Tandem pump?

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GregWalters
Caddy Fan
Posts: 77
Joined: Mon Oct 30, 2023 2:27 pm
Engine size/power: 2.0 TDI (140bhp)

Tandem pump?

Post by GregWalters »

Hi guys, new member just had my caddy dropped off to me!

2009 caddy maxi with a supposed seat Leon engine and 6 speed with around 200bhp 🤷🏻‍♂️ any idea where I can find engine code etc?

So it was bought as spares or repairs, with apparently high oil pressure and supposedly if left running for too long then diesel mixes into the oil.
So with a little research my guess is the tandem pump?
Would a seal kit be a sufficient repair or get a replacement? (May get a second hand one first to see if that fixes it and if so maybe get a new one)
Any other ideas if it’s not the tandem pump? (Injectors?)
Now I’ve received it I had a quick look and it is wet underneath the tandem pump too

How would they have known the oil pressure is high?
And how will I know if the oil pressure is back to normal once fixed? 😅

Thanks in advance for any help or insight!
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GregWalters
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Posts: 77
Joined: Mon Oct 30, 2023 2:27 pm
Engine size/power: 2.0 TDI (140bhp)

Re: Tandem pump?

Post by GregWalters »

Changed tandem pump internal seals and gaskets today, quite an easy job!
Just need to get an oil pressure test kit to see if that’s fixed the issue


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PeterAFox
200BHP+
Posts: 249
Joined: Thu Aug 24, 2023 8:14 am
Engine size/power: 1.9 TDI (104bhp)

Re: Tandem pump?

Post by PeterAFox »

You can decode the PR codes to determine the engine code.
A table of them should be pasted inside your service book, and (I think) inside driver door frame. They are also available on Erwin (which costs) - you need your VIN.
The info from them is sometimes very useful - just google 'VW PR codes' for tables of what they mean
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GregWalters
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Joined: Mon Oct 30, 2023 2:27 pm
Engine size/power: 2.0 TDI (140bhp)

Re: Tandem pump?

Post by GregWalters »

Thanks, from my investigation yesterday I’ve figured it has an ARL engine in it, and it had a bls previously (and still has the bls egr/asv)


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GregWalters
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Posts: 77
Joined: Mon Oct 30, 2023 2:27 pm
Engine size/power: 2.0 TDI (140bhp)

Re: Tandem pump?

Post by GregWalters »

So, not sure what the oil pressure was previously
But I’ve changed all the tandem pump seals
Just checked oil pressure and seen that it’s supposed to be 30psi at 2k rpm when hot
Mine was running at 50psi 2k rpm after idling for around 5 mins
BUT the oil level is high, shall I drain some oil out first and then re test? And also I don’t know how old the current oil is and how much diesel has been mixed into it etc (as level has risen)

What sort of pressure would be shown if say injector seals were leaking?

The tandem pump seals could have sorted the issue but I don’t want to drain and replace the oil with new just in case there’s still a diesel leak somewhere
Or do I just do the injector seals just in case


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PeterAFox
200BHP+
Posts: 249
Joined: Thu Aug 24, 2023 8:14 am
Engine size/power: 1.9 TDI (104bhp)

Re: Tandem pump?

Post by PeterAFox »

not sure of your setup, but for mine VW say to test high pressure pump (tandem):
Coolant minimum 85°C, fuel filter and lines should not be blocked, non-return valve in fuel supply hose and injectors must be OK,
@ 4000 rpm
pressure should be a minimum of 7.5 bar.

I've tried to find a maximum value some months ago, but never found it.
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GregWalters
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Posts: 77
Joined: Mon Oct 30, 2023 2:27 pm
Engine size/power: 2.0 TDI (140bhp)

Re: Tandem pump?

Post by GregWalters »

Thanks, is that fuel pressure or oil pressure?


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PeterAFox
200BHP+
Posts: 249
Joined: Thu Aug 24, 2023 8:14 am
Engine size/power: 1.9 TDI (104bhp)

Re: Tandem pump?

Post by PeterAFox »

(sorry for the delay)
that's for the fuel. There's a bolt you can remove to test it.
maybe worth also checking the vacuum is ok (the air hose pipe that goes to the brake system, N75, maybe the turbo etc.) - from memory, it should be over 28 inHg
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