Tuning a high(ish) mileage FSI

[doktorslowburn]

Hey all!

So over the past year I’ve spent a lot of time getting my 2007 MKV (FSI) up to snuff on its maintenance. I’ve done loads of stuff, not limited to but including:
- clutch kit, flywheel, rear main seal
- engine & trans mounts
- manual transmission fluid
- oil change with cam follower replacement
- timing chain AND belt, along with tensioner(s), water pump and serpentine belt
- brake fluid flush
- brakes & rotors
- replaced a leaky oil filter housing
- replaced fuel filter
- replaced brake booster hoses that were cracked
- installed a CTS intake
- installed oil catch can
- had a custom fitted Borla catback installed
- replaced spark plugs

So, now that all of the boring stuff is over, I want to tune it. I don’t want to go any further than Stage 1 for now. I have a local tuning shop that’s ready to do an APR S1 flash next week, but I thought I’d post here for advice first.

This car has 96k miles on it. It runs like a top- not a single engine code, zero misfires. Not leaking anything and holds a consistent boost pressure. I also did a compression test a few months ago, and while I forget the exact numbers, all cylinders were within the tolerance range and readings were consistent across all cylinders.

With the above in mind, is tuning this car essentially a death sentence due to its age? Is there anything else I should do to prepare, or should I avoid doing this altogether?

Thanks in advance!

 

[Michael gti07]

No, most tunes will not kill a car, but more aggressive tunes add more wear and tear. Going to need a boost gauge to diagnose, monitor performance. (I had a p3). I was pushing 8psi normal boost, and up around 18psi for spirited driving if I recall.
I had the 2007 dsg version, with a REVO stg1 eng/dsg tunes. I owned it till 168,XXX miles. Sold it to a buddy for his daughter, original hpfp died little more than 6 months later. Also had a carbon clean out somewhere after 90,000ish , I can't remember.
Revo left the American market a few years later. I was quite satisfied with it, but the DSG tune was my favorite. (Did local autocross for a year, was fun).
I've no idea what other tuners are available for a car that age, but if your a tinkerer, I would get a COBB, or other flash tuner to try out different engine maps.
After all, it really depends on how often you go wide open throttle.

Have you considered the hpfp cam follower upgrade that replaced the flat tappet with a cam roller?

 

[ROH ECHT]

You have all of the hardware requirements for Stage 1...no problem there.
Had you done a down-pipe you could've done Stage 2.
The only thing that you've done which will hurt, more than help, is the addition of a catch-can.
Removing (or having bought it that way) the PCV eliminates crankcase vacuum. Which helps with sealing at the seals, valve stem guides and seals, and at the rings.

A catch-can (CC) for PCV swap is mostly helpful for a race car almost always driven in boost...not on a daily which is mostly driven in vacuum. Yes, people say the catch-can helps with carbon buildup on the intake valves. But it is a very slight reduction and your car already has a built in oil separator in the top of the oil filter housing assembly, and another in the rocker/valve cover. The choice is keep the catch-can for the benefit of crankcase vacuum or add the CC and see more oil pass through seals and other spots where oil can seep out. The catch-can will mostly catch and store water...and a tiny bit of other fluid/oil:

If you choose to return the OE PCV, down the road, look here and make sure you pair the PCV with the proper rear vent tube (there are two designs of both PCV and rear vent tube): https://www.golfmkv.com/forums/inde...r-pcv-to-crankcase-breather-tube-info.378931/

The tune, even without having upgraded the HPFP internals, is going to increase the rail pressure. So you will need to learn of its new cam follower (CF) swap-interval. Stock tune rail pressure max's out at 110 bar, and the Stage 1 tune may max the rail pressure at 120 bar. The added pressure applies more force at the cam follower and tri-lobe. There are going to be people telling you the CF lifespan, in miles, is: every oil change, 5k, 8k, 10k, 15k, 20k, 40k or more. You'll hear them all. CF lifespan differs with everyone, so learn yours independently. The variables are: condition of the parts which produce rail pressure (tri-lobe, CF, pressure containment bits, HPFP and its piston seals inside its retainer nut)__type of oil used and freshness__how often, with the throttle, you increase rail pressure and duration__crankcase and oil pressure. I wanted to point this all out so you see how your CF lifespan will differ from others....so you don't simply do what another tells you regarding CF swap-intervals. Be consistent with the brand of oil and oil intervals, and the brand of CF. Be aware of how you've driven it and adjust your inspections accordingly. You'll want to replace the CF just when the black DLC (coating) begins wearing thin on the surface of the CF contacting the tri-lobe. Initially, you will be inspecting the CF more often. Eventually, you will determine you can go a certain number of miles for each CF. If you later change; I.e. the tune or HPFP internals and/or the oil type/brand, you will want to relearn the CF swap-interval.

 

[doktorslowburn]

No, most tunes will not kill a car, but more aggressive tunes add more wear and tear. Going to need a boost gauge to diagnose, monitor performance. (I had a p3). I was pushing 8psi normal boost, and up around 18psi for spirited driving if I recall.
I had the 2007 dsg version, with a REVO stg1 eng/dsg tunes. I owned it till 168,XXX miles. Sold it to a buddy for his daughter, original hpfp died little more than 6 months later. Also had a carbon clean out somewhere after 90,000ish , I can't remember.
Revo left the American market a few years later. I was quite satisfied with it, but the DSG tune was my favorite. (Did local autocross for a year, was fun).
I've no idea what other tuners are available for a car that age, but if your a tinkerer, I would get a COBB, or other flash tuner to try out different engine maps.
After all, it really depends on how often you go wide open throttle.

Have you considered the hpfp cam follower upgrade that replaced the flat tappet with a cam roller?

I have a boost gauge, just need to install it. It’s actually been sitting in the box for months, just haven’t gotten around to mounting it.
I’ve read APR is a pretty mild tune, which was one of the reasons I chose them.

I have not looked into actually upgrading the cam follower, just replacing it. But I’ll take a look at that.

Regarding the carbon cleaning- as far as I know, this cars never had it done. I’m the second owner and there’s no record of it being cleaned.

Would that be considered a MUST before tuning? It’s not showing any of the symptoms I’d expect to see from carbon buildup… no misfires, idles smoothly, no issues with power. I mean I’m sure there’s still buildup, but I feel like it’s probably not that bad.

 

[doktorslowburn]

You have all of the hardware requirements for Stage 1...no problem there.
Had you done a down-pipe you could've done Stage 2.
The only thing that you've done which will hurt, more than help, is the addition of a catch-can.
Removing (or having bought it that way) the PCV eliminates crankcase vacuum. Which helps with sealing at the seals, valve stem guides and seals, and at the rings.

A catch-can (CC) for PCV swap is mostly helpful for a race car almost always driven in boost...not on a daily which is mostly driven in vacuum. Yes, people say the catch-can helps with carbon buildup on the intake valves. But it is a very slight reduction and your car already has a built in oil separator in the top of the oil filter housing assembly, and another in the rocker/valve cover. The choice is keep the catch-can for the benefit of crankcase vacuum or add the CC and see more oil pass through seals and other spots where oil can seep out. The catch-can will mostly catch and store water...and a tiny bit of other fluid/oil:

If you choose to return the OE PCV, down the road, look here and make sure you pair the PCV with the proper rear vent tube (there are two designs of both PCV and rear vent tube): https://www.golfmkv.com/forums/inde...r-pcv-to-crankcase-breather-tube-info.378931/

The tune, even without having upgraded the HPFP internals, is going to increase the rail pressure. So you will need to learn of its new cam follower (CF) swap-interval. Stock tune rail pressure max's out at 110 bar, and the Stage 1 tune may max the rail pressure at 120 bar. The added pressure applies more force at the cam follower and tri-lobe. There are going to be people telling you the CF lifespan, in miles, is: every oil change, 5k, 8k, 10k, 15k, 20k, 40k or more. You'll hear them all. CF lifespan differs with everyone, so learn yours independently. The variables are: condition of the parts which produce rail pressure (tri-lobe, CF, pressure containment bits, HPFP and its piston seals inside its retainer nut)__type of oil used and freshness__how often, with the throttle, you increase rail pressure and duration__crankcase and oil pressure. I wanted to point this all out so you see how your CF lifespan will differ from others....so you don't simply do what another tells you regarding CF swap-intervals. Be consistent with the brand of oil and oil intervals, and the brand of CF. Be aware of how you've driven it and adjust your inspections accordingly. You'll want to replace the CF just when the black DLC (coating) begins wearing thin on the surface of the CF contacting the tri-lobe. Initially, you will be inspecting the CF more often. Eventually, you will determine you can go a certain number of miles for each CF. If you later change; I.e. the tune or HPFP internals and/or the oil type/brand, you will want to relearn the CF swap-interval.

Now, see that is good information. I had no idea the catch can was doing more harm than good. With that advice, I honestly might just yank it out. TBH it was more of a pain that it’s worth- I had to knock out the check valve from the rear PCV tube because when I installed the catch can it started making that ungodly ticking sound.

So, I’ll have to get a new rear PCV tube before I can take out the catch can, but that shouldn’t be a problem. I have a brand new stock PCV valve sitting in my shed.

Thanks for the advice on the CF. Right now I replace mine every oil change just to be safe- which has been twice since I owned the car. But I’ll pay very close attention to it starting out. It’s very easy to inspect so I’ll do it every few weekends.

Regarding the HPFP internals, would you recommend upgrading that right away?

 

[ROH ECHT]

Since the rear vent tube is now valveless, the PCV you would use is PN: 06F 129 101 'R'
PCV 06F 129 101 R has a valve in it, which is in the rear vent tube when using PCV 06F 129 101 P.
Regarding PCV and rear vent tube pairing....have a look at that thread I linked for you.

You should get more than 10k miles at stage 1 if the tri-lobe is in great condition and you use the proper oil. I would guess between 20k and 40k miles at stage 1. But do what you feel comfortable. Remember not to go over torque on those HPFP bolts. Their torque is just 10 Nm/7 lb*ft. If you strip the threads from the chain cover, the cover costs near $700. If you ever do strip them, you may then consider the roller follower conversion which comes with a modified chain cover and costs less than a new OE cover.

The HPFP upgrade is done for taking another step in tuning, and tuning for the HPFP typically requires a down-pipe upgrade. Doing the HPFP is for Stage 2+ tunes (for those with HPFP upgrades). The stage 2+ tune (most stage 2+ anyways) will then increase the rail pressure to 130 bar and the cam follower will then likely last just 8k to 10k ± miles...more or less depending on all of those factors I mentioned before.

The cam follower is still good if the black coating isn't worn away;
If the CF looks like the first, cannot yet see the metal, put it back in....like the second, and the metal is now visable, replace it.

As was mentioned by the other responder, before tuning a well used engine, might be wise to have the intake valves cleaned, but also the injectors properly serviced at the same time before the tuning session.
Proper injector service on ours is not just a simple clean and 6 bar pressure check. They need to be volume flow tested and their spray patterns observed as in the vid below.

You can see proper injector spray and volume testing here beginning at about 10 mins:

 

[doktorslowburn]

Since the rear vent tube is now valveless, the PCV you would use is PN: 06F 129 101 'R'
PCV 06F 129 101 R has a valve in it, which is in the rear vent tube when using PCV 06F 129 101 P.
Regarding PCV and rear vent tube pairing....have a look at that thread I linked for you.

You should get more than 10k miles at stage 1 if the tri-lobe is in great condition and you use the proper oil. I would guess between 20k and 40k miles at stage 1. But do what you feel comfortable. Remember not to go over torque on those HPFP bolts. Their torque is just 10 Nm/7 lb*ft. If you strip the threads from the chain cover, the cover costs near $700. If you ever do strip them, you may then consider the roller follower conversion which comes with a modified chain cover and costs less than a new OE cover.

The HPFP upgrade is done for taking another step in tuning, and tuning for the HPFP typically requires a down-pipe upgrade. Doing the HPFP is for Stage 2+ tunes (for those with HPFP upgrades). The stage 2+ tune (most stage 2+ anyways) will then increase the rail pressure to 130 bar and the cam follower will then likely last just 8k to 10k ± miles...more or less depending on all of those factors I mentioned before.

The cam follower is still good if the black coating isn't worn away;
If the CF looks like the first, cannot yet see the metal, put it back in....like the second, and the metal is now visable, replace it.
View attachment 254373


As was mentioned by the other responder, before tuning a well used engine, might be wise to have the intake valves cleaned, but also the injectors properly serviced at the same time before the tuning session.
Proper injector service on ours is not just a simple clean and 6 bar pressure check. They need to be volume flow tested and their spray patterns observed as in the vid below.

You can see proper injector spray and volume testing here beginning at about 10 mins:

Thanks again, the info you’ve provided has been very helpful. I do have a couple of follow up questions though.

So the spare PCV valve I have sitting around is 06F 129 101 P. I’m going to remove the catch can, and ideally I’d like to completely replace the rear breather tube with one that has the check valve still in it, which would be part number 06F103215B, correct? Or would it be better to leave the rear tube valveless and get the iteration of the front-mounted valve that doesn’t have the check valve inbuilt?

Also, regarding the carbon cleaning and injectors. Would you say that’s a complete showstopper for tuning, or just recommended? It’s hard to find someone to do that work around here for less than $1k, which is something I can’t afford at the moment. The best quote I got for a carbon cleaning last time I looked was $950.

Would it be something I could do down the road a bit after the tune is in place, or is this a critical pre-tune item?

 

[ROH ECHT]

Thanks again, the info you’ve provided has been very helpful. I do have a couple of follow up questions though.

So the spare PCV valve I have sitting around is 06F 129 101 P. I’m going to remove the catch can, and ideally I’d like to completely replace the rear breather tube with one that has the check valve still in it, which would be part number 06F103215B, correct?Yes, rear vent tube w/valve is: 06F 103 215 B - I prefer the open rear tube and PCV Rev.-R. Because if the PCV fails and a replacement isn't readily available, and I need the car, I can temporarily install my BSH PCV delete plate which pairs with the open rear vent tube. This happened but once, and for just three days.

Or would it be better to leave the rear tube valveless and get the iteration of the front-mounted valve that doesn’t have the check valve inbuilt? This is up to you and your preference. Having the valved rear vent tube is beneficial for when or should the passages through the valve cover open to the crankcase. A while back (more than a decade ago) VW/Audi made this change to the valved rear tube while removing the valve from the PCV. But have since returned to the valveless rear tube and the Rev.-R PCV. And I believed then the change was made for those passages sometimes developing openings where they should be sealed.

Also, regarding the carbon cleaning and injectors. Would you say that’s a complete showstopper for tuning, or just recommended? It’s hard to find someone to do that work around here for less than $1k, which is something I can’t afford at the moment. The best quote I got for a carbon cleaning last time I looked was $950...and injector services are an additional $150. If getting a shelf tune; the valve cleaning and injector service isn't really necessary. Because you get what you get with the tune. And so waiting will be OK. If were going to have a custom tune, then yes. You would want to do so because you would want to take advantage of every bit of inlet air and fuel you could provide for the tuner. This should answer the next question as well.

Would it be something I could do down the road a bit after the tune is in place, or is this a critical pre-tune item?

Yes? Just remember all of this for when it is tuned. If yours seems to have less power than another with the same tune...it may be due to intake valve buildup or from its injectors not performing optimally.

 

[doktorslowburn]

Thank you so much for your advice @ROH ECHT , you’ve been a massive help. I owe you a beer sometime.

 

[doktorslowburn]

@ROH ECHT one more question on this topic- I’m going to get a compression and leakdown test run before I go to the Dyno. Compression I know will work, but will the absence of the rear breather check valve cause an issue with the leakdown test?

I ordered a replacement breather tube WITH the check valve and plan on removing the catch can before getting it tuned, but my replacement breather won’t come in for several more days and I was hoping to get the testing done when I bring it in tomorrow for some other work.

 

[ROH ECHT]

@ROH ECHT one more question on this topic- I’m going to get a compression and leakdown test run before I go to the Dyno. Compression I know will work, but will the absence of the rear breather check valve cause an issue with the leakdown test?

I ordered a replacement breather tube WITH the check valve and plan on removing the catch can before getting it tuned, but my replacement breather won’t come in for several more days and I was hoping to get the testing done when I bring it in tomorrow for some other work.

Won't affect it at all. Both tests are only concerned with pressure inside the combustion chamber.

Compression test is OK when wanting to take a quick peak and to compare its current pressure with the manufacturer's health standard.

But a leak-down test is the one to do for pinpointing a problem.
Both of those tests check the sealing of valves and rings/pistons.
But the leak-down is done to isolate where a cylinder may be leaking.
Most pros will say do the leak-down when cold. The rest will say do the test when warm so you get better results. I would do the test when cold.

Each cylinder is tested at TDC on the compression stroke, so the valves are shut, and then it is pressurized. Once pressurized, you see if it holds pressure. Generally; 3% to 5% leakage is very good. If it bleeds the pressure quickly, you'll attempt to keep it pressurized at no more than 100 psi and search for the leak. While pressurized:
1) Removing the oil filler cap or dipstick to detect air escaping which points to piston ring leakage.
2) Detecting air escaping at the exhaust tips (so long as there are no exhaust leaks) reveals exhaust valve leaking.
3) Disconnect something from the intake manifold to check for intake valve leakage.