Thread: Got my oil test results

Originally Posted by robbotd5

Thanks Rick. What is an acceptable level of dilution? (%). I have a work ute so the Disco is a weekend play thing and I never take it on short trips and it is always at op temps. I used Oilcheck in sydney. I had just checked the oil pump bolt prior to changing the oil and used some loctite blue maxx sealant to hold the gasket in place so that could account for some of the silicon content. I will change the oil/filters and re test in 1500-2000k's time while monitoring the dipstick levels. So you recommend 15W40? I was thinking of Valvoline synpower 5W40? Still exy I know.

Regards
Robbo

As i said above, ideally 0.5% according to the experts I listen to, but the lower the better, no oil copes very well long term with fuel dilution.

A lot of cars these days are suffering, a lot of the DI petrol engines aren't coping very well either, there's a lot of fuel finding it's way past the rings in them too but it's being kept pretty quiet by the car companies.

Silicon from RTV gaskets leaches out for a while so yep, that is often a source.

The 15W-40 Ci-4/CI-4+ oil is a suggestion as you continue testing as
a) it's cheaper than a syn petrol engine oil
b) it's a more robust oil anyway and will cope better if it is a leaky injector (and seeing as the seals were changed after the last oil change, everything could be quite OK yet)
c) it won't be a problem starting/running at current ambients compared to a 5W-40. In reality you have to get a fair way below 0*C to for it to be an issue, although you can notice it in cranking speeds around 0*C.

Ultimately if you are going to go back to a 5 or 10W-40 I much prefer a proper diesel oil like Mobil Delvac 1, Caltex Delo XLD, Penrite SIN Diesel or Diesel SP, Fuchs Titan MC 10W-40, etc.
They are just beefier oils and usually cheaper than an equivalent petrol engine synthetic oil, or at least they have been for me over the last ten years.
ATM I'm paying under $170/20 litres of Penrite Diesel SP 10W-40 and that's the walk in off the street price at the local independent spare parts store. It's actually cheaper than the trade price I was paying at Bursons, so go figure.
For years I used Mobil Delvac 1 5W-40 in my engines and it was cheaper from the Mobil depot than buying Mobil 1 from K-Mart or anywhere else and it's a much 'stronger' oil than Mobil 1.

Just be aware that changing oils throws any potential future trending right out the window, but seeing as you've done some recent changes re the injector seals and gaskets it's hard to use that first test for any future trends anyway.

Thanks for that excellent reply Rick. I went this afternoon to speak with Ben from all 4X4 and he agreed that an amount of diesel could have been spilled into the oil when the injector seals were done. So I bought the 2 new filters, a 450ml can of Nulon Oil system cleaner and 10l of Penrite HPR 5 Diesel 5W40 semi synth oil. Added the cleaner and ran TD5 for 20 minutes. Shut down and drained sump. Left for 20 mins as I changed both filters. Flushed some excess new oil that I had lying around (mobil synth 10W40) through and drained. Left for another 20min to drain. Put sump plug back in with a new washer and torqued to 23Nm and filled to full line with the said Penrite oil and ran TD5 for 15min. Waiting now for a "cold" reading then I will top up to just under the full mark so I can monitor the level. I will drive a thousand K's or so and then get another sample done. Hopefully the fuel dilution will be well down on the previous 4.4% which equates to around 317ml of diesel in aprox 7.2 l of oil.
Regards
Robbo

Hi Robbo,have you drilled out the restrictor in the return fuel line at the filter housing'tis is on another thread concerning fuel dilution,I've done mine and semms to have done the trick,my mates 99' d2 has not suffered oil level rising and is much easier to prime with new fuel filter change,my 04' is impossible to prime even following procedure exactly,after doing mod,(takes about 30min or less) system now primes same as mates and so far oil level has not moved,maybe that is the cause and not different seals???,just a thought

Oil analysis, while a very useful tool, should be taken as more of a trend indicator than an overall value.

I have used commercial oil analysis companies a lot for work. I had a clean/new oil sample (never near an engine) come back with 0.5% soot. The oil analysis company said their accuracy is +/-0.5%!!!

Ben, I've seen results of that from sending the samples from the same batch to several different labs, all the results were different.

Fuel % generally can't be listed under 1% by any lab here, just their methodology and as you said their error ranges.
Some labs in the US can accurately test lower but you also pay for it.


I also know of dirty virgin samples, but the scarry part was that the oil was indeed contaminated (and it was an ultra expensive synthetic, seems the bottling facility wasn't too clean)
My oil analyst made me aware of a case here where an engine was showing wear metal issues and after eliminating all potential dust ingress paths the oil was swapped out for a major brands mineral oil and the engine showed 'normal' (ie, no wear) results.
Virgin sampling showed contaminated oil.

Originally Posted by rick130

ATM I'm paying under $170/20 litres of Penrite Diesel SP 10W-40 and that's the walk in off the street price at the local independent spare parts store.

Delvac1 E7/E6 full synthetic 10W40 20L drum is available at Mercedes Benz Truck dealers nationally for about the same price.

Fuchs Titan range is a very under rated oil also.

Gday all.
Just did a trip to Forster and back so the Disco has 381km on the new Penrite 5/w40 that I put in after flushing engine and changing oil/filters. I filled it to the bottom of the full arrow. Checked the level when we arrived at Forster after TD5 had cooled down and the level was 3 or so mm under the full arrow. Ariving home, same deal, checked when cool and the level is back to where it started, (just under the full arrow) both times on level ground. Is this usual? Also, if I had a cracked head, would'nt the oil level be noticeably higher? Sorry for draging this out fella's but it is realy bugging me.
Regards
Robbbo

G'day Robbo,mine does the same,the spinner(oil centrafuge) also holds about a cupful of oil and this can take a while to drain back into sump,you have to be patient when topping up or checking levels!I've also found pulling the dipstick in and out seems to drag oil up the tube raising the full mark.Unless it rises significantly I wouldn't loose to much sleep over it,still keeping an eye on mine since drilling out restrictor so will keep you posted,but ya' still gotta' love 'em