Oily questions

[mudgrip4]

I would appreciate some advice re my 88 4jb1t and its oil consumption habits - has done 175k. The truck has never really used much oil if filled only to the halfway mark between the upper and lower marks on the dipstick. If filled to the max it appears to sweat or force oil out of seals until it reaches the halfway point - an early lesson.

Has always given healthy puff of blue on start up- even with breather kit - but this blue disappears 50m up the road. Lately however, it has begun puffing a bit of blue after cruising at low speed thru town or idling along a track somewhere. Suggestion of valve seals - a fairly easy job.

To check it was not worn rings etc I did oil use checks with the last two oil changes - doing filters and oil at about 5000ks. Found it used almost nothing in the first 3500ks, then about 6-7 mms on dipstick from 3500 to 5000ks. Also puffed a bit more after 4000ks. Doesn't blow blue after deccelerating downhill - if this is relevant to a diesel.

Am wondering if this is an older motor telling me it likes only 4000ks now on oil changes before the oil gets a bit thinner and its additives start wearing out. Also mechanic I spoke to suggested maybe a change to a heavier grade oil from the Castrol GTD 15w40 I'm using now. Wonder about the value of this.

Will do the valve seals- and another check on when consumption occurs, but would welcome some input on this. Has anyone else had this experience? Mike.

[darkhunter]

try straight SAE 30W oil,super cheap has it forget the brand but is recommended for the 4jb1t and is about $60 for 5litres

[geeves]

I had a similar experiance using both castrol gtd and repco special diesal oil Changed to Caltex Delo400 and problem gone. Also noticed on the old oil that hotr oil presure would drop as the oil got old also crankcase fumes on old oil. The delo oil has none of this. If your in NZ you can buy this oil at the Warehouse for 27 per 5 liters

[mudgrip4]

Interesting - yes the oil pressure does tend to drop as oil gets older. What is the rating of the Delo400 oil, 15w40, sae 30 etc? Sounds good.

And just priced set of valve stem seals (8 for the 4jb1T)from a few places here in CHCH. Most prices aroung $7 - 9 per seal trade - incl from Blackwell Isuzu with their genuine ex Japan parts. Repco however offering set of 8 for about $16. Wonder how good they are.Any experience/comments? Mike.

[geeves]

Delo400 is 15w40 Be carefull though there are other oils under the dello name One of Isuzu 's recomend oils is Dello Gold but One of our members tryed this and found it good for evading following cops. (they get lost in the fog)

[Bruce]

I was given a 20 litre can of Delo 400 when I brought my MU, when I finished it I went to Delo 500 (now called Silver) and stopped using oil.
The 400 is for newer diesel motors CRD ect, but the 500 is recommended for Yanmar diesels.
I have been using Delo Ssilver (500) FOR 80,000 ks and am very happy with it. Well be putting an additive in my oil next change which they say will help with extra HP.
WAIT FOR MORE ON THIS EXPERTINENT.
Their FTC decarbonizer/deglaze has done great things for my old Perkins in the yacht.
More info on their web site www.costeffective.com.au

Cheers Bruce

[mudgrip4]

Thanks for advice guys - have a questionmark over straight sae30 for Canterbury conditions re its temperature range as sometimes we overnight in mountains with major snow and ice. Might not be optimum in these extreme conditions.

I think a friend and I will try Caltex Delo 400 or 500 this weekend. This is working well for both of you- just a matter of which actual grade might be best given my vehicle's 175ks (my cobbers is near 400ks and still going strong) and its symptoms above? What do you think? Mike A.

[draganlada]

When oil level should be checked ?
I check my before the first start in the morning and it is at MAX or bit over it.
Book saids 4jb1T holds 6 lit of engine oil , but I never pour more than 5 lit in at every oil change and I drain old oil out by driving left front wheel up the ramp so I can drain most of it out ( sometimes I leave it dripping over the night ).
As mudgrip pointed ,I allso noticed my oil catch can is catching more oil when oil level on the dipstick is high ( like engine wants to get rid of excess oil and after that it's ok )

[mudgrip4]

Your motor will force much more oil out if overfilled. Took me some time to find it out through experience, but 4jb1T should never be filled over halfway between the marker dots on dipstick. Later found this actually written on my bighorn rocker cover beside oil filler cap , but as with many other things, we only resort to reading the instructions when all is turning to custard.

[mudgrip4]

Have just had good talk with Caltex technical dept re the Delo oils - 400, 500, silver and gold. V interesting and clear answers.

The 500 is now being made obsolete. The silver is a 10 grade oil for machine and hydraulic parts only now. The gold is quite a high spec oil but is a cheaper version of the Delo 400 - not quite as good - produced as an economy product. He says the Delo 400 is their top diesel oil, and is developed from their best base oil. It is what they recommend for all, esp new (under warranty) diesels, and also for the older motors if customers are prepared to spend the extra $$$ for it..

Commented we should not use single grade 30 oil as it is too thick on cold start ups, taking time to flow, and will cause excess wear on start up. Also its highest temp range is not adequate for hottest parts of diesel motor - apparently piston rings area can generate over 200 degrees C. Single grade oils inadequate to deal with these variations.

Said multigrade oils thin and wear out over time and this can be exacerbated if diesels running with too much fuel - if showing too much black smoke. So the lesson is maybe 4000k changes if running more diesel through and puffing a bit of black, or tweak motors back a bit. A good point was made before by someone - Bruce?

So the Caltex Delo 400 is the one to try - though its possible his comments re Caltex products might just be specific to this NZ market - could be different for Aus etc? Mike.

[geeves]

dragon Which book says 6 liters in a 4jb1. The 4jg2 has this much but the 4jb1 only has 5

[darkhunter]

have a talk to some engine reconditioners about oil,sae 30 was looked up and recomended by a couple of diesel engine reconditioners,they said the isuzu diesel they would not use a multigrade,
they see the after mass of the engines so see what they recomend for you.
mtcw

[darkhunter]

this might help www.bobistheoilguy.com/visc.html

[geeves]

can you get straight sae30 with a suitable additive mix. I think engine reconditioners like reconditioning engines and with modern engines being as reliable as they are need to do somthing to increase there number of customers.

[mudgrip4]

Makes it interesting for we consumers when supposed experts - reconditioners and oil companies - disagree on right oils to use! Rang Isuzu (Blackwell Mtrs) here in Chch and they said they service all 4jbi and 4jg2 motors with Agip superturbo 15w40 - the multigrade. Use Mobil mx on new rodeos etc.

I think we often know more from experience than the workshop boffins - e.g. the right oils for the 4jbi gearbox - low cost multigrade without additives, or straight auto trans oil rather than the engine oils they recommend, some of which are hopeless.

Will have a crack at the Caltex Delo400 and check its performance. Perhaps darkhunter you can keep us posted on the sae30 you are running also. Thanks - Mike,

[3vilc]

from my experience i would go with the delo400.. seems to be a good oil for even large diesel engines. i work for a transport company and most of our japanese trucks run delo400. we have an old isuzu forward using delo400 that barely smokes at all having done almost 500000ks
just my 2c worth

[draganlada]

Alan, sorry for late reply.
I find info in books for oils and filters around spare parts shops.


Btw , I'm using penrite 20 w 60 grade and it holds right oil presure for full 5000 km.

For mudgrip4 ; When deepstick should measurre halfway ? is it early in the morning before first start or is it 10 minutes after hot engine was shut off ?
Pls responde on this question as I never got actual and exact ansver from few mechanicks I have asked .

Dragan

[mudgrip4]

draganlada - do your oil level check in the morning when all oil has drained down to sump - this is when it should be half way between the dots. Don't do check (if possible) after just driving vehicle as 4jb1T takes a long time for all oil to settle into sump. As others have noted, in the morning before driving is also best time to change the oil filter as all oil has drained out of it and there is no mess at all.

[3vilc]

has anyone any thoughts on putting castrol magnatec in the 4jg2? ive got a new bottle sitting here i brought for my car seems a shame to waste it. always performed well in my cars and it says its diesel and turbo rated. just not too sure how it would go, does the 4jg2 have the hydraulic injectors too? (mines not the electronic injection model)

[geeves]

It might be ok but personaly I would say no. Many petrol oils say they are ok in diesels and vice versa but its better to use an oil specificaly designed for the motor type. The amount of detergent in some diesel oils would damage a petrol engine and the detergents in petrol oils wont last in diesel