PD Injector Bore Wear...

[jimbote]

installed a set of PD 150 injectors this week for a customer done alot of work on this car aside from an auto>five speed>six speed it's recieved a 17/22, malone boost egt gauges etc. ....well when I pulled the injectors from the head I noticed some wear in the injector bore itself ....this is my first time r&r on PD injectors and wondering if anyone else has run into this....It "appears" that the side loading from the injector clamp has caused wear on the opposite side of the bore from minute injector movements....I cleaned and smoothed the side of the bores as much as possible...lubed them up and along with new injector orings and seals I'm crossing my fingers...car seems to run good but is a little slow on the start (was before too) ...and I just found this .... http://www.eurodrivers.ca/forums/sh...l.-Help-Wanted&p=226517&viewfull=1#post226517 ....so it looks like a not uncommon issue ...no pics of the customers bores but I have his old injectors and I'll shoot some pics of those showing the corresponding wear patterns... and this... http://www.vwaudiforum.co.uk/forum/showthread.php?101958-1.9Tdi-115.-Engine-swap

 

[jasonTDI]

Haven't seen it....can't be good. Those heads are spendy.

 

[jimbote]

ohh yeah....mileage is 208k....

 

[Sooch]

Take an oil sample in a few hundred miles and you'll know if the fuel is getting past the o-rings.

Unless that wear mark has some significant depth, I personally wouldn't worry about it. It would have to be deep enough to allow a fair amount of movement to reduce the compression of the o-rings before it would be an issue.

 

[jimbote]

Take an oil sample in a few hundred miles and you'll know if the fuel is getting past the o-rings.

Unless that wear mark has some significant depth, I personally wouldn't worry about it. It would have to be deep enough to allow a fair amount of movement to reduce the compression of the o-rings before it would be an issue.

any recommendations for an oil analysis lab?....I'll forward the info to the customer

 

[oilhammer]

I have heard of this, and I think it will become an issue as the PDs mile up. This is why I am leary of the VW reman heads that are complete, as I have heard of two of those having injector sealing issues. VW sells a NEW head for much less, but it is bare, and if you are going to add up all the bits together it does make the reman assembly at $3400 look reasonable.

I have installed two NEW PD heads with no problems, however. But getting the injectors in place, square, and tight is a bit of a procedure. The other thing I have seen is the injector block hold-down bolt holes stripping out... and once that happens, the block comes loose, and the injector bounces around in its bore and ruins the head.

I suspect a proper setup for boring and sleeving the injector holes (similar to what is done with lifter holes) could be used to save an otherwise good casting, along with threaded inserts for the hold-down bolts (a'la "case savers" on the old magnesium air-cooled blocks).

Seems the PD is fine so long as it is not messed with much or abused, but once it needs some mechanical work, it is just VERY difficult to get right.

 

[Henrick]

A remanned head is not always neccessary an ex-high-mileage one. You never know what you get. To be honest personally I don't like those remaned thingies. Although some people say there's absolutely nothing bad in getting a rebuilt alternator (since those are easily repairable) or a MAF when the core (the sensor itself) is always completely new while only the housing is being reused.

 

[Sooch]

any recommendations for an oil analysis lab?....I'll forward the info to the customer

I use Blackstone Labs, but there are others. Blackstone has never lost a sample of my oil and they are very quick. They also respond to emails promptly.

 

[A5INKY]

I last had my injectors out for a head rebuild (for guides and seals mostly) at ~193K. Injector bores looked brand new.

Oilhammer mentioned the hold down bolts, those make me cringe every time I torque new ones down. I swear I can feel them yielding...

 

[jimbote]

I last had my injectors out for a head rebuild (for guides and seals mostly) at ~193K. Injector bores looked brand new.

Oilhammer mentioned the hold down bolts, those make me cringe every time I torque new ones down. I swear I can feel them yielding...

yeah they do feel plastic under that 3/4 turn.... ....yeah I'm not sure why his bores looked so bad

 

[jimbote]

I use Blackstone Labs, but there are others. Blackstone has never lost a sample of my oil and they are very quick. They also respond to emails promptly.

I'll find and forward....thank you so much

 

[DanG144]

I have seen inector bore wear on several PD heads. One person had re-installed his own, had bore wear that he did not address at all. The new injectors hung up on the wear marks because he did not push them in all the way by hand; he figured the clamp would pull it into place - this was a mistake.

After that the bore wear was severe, but with not much to lose, I just polished them up, removed all the loose metal and sharp edges, lubed the bore, injector and orings with high temperature silicone grease (leaving no globs - only a sheen) then pushed the injectors in all the way by hand. Two years now and they are still holding.

It would certainly be better to have a clamp on each side, or 3 at 120 degrees.

 

[oilhammer]

They should have designed in a bridge, or some type of fixture, similar to a "main stay" over the main caps in the bottoms of some engines, to hold the injectors in place. Like a chunky ladder-looking thing.

 

[CGDoig]

That previous thread was mine on a local forum. I searched for quite a while after reading to find any info and could not, one page from a uk forum. Seems like a very uncommon problem.

 

[squishbang]

I had to dig up this old thread because it was difficult to find any information about this failure. Does anyone have any further input as to the cause of injector bores wearing out? I have seen this first-hand with the symptom of MAF sensor fault and misfire when warmed up on a BHW. The camshaft showed a moderate amount of wear, but I can't imagine it lead to this problem.

 

[JETaah]

I seldom see a PD head without the wear....wear to the injector from rocking and there must be wear on the bore although it is harder to detect because the color of the metal does not change like it will on the injector body. I noticed this way back in 2006 on a BEW.

If the injector rocks then that would explain the combustion soot in the fuel that creeps past the o rings.

The rock could be the combustion pressure or it could be due to the rocker arm not being dead center over the injector plunger and causing it to side load...or a combination of both.

 

[squishbang]

Thank you, Jetaah. I forgot to even mention the soot in the fuel system, this car had it. I have seen it in other VE, PD cars without symptom so I'm not sure what to think about it. As for the "rock", I want to hear more from others, as well...

 

[Dimitri16V]

Is there fuel in the oil ? Fast switching numbers in block 13 could be camshaft/lifters or injector bore wear
Pushing the injectors back in by hand and making sure they are fully seated before tightening the hold down bolt will assure there is no bore wear
I pushed them by hand , tap them with a hammer and then tighten the bolts

 

[jimbote]

Pushing the injectors back in by hand and making sure they are fully seated before tightening the hold down bolt will assure there is no bore wear
I pushed them by hand , tap them with a hammer and then tighten the bolts

there is bore wear on factory installed injectors ....the wear is from the way the hold down side loads the injector body... it's a design flaw and pushing in by hand will do little to mitigate the wear

 

[turbocharged798]

What's the result of the wear though? It doesn't seem to effect them much as there are plenty of 300K mile PDs out there with no issues...

 

[Dimitri16V]

the O rings take the beating . I guess incorrect installation would make the wear worse .
there is a reason the Piezo injectors had 2 bolts holding it in later engines

 

[jimbote]

What's the result of the wear though? It doesn't seem to effect them much as there are plenty of 300K mile PDs out there with no issues...

the result is the injector oring lands will wear deeper and deeper into the head on one side of the injector bore opposite the clamp ... i guess it depends on how resilient the orings are... the more the injector moves toward that side of the bore due to wear, the more the orings are eccentric to the oring groove in injector itself .... my head had significant wear when i pulled the injectors at just over 300k miles ... i sanded and smoothed the rough area to the best of my ability and the orings seem to be doing their job.... part of the problem with the wear is when you remove the injector ... the vw service tool for removal forces the injector in the same direction as the wear ... if you are not careful to pry the injector toward center during removal, the wear allows the injector oring land to scoop or scrape metal away from the bore starting at the top edge of the wear groove .... this further compromises the bore by removing material from the bore just where the injector orings need to seal ... just use care and caution when popping a PD injector out ... assume the bore is worn and force the body away from the wear during removal

 

[JETaah]

The bore is one diameter and the injector is another. Half of the difference between the two would be the clearance all the way around. Wouldn't slipping a piece of the clearance sized shim stock on the worn side keep the injector from tipping and aggravating the problem in the future?

 

[arlturkey]

The bore is one diameter and the injector is another. Half of the difference between the two would be the clearance all the way around. Wouldn't slipping a piece of the clearance sized shim stock on the worn side keep the injector from tipping and aggravating the problem in the future?

Is there any cure for injector bore wear , like cylinder liners/sleeves , as i know it is comman problem and for fixing changed head if the fuel leaks and its very expensive without handjob

 

[imahaare]

I swapped two injectors in my 2004 BEW PD with 285k miles. I replaced them with a pair of used injectors from a 2004 BEW PD with 105k miles. My bores looked shiney with no wear. The seals looked good and should, I would think, buffer any injector motion in the bores.

On the other hand, I had unpackged the last injector and in inspecting it noticed that the injector body had what appeared to be grinding on the injector body. Looking also at the injectors I'd pulled I saw the same grinding appearance on them. I assumed that it was some final assembly work to assure the bodies were true. But maybe not?

I also mention that my injectors missed after the engine reached 190 degress operating temperature.

 

[JETaah]

Can’t see the machining that you’re referring to but if it is the typical wear through the black ox coating it is not intentional machining of any kind. That is the wear as it happens to the injector as it rocks in the bore. You will have a mirror image of that wear in the injector bore. And it leaves a burr… unless someone ahead of you knocked the burr down.
The surface upon which the o ring seats does not get worn so it should not affect the sealing…it only makes it more hazardous to the o ring when installing and removing as the ring is dragged across the burr left in the bore.

 

[imahaare]

i mic'd the diameter of one both injectors both across the worn area and 90 degree rotation (non worn areas). I got 32.5 and 32.6 mm. So the injectors are clearly out of round. And, It seems to me that all 3 seals on the same side as the grinding show some buffing that is not evident on the sides without grinding. I also note that the grinding is in the same areas on both injectors relative to the electronics connection.

 

[markdave]

I personally wouldn't worry about it. It would have to be deep enough to allow a fair amount of movement to reduce the compression of the o-rings before it would be an issue. Speed Test