No. It will only be beneficial to the motor.
No, new oil isn’t going to suddenly dissolve the sludge and cause a stroke. I would definitely change the oil. I’ve been in similar situations on used vehicles and despite concerns, they motored on for many years. You’re only risking the cost of an oil change so…
An oil change in a commercial vehicle is going to cost more than $20.
Otherwise your point is valid.
Since this is a Ford Transit with a 2.5L engine, $20 for oil and filter seems reasonable.
fleet farm has 5qt/filter for 12.99 this week. $7 rebate too. my suv is happy now. oil is not purple but it seems ok. no funny noises from motor. yet.
This is a vehicle with a turbo-diesel engine, and op doesn’t even live in the US . . .
In my opinion, the oil and filter change will cost considerably more than $20
I wouldn’t even consider to do an oil/filter change for somebody for 20 dollar (over here), even if you paid me “under the table”.
I’ve been searching a bit on the net in Europe and the cheapest quality engine oil for a modern (less than 25 y/o) car from a safe source was just under 8 US dollar - a quart - in Poland.
My neighbor 2 doors over, paid around 150 dollars just for the oil for his Rover AFTER his discount - which is basically a BMW developed engine. That was excl. filter and he does the job himself.
Just did a search for a price for an oil/filter change for my Opel Astra. Cheapest place was a place called Quickpot, charging 879 dkr for for the job on the condition that it takes 4 liters or less. And they use oil by the name Total. I think it’s French and I have zero experience with it.
879 dk money = 135 of US money.
Hos QuickPot bruger vi motorolie fra Total, som er en af verdens bedste producenter af syntetisk motorolie. Total indeholder altid højtydende baseolier, hvormed der opnås optimal beskyttelse mod lave og høje temperatur i alle viskositetsklasser. De progressive additiver er udviklet, så motoren bliver renere ved høje temperaturer, og samtidigt øger de slidstyrken.
Olieskift med op til 4 liter olie inkl. oliefilter og miljøafgift
879,-*
$20 is a reasonable price in the US, if you do the job yourself, in your own backyard, so to speak.
The OP’s circumstances are very different from your own, being overseas and all.
Right or wrong, I’m under the impression, that OP is not in Your country either. The Ford Transit is a popular commercial vehicle over here so there MIGHT be a fair chance that he is in - say - UK, given his name. 
I wasn’t one of those suggesting a cost for the oil change but I still suspect an oil change no matter where it’s being done is a drop in the bucket compared to replacing the engine. So the oil change still makes sense, $20 or even $200… at least if it were my problem that’s what I would do…
Agreed. Even if I had the money for a replacement engine, I’d try to get some use from the current engine, and an oil change is just basic maintenance.
can’t help but wonder what other vehicle services haven’t been done in the last 50k miles (which for an ice cream truck/van could be a serious number of years.)
Trans service? Rear end? Coolant? Brakes??? and as someone else mentioned- all the equipment inside? If the owner didn’t take care of the vehicle, how can you be sure they took care of the equipment inside?
All I can say is good luck. I feel you are going to need it.
I dunno, we used to have this ice cream truck go past my house at about 50 mph going from one populated area to the next. The only ice cream truck where the music being played was an example of the Doppler effect as it sped past… kids always disappointed…
Change the oil. If you pull the plug and nothing or very little oil comes out, the sludge has settled in the bottom of the pan. Like OMG said, change the engine. It’s already dead, but just doesn’t know it.
And you still bought the van ?
Why not? Commercial vehicles have value running or not. Most of the vehicles that I have purchased were not running, let the next guy spend all his money on a new vehicle.