Petrol smell in engine?
Zesty - 18/6/21 at 01:02 PM
So when taking oil cap off my 2.0 blacktop turbo engine, I can smell fuel. Not good…
The car will be going into mountune for some bits and bobs in a couple of weeks, but in the meantime, whay could be the issue?
I’ve also noticed a few drops of oil on the floor of my garage. Not as concerned about that, as i should be able to diagnose that pretty easily.
Still, having had no experience of blacktops, are there any common oil leak areas?
Mr Whippy - 18/6/21 at 02:21 PM
If the rings are not sealing well the mixture can be forced past the pistons into the engine and contaminate your oil with petrol, or if it's
running insanely rich I suppose. Do you have much pressure in the engine if you block off the breather? Not good anyway as it will be cleaning off the
oil film on your cylinder bores and making them wear faster. Have you got your boost up to silly levels??
big_wasa - 18/6/21 at 02:35 PM
A standard Zetec Is one of the most oil tight engines you will find. What sump is on it ? This is where you want to start looking for leaks.
Again getting it checked over will show if it’s over fueling. But get the oil changed in the meantime.
Zesty - 18/6/21 at 03:15 PM
Racline baffled sump
10psi turbo
Does tend to flood a bit on ignition though, which may be the problem…
Especially when warm then engine turned off then back on, it can struggle to start, takes a fair few seconds to turn over.
coyoteboy - 18/6/21 at 03:20 PM
My turbo 4pot started to smell like that when I blew a ringland. Minor crack initially, progressed to full misfire.
Of course there's massive overfuelling and misfire as potential causes, as well as injector leak when powered off.
Zesty - 18/6/21 at 03:26 PM
What oil do you guys recommend for blacktops? And how many litres? Guessing 4.5litres with the race line sump?
And the ringland failure doesn’t sound good. Although I do know the previous owner noticed a fuel smell with this car, as I’ve found his posts on
here!
He said the car smelt of petrol after a drive, and made his garage smell of fuel…
[Edited on 18/6/21 by Zesty]
pigeondave - 18/6/21 at 03:58 PM
Millers Oils CFS 5w-40 Competition Full Synthetic Engine Oil
But my Blacktop is NA
I think volume depends on sump size but dont overfill or you'll get seepage through the front crank seal
Mr Whippy - 18/6/21 at 05:50 PM
quote:
Originally posted by Zesty
And the ringland failure doesn’t sound good. Although I do know the previous owner noticed a fuel smell with this car, as I’ve found his posts on
here!
He said the car smelt of petrol after a drive, and made his garage smell of fuel…
[Edited on 18/6/21 by Zesty]
Well that's just plain not right, need to find out what's going on. It does sound like it's to rich. Are the plugs black or tan when
you take them out? I'd also do a pressure test on the cylinders to see if they're balanced and even holding pressure as putting a turbo on
it is only going to make it worse. I'd even suggest lowering the boost till you know the engine is in top condition.
Zesty - 18/6/21 at 06:05 PM
I’ll have to take a look, and I’ll also get mountune to get to the bottom of it.
Does seems like it’s running rich, as it seems to be an ongoing issue according to his previous post on here. Which was a good 4 years ago. So I doubt
it’s anything major, although of course major enough to be sorted ASAP.
I think it may have to do with the fuel mixture, i have a feeling it’s running very rich and that’s why it floods on ignition. Some of this fuel must
be making its way through the cylinders…
Saying that, it could be a number of things! Will post an update when mountune have diagnosed it in a couple of weeks.
Oh and by the way, it was 2016 when the previous owner posted about the smell of fuel after driving, he said it made his garage smell.
Now this is interesting as the zetec blacktop had a full rebuild with him, including upgraded focus rs internals. So this confuses me. Why after a
rebuild and subsequent setup by devil developments is it still smelling of fuel?
[Edited on 18/6/21 by Zesty]
CosKev3 - 18/6/21 at 06:23 PM
Don't use it again on the oil that's in it now if it smells of fuel.
Good chance you will knacker the engine.
Fuel breaks the oil down
perksy - 18/6/21 at 10:07 PM
Sorry haven't read all the details, but is this running a standard ECU?
Faulty coolant temp sensor would do this or it could be a few things to be honest
Are you getting any smoke out of the exhaust? If so what colour?
cliftyhanger - 19/6/21 at 03:56 AM
quote:
Originally posted by Zesty
I’ll have to take a look, and I’ll also get mountune to get to the bottom of it.
Does seems like it’s running rich, as it seems to be an ongoing issue according to his previous post on here. Which was a good 4 years ago. So I doubt
it’s anything major, although of course major enough to be sorted ASAP.
I think it may have to do with the fuel mixture, i have a feeling it’s running very rich and that’s why it floods on ignition. Some of this fuel must
be making its way through the cylinders…
Saying that, it could be a number of things! Will post an update when mountune have diagnosed it in a couple of weeks.
[Edited on 18/6/21 by Zesty]
Get them to do a leakdown test, much better diagnostic than a compression test (although they have their uses)
Forced induction can make things go very wrong very fast if not set up correctly, so you are doing the right thing bu=y getting it properly checked
over.
I would use some decent oil, but don't go beserk as it may only be in there couple of weeks..... but even then it will need changing as it is
flushing the contaminated stuff currently in there.
Myke 2463 - 19/6/21 at 06:45 AM
quote:
Originally posted by Zesty
What oil do you guys recommend for blacktops? And how many litres? Guessing 4.5litres with the race line sump?
And the ringland failure doesn’t sound good. Although I do know the previous owner noticed a fuel smell with this car, as I’ve found his posts on
here!
He said the car smelt of petrol after a drive, and made his garage smell of fuel…
[Edited on 18/6/21 by Zesty]
With my Raceline sump they said 5 lt oil and remark dipstick when oil has settled .
Zesty - 19/6/21 at 06:52 AM
Not noticed any smoke colour, but every now and then there is a puff of black smoke on start up.
I’m leaning towards a rich fuel mix, but I’ll have to wait to see what the experts say/find!
perksy - 19/6/21 at 10:18 AM
Black smoke is rich mixture
If you can smell the fuel in the oil then the fuel is washing the oil off the cylinder walls which ain't good
Problem needs rectifying ASAP and then an oil and filter change
As said above it could be a few things: Leaking injectors, faulty TPS, faulty coolant temperature sensor, plus a few other things
Zesty - 19/6/21 at 10:22 AM
Why would faulty coolant sensor be a cause? Just out of interest- I like to learn!
perksy - 19/6/21 at 11:37 AM
Don't get the the coolant temp sensor mixed up with the coolant temp sender 
The temp sender tells you the temp of the coolant in the engine (temp gauge)
The temp sensor tells the ECU the temp of the coolant, When the engine is Cold the ECU will richen the mixture as a result (a bit like an old
fashioned choke on a carb)
Quickest check is with a multimeter and check the resistance at Cold and at Hot, but if you had an ECU that could be connected to with a laptop then
you could see what the ECU was seeing
Not saying this is your problem, but if the engine was being told by the sensor that the engine was cold when it wasn't, this would fool the ECU
into supplying more fuel
As said above this could be a few things
Is there any history of the car being set-up on the rollers?
Zesty - 19/6/21 at 01:45 PM
It was set up by devil developments, so it’s been ‘professionally’ setup. All a bit odd to me…
cliftyhanger - 20/6/21 at 07:52 AM
quote:
Originally posted by Zesty
It was set up by devil developments, so it’s been ‘professionally’ setup. All a bit odd to me…
Things go wrong, wires/connectors fall off, not everything can be done easily at a tuner, especially cold start (you get one go, and that is only if
the car has been sat unstated for a few hours, most tuners have to use experience etc for the settings)
And of course, owners fiddle with stuff!
Zesty - 20/6/21 at 07:12 PM
Well, took it to my mate Jonny’s (the lead technician at mountune) to have a little look over before I drop it down to their garage this week.
He wasn’t at all worried about the petrol smell in the engine, literally not even a slither of concern.
they’re going to fit an oil cooler, remap it, sort out any niggles and sort a new throttle cable.
He also said we should be running thicker oils in zetec turbos, purely because of the heat. I trust him of course, he knows what he’s talking about.
So they will sort the small oil leak and change the oil for a premium thicker one. He said it’ll sound terrible on a cold start - obviously, but the
thicker oil will be much more beneficial for the engine, especially when tracking it.
Looking forward to it coming back in a reliable and tip top condition!