Engine Problem Diagnostic and Oil Analysis

Tom & Ray - have been listening for many years and have happily learned from your discussions. Would like to recommend you consider Oil Analysis as a potential problem solving helper when folks have issues with engines - especially when they add that their oil is discolored or possibly contaminated. Not to plug one service - but Blackstone Labs has never let me down and their basic test is only $20 or so. It gives a tremendous amount of information about how well the engine is running and what state of repair the engine is in. Easy items like blow-by and head gasket failure (or imminent failure!) surely shows in the oil. Just my $0.02 - love the show.

They don’t visit here, so your post was in vain.


T&R rarely stop by here. There’re just us neophites.

Oil analysis is a good diagnostic tool when appropriate and when combined with other diagnostic techniques, but ther are countless problems that won’t show in oil analysis and other diagnostic tools that will generally determine the cause of things that would show up in oil analysis.

I’ll use blowby and head gasket failure as a examples, since you’ve mentioned them. While blowby would show up in oil analysis, it can also be determined with compression testing. A blown headgasket will not show up in oil analysis unless the breech involves an oil channel. Since the cylinders are surrounded first by coolant, a headgasket breech will typically be only from the cylinder to the water jacket. It’s symptoms will show up as hydrocarbons in the coolant and often overheating (from the 2000+ degree combustion gasses being blown into the coolant) and poor operation (due to low compression in the affected cylinder and sometime spark plug damage).

In short, oil analysis is a good tool, but just as a commpon screwdriver is only appropriate for certain repairs, an oil analysis is only appropriate for certain diagnosis. It takes a lot of different tools to do the job.