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Golf R Internals Swap - Opinions Welcome

clockwise33

New York Giants Fanatic
Location
NJ
I'm starting the tear today to swap MK6R rods and pistons into my K04 MK5 GTI. I picked up the rods/pistons (pictured) from a wrecked MK6R w/ 50k miles for $155 and will be installing them w/ new bearings and rings. I went back and forth on whether to go this route vs drop-in H beams, and I ultimately decided on the OEM+ approach with added benefit of stronger, lower CR pistons that are matched to my current turbo and injectors.

2 aspects of the install that I'm not decided on come down to cylinder honing and thrust washer replacement. The engine has 118K miles and doesn't consume much oil at all, maybe 1 qt per 5000 miles. VAG doesn't mention hone or deglazing in the shop manual, just check piston clearance and ring gap and go. Another consideration is I do not plan on pulling the crank, so honing will be done with the crank insitu, with any effort possible to protect the crank journals from debris. On the thrust washers, I'd like to replace them if possible because I've been running a stiffer pressure plate for years. I figure they can be removed/reinstalled by removing the 3rd main cap, leaving the crank in place. Anyone see any reason this can't/shouldn't be done?

Any advise is appreciated.

 

clockwise33

New York Giants Fanatic
Location
NJ
To update on the status of my little project, everything came apart without incident. I'm really pleased with the condition of the internals. The rod bearings are in excellent shape, the balance shafts have no play and spin freely and the inside of the engine is really clean.

I've included some comparison shots of the Golf R and GTI internals. The R rods are significantly beefier, including larger rod bolts. I'm going to borrow a micrometer from work and take some measurements of everything. I'll update the thread when I've made some progress putting everything together.











 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
I would say forget the honing. I rebuilt mine at 120k miles due to a ring being stuck in the piston groove on the #4 cylinder. There was evidence of a bit of piston skirt contact in the cylinders such as what I see in your pics. But there was no depth to them, only a bit of polishing. My VW tech, Techtonics, and head rebuilder said just new rings and rod bearings are what they would do for the block in its condition. It's at 151k miles now using less than 0.5L/5k miles. Basically, if you still see crosshatching and you cannot see much glazing throughout the depth of the cylinder...it should be fine. Hone only to restore crosshatching and remove glazing.
 

clockwise33

New York Giants Fanatic
Location
NJ
I would say forget the honing. I rebuilt mine at 120k miles due to a ring being stuck in the piston groove on the #4 cylinder. There was evidence of a bit of piston skirt contact in the cylinders such as what I see in your pics. But there was no depth to them, only a bit of polishing. My VW tech, Techtonics, and head rebuilder said just new rings and rod bearings are what they would do for the block in its condition. It's at 151k miles now using less than 0.5L/5k miles. Basically, if you still see crosshatching and you cannot see much glazing throughout the depth of the cylinder...it should be fine. Hone only to restore crosshatching and remove glazing.
Very helpful, thank you. I still haven't made up my mind on the honing. I'm going to ask around some shops that are local to me.

Something else that came up in the tear down was related to the oil pump, I used the 12 point bolt on the balance shaft sprocket to counterhold when removing the oil pump sprocket bolt. The shop manual said "counterhold using center bolt of vibration damper" and I now realize they meant the crank pulley. I'm probably overthinking this, but I'm concerned I may have tightened the balance shaft sprocket bolt. I can't be certain that it spun, however I noticed that the sprocket (which is supposed to be decoupled, like a DMF) is quite difficult to move back and forth. Does anyone have an extra oil pump on the shelf who can tell me if this sprocket is supposed to be tight?
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Very helpful, thank you. I still haven't made up my mind on the honing. I'm going to ask around some shops that are local to me. That's a good idea. I asked because my idea of glaze and cross-hatch is likely different from what a more experienced rebuilder may think. Then I just trusted those two and let it go, again, as they thought it was fine.

Something else that came up in the tear down was related to the oil pump, I used the 12 point bolt on the balance shaft sprocket to counterhold when removing the oil pump sprocket bolt. The shop manual said "counterhold using center bolt of vibration damper" and I now realize they meant the crank pulley. I'm probably overthinking this, but I'm concerned I may have tightened the balance shaft sprocket bolt. I can't be certain that it spun, however I noticed that the sprocket (which is supposed to be decoupled, like a DMF) is quite difficult to move back and forth. Does anyone have an extra oil pump on the shelf who can tell me if this sprocket is supposed to be tight?
←No idea on this one. :iono:
 

clockwise33

New York Giants Fanatic
Location
NJ
I took some measurements of the Golf R and the GTI rods that I'll share for posterity:

Golf R rod weight w/ bolts: 615.4g
GTI rod weight w/ bolts 547.7g

Golf R rod dimensions at thinnest point: 14.41mm x 21.30mm
GTI rod dimensions at thinnest point: 12.07mm x 18.15mm

So the Golf R rods are 12.4% heavier, 17.5% wider web, 19.4% wider flange relative to the GTI rods.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Will likely be the only internal upgrade I may do...but only if I do plan on going ahead with a different than K04 turbo. TTE420 would be a nice one. Just going to have to convince myself the extra $1000+ for the turbo and then tuning will be worth it...and that is all contingent on not needing to swap injectors or much more.
 

Finder

Ready to race!
Location
Canada
I would say forget the honing. I rebuilt mine at 120k miles due to a ring being stuck in the piston groove on the #4 cylinder. There was evidence of a bit of piston skirt contact in the cylinders such as what I see in your pics. But there was no depth to them, only a bit of polishing. My VW tech, Techtonics, and head rebuilder said just new rings and rod bearings are what they would do for the block in its condition. It's at 151k miles now using less than 0.5L/5k miles. Basically, if you still see crosshatching and you cannot see much glazing throughout the depth of the cylinder...it should be fine. Hone only to restore crosshatching and remove glazing.
When I did mine last year I used a 3 1/4" (83mm) Flex-Hone tool (Silicon Carbide, 240 grit) to remove glazing and restore crosshatching.
It's very easy to use, you only need a drill with low speed.
Worked out great.
 

clockwise33

New York Giants Fanatic
Location
NJ
When I did mine last year I used a 3 1/4" (83mm) Flex-Hone tool (Silicon Carbide, 240 grit) to remove glazing and restore crosshatching.
It's very easy to use, you only need a drill with low speed.
Worked out great.
Thanks for the input. I'm pretty much settled on not honing. I've gotten a lot of feedback that shops and dealers usually don't hone, especially if there was no history of oil consumption. I don't want to run the risk of screwing it up.

What is the word on reusing the timing belt tensioner? The timing belt and related components only have 33k miles and I'd rather not replace if unnecessary.
 

clockwise33

New York Giants Fanatic
Location
NJ
Update: The dealer could only locate 7 Golf R bearing shells nationwide, and one of the 7 they gave me was badly scratched, classic. So I have the last 2 bearing shells coming from ECS. Some pics of the progress and a comparison shot of the BPY and CRZA pistons:

The CRZA pistons are very similar to the BPY pistons, aside from the lower CR dish and larger valve reliefs. The top ring for the CRZA is rectangular w/ internal bevel as apposed to the BPY tapered face.



Cheap Amazon ring compressor and pliers worked great. Note the moly/graphite coated rod bearings that come in the CRZA. Fairly exotic for a mass produced engine.



 
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ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Hey, not sure what you are doing with the head...but would be a good time to replace the valve stem guides and seal...and have it shaved if needed. Mine was in the $400 range to have done...plus the cost for seals and guides. I went to a trusted machine shop guy referred to me by Techtonics Tuning (TT is twenty minutes away) here locally.
 

clockwise33

New York Giants Fanatic
Location
NJ
Hey, not sure what you are doing with the head...but would be a good time to replace the valve stem guides and seal...and have it shaved if needed. Mine was in the $400 range to have done...plus the cost for seals and guides. I went to a trusted machine shop guy referred to me by Techtonics Tuning (TT is twenty minutes away) here locally.
I'm going to run the head as is. From everything I've saw in the tear down the engine is really healthy at 118k miles and I've never had excessive oil consumption or running issues.
 

clockwise33

New York Giants Fanatic
Location
NJ
Update: Its alive! Started it for the first time last night. I'm following the IE new engine break in guide - fill with 30w break in oil, crank engine with injectors unplugged for several bursts, then plug in injectors. At first it didn't want to start, but once I cleared the fault codes for injector communication it started and idled perfectly. I drove it around the neighborhood and to the beer store and got no fault codes. I'll post more feed back and logs once the break in is over and I switch to normal oil.
 

clockwise33

New York Giants Fanatic
Location
NJ
Thank you. I'm eagerly awaiting your next update on your build. I'm guessing the tuning is still the hold up? I've been researching custom tuning for my new setup in order to get the most out of the K04 and I've heard that UM and Malone are pretty good with MED9 custom tuning and offer free updates. May be worth a shot if you hit a dead end.
 
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