How to change your cam follower inside. (Now with debate about failures and their cause.)

[jc@douglas]

i have never seen a vr in person takin apart but i would assume it is alluminum...i may have to tear a couple cars apart if i have time at work tomorrow

[GolfRS]

What i'm wondering is why Autotech didn't follow the OEM piston tip design, and went with a simple tip.

On a side note, i just "modified" the Autotech tip slightly, to see the effect it will have on the inside of the follower......

[enginerd]

I somehow picture you taking apart a perfectly good brand new car to look inside lol.

measure the ID so you know the clearance used on the Roller follower design, also the groove design depth/radius.

If you can take a pic of the cam surface. This may not be all that crazy an idea afterall. VW is probably working on the same thing. oem pump or otherwise I bet there are plenty of people going to the dealer under warrantee for this.

[enginerd]

Quote, originally posted by GolfRS »

What i'm wondering is why Autotech didn't follow the OEM piston tip design, and went with a simple tip. On a side note, i just "modified" the Autotech tip slightly, to see the effect it will have on the inside of the follower......

they were using a titanium retainer to keep the weight of the piston down so they could use the oem spring and slightly heavier larger stepped piston. they got the weight down but lost the oem wobbler feature.

[GolfRS]

Quote, originally posted by enginerd »

they were using a titanium retainer to keep the weight of the piston down so they could use the oem spring and slightly heavier larger stepped piston. they got the weight down but lost the oem wobbler feature.

Do you by any chance have the analogy of piston length vs pump efficacy ?
Meaning how much of the pump's ability is lost or gained if the piston is longer or shorter by (for example) 1mm ?

[rbradleymedmd]

Quote, originally posted by enginerd »

they were using a titanium retainer to keep the weight of the piston down so they could use the oem spring and slightly heavier larger stepped piston. they got the weight down but lost the oem wobbler feature.

Is this along the same line of thought that the KMD pump uses as well?

[enginerd]

At these low pressures the concern for piston length in the bore is more related to siezures and wear than bore leakage. Shortening the length decreases the L/D ratio and the tip and edge loads go way up. It's also very difficult (nearly impossible) to cut the end of the piston without screwing up the heat treat and the OD geometry.

[GolfRS]

Quote, originally posted by enginerd »

At these low pressures the concern for piston length in the bore is more related to siezures and wear than bore leakage. Shortening the length decreases the L/D ratio and the tip and edge loads go way up. It's also very difficult (nearly impossible) to cut the end of the piston without screwing up the heat treat and the OD geometry.

In layman's terms ?

If someone was to shorten the piston tip and add a spacer making up for the total length, would that have any adverse effects ?

[EL_3grab]

Would it be possible to machine a new HPFP housing to utilize the new HPFP with roller follower from the new CCTA engine? 150bar anyone?

From glydingsoul

[chris@revotechnik]

Quote, originally posted by jc@douglas »

you know anyone with etka? if so i can check price right now from home if you can get me the part number

its on my other laptop but I'm not in the mood to break it out.. tomorrow is fine.

[chris@revotechnik]

Quote, originally posted by GolfRS »

On a side note, i just "modified" the Autotech tip slightly, to see the effect it will have on the inside of the follower......

I did some stuff to mine also. we'll see when I pull it.

[dietcokefiend]

Has anyone successfully replaced their follower after a previous one had started wearing, and had the new one hold up for good amount of time? On that same note, did the cam surface change texture, or show further signs of wear?

One of these days I am going to pop open the side and see what version of the cam I have and also check for wear, but right now its a mixture of fear for what I could find, and lack of garage space keeping me out.

While I understand that you are going to hear about more failures than good stuff online, this does seem like a problem that might crop up on any car depending on the variables at play.

Now for those if you saying that replacing a follower on a pre-worn cam is a bad thing, and both cam and follower need to be replaced at the same time... how can that be?

I think can think of many cars that use shims on the followers that get replaced to adjust for clearances, and those dont wear down the lobe surfaces. This has been going on for ages, some including regular maintenance adjustments, but those dont have wear problems with one surface being new, and the other being worn as long as the cam surface is undamaged.

[jc@douglas]

i just checked out a 3.6 fsi passat and the the fuel pump is directly to the cylinder head unlike our cars where it is bolted to the side cover, from what i understand the aligning tab on the cam follower is held in place by something inside the cylinder head not the actual head its self...not sure what though

[VW03Getta]

so you're saying its actually running off of one of the valve camlobes?

[jc@douglas]

no it is prob running off a cam lobe like the 2L fsi but it's location is different their for the pump as actually bolted to the cylinder head

[jc@douglas]

i would check your cam follower and cam lobe yourself don't trust them, you are loosing fuel pressure for a reason

[jc@douglas]

how can they tell if the cam lobes are worn down threw the cam follower hole? you need to look at it from the side or measure the lift and make sure it's proper

[b00stin_02917]

ugh today wasnt good... i decided to check my build date hoping id get lucky and rock a B cam setup.. well build date = 03/06 my buddy has a 01/06 build! ha ha now i deffently have to check mine and his..

[magilson]

Quote, originally posted by jc@douglas »

i would check your cam follower and cam lobe yourself don't trust them, you are loosing fuel pressure for a reason

But I though Chris said the best people to take it to is your dealer?

[GolfRS]

Quote, originally posted by plutoR »

Ok , JC I am with you there. Prior to the HPFP mod , I had no issues - a bit of low pressure here and there but not down to zero bar . Wouldnt a cam issue have reared it's head then ?

Its probably the KMD pump seizing.There was another person with that issue in here.

Remove and check the pump motion, and contact KMD for a replacement.

[ExPunkStar]

What build dates are affected? My car was purchased July 31, 2006. How do I verify my build date?

[rbradleymedmd]

Build Dates seem to not play a factor in which Cam a car has...unless the car is an '05 Audi (experts...please feel free to correct). My car is an 06 Passat with a build date 2/12/06 and I have the "B" Cam.

[vRStu]

Guys a quick thought here -

When you pull your pumps and fit the new ones are you putting CYL 1 at TDC?

I'm just wondering if you don't put it to TDC and the first rotation of the lobe strikes the follower on the not hardened face it can cause a stress fracture.

[dietcokefiend]

The way the cam is shaped it is 3 equal peaks that would the follower on the same hardened surface each time, non cycle dependent.

[vRStu]

Ok, but I have read a couple of DIY on the FP and none mention TDC (Including post one of this thread) however the Skoda Factory manual I have is quite explicit about it.

Has anyone checked the Bentley for the GTi?

[Arin]

I'll be honest, when I did my pump no directions existed. I wasn't at TDC, unless it just happened to be there out of luck. The install went w/o a hitch.

[rbradleymedmd]

x2

Quote, originally posted by Arin »

I wasn't at TDC, unless it just happened to be there out of luck. The install went w/o a hitch.

[GolfRS]

Quote, originally posted by rbradleymedmd »

x2

x3

Just had to push it in a bit to tighten the screws

[ExPunkStar]

Quote, originally posted by rbradleymedmd »

Build Dates seem to not play a factor in which Cam a car has...unless the car is an '05 Audi (experts...please feel free to correct). My car is an 06 Passat with a build date 2/12/06 and I have the "B" Cam.

Well my door panel is labeled: Mfg. Date 05/06. Guess I need to pop off the vac pump now...

Also wondering for those of you who have serious or abnormal wear to the cam or follower, did you baby the car and break in your engine for the first 1000 miles?


Modified by ExPunkStar at 3:11 PM 4-7-2008

[shue333]

my cam lobe was all silver, and everyone else's is black on top. should that concern me?

[Arin]

Angle of photo or worn followers.
It should be black for the most part. That's the protective 'first layer of defense' coating.

[SleepinGLI]

mine was all silver as well... Which is why im taking it in. However if they do the camshaft/follower, im going to install a hpfp as soon as i get it back.. Gunna try to break in the cam/follower WITH an aftermarket HPFP and see if that makes any difference

[shue333]

Quote, originally posted by Arin »

Angle of photo or worn followers. It should be black for the most part. That's the protective 'first layer of defense' coating.

i'm so confused

[shue333]

Quote, originally posted by shue333 »

i'm so confused

\

nevermind. i just re-read the TSB. i got it

[NoRegrets78]

Anyone wants a brand new follower, $45 shipped! Let me know.