Should I bother with a UOA given conditions?

[cchase]

Hi all, this is my first post so bear with me.

I have a 1993 Chevrolet pickup with a 5.0 engine in it. The engine currently has 168,000 miles on it. I ordered some sampling kits from Blackstone because I was curious how the oil did. It's used Mobil 1 10w30 or 5w30 for its entire life on 3,000 mile changes.

My question is whether it is worth it or not to get a used oil analysis on this change, this vehicle is not my daily driver anymore. The oil that is in it right now has been in it for a few months. It likely won't even get to 3,000 miles until next spring. More importantly, the driving in that time has been extremely erratic with frequent start for a minute or two to move it and that's it, weeks without any real driving, numbers of days without being started, then some extended highway trips and towing 6,500 lbs last weekend. In addition, I replaced the spark plugs a month ago and always use anti-seize for this, reading through the forums here I have heard that can add things to the used oil analysis.

Given that the use has been erratic, the interval long on time, and several one-time events have occurred, is it worth spending the money on a used oil analysis when it is not very representative driving?

The only reason I approached the idea of doing a used oil analysis is because I'm a sucker for information. Also, the trucks last engine was used only for highway driving as a commuter with minimal "truck" duty and lasted 200,000 miles using only Mobil 1 10w30 and 3,000 mile OCI, at which point one of the valves stopped sealing and the engine was replaced. The truck has 368,000 on it right now and as I mentioned, the current engine has 168,000 and I am worried that something like the last engine will happen to this one. There wasn't any noticeable warning that the other engine was going to die. I've recently compression tested the engine to make sure it's healthy and the numbers are all within 12 psi of each other and on spec and I don't think there is any leakdown so it seems mechanically sound for now, just want to see if I can figure anything out ahead of time.

Thanks for any input and sorry for the long post.

 

[Gunatics_Adler]

Well a used oil analysis will help identify if the engine is starting to go out by testing for elements used in bearings and hard parts like camshafts. It will also tell you if certain things are going on like coolant leaks or if your air filter is doing its proper job. I say if you got the cash and can afford it, it might allow you to get several thousand more miles out of it by identifying small problems before they cause catastrophic damage. Id rather identify a head or intake gasket leaking and fix it, than to let it harm a much more expensive to replace engine.

I plan on doing one on my 440 New Yorker when I dump the oil to see how healthy she really is for 76k miles.

 

[Zaedock]

With 368,000 miles you've had the life of two vehicles in one. Personally, I think a used oil analysis is nice to check, but you've done pretty well without one! Info is cool, but at this point ignorance is bliss.

 

[StevieC]

to BITOG!

 

[demarpaint]

Originally Posted By: Zaedock
With 368,000 miles you've had the life of two vehicles in one. Personally, I think a used oil analysis is nice to check, but you've done pretty well without one! Info is cool, but at this point ignorance is bliss.

Took the words right out of my mouth. I'd save the money and change the oil sooner if you have any doubts. Especially if you have no loss of coolant or anything strange happening with the vehicle. So far you've done a fine job taking care of the engine!

 

[PT1]

WOW....400k...nice. Keep driving it and when it goes it goes.

 

[tomcat27]

First: welcome! second: good job on your truck! now... I've gotta ask: if you had a burned valve, why a whole engine instead of simply a valve job? I'm simply curous... I've done similar things: like a whole rebuild when all I had was a blown head gasket and a little piston slap. (the car was donated to me not running)

 

[Gunatics_Adler]

My dad once rebuilt his 455 Olds when it popped an intake gasket. Sometimes, gear heads just need a reason to tinker with an engine.

 

[cchase]

Thanks for all the replies and the welcome. I've been reading through the forums off and on for a few years and decided to finally join last night.

Quote:
I've gotta ask: if you had a burned valve, why a whole engine instead of simply a valve job?


At the time the replacement long block was something like $1200. Was cautioned against a valve job on an engine with that many miles, don't remember the specific reason. The old engine is still kicking around at a friends house.

Here's how it looks these days:

So far this engine is running perfectly, compression is spot on with specs, doesn't burn any oil between changes, no coolant, etc etc so I am hoping the other engine was just a fluke.

 

[gathermewool]

If for no other reason a used oil analysis will give you a snap shot of how the oil is holding up. It may not be representative if you drive for 10-15 minutes before draining, but the prior fuel dilution and cold starts will show themselves in shearing of the oil, faster TBN depletion and a lower flash point. While the wear metals may not indicate a potential failure, the other elements could help you nip a small coolant leak in the bud. PLUS, like you, I'm a sucker for data!