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Loads of white smoke from my 1.8t all the time - turbo? rings? will gauges help work it out?

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#1 · (Edited)
Hi All,

I did a little search but can't find any specific information on this situation so here's a new post. Forgive any naivety here as I'm still new :)

My understanding is that the N75 valve on my 1.8t BAM car is basically the factory boost control valve that works in conjunction with the ECU to control boost via the waste gate.

Now I am looking at an Innovate Motorsport SCG-1 boost controller and gauge. For a couple of reasons, partly to display more info from the car but also to be able to cap or cut boost in certain conditions and have the control in the car. With the stock setup this can only be controlled in the ECU programming and I don't have software for that (can anyone recommend any?).

So the question... can I run both the N75 and the SCG-1 on the same car?

I'm thinking theoretically yes, but I am not sure how they might interact or annoy each other?

Thanks in advance


24/01/2024 UPDATE - changed the title of this post to be more appropriate to the discussion below from "Aftermarket boost controller and stock boost controller on the same car" to "Loads of white smoke from my 1.8t all the time - turbo? rings? will gauges help work it out?"
 
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#39 ·
I would agree with David..

White smoke Is oil leaking past the turbo (turbine side) seals and coming out the exhaust.
If oil is combusted it comes out blue (eg rings or pcv etc)
If black smoke comes out the exhaust pipes that's unburnt fuel.

Unless you're losing loads of coolant then that's the headgasket but it'll be running pretty bad to get that amount of smoke and usually smells sweet..

Hmmm... I just read you said there's a puddle of oil on a piston..
 
#40 ·
Yes indeed, that was one of my previous theories and it totally makes sense given that very white cloud like smoke and the clear head gasket test.

But now the oil in the cylinder says otherwise. We scoped that about 30 minutes after stopping the car and it seemed to be running ok apart from the smoke. We subsequently scoped the other cylinders and all are the same. A little puddle of liquid. I didn't swab the others but I think its a safe bet that they are all oil.

Yesterday we moved it from the garage because I have other things to do, and I want time to think. When we did, it was most definitely oily smoke (as you would expect) and its started to idle and run a bit lumpy for the first time.

So I'm back to thinking either rings or severely ruined valve seals. Given the short time period between stopping and seeing the oil, I'm leaning towards it not being valve seals. Add in the leak down test (which may have been right all along) then I think I am going to go for rings unless someone can give me any other counter arguments.

It's just a bit of a ball ache because the 'while I'm in there' parts will all add up.
 
#41 ·
The oil on the piston won't smoke like in the video, that might be another issue, valve stem seals as mentioned, and i can't see how oil would pool on the piston from bad rings.

Valve stem seals can be done without removing the head. A friend who had an independant VW Audi garage had a modified spark plug to pressurise the cylinder and hold the valves up while swapping them.
 
#44 ·
I thought valve seals but the leak down did suggest piston rings and the oil was there very quickly after stopping. Maybe it’s both. I agree on the rings not likely to leave a little pool.
I have seen that method for replacing them but I’ll probably take the head and replace the valves while I’m at it as that’s a future job that I can at least tick off.

I suppose if I replace rings and seals (plus do all the other work I was going to do anyway like rods) then have the turbo rechecked at the same time….. hopefully we’ll catch whatever the issue is!


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#54 ·
Thanks all for your help on this. Really very much appreciated.

Now I’ve had time to be less annoyed at the stupid car and watched the video again I think i will start with the turbo out again (3rd times a charm).

That means I can check the drain and the turbo itself. I not have that much pressure in the crank, and it did it with the pcv hoses disconnected so I’m confident it’s not positive pressure.

I did find a pin hole on the downpipe the other day and what looks to me like an oil stain which would explain the puff from the back of the engine bay …



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#55 ·
I get a bit of smoke from the back of the engine for a little after restarting especially at the moment, but that's still blowing when it's cold. It's okay after about 5 minutes, I assume its the turbo to manifold gasket, which seals up once its warm. I'll take a look on the ramps.
 
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