Oil getting into throttle body electrics

[Wintord]

Hopefully someone can give some advice.

I have a mk 2 focus 1.6 tdci.

Previously had a barrage of electrical issues with it which finally after 2 months managed to resolve them all, to the point no fault codes are now present. (which was couple of damaged cables behind cluster and a failed instrument cluster).

But after this I was left with a car that had a engine malfunction showing on the dash screen, with zero codes and no engine warning light, crank no start. After several hours of messing about it finally spluttered into life in a cloud of black smoke and it struggling to keep it self running (No idea what made it decide to start). A few mins of gentle reving to stop it stalling out, it cleared all the smoke out and idled and reved fine, with the engine malfunction still showing. Took it for a short drive no power struggling to pull, with no clue to what it was.

More checks done only thing we found was the wiring connecting to the sensor on the throttle body caked in oil, cleaned it up took it out couple mins drive pulled has normal, engine malfunction gone, went back home. Parked up, left it five mins started it again engine malfunction back, car no power. A quick check of the sensor electrics and caked in oil again.

Due to 3 mobile mechanics previously coming to look at it and not able to tell what was wrong due to no codes and saying they can't help, I thought against my better judgement lets speak to ford, surely they may know who so much oil is getting in there, oh what a waste of time, they just gave a list of a several parts to replace in the hope it solves the issue. My normal garage who does all the work don't come out and with the car its running is probably not that safe to drive to them.

Is it has simple has the sensor seals have failed or the throttle body seals have failed or is there something further back causing to much oil to get there in the first place. I have not noticed any excess oil loss when levels checked pre all the cars issues.

Any suggestion appreciated to know where to go with this.

[TomsFocus]

There is generally a thin coating of oil throughout the intercooler and boost pipes.  This is just from the crank breather and doesn't suggest a fault.  (Unless there's a large amount.)

Having said that, the throttle body is not designed to have oil in it, and they do regularly leak, especially when mounted with the plug at the bottom where oil sits and seeps 24/7.  Mounting them with the plug on the side or top is a better idea where possible.

So yes, I'd say it just needs a new throttle body.  Not really worth buying a used one as most will be in the same state now.

[unofix]

1 hour ago, Wintord said:

had a engine malfunction showing on the dash screen, with zero codes and no engine warning light,

Such is the system, that you can't have an engine malfunction warning light with out having a code. There has to be a live DTC, or a stored DTC in order for the light to be set.

The situation is that generic code readers, no matter how good, or how expensive, can not read all Ford specific diagnostic trouble codes in 99% of cases. Only Ford's own equipment or the software FORScan can read both the HS and MS canbus and read the Ford specifics codes.

[Tizer]

With this being a Diesel, the Throttle Valve is just something that is almost fully open when the Engine is running under Accelerator Power, closes partially on the overrun and completely at switch off so is easy to Live Monitor with FORScan. It is nothing like the Throttle Body in a Petrol car.

The MAP Sensor is right next to it and if that is covered in oil then it could cause problems but as @unofix said there should be a Fault Code. Again it is easy to Live Monitor with FORScan.

[Wintord]

Thanks all for the replies.

I would not say the pipes look overly oily, more just a coating from what I can see looking around the throttle body area. So far from mobile mechanics that came out they used an autel scanner and the others had a snapon one. when checking issues.

I personally got the OBDLink EX from the link on forscan website and thats what found me all the electrical issues I was having. But it is now showing no codes anywhere on the car, but have the above issue. Which I find strange has do the local ford dealer.

I think it obviously needs a new throttle body either way amount of oil seeping into connector plug even if that aint the fault, but I also need to learn the live data and work out what am looking for in there to check that is the actual issue with it.

Any advise on what I need to monitor to make sure it is the throttle body causing the problems.

Failing that it will have to go to ford and see if they can dig any codes from it, which I would rather avoid, getting there should make it, has it is all down hill, but doubt it has got the grunt to get back up them for me to then fix it at home, it barely crawled back up a shallow hill the other day never mind a long steep one, so be stuck with them sorting it out then.

 

[Wintord]

Thanks all for the replies.

I would not say the pipes look overly oily, more just a coating from what I can see looking around the throttle body area. So far from mobile mechanics that came out they used an autel scanner and the others had a snapon one. when checking issues.

I personally got the OBDLink EX from the link on forscan website and thats what found me all the electrical issues I was having. But it is now showing no codes anywhere on the car, but have the above issue. Which I find strange has do the local ford dealer.

I think it obviously needs a new throttle body either way amount of oil seeping into connector plug even if that aint the fault, but I also need to learn the live data and work out what am looking for in there to check that is the actual issue with it.

Any advise on what I need to monitor to make sure it is the throttle body causing the problems.

Failing that it will have to go to ford and see if they can dig any codes from it, which I would rather avoid, getting there should make it, has it is all down hill, but doubt it has got the grunt to get back up them for me to then fix it at home, it barely crawled back up a shallow hill the other day never mind a long steep one, so be stuck with them sorting it out then.

 

[TomsFocus]

Have you tried leaving the throttle body unplugged?  It should be wide open as default I think.  That will trigger a fault code but shouldn't trigger limp mode.

[Wintord]

No I havent tried that yet, am learning has I go will give that a go when finished work in abit. thanks.

[Wintord]

On lunch break had a quick scan of some live data. This time 4 out of 5 starts of the engine it has no malfunction come up data all seemed ok. Am not sure if I am checking right ones but monitored anything that mentioned throttle, which there didnt seem many (what would the throttle body be listed has in forscan for live data) and the maf.odbII, g/s. (presuming that is the mass air flow sensor).

The one time it came up with engine malfunction before it started, I noticed when reving the car around the 3000rpm mark the revs kept dropping and quickly returning to where it was, the maf.odbII, g/s was dropping quickly and then shooting up again in time with the revs changing on the engine.

Now it seems to have decided to be intermittent, is going to be even more a pain.

Am abit of a duck out of water on this one, older engines am fine working out whats wrong, but all this electronic and sensor stuff am lost with.

Best bit am just the person who has to repair it, I don't drive its my partners car and she likes to make sure I know its not working lol.

[TomsFocus]

I think it's called EGRTV on that engine.  (EGR Throttle valve)

[Wintord]

Had it for a run, drove half mile no issues, stopped car, turned it off waited couple mins ignition on, engine off, engine malfunction.

Grabbed laptop and scanned this, Hopefully you understand it better than me.

Foot was to floor when trying to move off and was barely moving.

Was going to mess about and run it without the connector for throttle body not connected but it is now pooring down here and something is now making a horrid binding noise from sitting nearly 3 month and apparently the breaks feel crap so something else to fix, when get this engine right.

 

[TomsFocus]

That huge MAF spike at startup looks odd.

@Tizer might be able to advise further on that.

 

[Wintord]

Will wait for further advise on that.

I did notice when around 3000 rpm. The revs would go up and down on own around 300rpm and at same time maf readings dropped then spiked up at the same time matching the revs dropping and climbing.

Also the sensor wire from the throttle body which I left layed on top of engine disconnected has left a puddle of oil under it. So quite abit of oil has found it's way in there. Is there any easy way to check if there is excess oil sat down at the bottom of the pipe where ever it goes to. Looking at it, it looks a pain to get to bottom end of it.

[Tizer]

That looks a bit strange and a bit meaningless without the PID's for MAP, RPM, Speed and Accelerator Position as well.

I'm not sure if your earlier Mk 2.5 is the same as my old later Mk 2.5 but for comparison at Idle I would expect from my 2010 TDCI.

MAF to be steady between 5 and 10g/s and no spikes as Tom said.

MAP to be 100kPa

Throttle Valve between 90 and 100%

[Wintord]

Does anyone know what they sensors are called in forscan as listed by tizer. So know when I get home what ones to log.

Thanks again for everyone's time who are trying to help me work this weird hidden fault out.

[TomsFocus]

13 hours ago, Wintord said:

Is there any easy way to check if there is excess oil sat down at the bottom of the pipe where ever it goes to. Looking at it, it looks a pain to get to bottom end of it.

If it's a 110bhp model then it'll have an intercooler fitted just behind the front bumper.  That is the lowest part of the boost pipework and where oil will collect.  It's not unusual to pour around half a cup of oil from a 10 year old intercooler if it's still original and never been removed as it builds up over time.

I think those PID's are all named pretty clearly in Forscan.  You've already got MAF and throttle valve.

If it is a 110ps model, there may be a second throttle valve for the intercooler bypass.  I'm not sure what that one is called on Forscan.

[Tizer]

1 hour ago, TomsFocus said:

 

If it is a 110ps model, there may be a second throttle valve for the intercooler bypass.  I'm not sure what that one is called on Forscan

If it's the one with the Bypass then the figure I quoted for the Throttle Valve will be different, my one was different. 

3 hours ago, Wintord said:

Does anyone know what they sensors are called in forscan as listed by tizer. So know when I get home what ones to log.

Thanks again for everyone's time who are trying to help me work this weird hidden fault out.

Use the search function in FORScan if you don't want to scroll.

[Botus]

On 4/18/2024 at 8:34 PM, Wintord said:

Also the sensor wire from the throttle body which I left layed on top of engine disconnected has left a puddle of oil under it. So quite a bit of oil has found it's way in there. Is there any easy way to check if there is excess oil sat down at the bottom of the pipe where ever it goes to. Looking at it, it looks a pain to get to bottom end of it.

the stuff leaching into the loom is NOT oil - it looks like oil, but its really a corrosive mix of old combustion gases, acids, water and oil mist - all recycled via the engine breather - clean oil on electrics is not conductive and is a good thing (as it stops corrosion and cools things)

the best way to make it vanish is to keep the breather system working, have a functioning EGR so tractor engines keep themselves warm in winter, drive and maintain operating temps on the engine (no stop start, no short journeys), when fully warmed up use the performance to keep the piston rings remembering what their job is, buy quality tractor fuel etc.

it is very common to have this leaching corrosive filth leak on Mercedes to destroy electronics (its a German design feature), contact cleaner in the loom, service the car - clean it out of the intake system on your driveway using 1000ml of 50 50 water / methanol mix.  Atomised into the inlet (after the air clearer) and blip the throttle to 3k rpm to get the EGR to clean up too... doing the 1000ml mist over 15-20 mins on a hot engine - as the gunk comes out it will smell like you are burning paraffin and likely might get some clouds of filth out the back - stop part way and let CATS and DPF warm up again if needed

[LarsfromNorway]

On 4/17/2024 at 1:46 PM, Wintord said:

Is it has simple has the sensor seals have failed or the throttle body seals have failed

Yes. I had the same on mine with oil seeping out of the connector on the butterfly valve leaving the parts under it covered in oil. But no fault codes. Just an annoying oil leak. I bought a second hand one but first making sure that it had no leak there.