oil question

[john robertson]

I change my oil very frequently, usually at 1000 to 1200 miles. I've noticed for quite some time that it turns dark pretty fast, let's say at 300 to 400 miles. By the time I change it, it's pretty black and was wondering why. What's odd is that I have other turbo cars, and I follow the same regimen on oil changes, same oil, same filters, in fact, I might go up to 2000 miles on those cars, because I don't drive them as much or as hard as my GN, but the oil in those cars doesn't turn "black". It's not something I'm worried about because it runs great, but just wondering if there's any changes I could make to prevent this from happening.

[Steve Wood]

I have not seen that difference between similar cars.  Normally, the color is a sign of the additive package reaction to heat and is not a sign of old or dirty oil.

My only thought is to send a couple of samples from different cars in for an oil test (mileage, etc. being similar) and see if anything is contrasted on the results.

It's an interesting question.

[nocooler]

Excessive oil temps and combustion contamination can make it dark in a hurry.
1000-1200 is a little ocd in my opinion. What oil are you using? 

[john robertson]

Ya know, oil's cheap and still, I could check to be exact, but it's at least a month between changes on my GN, much longer on the other two because I don't drive them as much. The brand doesn't matter because I'm getting different results with the same oil. Also, I have two oil filters on two of the cars via turbo-lubers.

[john robertson]

I have not seen that difference between similar cars.  Normally, the color is a sign of the additive package reaction to heat and is not a sign of old or dirty oil.

My only thought is to send a couple of samples from different cars in for an oil test (mileage, etc. being similar) and see if anything is contrasted on the results.

It's an interesting question.

That's probably the only way I would know. I thought perhaps there was some common explanation for it like a PCV valve or something.

[earlbrown]

Dump a can of Restore in there on your next oil change.



The black is carbon that makes its way past the rings into the crankcase (from burning hydrocarbons).

For funzies, do a compression and leak down test beforehand.     It never stops being odd seeing that stuff actually work.

[john robertson]

Hey, thanks for that Earl. I'll have to try it. As I mentioned, the car runs terrific but have wondered for some time now why the oil darkens so quickly, noticebly at 300 miles. Compression Test? Leak down? I haven't even fixed my torque converter lock-up on my El Camino yet! GN is fine though.

[john robertson]

Just read some positive comments about the RESTORE additive. Maybe I will run a compression test, and replace my plugs while I'm at it. Let you know what I find.

[earlbrown]

Most people (including me) dismissed it as ''rebuild in a bottle'' snake oil.

but the science if valid.    Basically it's got a buttload of suspended microscopic aluminum.   If you look at a cylinder wall with a microscope all the millions of tiny scratches are very jagged and basically have millions of tiny glow plugs jutting out of them.   Since that's higher than the melting point of aluminum, they get 'tinned' like a soldering iron tip.  At that point the surface is smoother and the glow plug goes out.

Back in the 90's the owner of the Yamaha shop I raced out of had a friend that maintained a huge fleet of 305 Chevy pickup trucks for Auburn AL.   He was looking at having to buy something stupid like 45 crate engines because the trucks were all out of spec compression wise.     Just for the hell of it, he dumped a bottle of Restore in each one, put 500 miles on them and ran another compression test.

  Every single one of them was back up and now within 10% of each other.


Back then we didn't have youtube.   There's plenty of videos on there with people running that exact test and I haven't seen one that failed yet.



Now I'm not saying it'll fix a busted engine, but I've seen with my own two eyes it will help with ring seal.    And obviously, the worse the seal when you start, the greater the gains to be had.


I've been meaning to do a before/after on my GN since it's only got a couple thou on the engine I built about a decade ago.   I never think about  it since I change the oil about every 5 years or so.

[john robertson]

Well, after reading some favorable reviews about it, I decided to do a compression check, and found my cylinders running between 130 and 140. I expected better, but it is what it is. Like I said, I'm quite happy with it's performance, but now, I'd like to see if this product will increase the compression as advertized.

[Steve Wood]

Me, too!  😂

[john robertson]

I had just changed my oil the other day, (I use conventional 20W50) and hadn't gone anywhere, so figured I'd go out and get some "Restore". Added it, and I guess I'll give it about 500 miles and then re-check the compression. Actually, I'll be shocked I tell you, SHOCKED, if my compression numbers increase. 

[Steve Wood]

)Another "Me, too!" but Earl is not the only guy that I know that swears by it

[reality]

It will lower your temp 10 degrees. Actually seen on 2 tb's

[Just a Six?]

I use anything on sale in 20-50 or 15-40 & mine does the same thing altho I only put that kind of mileage during a whole season. The motor is about 10 years old now with a good half a dozen track days so when it comes out in spring I'm going to check the compression & add a bottle to see what happens. I'll try to remember I'll post the results next fall. Glad you posted this up.