O- ring in engine needs to be fixed?

I have a Ford Focus and I was told the o-ring in the engine needs to be fixed. He said he needs to check again to make sure that's the problem. I have no idea what any of that means but could anyone guess an estimate of the cost for repairs? This is all the information I know that he told me so sorry if I didn't explain well

Added (1). He said that there's no pressure from the engine and something is wrong with the o-ring, I would just like to know what the cost would be like

All depends on where the o-ring is. That is something you failed to mention. Why didn't you ask them what they thought it would cost?

2000-2004 Ford Focus Water Pump O-Ring?

Any antifreeze leak is dangerous because if coolant runs low and it overheats, engine damage, like the head gasket can cost a thousand dollars to change.

Problem is, there's a whole bunch of O-rings in that engine, just depends which one. One common failure point was the thermostat housing, it is plastic and warps. You actually have to get a whole new housing which comes with an O-ring, with new coolant that repair may cost $200.
What kind of problem were you having? If leaking, do you know what?

Find another mechanic that explains it better to you. O-ring in the engine doesn't cut it. How about telling us what the problem is?!

Even with your update it's not helping. An o-ring is just a round rubber seal, that seals "something" in.

There are O-rings keeping in the engine oil, likely the coolant, brake fluid, aircon, the clutch fluid, fuel etc.

One is apparently leaking…

The rest is a mystery. Ask for a more detailed explanation and an estimate to repair it, and people can comment better on what is actually wrong and if the repair seems reasonable.

Not enough info!

If you tell us what kind of problem you are having with your car we may be able to figure out what O-ring your talking about to give you an answer.

Get a written estimate. This sounds like another con job.

He needs to check "again"? Baloney!

Can you start with why "he" was asked to check the engine?

And if "he" found a problem, why check again?

A leak, right?

You type a statement and put a question mark there.
Thanks.

Psychic readings are made with oda-mae in the apartment upstairs.

O rings are sold in the parts department.
They need info.
You need a technician.
and a diagnosis.
Testing.
And information research for correct
current proper repair, to prevent repeat repair.
Thats why Ford has a service department.
Call there.
ask for service, a service advisor, tell them.
see what they ask.
Get them the answers.
They look it up. If there's a bulletin… Is there an updated part number listed there?
Then they can switch the call to parts
And tell that number to the parts person.

Simple, right?
That is the one and only way to get it right.
unless you go around to the front counter, then they look it up by application. If they try to order it, they get corrected with the new number, and then they have to call you.
If you show up looking for it, you better have the slip proving it was ordered.

if the bulletin had updated parts or procedures, you could get the idea
to make a lasting repair from their proven correction.
Having an extended service policy contract gets coverage beyond powertrain warranty.

Other wise, you pay, and it's cheaper than an engine.
The engineering update has been done, you don't have to redesign it, like the olden days.
When the mechanics had to make their own parts
Because part numbers were a matter of national security.
2 weeks later, the wrong side comes in.
after you have the staff beaten and threatened,
They find it on the shelf right behind them…
Those days are through.

Now they have a lady parts man, and she apologizes throughout the experience of ordering the right part… For the wrong side.

Then you just use a can of sealer from the parts store.

GO BACK andand ASK AGAIN! The O ring can be found in MANY places including the OIL FILTER! I would ASSUME that is what is meant here! BYE NOW!