Tips for obtaining good sample for analysis?

[LoneRanger]

2005 VW TDI. 9000 miles on a fill of Mobil 1 ESP 5W30. 50,000 miles on the car. I sent off for a Blackstone kit but it hasn't arrived yet and I need to change the oil today. I've never sampled before and want to get a good one. I will drive the car up to operating temp and pull the pan plug. From there, any tips on how to collect a good sample? My drain pan is not clean, so I will probably have to go the messy route and interupt the drain stream with a clean container of some type (?)

 

[DieselTech]

Drive the car until it is at operating temp for about 10 miles. NO idleing!!

Start to darin oil and catch your sample from the middle of the drain. This will ensure any contaminates around the drain hole are gone.

This will give you a accurate sample

 

[hate2work]

Just use a very clean plastic jar with a lid and catch some oil from the drain stream about halfway through the drain. Cap it and wait til the kit arrives, then transfer it to the sample jar in the kit. Oil can be stored for several months before sampling without changing the results, so no worries about a few days til the kit arrives.

 

[demarpaint]

Originally Posted By: DieselTech
Drive the car until it is at operating temp for about 10 miles. NO idleing!!

Start to darin oil and catch your sample from the middle of the drain. This will ensure any contaminates around the drain hole are gone.

This will give you a accurate sample


Just a quick question re: getting a good sample. If a car is driven on the highway for lets say 30 minutes then shut down wouldn't it be best to take the sample based on how the engine is actually used? In this example after a 30 minute drive?

Now if someone uses a car for a 1 mile trip and shuts the engine off for 8 hours then drives 1 mile home shouldn't the sample be taken after the 1 mile drive?

I'm not trying to start trouble I'm asking a question. I would want the sample to best represent how the engine and oil are being used. No false readings, if the guy making the 1 mile trip decides to run his engine longer getting the oil to operating temps would get a report that might not be as accurate based on how he uses the car. JMO

The oil in the second report would be loaded with contaminants, and probably get a lousy report. However that report would accurately represent the condition of the oil under actual use.

 

[DieselTech]

The problem with a 1 minute drive and not knowing someones driving habits it there could be condensation in the sample. Getting the oil to temp with a good drive will burn off the condensation. If the vehicle has a habit of short trips it could have excessive fuel in the sample aswell. You want this stuff burned off before you sample
http://www.blackstone-labs.com/gas-sampling.php

Also getting the oil to temp will get the contaminates in suspension again. When you walk out in the morning where would wost contaminants be.....in the bottom of the pan. So would sampled wear numbers be off, Possibly. The company that analizes the samples reccommends warming the vehicle for a reason

I do wish people would see the benefit to taking their vehicles for a drive on sunday or something. I have mentioned several times when people have concerns to short driving and god forbid they spend 3 gallons of gas on a decent little trip to get their vehicle to temp.

 

[hate2work]

Originally Posted By: demarpaint
Originally Posted By: DieselTech
Drive the car until it is at operating temp for about 10 miles. NO idleing!!

Start to darin oil and catch your sample from the middle of the drain. This will ensure any contaminates around the drain hole are gone.

This will give you a accurate sample


Just a quick question re: getting a good sample. If a car is driven on the highway for lets say 30 minutes then shut down wouldn't it be best to take the sample based on how the engine is actually used? In this example after a 30 minute drive?

Now if someone uses a car for a 1 mile trip and shuts the engine off for 8 hours then drives 1 mile home shouldn't the sample be taken after the 1 mile drive?

I'm not trying to start trouble I'm asking a question. I would want the sample to best represent how the engine and oil are being used. No false readings, if the guy making the 1 mile trip decides to run his engine longer getting the oil to operating temps would get a report that might not be as accurate based on how he uses the car. JMO

The oil in the second report would be loaded with contaminants, and probably get a lousy report. However that report would accurately represent the condition of the oil under actual use.


You have a good point. It's kind of like the guy that's out of shape who goes on an eight week crash exercise course before his check up, then passes the exam with good results, and then goes right back to being lazy. Those results don't mean squat because that's not how he really lives.

 

[LoneRanger]

I drove it about 20 minutes, plus it had been driven around town 3 hours prior, so was still warm... but put the 20 minutes in anyhow to get the oil hot and mixed. Captured sample from about mid stream... huge mess since I had to move catch pan aside to get my sample container into the stream (close clearance, I drain it level on floor -- no ramps or jacking). Worth it though. I obtained a good approx. 8 ounce sample captured w/ brand new plastic container with lid.

Now to get that kit. Going to order a TBN test in addition to the standard testing. I will be interested to see where the TBN is on this oil after 9000 miles.

 

[Bruce T]

Besides catching oil from the middle of the drain, I've also been told to never wipe oil off the jar threads with a towel. The materials on the towel can contaminate the sample. Put the lid back on first, covering the threads, then wipe off the jar.

 

[bigdawg74]

Originally Posted By: demarpaint


Just a quick question re: getting a good sample. If a car is driven on the highway for lets say 30 minutes then shut down wouldn't it be best to take the sample based on how the engine is actually used? In this example after a 30 minute drive?

Now if someone uses a car for a 1 mile trip and shuts the engine off for 8 hours then drives 1 mile home shouldn't the sample be taken after the 1 mile drive?

I'm not trying to start trouble I'm asking a question. I would want the sample to best represent how the engine and oil are being used. No false readings, if the guy making the 1 mile trip decides to run his engine longer getting the oil to operating temps would get a report that might not be as accurate based on how he uses the car. JMO

The oil in the second report would be loaded with contaminants, and probably get a lousy report. However that report would accurately represent the condition of the oil under actual use.


I was thinking the exact same thing.


Originally Posted By: DieselTech
The problem with a 1 minute drive and not knowing someones driving habits it there could be condensation in the sample. Getting the oil to temp with a good drive will burn off the condensation. If the vehicle has a habit of short trips it could have excessive fuel in the sample aswell. You want this stuff burned off before you sample




Actually, I think I would want it in there to show up on the report. Which is better for someone who does a lot of short trips:

1) A report based on a sample with condensation/fuel burned off so it (falsely) looks ok to extend your OCI or...
2) An accurate report based on what your oil condition normally is, and therefor, may recommend changing your oil more frequently.

As someone who does mostly short trips myself, I would want the latter, as opposed to the former.

 

[demarpaint]

That was my logic. No point in knowing how the oil is doing after a good run if the car is only used for short trips. OTOH taking a sample after a short run from a car used for long trips might skew the results as well. JMO

 

[scurvy]

Originally Posted By: LoneRanger
2005 VW TDI....
From there, any tips on how to collect a good sample?

My preferred method on my 2006 Golf TDI:
Drive car to get fully warm, or pop hood after returning home from work. Get sample container, Blackstone sampling pump & new tubing; assemble. Pull dipstick, insert tubing, pull sample. Cap sample bottle, shake & pour back into engine. Pull second sample. Cap, mail to Indiana.

If you insist on doing it from underneath:
Warm up as before, put on ramps, remove Dieselgeek skidplate, acquire drain pan, socket, sample container. Pull drain plug. Catch oil from approximately the middle of the stream. Cap container first before wiping exterior. Mail to Indiana.

The pump is great because you can sample at any time from the top side - excellent for a mid-OCI UOA to see how it's holding up.

 

[daman]

Don't over think this simple task,you want the oil hot/@ operating temp then catch sample mid drain,simple done.

 

[21Rouge]

Originally Posted By: scurvy

The pump is great because you can sample at any time from the top side - excellent for a mid-OCI UOA to see how it's holding up.


Agreed except some vehicles (mine for example) is unable to accept tubing down the dip hole; sharp bend or such and so one is unable to pump any or much up.

 

[bigdawg74]

Ok, well I just got an email back from Blackstone Labs. I asked about sampling procedures for short trip vehicles. Here is their response:




At 03:45 PM 4/12/2010, you wrote:
> Comments = I do mostly short trips, so I am concerned about condensation/fuel in my sample. Should I warm the vehicle up prior to collecting sample (20 minutes), or maybe just 1 or 2 minutes to get a more accurate sample in relation to how the vehicle is driven? (We are debating this over on the BITOG board)


John: Thanks for the e-mail. I wouldn't do either. Just get a sample with the engine cold. That way we'll know exactly how much water and fuel is accumulating on a normal basis. Try to avoid starting the engine right before taking the sample (like 5 minutes before). That puts extra fuel into the oil due to the engine needing to start on a rich mixture and doesn't give accurate results.

Let me know if you have any more questions.

Sincerely,
Ryan Stark
Blackstone Labs



So, it seems like in order to get an accurate UOA, one needs to sample it correctly. Of course, I wouldn't want to do this in the middle of winter, though.