Smoking GTI

[Trubs]

Have a 2008 Polo GTI thats done 140k with an intermittent smoking issue. Initially when the car was stock I didn't notice this at all. I did a few mods (2.5" Catless downpipe, Turbosmart recirc valve, Forge TIP).

It was fine for a month or 2 but I started seeing smoke when coasting in 5th gear on the motorway going down long hills, I'd accelerate at the bottom and see a puff of smoke in the rear view mirror and it would go away. Didn't think too much of it as it wasn't that bad to start with.

I ended up replacing the thermostat and while I had it idling to get it up to temp and checking for coolant leaks it started smoking quite bad and filled up the shop with smoke, gave it a couple of revs and it cleared up and didn't do it again even after letting it idle for a while.

I've had the car remapped since then and I seem to be noticing the smoking more, after coming to a stop, sitting in traffic for a while, coasting down hills.

I've replaced the the PCV Hockey puck (genuine part) on the top of the TIP as it was oily, I also replaced (with genuine parts) the crankcase breather lines and one way valve (one of the plastic lines was cracked and the one way valve was shot) now this seemed to fix it for a couple of weeks, didn't notice any smoking at all, now all of a sudden its back. While I had the TIP off when replacing with the forge one I had a look at the turbo and it looked clean and didn't have any play in the shaft.

I'm using Liqui Moly 5w-30 and have been servicing it every 7500-10000kms and its been using just over half a liter of oil every service period.

Now I'm guessing its either turbo seals or stem seals and I keep finding mixed information online. Do I try some thicker oil like 10w-40? I'm suspecting its more likely going to be stem seals.

[h100vw]

I would run thicker oil. I use a Liqui Moly 10w40. Doesnt seem to use a great deal. But TBH I don't run full service mileage anyway. I do trackdays and stuff and I am always dropping the oil.

If the crankcase cant breathe well, it can make it hard for oil to drain out of the turbo. When the car is at idle. There's more oil in the sump, this will cover the oil drain. When you are driving the oil level drops, as more of the oil is in the engine/head. So the oil can drain better.

If the pressure in the crankcase is high, say because you fitted a catch can with pipework that is too small in diameter. You could let yours breathe to atmosphere for a while to test the theory.

Gavin

[Trubs]

I would run thicker oil. I use a Liqui Moly 10w40. Doesnt seem to use a great deal. But TBH I don't run full service mileage anyway. I do trackdays and stuff and I am always dropping the oil.

If the crankcase cant breathe well, it can make it hard for oil to drain out of the turbo. When the car is at idle. There's more oil in the sump, this will cover the oil drain. When you are driving the oil level drops, as more of the oil is in the engine/head. So the oil can drain better.

If the pressure in the crankcase is high, say because you fitted a catch can with pipework that is too small in diameter. You could let yours breathe to atmosphere for a while to test the theory.

Gavin

Thanks for the reply, I'm not running a catch can or anything all that is OEM.

I am unsure on the best way to let the crankcase breathe to atmosphere?

Also will probably try some thicker oil this week and see how it goes when we go away for the Christmas break.

Forgot to mention the car runs and boosts totally fine and feels good.

[Rdubya]

Thanks for the reply, I'm not running a catch can or anything all that is OEM.

I am unsure on the best way to let the crankcase breathe to atmosphere?

Also will probably try some thicker oil this week and see how it goes when we go away for the Christmas break.

Forgot to mention the car runs and boosts totally fine and feels good.

I am having exactly the same issues with my 2007 Polo GTi. Coast downhill in 5th, smoke when I accelerate. I have tried thicker oil, no good. I have just had the valve stem seals replaced, and I swapped out the turbo with a lower mileage spare that I had sitting around, but symptoms remain. Mechanic thinks that the smoke will settle after a week or two now that the stem seals have been replaced...??? Apparently the old ones were rock hard.

I might look at deleting the PCV etc and installing a Ryco catch can using large diameter pipes. Not sure what else to do at this stage. I don’t think piston rings are a problem because it would be smoking all the time.

Let me know if you figure it out and I will do the same.

[Trubs]

I am having exactly the same issues with my 2007 Polo GTi. Coast downhill in 5th, smoke when I accelerate. I have tried thicker oil, no good. I have just had the valve stem seals replaced, and I swapped out the turbo with a lower mileage spare that I had sitting around, but symptoms remain. Mechanic thinks that the smoke will settle after a week or two now that the stem seals have been replaced...??? Apparently the old ones were rock hard.

I might look at deleting the PCV etc and installing a Ryco catch can using large diameter pipes. Not sure what else to do at this stage. I don’t think piston rings are a problem because it would be smoking all the time.

Let me know if you figure it out and I will do the same.

I ended up changing out the oil for Liqui Moly 10w40, also removed my lower boost pipe and a significant amount of oil drained out which makes me think my turbo oil seals are no good. Didnt really see it smoke for a week, but yesterday had a friend following me and he said that he saw small amounts of smoke when I was coming off boost and slowing down to a stop or coasting down the hill.

Might get the turbo sent off and see if it can get reconditioned in the new year.

[Rdubya]

I ended up changing out the oil for Liqui Moly 10w40, also removed my lower boost pipe and a significant amount of oil drained out which makes me think my turbo oil seals are no good. Didnt really see it smoke for a week, but yesterday had a friend following me and he said that he saw small amounts of smoke when I was coming off boost and slowing down to a stop or coasting down the hill.

Might get the turbo sent off and see if it can get reconditioned in the new year.

Looks like it was the valve stem seals that were causing the smoking exhaust on start up and after coasting. I also found that the PCV was stuck closed, so I installed a Ryco catch can using 19mm hose. No more fumes in the cabin

[Trubs]

Looks like it was the valve stem seals that were causing the smoking exhaust on start up and after coasting. I also found that the PCV was stuck closed, so I installed a Ryco catch can using 19mm hose. No more fumes in the cabin

How did you end up doing the catch can?

Thinking of possibly going down the route of a hybrid k300 turbo, and a single pass front mount intercooler if I can find the parts from a TT or S3 locally otherwise Ill probably just order the Airtec one made for the car. And potentially the Link G4X Ecu.

Then getting a safe tune that wont upset the stock rods.

[h100vw]

I'd advise a k280, better suited to road driving. I have a k300 and it's not as user friendly as the 280 builds I have done for customers. No need to do a link. I can assist with tuning your stock ECU. Just need some free software, a check eBay cable and some long roads��

[Trubs]

I'd advise a k280, better suited to road driving. I have a k300 and it's not as user friendly as the 280 builds I have done for customers. No need to do a link. I can assist with tuning your stock ECU. Just need some free software, a check eBay cable and some long roads��

I have only just started looking at new turbos, I’m only really after a direct bolt on and from what I’ve read people like the k300s or k280s over a ko4-001. What makes the k300 less suitable to road driving? Does it come on boost later?

Appreciate the offer with tuning the ecu but I’ve already had it tuned by a local company on their dyno and I’d have no idea what do to trying to do it myself so I would probably end up taking it back to the same place. Currently makes 147kw at the wheels.

[h100vw]

I have helped plenty of guys tune remotely but the choice is yours, if you are happy with them no need to swap. My mate that tunes for me has done lots and lots of big turbo me7 stuff. Flashing ECUs and taking logs is pretty easy. The important part is having a road to log on. Most tuning shops wouldnt be interested in loaning out their dyno for 3rd party tuning, which I understand.

These are both direct bolt ons.

Port a stock manifold, the big bore ones dont flow well enough, mine made 10kw everywhere when I swapped out the bog bore 034 style one for a ported.

the K300 has a spikey nature and lights up the front wheels too easy, even with a linear throttle its hard to prevent.
The 280s come on boost a little softer and pretty much with the perfect amount of wheelspin. No need for rods at all.