign of excessive blowby which can be tried to reduce by utilizing cleaners to remove deposits in the piston crown-upper ring area. If you suspect too much blowby you can take it to a competent diesel mechanic to perform a compression leak down test on it. If you do not absolutely trust your dealership I would take it to an independent third party for the test.

On oils for your Japanese diesel, big can of worms, I don't know if it has ever been resolved here on BITOG. If you go away from the OEM oil, I would stick with ones that have low to no magnesium, high calcium formulas, diesel rated, JASO DH-1 for sure, and read up on the following.

http://www.box.net/shared/static/mcyb32zcwo.doc
https://bobistheoilguy.com/forums/posts/1082005/
http://www.bobistheoilguy.com/forums/ubb...true#Post537040
http://www.bobistheoilguy.com/forums/ubb...true#Post533074
http://www.bobistheoilguy.com/forums/ubb...true#Post532857
http://www.bobistheoilguy.com/forums/ubb...true#Post532727

LE makes some great products, and if you can get your hands on it that LE 8800 is a good oil, I would pose the question to them specifically related to how they address the concerns of the high-speed Japanese diesel though, and if they have a magnesium content to the detergent in that oil.

 

[fpracha]

thank you jmac for the informative steps, will do the necessary actions and later post the results.

 

[fpracha]

jmac, if there is magnesium present, what is the main concern for diesel engines ?

 

[jmac]

Hi fp,

From the first link I cited, "A piston design which uses a reduced clearance between the piston and the cylinder wall is able to have
the top-ring located lower on the piston- However the reduced clearance between the piston and the
cylinder wall can produce problems if hard carbonaceous deposits form on the piston crownland and
polish off the cylinder wall "cross hatching". Cross hatching is a fine pattern of intersecting angular lines
on the cylinder wall surface which contributes to the control of oil flow up the cylinder surface, thus
controlling oil consumption. If the cross hatching is polished away, even in localized areas around the
cylinder wall, increased oil consumption results.

Control of hard carbonaceous deposits in the top-ring-land is the major requirement in diesel engines with
reduced clearance between the piston and cylinder wall, as Is typical of European and Japanese diesel
engine design. Certain other engine design and operational characteristics in Europe and Japan place
additional requirements upon the lubricant."

As a detergent. magnesium leaves a harder ash behind if burned and allowed to form as a deposit while calcium is a softer ash type. If this harder ash forms in the critical area of piston-crown to cylinder wall area above, it could lead to bore-polishing at an increased rate, which to correct would require cleaning the rings and pistons and re-honing the bore to alleviate. So my recommendation is an err on the side of caution type of thing. Even today I think you would find that oils specifically formulated for Japanese diesel designs with lower-on-the-piston ring configuration would not use magnesium as part of the detergent package unless the thermal stability of dispersants has vastly improved, and maybe not even then.

 

[jmac]

(edit time ran out, but wanted to add)

This is not as much a concern for NA design engines which have thicker crowns, higher ring placement on the piston, and larger sumps to keep oil temperatures reduced and can utilize low ash-lower detergency, higher dispersant formulas.

The advent of later oil specs like CJ may have changed all this but I have not seen or simply don't recall papers or studies that have specifically addressed this, not to say they are not out there. I have seen where many on certain forums like toyota-diesel have used premium North American (NA) HD diesel oils for long terms with success, but many of these formulas have only recently (in the past several years) started including magnesium in their detergent packages so the jury may still be out on these formulas with regards to engine designs like 2C which you have. It may be time to pose the question to the additive suppliers such as Oronite or researchers at SWRI. If you pose the question to japanese designers I think you still get the response, "no greater than CF."

 

[fpracha]

jmac, thanks again, the document seems old as 1995, but so far used toyota motor oil so no worries i guess! will decide soon on the actions.

 

[fpracha]

hello jmac,

Finally decided and converted to Monolec LE 8820.

So far results look great as consumption is pratcically stopped although just driven 900-miles.

Surprisingly fuel economy has increased by about 9.5% !

thanks!