Ford Transit Forum

by **Tony_C** » Thu Apr 16, 2026 4:11 pm

I have an issue with my oil being contaminated by a lot of hard carbon particles. I have had to replace the oil pump and turbo. Now doing the injector seals and camshaft cover seal. Any advice on where this is entering the system would be appreciated. No driving issues or fault codes, it was the failed turbo which made me drop the sump and find the issue with the oil. I have read a lot about carbon sludge caused by leaky injector seals but this is not sludgy and is very grainy. I have done an injector leak off test which was surprisingly ok. The van is a 2015 2.2 Transit Custom.

by **metalworker0** » Thu Apr 16, 2026 5:16 pm

The only thing i can think of is that it was run on poor cheap oil most of its life then ran on flushing oil or high detergent oil .
i did try to look it up on the net, most of the answers were about sludge type carbon -- even after i typed in "grains" .. of those answers were .. worn rings .. bad injectors .

i would look carefully at the breather system though. not much written about this .. or parts named or labeled in the part diagrams ... but places to look are any pipe work coming out of the block or cylinder head/ rocker cover that are connected to the boost pipes or air filter , the rocker cover itself has a chamber in it .. that can get plugged up .. the rocker cover also has small orange rubber one way valves that can and do fall out -
https://i.ebayimg.com/images/g/UYwAAOSw ... l1600.webp
-- what effect this has i don't know but it cant be good.

My own experience says .. this grainy carbon appears in engines that have done high miles and are close to the end of life, the build up appears first in the rocker cover. and there would be a fair bit of stinky smoke coming out of the oil filler hole if taken off whilst running .. not to be confused with chuffing from bad injector seals ..

What i don't know --- if injector seals become bad, if the resulting pressurisation of the crankcase and chuffing, whether resulting disturbances could cause carbon deposits to flake off .. and end up in the oil of an old engine.

or if last driver was sedentary and slow . and never went above 2500 revs .. and your driving style is fast .. which lead to build up accumulated by him driving slow, coming loose

all the best.mark

by **Tony_C** » Thu Apr 16, 2026 10:23 pm

Thanks for the response. The van has just under 100k miles on it. I bought it at around 75k miles. It does quite a lot of short journeys and I probably keep revs on the low side. Taking the cam cover off I've noticed that a previous owner/mechanic has broken the rocker carrier which holds injector #1 in position. Although it didn't feel any easier than the other injectors to remove and didn't have any obvious play. The gritty carbon deposits are stuck to the inside of the cam cover and are not easy to remove, to the point where I'm just going to order a new cam cover along with a new rocker carrier.

Could EGR valve or DPF be a potential source of carbon in the oil other than leaky injector seals? I had a look at the DPF on Forscan after I installed the new turbo and it was at 50% load. The differential pressure didnt seem to spike with increased revs so there no obvious issue there to me. I was told the DPF was replaced when I bought the van due to emissions failing the MOT.

Any further thoughts welcome.

Short video under the cam cover here: https://www.youtube.com/shorts/Wv-7bi92Lgc

by **metalworker0** » Thu Apr 16, 2026 11:40 pm

I don't know if its a trick of the light or over exposure .. but i see grit, what's looking like a white metal to me - aluminium or bearing material.. quite large .. not fine .. like you would get if the timing chain was rubbing on the aluminum around it.

as regards the egr letting crap into the engine ... well that would enter above the pistons

dpf .. there is no chance of it putting anything it catches back into the engine

a failing turbo could put metal in through the breather system--- but this is me looking at your video and maybe believing this stuff is metal

if the turbo has gone in the past , then the intercooler would be to be replaced or very thoroughly cleaned out

other places of entry, is the big convoluted rubber hose that connects the air filter to the turbo THEY SPLIT. then you would be getting all sorts of unfiltered stuff into the engine both above the piston and into the crankcase.

I simply guess, the video you made could be very misleading from my eyes point of view.

all the best.mark

by **Tony_C** » Fri Apr 17, 2026 8:24 am

Ok thanks for the input. I'll have a closer look at the EGR, intercooler and turbo air intake hose. I havent found any obvious metal yet. These large gritty bits everywhere are hard but they disintegrate when rubbed between your fingers. I havent found any obvious bits of metal yet, but once I get the rocker carrier off I can get more of it out and have a good look. Cheers