how can one tell 100% that the oil was changed

Messages
1,330
Location
Washington for now
Thread starter
was over at my sisters house helping her with something . while there i took a look as her vehicle . i checked the oil and it was dark and about 1/2 quart low. i asked her when she got her oil changed last. she said she just got it changed at the toyota dealer a couple of days ago. i looked a the reciept and she has put about 60 miles on it since. looking at the oil i am suspicious if they changed it or not. two things got me. the color and the 1/2 quart down. i told her my suspicions and she asked how do we prove it? So that is the question. how does one prove that oil was never changed ?
 

LvR

Messages
86
Location
SA
If you know the brand and spec oil supposedly used send off for a UOA and compare with whats found ............... else all bets off imo
 
Last edited:
Messages
13,322
Location
1/2 hr N.E. of Detroit
Familiarity with the vehicle is the best evidence. One should know how the oil dipstick looks right after multiple oil changes. One should know what the dipstick looks like 1K into the OCI, evidenced by multiple oil changes. Past history is the best way to acknowledge something went wrong with that just recent oil change. I just went thru this with my Hyundai dealer, after getting my (1) free oil change. The vehicle returned to me had dark oil - not clear. Appears as if the bolt was removed - a new washer inserted and then screwed back on. Looks like I received three new quarts of oil, instead of five. I argued with head of mechanics for a few minutes over the phone. Told them they will never touch that oil pan bolt again, on my dime. I changed the oil again the next day. Put in five quarts of Valvoline Advanced Synthetic. Dipstick is super clear again, almost 1K later.
 
Messages
34,652
Location
NY
These threads seem to be popping more frequently, here's my take. Proof it was changed beyond a shadow of a doubt comes in two forms. 1. DIY. 2. Watch the person who does it. Unfortunately anything else is based on trust, a hunch, or pull a sample and perhaps analysis can shed some light.
 
Messages
11,050
Location
Florida, Cape Coral
I agree with dermapaint. I do my own oil changes but, let the dealer do the first free one. However, the dealer whisks the vehicle away to a stall where you only see the tail lights. I ask to be at the car and was told NO. End of any future dealer service except warranty work. Ed
 
Messages
5,124
Location
Atlanta,GA
Answer: Blot Test. Just blot some oil on a piece of white paper and let it dry. Dirty oil will dry black. Newer oil will dry an amber to light brown color. Blot Test
 
Last edited:

Bud

Messages
2,801
Location
Texas
DIY is the only way to know for sure. Most garages won't let you in the bay due to liability issues.
 
Messages
432
Location
AZ
set hidden camera under facing the drain plug... review footage after. or best of all DIY!!! Blot test is kinda ok, but if they didn't let it drain all the way could give 1/2 false reading.
 
Messages
607
Location
The ATL
I can't answer your question, but I would go ahead and drain and refill with new oil just to be sure. Toyota dealer didn't change the filter on my brother's Tundra once. Needless to say he does his own oil changes now. Toyota corporate got a call about that one. smile
 
Messages
4,103
Location
SW Ohio
While a dealer or shop might not let the old oil drain for 6+ hours to get every possible last drop like some feel is necessary, how do they really benefit by pulling a car into a bay, hoisting it up, and doing nothing ? They save $10 by not changing either the oil or filter ? It makes little sense for them not to do the work....
 
Messages
9,373
Location
Canuck living in California
I have trouble reading the dipstick on my 180k mile Mazda 3 after an OC for about 500-600 miles because the oil is so lightly colored and transparent. So if the oil is obviously dark only after 60 miles, chances are it was never changed. And I don't think you need to prove to the dealer it wasn't changed. I would simply go to them, show them the oil color and see their reaction. If they value their reputation, they will change the oil with no to little fuss. If not, simply don't use their services.
 
Messages
607
Location
The ATL
Originally Posted by hallstevenson
While a dealer or shop might not let the old oil drain for 6+ hours to get every possible last drop like some feel is necessary, how do they really benefit by pulling a car into a bay, hoisting it up, and doing nothing ? They save $10 by not changing either the oil or filter ? It makes little sense for them not to do the work....
Sure it makes sense, especially when you figure they change oil on hundreds of vehicle every month. A filter here or there, oil not changed here or there. That's huge $$ every year. The Toyota dealer here was busted because I had Steelman Security Seal on the oil filter housing.
 
Messages
5,442
Location
MTL, CANADA
What vehicle are we talking about? That would likely help. In my experience, the oil should look a light amber, but I only have experience with 2 Toyotas (corolla and venza).
 
Messages
13,322
Location
1/2 hr N.E. of Detroit
Originally Posted by Killer223
set hidden camera under facing the drain plug... review footage after. or best of all DIY!!! Blot test is kinda ok, but if they didn't let it drain all the way could give 1/2 false reading.
That hidden camera will really appreciate the full car wash afterwards. It may be waterproof. But is it soap/wax-proof?
 
Messages
1,896
Location
missouri
When I used to have to use one of the quick lube places due to where I lived, I would check the oil before I took it in, I would take my ball peen hammer and make a small dent on the bottom of the filter like it got hit by rock. In those days I was much more flexible. Also I would check my brake, transmission, power steering, and radiator. Some will try charge you extra to top up those. It goes without saying to police your car carefully to make sure no bank statements etc are in there from the drive thru. When I picked it up, right in the parking lot where they could see. I checked my dipstick and filter and looked for leaks. If you do not do that then other than a used oil analysis no way to tell. Rod
 
Last edited:
Messages
1,330
Location
Washington for now
Thread starter
ok thanks guy. i am going to change it for her just to be sure. onething about dealer oil change is that you never see the car. they wisk it away and come back later. at least at the quick change places one can see them work most of the time.
 
Top