After 2 months of rebuilding my new toy... originally bought for $500 (drive shaft, tie rods, brakes, water pump, master cylinder, wheels, tires, serp belt, ARB bull bar) I finally got up the nerve to drive it from Denver (where I work) to Crested Butte (where I live... 228 miles away over 4 mountain passes.)

A week prior, I had changed the oil (10w-40) filter, and added the proper dose of Blue Devil engine stop leak hoping to address a small oil leak. I drove it around town for that week, getting it up to temperature/highway speed, making sure everything was in working order in preparation for the big drive.

On the drive, 29 miles in and after sustained climbing, my oil pressure light comes on. Luckily, I was right next to a big parking lot and got off the highway quickly and shut the engine off. I immediately fire up my mobile hotspot and got on here reading threads about how I may have anything from too light weight of an oil, to a broken sensor, to a bad oil pump, to a ruined engine. After sitting and thinking for about 30 minutes, I take a look around, check the oil, check under the truck for leaks or lost fluid. When all seemed well, I decided to turn the truck on momentarily to see if the indicator light was still on. I did not get far enough to see if the oil pressure indicator was on because the engine sounded so bad I immediately shut it back off.

After another half hour of pacing/googling/headaching, I decide that my next course of action would be to drive (I had my wife following me in my VW) to the nearest auto parts store and borrow an oil pressure gauge along with the fixings for a new oil change. The oil pressure gauge was not available, so I went with just the oil change. Got back to the truck, changed the oil, spent 45 minutes looking for the pressure switch that once found, I decided was too inaccessible to remove and test on the side of the road.

Time to test it, turn it on, prepared to turn it immediately back off. It sounds like crap, but immediately starts to get better. After idling for about 30 seconds, it is now sounding pretty good minus what I could only describe as a knock. (I've never stood next to a car that I knew had a knock, and had trouble finding a good youtube on the side of the road to conclusively diagnose.)

After 5 minutes I decide that the truck has started running well enough that I was ready to give it another try. Got on the road and over the next few miles it ran smoother and smoother until by the time I finally reached my destination, I was driving windows down, radio up, loving life because it was driving so unbelievably well.

So, as I was driving I developed a theory based on what I had read on the forums on the side of the road. It's my thought that the blue devil decreased the viscosity of the oil just enough, that it threw the pressure switch just as a very light weight oil (5w-30) has been described to do in other threads. This theory however does not explain why the engine sounded so bad for those few seconds during the initial restart, and then for 30 seconds after the oil change.

Any theories, speculation, anecdotes or whatnot would certainly be appreciated.

 

You got ripped off. I paid 200 for mine with 125k on it.

 

Don't use a stop leak on your engine, maybe a accessory pump, but that's it. Its a band aid fix, it will never address anything for longer than a month. It normally does more damage than good.


My questions for you, to help further understand your situation:

Is the blue devil stuff thick or thin?

Did the oil light come on while driving or at idle?

When you were driving it, it ran rough? then got better and better? now you have a rod knock? Am I right?

 

Dane,

"Is the blue devil stuff thick or thin?"
Blue devil is very thin, you don't add much but it would thin out the oil a hair. Which could lead to poor oil pump performance.

"Did the oil light come on while driving or at idle?"
The oil light only came on once, while driving up a sustained (15 miles), steep hill (5000-9000 feet over those 15 miles) at ~60mph. After the oil change it never came back on again.

"When you were driving it, it ran rough? then got better and better? now you have a rod knock? Am I right?"
Prior to the light coming on, it was running smooth but was rough when I pulled over due to the light coming on. It also ran rough immediately after refilling the engine with fresh oil (and new filter.) As the fresh oil circulated the engine began to run smoother until it was running like a dream 100 miles later.

 

I sorta think the Blue Devil thickened the oil, and your engine has a lot of carbon build-up, so the gooey oil wasn't flowing.

I'd do some googling and figure out the most aggressive engine cleaning treatment.

Then I'd perform that cleaning treatment and change the oil again.

Then I'd run either Rotella T6 or M1 TDT - you should stay away from 15w-40 because when the oil is cold you're likely starving your engine.

 

Thickening the oil is a bit counterintuitive, but I guess it is possible. Blue Devil is supposed to swell gaskets and o-rings so I guess it could have interacted with engine sludge/carbon to thicken the oil.

When I bought the car it was towed to me and it was 2 quarts low. I topped it off so I could run it to test the water pump I just installed. Once the coolant system was running again I then did a full oil/filter change and put about 300 miles on it. Then, after reading about these engines I did a anti-sludge treatment I added a dose of an engine cleaner and chained the oil again. Add those to the one I did on the road today and that's 3 oil changes in 500 miles including a flush.

The oil that was removed today was slightly dark but far better than the oil after the flush and did not have an odd or overly thick appearance. It was still somewhat clear and amber colored.

 

1) Why did you feel the need to add stop leak in the first place? Where is the engine leaking oil and how bad is it?

2) If I were you I would invest in an oil pressure gauge ASAP. Your oil light may be off but it may only be 1-2 PSI over the minimum to trigger the light. If your pressure is low then I would suspect you may have cracked oil pump gears ($100).

I bought the glowshift tinted 7 color oil pressure gauge $60 and a sandwich adapter $30 for easy install.

GlowShift | Tinted 7 Color Oil Pressure Gauge with Electronic Pressure Sensor

 

1)I ran 10w30 for a year and my engine loved it, I doubt that it would've thinned it out enough. I asked because normally stuff that you add in engine oil thickens it to increase oil pressure just a tad.


2)So the oil light came on while you WERE NOT idling? While driving up a hill with the engine under load? Correct? Still a little unclear about your answer, sorry for reasking.

 

Your re-asking is actually a great thing because it made me realize the exact circumstance that I did not describe (or understand) properly. The oil light came on just as I crested the hill so I had been climbing hard and then let off the accelerator, letting it go back down toward idle when I noticed it was on. Due to the placement of the oil light, its visibility is partially obstructed by the steering wheel in my prefered driving setup so the exact moment when it came on may never be known.

 

1.) The decision to add stop leak seemed like an easy one at the time. I have an oil leak somewhere on the block. I have yet to determine the exact location (I know, I know, no need for a lecture there.) Blue Devil, formerly advertised as White Shepherd, seemed to be raved about for solving just that issue. I searched looking for horror stories and didn't find any. I was in the additive section of my local APS and just went for it. All that said, we are where we are now and stop leak may have been the cause so I'd advise others to proceed with caution.

2.) I was actually going to save this for a different thread, but I'm underwhelmed by the amount of information provided to the driver by the dashboard and would like to add Oil Pressure, a real temperature gauge, battery voltage and ambient temperature but have yet to start the search for a good way to add all of those and maybe others without cluttering my dash like the mad scientist I wish I was.