Picasso 1.6 16V: oil in throttle body plug

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mnde
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Re: Picasso 1.6 16V: oil in throttle body plug

Post by mnde » 27 Aug 2019, 22:08

So: journey to work this morning: P0141 pending code stored, which I cleared. Journey back home, route reversed, no code stored! Live data looks ok, 2nd lambda reacts to snap throttle test, Long Term fuel trim -4.7%. I might get a chance on Thursday to swap the lambda sensors around....

Mark

picassodad
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Re: Picasso 1.6 16V: oil in throttle body plug

Post by picassodad » 28 Aug 2019, 16:15

Please keep the feed back/progress coming, all very useful info.

As said hopefully this is whats wrong with the lads 1.8 as there was an oil drip down by the oil filter seen just after he bought it, which I put down to a "not what I would call tight" oil filter.

mnde
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Re: Picasso 1.6 16V: oil in throttle body plug

Post by mnde » 28 Aug 2019, 20:58

picassodad wrote:
28 Aug 2019, 16:15
Please keep the feed back/progress coming, all very useful info.

As said hopefully this is whats wrong with the lads 1.8 as there was an oil drip down by the oil filter seen just after he bought it, which I put down to a "not what I would call tight" oil filter.
Fingers crossed for you! Latest is I found a new P0141 pending code stored when we arrived at work this morning.. No really noticeable hesitation issues. I left the code stored this time. By the time we arrived home after stop start in heavy traffic most of the way, the code had cleared itself, and the monitors reset yesterday after I cleared the code have passed again (catalyst, O2 heater). Long term trim was showing as -3.7%

It's gonna be touch and go tomorrow to do during my lunch hour working from home, but I'm at least to try checking again for residual oil, cleaning, and swapping the lambda sensors around. I'll report back. Becoming more of a concern to get it as right as I can do as the MOT is due on 4th Sept! At the moment I've only got the live readings from my OBD reader and the MPG calculation on the dash to tell me roughly whether the emissions are within the legal limits...

Cheers,

Mark

mnde
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Re: Picasso 1.6 16V: oil in throttle body plug

Post by mnde » 29 Aug 2019, 21:31

Well I only had a short amount of time to do anything earlier, and was thwarted by lack of copper grease which I thought I had, and no time to get some, so the lambda sensors stayed put.

However, I did find a little more oil in the lower lambda connection and some on the wires where they come out of the sleeve and enter the top of the connector plug. After cleaning with a blast of contact cleaner and drying thoroughly with compressed air I swear the throttle was more responsive and the car gained a few extra horses. Amazing. And no P0141 code set. (LT fuel trim now down to -3.1%) Well, it was only a shortish journey to the gym. I celebrated by taking it for a jetwash afterwards :)

I'm thinking if I've found more oil there at the lowest point in the harness, then there may well be some in the ECU plug again. That's for another day!

Mark

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white exec
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Re: Picasso 1.6 16V: oil in throttle body plug

Post by white exec » 29 Aug 2019, 21:55

Leaking engine oil that has done a bit of work will likely be electrically conductive, due to its carbon content. My guess is that this could cause sensor readings to be slightly altered (or worse) if it comes into contact with their connections. The greater the quantity, the more the effect.

mnde
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Re: Picasso 1.6 16V: oil in throttle body plug

Post by mnde » 05 Sep 2019, 16:19

white exec wrote:
29 Aug 2019, 21:55
Leaking engine oil that has done a bit of work will likely be electrically conductive, due to its carbon content. My guess is that this could cause sensor readings to be slightly altered (or worse) if it comes into contact with their connections. The greater the quantity, the more the effect.
I agree with this analysis.

Latest news is that the Picasso passed its MOT with flying colours on Monday!! Emissions slightly up compared with last year, but still well within legal limits. Phew. All my cleaning out of oil from connections has paid off! Still not entirely out of the woods as I had the EML come on yesterday morning at low speed, with a DTC of P0141 (the same old rear lambda sensor heater circuit fault), so I need to go another round with contact cleaner, then think about changing the lambda - but I don't want to until I've opened the connector one day and found ZERO oil in there.

Cheers,

Mark