[Chas2]

Took my 2.8 to the dealer for my 2nd oil change. After an 8 mile trip home I garaged it and checked the oil level. The oil was pitch black, obviously having not been changed. The tech was half way sharp as he wiped around the oil fill plug and filter making it look a though he changed it. The dealership manager confronted the tech who swears he changed both oil and filter and that the black color of the oil is typical of a diesel. Having driven diesels for some years I told them diesel oil does get black---but not in 8 miles of driving. Why when I had my first oil change and drove home and checked it was the oil clean --- shrugged shoulders. Bottom line is dealer took a sample and says he'll send it out for analysis, he says you say it wasn't changed and my tech who is well respected says he did. Is it possible for an analysis to determine how old the oil is, or as I suspect is it just going to reveal metal fragments and contaminates. Is there anything I should request the analysis look for that could prove its oil with 7ks of miles on it not 8 miles. Thanks!

 

[Chuck_B]

I changed mine just a few days ago. I checked/set the level as soon as it filled the filter. It was already black at that point, 0 miles. Enough oil remains in the head and on casting walls to do this. Oil cooler stays full as well.
Sporting of the dealer to analyze a sample. The lab will know what to look for so long as they know why the sample was pulled.

 

[NormWild]

It depends really how long he let it drain. Most shops will put the plug back in as soon as the stream breaks, which leaves a good deal of oil still in the pan. Not to mention all the oil still left over in the rest of the motor. The oil in these diesels gets so black that I could see a half a quart darkening up the new oil. I just changed mine out, and was surprised to see the oil was already looking black after the ride home, and I KNOW the oil was changed. I'm changing it myself from now on, so I can let it sit and drain everything out.

 

[Brayan Rosales]

It depends really how long he let it drain. Most shops will put the plug back in as soon as the stream breaks, which leaves a good deal of oil still in the pan. Not to mention all the oil still left over in the rest of the motor. The oil in these diesels gets so black that I could see a half a quart darkening up the new oil. I just changed mine out, and was surprised to see the oil was already looking black after the ride home, and I KNOW the oil was changed. I'm changing it myself from now on, so I can let it sit and drain everything out.

Ditto, thats why i do my oil change, i let is drain while i vaccum, and once it's fully drained I add about 1/2quart to push out any sooth, then when that drains, I plug and fill

 

[Chas2]

Left Out

What I didn't include in the post was that they agreed to change the oil again on my return visit to see the general manager. I insisted on being present for this change as the same tech was changeing the oil and I was concerned he would through some sand or something abrasive in the fill hole to spite me, and that would not be detected on the dip stick. Bottom line is I get home having driven the same 8 miles home -- check the oil level and it's clean. Looked the same as my first change at 5k, slightly darker than new but obviously clean. I could easily see the hash marks on the stick through the oil, not so with my 7k oil--it was tar black.

 

[dmaxjr]

What I didn't include in the post was that they agreed to change the oil again on my return visit to see the general manager. I insisted on being present for this change as the same tech was changeing the oil and I was concerned he would through some sand or something abrasive in the fill hole to spite me, and that would not be detected on the dip stick. Bottom line is I get home having driven the same 8 miles home -- check the oil level and it's clean. Looked the same as my first change at 5k, slightly darker than new but obviously clean. I could easily see the hash marks on the stick through the oil, not so with my 7k oil--it was tar black.

It was the extra silicates in the sand that made it look cleaner the 2nd time.:surprise:>

 

[Chuck_B]

Or maybe the fact that it had been changed twice.

It was the extra silicates in the sand that made it look cleaner the 2nd time.:surprise:>

 

[Toughsox]

Right here I'm calling bullshit

he says you say it wasn't changed and my tech who is well respected says he did.

Unless this tech is the old timer in the shop and cant get around like some of the younger guys....the guy that does the oil changes is usually one of the lowest guys on the experience ladder. The better techs do the oddball, hard to diagnosis, higher paying (for the dealership) jobs.

A shame that you have to question the dealership but sadly.....they bring it upon themselves. So many here have gone in for their free oil changes and tire rotations only to find (after marking the tires) that nothing was done.

Personally, where I bought my truck I would buy from again and again.....but I wouldnt trust them to add washer fluid without thinking they screwed something up.

 

[404 Not Found]

If they did it right, it should look dark but still very much transparent. It it was tar black, then something is wrong. The tech brought it on himself. He should have shown you the dipstick like an oil change shop does. Shops do that to avoid such problems. Instead, he closed the hood and said your truck is ready. It's your megabuck engine. You handled it right except for not checking it right when it came out of the shop which I'm sure you always will now.

 

[jdecker94]

honestly, it depend son the engine on how dirty the oil gets. I have 2 old diesel tractors, an old yanmar with 6000+ hours and a kubota with 2000+, both still run perfect. every oil change i drain the oil, add a couple quarts of diesel, drain that, then add oil and new filter. the yanmar blackens the oil instantly, the kubota wont for 10 hours or so. i know these arent new, common rail, turbocharged engines. diesels none the less though. just my 2 cents.

 

[lqdchkn]

Im the only one thats changed my oil and I always change the filter with it at the same time. I only put in 5 qts. run the motor for a few min while I check for leaks, ensure the filter is full, etc, then let sit 10-15min, check the level and top off as necessary.

I can tell you that in the above time the oil is much easier to see (starting to get dirty) after just that few min idling than if I try to check it without running it at all.

IMO 8 miles would be more that enough time to blacken the oil from a fresh change.


I also agree that the second time it checked cleaner because it was changed twice and everything was basically "washed" in new oil twice.


Only way to be sure you were screwed (or not IMO) was if you would have taken a sample and sent it to BlackStone for analysis. They could easily tell you if it was fresh or not

 

[Toughsox]

You handled it right except for not checking it right when it came out of the shop which I'm sure you always will now.

Or......drumroll...... be 100% sure and change it yourself. 0

 

[DougC]

Or......drumroll...... be 100% sure and change it yourself. 0

Gas engine for me-but I won't be taking "advantage" of the free oil changes! :wink2:

 

[Toughsox]

Gas engine for me-but I won't be taking "advantage" of the free oil changes! :wink2:

The last 5 new cars I have bought I have always refused their free oil changes and ALWAYS told my dealer that the deal hinges on him throwing in at least a half dozen oil filters. I have never had a dealer turn me down at that point of a purchase. (although, one guy did ask me to sign a paper stating I would not come back and demand free oil changes.) :laugh::laugh::laugh::laugh:

 

[madcratebuilder]

I've done many many oil changes in the old GM 6.2's and 8 miles is more than enough to make the oil black.

 

[ckundred]

I took my Canyon diesel into the dealer for my first "free" oil change and DEF top-off at 2800 miles about a month ago. I was heading out on a trip from the Bay Area in California to Colorado. On my way home from Colorado about 2500 miles into my trip and about 200 miles from from my home I got a "poor quality DEF" message and the computer was going to limit my max mph. I found a gas station and added a gallon of DEF, and 15 miles down the road the message went away. The next day I went and got a 2.5 gallon jug of DEF and my DEF tank took it all. That's 3.5 gallons of DEF used over approximately 3,000 miles...I'm guessing at most I should have used less than 2 gallons. What it tells me is that 1. my dealer used poor quality DEF when they gave it to me after purchase and 2. It's highly unlikely that at my "free" oil change and DEF top-off they added any at all. So how certain should I be that they even changed my oil? Dublin GMC in Dublin California--I'd stay away from them...I think the auto manufacturers have done a good job of better policing the sales tactics of their dealers but there's a lot more that needs to be done on the service side--I'd be concerned if I were letting these service centers/dealers proudly display my brand.

 

[100MPG]

I would not let any dealer change my oil or even add windshield washer fluid on my new truck.

 

[will e]

I am not running a diesel, never have, so I don't have an opinion on how black the oil might be. On gas engine cars it doesn't blacken up that quick. I did have the dealer change my oil, rotate the tires and do the MPVI. I figured having the dealer change the oil will cause less issues if there is ever any warranty work required. Next time I head in I will look at the oil before and after. Also I guess I need to mark the tires to make sure they do the actual rotation.
When I buy tires I usually go to Discount tire. They rotate for free. You can watch them do it.

Normally I change my own oil but I now own two cars with warranties, and the Caddy gets free oil changes, so for now I will have the dealer do it.

Thanks for the tips! I will be watching a bit closer now.

 

[DB/SB]

I actually trust the dealership that I purchased mine from. Been doing business with them for some time now as have other family members.

 

[boborc]

The Dealerships vary some have problems with the say work was done and never do it such as oil changes. I got the no oil change oil change on my first trip to the dealer for a free one. Called them on it and was told to come back Monday to file a formal complaint. Never did called GM and complained there not to mention on every social media site and review site. So if that just caused 2 people not to buy from them or use them for service they loose a lot more than the cost of that oil change.I worked in a dealership many years ago and used to watch mechanics get parts from the parts window, throw them in the garbage take the customers car for test ride to get food and call the job done. A frequent scenario where I worked. I thought thing would have changed by now but guess not. That's why I do everything myself. I gave them a shot and they failed. Unless its warranty or recall no dealership for me.