Hi all,

About 6 mo ago, I had the timing belt and the cat converter replaced in my 2013 Fiesta (100k miles), and I was hoping to get another 2-3 years from the car before buying a new one. A month later after the job was done, I started noticing a small oily spot appearing on the floor under the engine in the garage. I put an aluminium plate at the spot to take a better look at the fluid (attached as Fig 1, looks like oil to me, defo not AC condensate). Since the car drives fine (no white smoke, no overheating, no oil light etc) I kept putting off checking what was going on. I only was checking the oil level every now and then, and it showed (still does) as "full" (at the upper tick mark). Today I finally jacked up the front of the car and found an oil drop hanging off a screw belonging to the exhaust clamp (probably the lowest point, shown in Fig 2). The gearbox and the underside look "oily" but I can't pinpoint the source (Fig 3). In 6 months prob 100-200 ml has ended up on the floor in total, so I think this would not be easy to observe by checking the oil level.

The oil pan plug screw is fine (a mechanic once forgot to tighten it, so I was suspecting that first). I wonder if this time the shop did not tighten the engine head properly. I am suspecting the head gasket, b.c. I believe the "oiliness" can be traced all the way up to the head, but I might be wrong (Fig 4)

Or is it another problem altogether, and the recent timing belt work was a coincidence? 

P.S. This must be a common problem, and before posting I tried to read through "oil leak" search results on the Fiesta subforum. But after reading the first result and going back to the list I am being told "to wait to do another search." 

Thank you all in advance!

 

Edited September 15, 2025Sep 15 by runcyclexcski
year corrected

If it's oil then it has to be engine or gearbox but it looks like engine oil to you?
The main issue is that you say that the level hasn't dropped (200 ml should be a visible sign)?
From what you say, the leak appears to be coming from the top end (cylinder head, camshaft seal(s), cam cover etc) - perhaps associated with the recent work?
Certain that it isn't gearbox - is that level OK (but this would be from driveshafts or between engine and gearbox)?
SO... in the absence of an exact source, I'd add some engine stop leak.
If it's a seal, it will allow it to swell and the leak would stop/reduce.
If it's a gasket obviously including head gasket (a much more expensive job) then it won't help but unless you can wash the engine down and locate the source, you need to start somewhere.
 

RIght, so I would have to hose down the engine to identify the source.

The head gasket replacement was a part of the timing belt job, so I doubt it blew. To properly identify the source I would need a lift and/or a trench under the car, I have neither. 

The headgasket is not usually part of the timing belt job.  It would not be replaced unless it was showing signs of leakage.  Are you sure it wasn't just the cam cover gasket that was replaced?  That is more likely to be leaking oil.

I  did ask them to replace the head gasket. Re: the cam cover one -- I did not ask them to replace it, so prob not. But will check with the receipt I have.

Is it the 1L Ecoboost?

The valve cover is a common culprit following a belt change as the rubber seal hardens and compresses over time resulting in a less-than-perfect fit if it is reused. There are also some engine block joins that ideally need some silicone on them before the valve cover is put back and I could imagine some might forget to do those. Either way look higher up the engine and see if there are any telltale signs where it is coming from.

For the front-right wishbone, check that isn't just a consequence of the oil filter fitted horizontally on the back of the engine so some spillage is inevitable when replacing.

Incidentally, personally I wouldn't consider adding anything like leak stop. The tolerances on this engine are tight and I think it could do more harm than good.

I've had good success with it but obviously NOT on any wet belt, sorry!

MJ -- yes, it's the 1L ecoboost. I do not know how proper of a job they did. They did take their sweet time; this was a shop in Germany; not a dodgy one, but not a Ford dealer. Should have prob asked a Ford dealer to do this. The car is imported UK >> DE

22 minutes ago, Shearers said:

I've had good success with it but obviously NOT on any wet belt, sorry!

I wasn't thinking of that but actually that's a very good point! 

19 minutes ago, runcyclexcski said:

MJ -- yes, it's the 1L ecoboost. I do not know how proper of a job they did. They did take their sweet time; this was a shop in Germany; not a dodgy one, but not a Ford dealer. Should have prob asked a Ford dealer to do this. The car is imported UK >> DE

Reusing the valve cover gasket is likely commonplace if it looks in good condition so I wouldn't assume it's a sign of dodgy work. 

(Full disclosure: I didn't replace it when I did mine, and it ended up leaking! 😂) 

10 hours ago, MJNewton said:

Reusing the valve cover gasket is likely commonplace if it looks in good condition so I wouldn't assume it's a sign of dodgy work. 

(Full disclosure: I didn't replace it when I did mine, and it ended up leaking! 😂) 

But you were doing it first time as a DIY attempt.  Presumably you'd replace it as a matter of course if doing the job again? 

This is what's annoyed me about a lot of the 'professional' jobs I've had done lately.  Mistakes being made that could be understood from a first timer, but lessons should have been learnt long ago for people claiming to be professional and getting paid for their services!

2 hours ago, TomsFocus said:

But you were doing it first time as a DIY attempt.  Presumably you'd replace it as a matter of course if doing the job again? 

 

Given mine leaked I would, not least given how much of a hassle it is to remove the valve cover again what with all the components that live on top of it. But truth be told if it hadn't leaked (which I'm sure many don't) I do wonder if I would still replace it. That might just be thriftiness on my part though, and a professional mechanic will of course just be passing on the cost to the customer anyway and should certainly be aware that time is money and so doing whatever is necessary to avoid the need for rework should definitely be considered.

I still don't think reusing is a sign of a bodge, perhaps more just stopping short of what one might consider to be best practice.

This could all be a moot point though of course as the oil might be coming from somewhere else entirely!

Looks like I have to go back to the shop, and to ask my wife to convey my disappointment to them in German (if I think it's their fault).

I'd just start by asking them if they can work out where it is coming from. I think you are a long way off knowing they're at any fault here. 

MJ -- OK, I will do that.