Oil leak and misfires

[OWNIT]

So my 2009 Tiguan head been at the mechanic for a week or so and issues still haven't been resolved.

Basically my car, since I bought it a couple of years back, has always been misfiring inadvertently. It would would happen every now and then, and go away.

In recent times it's getting worse and worse and the car has been leaking a lot of oil.

So my mechanic first replaced this part that sits underneath the rocket cover (?), Thinking it might fix the oil leak. It felt like it helped at first, but it eventually got worse again (in a couple of weeks)

Now the misfire..

First he found that two of the coils were bad, and replaced the 4. Still misfiring.

Then he found carbon build up in the manifold. Cleaned it. Still misfiring.

He's checked the injectors and they seem fine. He said something about a wet and dry compression test showing to with discrepancies, which would indicate serious engine issues, but he thinks it's unlikely the car is not blowing smoke, was driving fine when it want misfiring, etc.

Now here's thinking maybe the wiring to the coils?

I'm wondering if anyone here has experienced anything like this? I'm very worried that it might be something that will just cost an absurd amount to fix....

Car has done around 160k

[h100vw]

He your man scanned the ECU for faults. That's the first thing to do. It would pick up dodgy wiring.

Gavin

So my 2009 Tiguan head been at the mechanic for a week or so and issues still haven't been resolved.

Basically my car, since I bought it a couple of years back, has always been misfiring inadvertently. It would would happen every now and then, and go away.

In recent times it's getting worse and worse and the car has been leaking a lot of oil.

So my mechanic first replaced this part that sits underneath the rocket cover (?), Thinking it might fix the oil leak. It felt like it helped at first, but it eventually got worse again (in a couple of weeks)

Now the misfire..

First he found that two of the coils were bad, and replaced the 4. Still misfiring.

Then he found carbon build up in the manifold. Cleaned it. Still misfiring.

He's checked the injectors and they seem fine. He said something about a wet and dry compression test showing to with discrepancies, which would indicate serious engine issues, but he thinks it's unlikely the car is not blowing smoke, was driving fine when it want misfiring, etc.

Now here's thinking maybe the wiring to the coils?

I'm wondering if anyone here has experienced anything like this? I'm very worried that it might be something that will just cost an absurd amount to fix....

Car has done around 160k

[OWNIT]

He your man scanned the ECU for faults. That's the first thing to do. It would pick up dodgy wiring.

Gavin

Just reports misfires

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[h100vw]

PCV on the front of the motor.

[OWNIT]

PCV on the front of the motor.

Can you please elaborate? And roughly how much to fix?

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[Lucas_R]

Oil leak and misfires

Can you please elaborate? And roughly how much to fix?

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I had to replace the PCV (positive crankcase ventilation) on my Mk6 GTI earlier this year (same engine as your Tiguan). I got mine from USA because it was about $200 cheaper than buying locally.

OEM PCV Valve Assembly - 2.0T TSI - 06H 103 495 E

[OWNIT]

I had to replace the PCV (positive crankcase ventilation) on my Mk6 GTI earlier this year (same engine as your Tiguan). I got mine from USA because it was about $200 cheaper than buying locally.

So how much were you getting quoted here?

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[Lucas_R]

So how much were you getting quoted here?

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About $550 from memory. Got it from overseas much cheaper. See link in my previous post.

[OWNIT]

So my mechanic first replaced this part that sits underneath the rocket cover (?), Thinking it might fix the oil leak. It felt like it helped at first, but it eventually got worse again (in a couple of weeks)

Turns out, this was actually the PCV. So back to the drawing board.

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[Lucas_R]

Ok so you have had the following cleaned/replaced:

Ignition coils = replaced
PCV = replaced
Inlet manifold = cleaned
Injectors = inspected to be ok

Ignition coils are a very common failure on these engines - especially once the car has a few years under its belt, so its good that these have been replaced. Assuming your mechanic has scanned the car for faults and there is either nothing there or you have looked into all of these errors, i would start looking at your fuel system.

Make sure the fuel filter has been replaced (these are under $50) recently with a genuine VW (or reputable brand like MANN) filter. Make sure you are using good quality 98 RON petrol like BP/Shell etc. Then start looking at the HPFP (high pressure fuel pump) on the top of your engine. This mechanical pump is generally very reliable but i have known of a few to fail on the 2.0TSI engine which causes misfires and loss of power. Here is a link to the HPFP for your engine, luckily they are not stupidly expensive: https://www.ecstuning.com/Volkswagen...ump/ES2780219/ (American website so factor in exchange rate and shipping - but it will still be much cheaper than buying locally.

My last point would be.....given that your is an 09 model which is one of the first Tiguans around, VW have revised several items since then, such as:

- Timing chain tensioner and timing chain (old design which your car will have can fail and causes the timing chain to slip - can cause the engine to blow. If you are very lucky the timing chain will just skip a few teeth and put the timing out.
- The PCV but you have already had this changed
- The diverter valve design. The older version (which your car will have) is prone to failure due to the diaphragm ripping. The revised design does away with this and is more robust. A leaking diverter valve would cause a loss of power and may cause misfires (you would probably get an error for turbo boost too). See link to the revised item available from a local Aussie shop: VW 2.0T OEM Upgraded Piston Diverter Valve - $115.00 : Dub Addiction

[OWNIT]

Ok so you have had the following cleaned/replaced:

Ignition coils = replaced
PCV = replaced
Inlet manifold = cleaned
Injectors = inspected to be ok

Ignition coils are a very common failure on these engines - especially once the car has a few years under its belt, so its good that these have been replaced. Assuming your mechanic has scanned the car for faults and there is either nothing there or you have looked into all of these errors, i would start looking at your fuel system.

Make sure the fuel filter has been replaced (these are under $50) recently with a genuine VW (or reputable brand like MANN) filter. Make sure you are using good quality 98 RON petrol like BP/Shell etc. Then start looking at the HPFP (high pressure fuel pump) on the top of your engine. This mechanical pump is generally very reliable but i have known of a few to fail on the 2.0TSI engine which causes misfires and loss of power. Here is a link to the HPFP for your engine, luckily they are not stupidly expensive: https://www.ecstuning.com/Volkswagen...ump/ES2780219/ (American website so factor in exchange rate and shipping - but it will still be much cheaper than buying locally.

My last point would be.....given that your is an 09 model which is one of the first Tiguans around, VW have revised several items since then, such as:

- Timing chain tensioner and timing chain (old design which your car will have can fail and causes the timing chain to slip - can cause the engine to blow. If you are very lucky the timing chain will just skip a few teeth and put the timing out.
- The PCV but you have already had this changed
- The diverter valve design. The older version (which your car will have) is prone to failure due to the diaphragm ripping. The revised design does away with this and is more robust. A leaking diverter valve would cause a loss of power and may cause misfires (you would probably get an error for turbo boost too). See link to the revised item available from a local Aussie shop: VW 2.0T OEM Upgraded Piston Diverter Valve - $115.00 : Dub Addiction

I'm thinking/hoping there's a possibility that the PCV valve was faulty/incorrectly installed etc. mechanic is looking into this.

He's also going to check out the timing chain tensioner/timing chain and the diverter valve.

Not sure where we're at with the HPFP

The mechanic is suggesting it could be an issue with the motor. Not sure, but it apparently drives fine and misfires mostly on idle.

I usually use 98 from Caltex. The car says 95 though?


This is really doing my head in. I'm probably already down 2-3k, if I'm down a motor probably looking at another 5k. I'm done with this car, almost want to just find a way of getting rid of it without losing too much on it and just start all over again with something new...




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[h100vw]

Is your mechanic a VW specialist?

I'd be looking for one if not.

[OWNIT]

He's not...


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[Lucas_R]

He's not...

What city/town are you located in? We might be able to direct you to a well known VW specialist dependent on where you are.

It sounds like your mechanic has covered the basics, but given that the issue persists - it might be time to look at taking it to someone who specialises in VW/Skoda/Audi.

[OWNIT]

South east Melbourne, Mulgrave area... I'll give him another day or so to try sort out this mess...


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