Loud tapping from top end

geordi · **Posted:** Tue Aug 14, 2012 11:11 pm

I hate this thing sometimes. Driving along just fine, I'm driving up that dammed bridge here in Savannah and trying to get around someone who decided that 45 was just too fast for them. The Jeep pulled the hill great, but I saw my boost gauge climb steadily to 21psi (didn't spike) and I could hear the turbo for the first time in a long time. That is usually the indication of something I'm not going to be happy about. The idiot light came on, with what I'm assuming is a code for overboost, and it went into limp mode.

I rebooted the ECU and didn't think anything more about it. About 3 minutes later, I start hearing what sounded like the fan blades impacting part of the shroud, it changes with engine speed. I know it isn't leaking oil, b/c I had already driven farther than I did when my turbo failed and killed the engine, and there was NO SMOKE and NO loss of power. Just this noise.

Inspected the front end, couldn't locate anything obvious, but the noise wasn't there at idle at that point. Drove it back home, now the noise is constant even at idle, and seems to be once per cycle (tapping about 4 times per second) and on the exhaust side near the turbo.

I'm not starting it again, but it looks like now I get to tear down the top end. Oh goody. Just how I wanted to spend my week. Thoughts? What am I looking for?

racertracer · **Posted:** Wed Aug 15, 2012 3:50 am

Oh brother, the only thing I can think of is a skipped tooth, good luck with this one.

Glend · **Posted:** Wed Aug 15, 2012 4:20 am

Could you set the engine at the usual 90 degrees ATDC as if you were going to change the belt, then remove the cam locking hole covers and check the alignment of the cams with the holes (an inspection camera with LED lights on the end is great for this). If the holes are all aligned then you haven't skipped a tooth - assumed.

geordi · **Posted:** Wed Aug 15, 2012 9:05 pm

Ok... It has been torn down, and I have the valve cover / cam holder off. Jeez, what a mess of a job that was. Several lakes of brake cleaner are about to be drained when I go at this thing to clean it out, BUT the good news first:

The SEGR and Keith's tunes do a great job at keeping the intake clean. The entire intake track is coated with a thin layer of oil, but that is all.

Now the findings:

Not a single rocker is damaged. None. The roller bearings are all smooth, none appear to have any play at all.
I cannot compress the lifters by hand, or with a set of pliers. I only tried on one, and while it's head would rotate in relation to the body, that was all I could get it to do. Maybe it will do more after I clean it with brake cleaner, but right now, if you told me they weren't supposed to compress... I would happily believe you.

Timing observations:
The tensioner was tight and the window was where I remember it being when I did the timing belt 20k miles ago. It had not moved that I can tell. The belt felt as tight as all the others I have done when they are properly tensioned. When I loosened the tensioner bolt, a significant amount of tension was released when it relaxed.
The timing was not correct, the intake cam seems to have been advanced (clockwise) from the correct position by at least 1-2 teeth, while the exhaust cam was correctly in line with the crankshaft.

I usually set timing by inserting the intake cam key first, and then checking the exhaust cam - This was not possible, the hole seemed to be "above" where the key was, meaning I would have needed to rotate the cam backwards to get it to line up. The crankshaft was also not vertical at that point, but was just past it clockwise. The exhaust cam hole was not available, no matter what. I reset myself (thinking that maybe the exhaust cam wasn't correctly positioned because it was 180 degrees out) and tried again with just the exhaust key after rotating the engine 180 degrees. I was right, it had been 180 out, and now the exhaust key was in place, and the crankshaft was vertical like I expected it to be... But the INTAKE cam would not seat - The hole was "below" because the cam was too far clockwise to properly seat.

Other observations: The threads in the intake cam keyhole are not good, it would seem that my idiot mechanic that replaced the engine (and ruined 3 sets of rockers setting the timing by braille when I had GIVEN HIM the service manual) may have used the key tool to hold the cam against unlocking the cam bolt, and ruined those threads. I am not pleased. The cam bolts both had an INSANE amount of torque on them, I needed to use a 2-foot breaker and both my arms for a LOT of force to crack them loose. I have loosened LUGNUTS with less force (and that same bar) than these took. Obviously overtorqued.

Speaking with Keith at GreenDiesel, he suspects that what I was hearing may have been valve contact with a piston, but that it was just on the edge of contacting and did not damage anything. I would love to have a look at the top of the cylinders, but I do not have a small enough scope. All the valve heads seem to be at the same height, checked with a straight edge.

At this point, I need to acquire new o-rings for the injectors and clean everything, then I can think about putting it back together. What I may do is rotate the engine a couple times by hand and see if I feel anything odd, obviously placing the crankshaft key in place this time since the timing will need to be completely re-done to spec. I'm not expecting to feel anything off however. Neither Keith nor I can come up with any idea why or how the cam would have gotten out of position, other than maybe the belt stretched a little with the stress of my flooring it, and if it was already not-perfectly-timed because of the ruined threads of the intake keyhole... It just started kissing the piston OR I was hearing combustion from the exhaust stroke being let into the intake stroke as it opened too early.

Thoughts?

DOC4444 · **Posted:** Wed Aug 15, 2012 11:55 pm

So, I gather there have been numerous examples of rockers being destroyed by piston/valve contact, but the motors show no ill effects after rocker replacement?

The motors I have worked on over the years bend valves with just slight contact.
I would want to do the following in your situation.

Since the injectors are out, perhaps you can get an adapter to fit a leak-down tester. If you are not familiar with this, one at a time, you set each cylinder so the piston is at TDC with the valves closed. You put 100 PSI of air in and it measures the pressure in the cylinder. If you get 95, that's 5% leakage, very good for gas motors. Listen for hissing at the exhaust pipe. That indicates leaking exhaust valve/valves. Listen at the intake for leaking intake valves and listen at the breather for leaking rings.

I would be much more comfortable buttoning it back up at this point if none of the cylinders show significantly greater leakage than the others. Keith may know what is an acceptable amount of leakage for the age of your head.

Always appreciate your contributions.

DOC

geordi · **Posted:** Thu Aug 16, 2012 12:34 am

With the valve cover still off, I can certainly validate that all the valves are closed, no matter what position each cylinder is in. I also know that the only way in or out to each cylinder right now is the injector hole, and since I can't get my borescope down into the cylinder through that hole, I like this idea. I was thinking of a similar idea using shop air through the glow plug hole, but you gave me an idea.

With some simple parts from Home Depot, I can create a rubber blowgun-tip seat that I can just hold down against the injector hole to seal it, and above that, have a pressure gauge and the air trigger from the compressor. My compressor has a variable output, so I can easily set that for 100psi, then just lean on the trigger into the cylinder and see what the gauge reads. If there is any noise / bubbling / activity from any of the 4 valves around each cylinder... Bingo.

Now, I will say this: My own engine - The one that I am currently working on - has already trashed THREE FULL SETS of rockers because the blithering idiot mechanic that replaced the engine didn't bother to read the service manual that I provided to the shop. Ask me how livid I am about that. They made me pay for one set of rockers, and quietly put all the parts into a few boxes, and I didn't count up the number of lifters until about a year ago. They also sent out the head during one of these episodes to be inspected - That was the one that they told me about, after it had jumped timing because the moron over-torqued the tensioner bolt and it sheared the hole WHILE IN MOTION. All 16 rockers were smashed.

No valve damage was found.

This is the designed-in failure mode for this system, and it is *possible* that I got close enough to the danger point without actually having contact, and what I was hearing wasn't contact, but was in fact the end of the combustion event happening at the same instant that the intake valve was opening - Causing a shockwave to echo around inside the intake runner.

The only evidence I have to point at this theory as even remotely possible is from my boost gauge - Driving home with this noise happening, I was certainly not pushing the engine. Just going smooth and slow to get home. These engines have already proven that if something really catastrophic wants to happen... You won't be able to drive for more than a minute or two before REALLY bad things happen, and you are immobile. I had already driven 12+ miles by that point, but I noticed that at 55mph, I was reading over 15psi of boost. This is not normal. For that speed and 5th gear, my boost level is typically around 6-7psi, MAYBE up to 10 if I am slowly accelerating. NEVER 15 for steady cruise at that slow speed. Even at 75mph steady cruise, my boost gauge is reading a fairly constant 10-12psi.

Something was increasing the boost level, and through all of this, I had NO SMOKE at the tail. Believe me, I was looking at the headlights of cars behind me for that indication of turbo problems or oil leakage.

I need to go out tomorrow to get new o-rings for the injectors anyway, and LOTS of brake cleaner for the injector holes and everywhere else. For my own peace of mind (and since I think I can do it for about $20 and not need to change anything else on the engine) I will get the parts to check for leakage too.

msilbernagel · **Posted:** Thu Aug 16, 2012 1:08 am

Re: The threads in the intake cam keyhole are not good...

My recollection is that this is the second torque value that is incorrectly listed in the service manual - that same mechanic that caused you trouble earlier may have set the torque wrench to the SM value without asking himself "does this torque value seem realistic for that itty bitty thing"? :lol:

Any clue as to why the thing jumped teeth in the first place?

Recovering is important, but I'm sure you're already thinking ahead to avoidance too...

Mark

geordi · **Posted:** Thu Aug 16, 2012 2:00 am

Thinking about that, and this is what I have come up with: I'm not sure it DID jump teeth, but how would the intake have ADVANCED itself? Whoever jumped would have become retarded in relation to the crank, since that is the power wheel. Further thoughts:

1: The tensioner was tight and the position of the "window" is where I remember it being when I set the timing with this Gates belt from Amazon.
2: The tensioner did not slip in any way that I can tell, and the bearing is still smooth and solid. All of them are.
3: The number of miles on the belt since I did the timing job is about 20k. The last belt was installed when the engine was, and it had about 50k on it (from 60k to 108k) when I did the timing job myself.
4: When I did the timing job, I was not easily able to match up the crankshaft key, because of the belt stretch (or I thought at the time), and I did not know enough at that point to check the position of the holes in the crank pulley. The cam keys were in, but basically all I did was match the new belt tooth-for-tooth with the old belt's position.
5: I also did not know enough at that time to rotate the crank backwards 1/2 tooth past vertical, to catch the belt from the fuel pump and apply just a little bit of tension to "hold" it in the teeth at proper 90-ATDC (vertical holes in the pulley). I know that now.

IF the idiot mechanic had not properly set the timing and the crankshaft was slightly advanced or the two cam pulleys were not properly set (entirely possible) then I matched that with the new belt, and when it stretched in after 20k miles, it advanced even more to the point where there was just the slightest overlap in valve openings. The largest indicator of this to me, is the boost gauge reading while driving home. That pressure had to be coming from SOMEWHERE, and my turbo isn't ever that good! I hadn't ever unlocked the cams until today, so I was trusting that the mechanic had gotten them in the right position. That may not have been the best strategy. Because of the damage to the threads of the intake cam keyhole, I will be swapping valve covers back to the one my CRD originally came with. All the other parts appear to be the same condition, and both sets of cams are smooth and oily.

I will know more tomorrow, and you guys know I will share my findings - Above all, the lesson is this: The timing job is NOTHING TO SCREW AROUND WITH. It needs to be done right, every time. - On that... Keith said that the cam gear bolts should be 80ft-lbs, which is what my service manual says under the timing procedure and under the camshaft replacement procedure. What does your service manual say? Is that the right value? (I plan to use 80 just b/c that is what Keith said, and I trust him more than the book, but it is nice to see they agree)

msilbernagel · **Posted:** Thu Aug 16, 2012 3:10 am

Re: "On that... Keith said that the cam gear bolts should be 80ft-lbs, which is what my service manual says under the timing procedure and under the camshaft replacement procedure. What does your service manual say? Is that the right value? (I plan to use 80 just b/c that is what Keith said, and I trust him more than the book, but it is nice to see they agree)"

I must have misread the original post - I was not referring to the cam bolts (front), but the little ones that go into the alignment access holes on either side of the engine cover. I don't recall the torque value listed, but that one and the fan pulley mounts are both incorrect in the SM.

On alignment, I used both the pin for 90-ATDC and GDE's kit for the cam alignment pins. I know that not everyone has done so. Most seemed to have turned out fine but in some cases it may have resulted in misalignment due to the margin of error with non-standard tools (allen wrenches, hand-ground bolts, etc). Extra caution seems prudent, as it appears that there's only one right spot; hitting it takes full attention to the detail and leaves no room for 'almost' aligned on any of those three pins.

One odd thing I've seen (in this forum) cause a slipped tooth or two was a sudden jolt to the accessory belt sufficient that the intertia of the engine internals overcomes the timing belt's ability to hang on - such as when the serpentine belt broke/slipped off and wrapped around the crank pulley briefly (once case). If nothing has forced an abrupt accel/decel of the crank... you're prob Ok here. Just a thought tho.

Mark

Glend · **Posted:** Thu Aug 16, 2012 7:12 am

Good result, glad there is no major damage.

Even if you have it locked up correctly, it's easy to misalign the belt in that section between the Injection Pump and the crank sprocket, and the rest willl still look good and the tensioner will tension. As documented in some of the writeups you need to back the crank (counter clockwise) slightly to get the crank sprocket teeth to grab the belt properly. You can easily have a one tooth slip right there if that isn't done.

geordi · **Posted:** Fri Aug 17, 2012 8:31 pm

Valve damage has been confirmed - The pressure test was inconclusive, but the results from putting it back together and setting the timing properly can't be ignored. It is still tapping.
The sound is a bit different now, possibly also b/c I am not completely sealed in the injector holes, but I will know more about that once I tear it back down again... This time, to fully remove the head. Ask me how thrilled I am about this development.

Anyone want an EGR valve? I have a feeling that it might accidentally "fall off" my engine block and be forgotten.
Since I am pulling the head, I will NOT be using the TTY bolts when I put it back together. I've said for a while that I would be using the ARP studs, looks like I get my chance for that, but it will take some time - I still have to be out of town next week, so this is going to progress slowly through this weekend, then I'm stuck waiting for the studs and hopefully a gasket by itself to arrive when I get back.

Once it is running again... I think it will be for sale. I'm reaching my limit. I work in an extremely short-notice industry, where if you aren't ready to go with 48 hrs notice, you can easily lose out on a grand per day paycheck. Added to that, if you commit to a gig and then don't show or leave them hanging to replace you with even less notice than that... Your name is mud and it can REALLY cost you. I can't take those kinds of chances. When I was going to school, it was less of an issue. Now, I'm driving long distances on short notice, and I need a reliable vehicle. Case in point: I have a job for MONDAY, and I have no way to get there right now, I will have to either borrow a car or have my family drive 500 miles.

My needs for towing aren't anywhere near what they had been, and I can just as easily not do those kind of jobs, or I can rent a truck on the off chance that I DO need to tow big numbers. My small generator (20kw is small?) only weighs in at about 2500 lbs - Something manageable by just about anything with wheels. Namely, something more reliable.

Keep your eyes open for me, because I'm offering a great deal. I'm not in any hurry, and the CRD WILL be working properly before I sell it... But this is the package: The CRD, ALL my spares (about $5000 in parts), the full CRD factory tool kit (some items even still factory-sealed), and an advanced laptop-based scanner that can read and probe EVERY SYSTEM, not just the engine controller. For the right deal, I'll even throw in a laptop to run it on. KBB says the Jeep itself is worth 10k in private sale, and I figure with all the extras (including the gauges which are working great) that I'm easily in the 14k ballpark, maybe fully 15k. Just the two cams in my other valve cover are worth 400 each, for example. Lots of good spares and some brand new parts.

What am I looking for? Either one of these two vehicles, color doesn't matter much to me, condition and options subject to discussion: 2003+ VW Jetta TDI Wagon with the automatic transmission or DSG (on the newer ones), or a 2006 Jetta TDI Sedan also with the DSG. I owe $3000 still on the CRD, and I would like to be done with payments for a long while... So if we can work something out, great. I'm not in any hurry.

ChooChooman74 · **Posted:** Fri Aug 17, 2012 9:26 pm

Dude, we will hate to lose you in the CRD community, but you got to do what is best for you.

Sent from my DROID BIONIC using Tapatalk 2

geordi · **Posted:** Fri Aug 17, 2012 10:09 pm

Oh, I'm sure I will still be here, and I can easily do timing jobs for people without the rest of the special tools, there are only 3 special tools needed for the timing job.

But yea, the reliability issue with these has really gotten to me lately, and I had a long talk with Keith that also gave me some insight about VM as a designer of engines... It wasn't inspiring.

I'm happy to share my knowledge with the group here, and I don't plan to list my jeep anywhere else because the group here knows how they are and can appreciate the mods that I have done to aid in the reliability - All my personal stuff such as the various items in the middle of my windshield, that can all come out easily to return to a stock appearance.

The main things that make this a better vehicle are the reliability upgrades:
GDE transmission tune
GDE engine Eco Tune
EVIC installed, works perfectly except for TPMS system (needs to be programmed into the computer by a DRB3)
SEGR used since 30k vehicle miles
Steel 7v glowplugs
GENUINE Renegade Roof Lights
EGT gauge - probe pre-turbo, reads ACTUAL highest cylinder temps
Oil pressure gauge, probe mounted in main oil gallery, shows ACTUAL pressure provided to cylinders
Boost gauge, probe mounted at exit of intercooler
Oil changed on about a 5k mile cycle now, or less
Replaced Turbo 10k ago
Upgrades torque converter (new 10k miles ago)
New transmission (40k miles currently on it)
New transfer case (50k miles currently on it)
ONLY synthetic fluids ever used
New struts 30k ago
New engine mounts 5k ago
New transmission mount 2k ago
2 new tires (BFG Long Trail stock size) 2k ago
Sony MP3 CD player with aux jacks
EHM
New MAF sensor just installed
Cat delete (still have it however, will be getting it from home next week)
Magnaflow Muffler
Tow Package
Front Tow Bar Package - This is $1050-$1200 by itself!

Condition: NO DENTS or accidents!! Ok, the plastic bumper cover on the front has a couple spots where the paint is popped off, possibly from people parallel parking by braille... But the plastic isn't cracked at all. The driver's fender flare needs a touch-up of paint from something dumb I did on a film set, but that is it. Why haven't I touched up the paint? Because my painting skills suck. I don't want to screw it up, so I've just left it as it is.

I might ask a lot of my vehicles, but I also take great care of them. I'm insane about the maintenance, which is partly why this vehicle frustrates me so much. I can't afford to have 2 vehicles, so that I can use this as a toy. I need this to be available to me for my work, and it doesn't want to be. This will be a great deal for someone.

racertracer · **Posted:** Sat Aug 18, 2012 3:53 am

Sorry about the bad luck but you have spare parts, tools, knowledge to quickly tare it down and put it back together .... you can't stop now.

I say keep the fun mule at the ready and get a sturdy TDI as a DD like you wanted to do originally.

The CRD is a proven 300,000 mile vehicle outside the USA and you made yours to be that with the proper modifications.

You just need to minimise the mishaps because it's scary.

Hoosier CRD · **Posted:** Sat Aug 18, 2012 6:34 am

Hey Geordi,

Man, I hate to hear that you are having issues with your tractor. I hope that things go well for the re-assembly.

I have to tell you, of late I too have been considering a Jetta TDI. Have not pulled the trigger as of yet, not sure when/if I will, but looking none the less.

Please do keep us informed on the progress of this most recent elbow-deep endeavor. I feel safe in saying that WE are with you in spirit, sir.

All the Best,

Hoosier CRD

P.S. Too bad more of us aren't closer together to imbibe and commiserate with you.

geordi · **Posted:** Sat Aug 18, 2012 7:52 pm

Imbibing sounds like a good plan - Thankfully I have a well-stocked closet of rum, seeing as I'm 'motivationally challenged' at the moment.

So the afternoon's adventure is over, and the cylinder head has been removed. The turbo has also been pulled, the thermostat, the airbox... and a great deal of other components that make me NEVER want to be this deep in this thing again.

What have I discovered on the underside of my head then? Smashed valves perhaps? maybe an impact point? A shiny divot in one of the pistons? All wrong.

Nothing. Nothing at all unusual to be seen.

Have a look at the pictures here then, and tell me if YOU can see anything off about this. The pistons themselves all seem fine too, although I need to drain them of coolant that washed out of the head when I picked it up. The head gasket looks perfect, there are NO indications at all of any combustion leaks, and again, nothing obvious to indicate where that tapping had developed from.

edit: I'm a moron, here is the link to the pictures: https://www.dropbox.com/sh/c0npjrm81kuwgxx/t0V1RQfnQK

When I pulled the codes 2 days ago, this is what I received from the computer:
P0101 - Mass air circuit range / performance problem (at 59mph)
P0107 -MAP circuit low input (Probably b/c I pulled the codes when the engine was in pieces and it was unplugged)
P0113 - Intake Air Temp Circuit high input (maybe again b/c the engine was in pieces?)
P0118 - Engine Coolant High Input (Ok, this has to be b/c it was in pieces now)
P0193 - Fuel Rail Pressure Circuit High input (yup - it was disconnected at that time)
P0234 - Engine Overboost Condition
P0303 - Cylinder #3 Misfire Detected (Ah HA!)
P2294 - Fuel Pressure Regulator #2 Control Circuit (yea, b/c the whole rail was on the table)

So it detected #3, which is exactly where I had THOUGHT I heard the tapping coming from. So it looks like one of those 4 valves is buggered... Not that I can see it from the outside.
The next step will be taking the entire head on Monday to a shop to be looked over and tested... How that will be done is anyone's guess. The shop that did the engine replacement for me DID send out the head to someplace in South Florida, so maybe I will be taking it to the same place. I'm also contemplating taking the 4 injectors to a Bosch shop I know so they can be tested and cleaned... but maybe that doesn't need to be done just because the engine WAS running well up until the tapping started.

MRausch82 · **Posted:** Sun Aug 19, 2012 12:53 pm

I am wondering if it is an injector problem.... I have seen tapping that sounds like a valve on some VW diesel engines, though they are the old Bosch VE pump systems. It is usually from a stuck or somewhat sticky injector. In those instances, I had no abnormal smoke. The tapping went away on its own in each instance, however. That said, I know of some in which the injectors were rebuilt or replaced because they did not go away on their own. I realize that system is not like our common rail system, but perhaps something similar has occurred? Either way, having the head checked is not a bad idea since it is already apart...

striperman36 · **Posted:** Sun Aug 19, 2012 9:54 pm

Geordi,
Take care, maybe take a vacation, walk away, once you have a ride...

Sounds like you work in IT...

Is your brain at least the CRD downloadable? :BANANA:

geordi · **Posted:** Sun Aug 19, 2012 10:59 pm

striperman36 wrote:

Geordi,
Take care, maybe take a vacation, walk away, once you have a ride...

Sounds like you work in IT...

Is your brain at least the CRD downloadable? :BANANA:

I don't work in IT, although I used to... No, I'm in the entertainment industry - I work as a Sound Mixer on TV or Films, and I also work as a stagehand / AV tech / Camera op / Rigger for live events, corporate tradeshows, stage shows, and concerts. It is freelancing work, which is why my schedule is both very open and flexible, but also can be completely insane.

Now, your last sentence there... What? Engrish Prease?

jkbkwarner · **Posted:** Mon Aug 20, 2012 4:23 pm

Geordi,

I've been in a similar mind frame as far as the need for a reliable form of transportation. Especially with costs and priorities it has been a challenge to keep the CRD running. I'm not as mechanically inclined as you seem to be, so it has been more expensive and frustrating when the Jeep is down. Then trusting a "mechanic" to perform the most efficient/cost effective work in a timely fashion has had my wife say: "We should just get rid of it."

Of course I balk at the thought (out loud), but sometimes I feel it is time to move on. And yet, I keep feeling that I won't be any happier or better off without it. For me, it's stock now, but as I learn more on this forum, I envision participating for years to come both on the forum and on the wheeling excursions. Lifting, skids, bumpers, winches, wheels/tires, towing, camping and other custom mods. The Jeep is truly a Sport Utility Vehicle.

So I hope, along with many others, that you do what is best for you,

Good luck!!

Loud tapping from top end

Who is online