C5 Throttle body issue

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ADY-ULTRAS
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C5 Throttle body issue

Post by ADY-ULTRAS »

Hi guys! My throttle body is full of oil moisture (engine 1.6 Hdi). I took it out, clean it, but it's bleeding again. I didn't notice any cracks but I can see that the moisture comes through the electrical plugs. I was thinking to remove the plastic cap and to try to put some sealant but I was afraid not to broke it. Can it be fixed or needs replacement? Anyone had problems like this?
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Re: C5 Throttle body issue

Post by xantia_v6 »

Can you post a picture of the moisture? I am curious to see what it looks like.
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

I made this picture of it. Most of the moisture comes from the big plug on the right....
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Re: C5 Throttle body issue

Post by mnde »

Hmm interesting... What made you check inside the throttle body?
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

I just remove it in order clean it. I thought maybe there are some bolts loose or maybe I can fix it but that part that leaks can't be removed, or at least I couldn't remove it. The leaks is through the sensor plug on the right. Any solutions?
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Re: C5 Throttle body issue

Post by mnde »

When you remove the plug is it full of oil itself? In my case (see my post in this forum) I thought it was a leak from the throttle body out via the plug, but in actual fact oil was leaking *into* the throttle body from the sensor plug via the wiring. It would be beneficial to know where that oil is coming from.
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

Yes, the plug is full of oil.
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Re: C5 Throttle body issue

Post by mnde »

ADY-ULTRAS wrote: 06 Sep 2019, 02:44 Yes, the plug is full of oil.
OK so it seems there are two possibilities why you have oil here. Either there is a breathing issue and there's an excess of oil vapour being deposited in the throttle body via the breather pipe, which is condensing as it cools, in which case I'd start by checking the condition of the air filter and the breather hoses. Or less likely (but it happened to me) you may have a leaking oil pressure switch which is pumping oil into the electrical harness and oil is ending up coming into the throttle body via the socket plug. Obviously my throttle body is a different design to yours, but on mine I couldn't figure out how oil from inside the throttle body was making its way into the socket plug (even though that's the lowest point on the body) - so it made absolute sense when I found out oil was actually ending up in the plug socket having entered from the *outside* i.e. having travelled round the wiring harness, from the leaking oil pressure switch (see my post "Picasso 1.6 16V: oil in throttle body plug").

Either way my suggestion is to find why oil is collecting there rather than looking at a way to stop it leaking out of the joints in the photo.
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

Ok, thanks. I will look again and see what's there.
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

I looked again at the throtle body and took again some pictures. From my point of view, the oil comes from the big sensor and through the plug which looks full of oil on the bottom half. Can I take it out and add some sealant or can I find that sensor to buy separately? I was thinking to take it out gently and add some sealant but I'm not sure if it works.
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Re: C5 Throttle body issue

Post by Doo »

It is entirely possible the PCV (Positive Crankcase Ventilation) valve is leaking allowing the vacuum of the air intake to suck it up.

As previously suggested, perhaps there is a leak at the pressure switch (allowing oil to "wick" up the loom) or more likely, blocked crank case to cam housing breather is blocked.

I recall back in the day, Vauxhall (Opel) camshaft housing had a filter that we called a biscuit which would block within months causing all manner of nonsense.

Modern day (since the late 80's) emissions had to have crank case pressure/oil vapour burned up by forcing it into the breather/air intake system to allow it to be burned up in the fuelling process.

Great for the planet, not so great for the engine....

Anyway, if the breathing system gets blocked, oil pressure forces oil vapour to build pressure and somethings gotta give.
Has anyone seen the plot? :?
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

Any idea where is that "biscuit" filter and where is the pressure switch? I was looking around but the only oil area is on that lid and switch from the pictures... if the PCV causes the leak, can be changed or repaired? Where is that as well? I was looking to buy a second hand throtle body but if the issue is not from it, I will be in the same position but with less money in my pocket....
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

No one has this issue?!? I'm the only one?
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Re: C5 Throttle body issue

Post by Doo »

ADY-ULTRAS wrote: 13 Sep 2019, 20:29 No one has this issue?!? I'm the only one?
Hi, sorry for the delay.... I may have confused the issue :? The biscuit was on the old Vauxhall/Opel engines.

I have done some digging and it seems you can buy the PCV valve, but it's a bit of a pernickity job.

I would imagine the possibility is the oil "may" be seeping out of the oil filler cap (just looking at your photo) due to a build up of pressure in the cam cover.

Best thing would be to undo the cap and rub your finger over the oily bit to see if the oil feels grainy. If so, it's entirely likely the whole lot is blocked and pressure is allowing the misting oil to escape via the oil filler cap.

You can buy a new cam cover with all the necessary bits including a new gasket.

But check if it "is" the filler cap that is leaking.

There is another possibility and that is the turbo may be worn and oil is blowing by #-o But again, this needs to be investigated.

The problem of trying to diagnose over the net 8-[

Here's a link to the replacement cam cover anywayhttps://www.ebay.co.uk/itm/233284837485

Let us know how you get on :) and good luck :wink:
Has anyone seen the plot? :?
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Re: C5 Throttle body issue

Post by ADY-ULTRAS »

Hi and thanks for your reply!
I checked the turbo and the oil lid, both are ok. Definitely the oil comes through the throtle body, through that plug.
Now, I was thinking to buy the PCV valve, but I can see that the whole cover has a fair price and I think is coming with a new PCV valve already, no?
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