996TT Oil sampling

[laalves]

Hi all,

I'm considering starting to monitor my engine oil using the services of oelcheck.de. They sell a handpump with a 3m tube to extract oil from cars with dipstick, i.e., wet sump engines.

Does any one know if I can reach the oil tank in my TT with a 3m tube down the oil filler or is there any mesh in between to prevent this?

[Loren]

The oil filter attaches to the oil cooler mounting bracket - too many turns there I think.

I think you would be better to go down the oil filler tube to sample your oil in the tank.

[laalves]

Thanks Loren. So you believe that I may extract oil via the oil filler without any obstacles in between?

[Loren]

Yes, but I still do not like oil extraction tools as I think they tend to leave all the dirtiest oil and debris in the engine.

[laalves]

You're absolutely right and I would never do an oil change with an extraction tool. This is to take a small oil sample for analysis.

[wross996TT]

You're absolutely right and I would never do an oil change with an extraction tool. This is to take a small oil sample for analysis.

You're missing Loren's point (I think). Doing analysis of oil extracted is not really analyzing the oil properly. It is a biased sample of the oil which likely will not contain some of the contaminants possibly present in your oil.

[Loren]

wross996TT is correct and that was my point. IMHO a better analysis is from drained oil and a separate inspection of the oil filter element.

A good lab should be able to tell how to get the "most accurate" results from their tests.

[laalves]

I understand your point but it is arguable. The oils taken from the oil tank is not necessarily biased. If you take the sample from drained oil it might have an excessive degree of contamination, since heavy contaminants might accumulate in the bottom area and stay there for years. In a new car I agree that drained oil it's best, and an older car (11 years, 142000km) there may be the whole history of contamination, instead of just since the last oil change, which is what you should be looking for.

I work in aviation and have been taking oil samples from piston and turbine engines alike for years, and this is a long standing discussion in the community: where it is best to take your samples from! ;)

[White987S]

My 993 Turbo is coming up on 17 years old (young!:)). I've been doing used oil analysis with Blackston for about 4 years now. 2 oil changes per driving season. My oil sample is always pulled during the oil change. Oil is hot. And drawn from the middle of the drain interval. Not early and not late. This is how Blackstone Labs recommends it's done. FYI.

[jpflip]

I am getting my oil analysis from Blackstone and here's a link that explain in a simple way how to get sample. Like in the aviation (I am also an aircraft mechanic) the important thing is to get the engine up in temperature (after a ground run). Blackstone suggest to drive the car for at least 20 minutes. So far, I always got the sample while changing the oil from the crankcase. I feel I got "the reality" of the engine oil state by getting it from the base of the engine..... Remember, at any time you can remove the plug from the crankcase and get somewhere around three liters without draining the oil from the tank. Of course you have to have a good working check valve at the base of the oil tank ;-) Here's the link: http://www.blackstone-labs.com/gas-sampling.php

Agree with White987S since we did our post at the same time !

Edited May 17, 2013 by jpflip