Brainfarted intake port clean. Suggestions needed.

2002 Jetta wagon, ALH, 310,000 miles. Purchased at 220,000 miles. I don't know if the engine has ever been apart.

warning, Ph.D. dissertation follows. But, I want to give every detail.

It was running way low on power (had been for a many months). MPG was still good, 41-43 mpg typically. I put vacuum on the VNT actuator just before starting the intake change yesterday, and the actuator moved good.

Suspected a clogged intake. So, I was merrily swapping out the intake right up until the point where I decided to go ahead and scrape the carbon out of the intake ports. The intake was heavily caked. The plenum right after the EGR valve was nearly closed. Maybe you could get your pinky in the remaining opening.

Anyway, I decided to follow others' footsteps here and rotate the camshaft until the intake valve was closed then scrape away with various utensils and vacuum and blow the crud out of the port. Cylinders 1 and 3 were already in a good position, so I did those two. Ports looked so much better. Was feeling really good about things. Moved to cylinder 4 and got to work. After a good bit of scraping, it was time to vacuum. When I looked down the port, I realized I forgot to rotate the cam. The valve was at maximum lift. Doh!

So, I thought I'd try to blow any junk out of the cylinder. I jimmied a small diameter stiff plastic tube to the vacuum hose, fed it down into the cylinder and set the vacuum to blow.

It was kinda like Spaceballs...
https://www.youtube.com/watch?v=qgdzo-7HYQI

And, then it goes downhill from here. I moved to #2. Thinking I had rotated the cam properly, I got to work. Vacuumed, and the intake valve looked open still. Well, I was looking at the exhaust valve lobe. Insert many expletives here. Did the same suck to blow thing down in the cylinder.

And, now the real conundrum. I decided to turn the engine over a couple turns to check on things. Was turning the engine by the cam sprocket and hit a hard stop. As I watched the timing belt, it would nearly skip a tooth with forcing. And, then I became worried it may have already skipped a tooth because I kind of felt a tension and release earlier. (I assumed it was hitting TDC compression on one of the cylinders.)

So, I jacked with the tensioner and was able to skip the cam sprocket back one tooth and tried turning again (now at the crank shaft bolt). No go. Still hitting a hard stop. I cannot be 100% certain that the crank sprocket didn't skip a tooth while releasing the tensioner.

This is where I'm at. I need suggestions on how deep I need to go. If the timing is off, what's the best way to rescue it? I need to get back to #1 TDC, but the engine won't turn. Also possible that there's a mass of incompressible carbon in the cylinder. Am I looking at head removal?

Any comments welcome (including snide remarks about how big a dumb ass one can be).

Brett

Proverbial **** happens. You should have checked the timing first before changing anything. I would start by making sure the timing is right. You could probably pull injectors to sweep any junk from the cylinders if there is any. Maybe borescope the cylinders to try and determine if there was piston to valve contact. If the valves have been damaged the would need repaired.

You may have ruined the TB tensioner too.

Dieselmonkey02 said:

You may have ruined the TB tensioner too.

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this ^^ never turn the engine over via cam sprocket no matter how many times you watch the tdiclub tb video ...bad practice and your belt should probably be replaced now too ....

When is the last time the timing belt was changed?

If you haven't changed the timing belt during your ownership period ... it needs a new one anyhow. And a new tensioner, and a new water pump.

Set the timing correctly with the existing belt before you change any of that stuff to establish whether carbon in the cylinder is stopping the piston.

Do not turn the engine over from the cam sprocket. always in the direction of engine rotation from the crank. Turning from the cam in the direction of engine rotation is essentially turning the engine backwards because you are pulling against the tensioner instead of the run between the cam and crank and could caused jumped timing. Do you have the timing indexing tools?

Safest way is to remove the cam so the valves are closed then you can get the crank to TDC. Also be able to see if carbon is holding valves open or if pistons are hitting chunks.

Remove all plugs for easier turning and better feel.

I don't think you necessarily damaged the belt system. It's a bad practice as I've said for years but many do what you've done. Even the instructions on this very site say to rotate using the cam.

KLXD said:

Safest way is to remove the cam so the valves are closed then you can get the crank to TDC. Also be able to see if carbon is holding valves open or if pistons are hitting chunks.

Remove all plugs for easier turning and better feel.

I don't think you necessarily damaged the belt system. It's a bad practice as I've said for years but many do what you've done. Even the instructions on this very site say to rotate using the cam.

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the instructions on this site are wrong and need to be amended... continental warns against rotating the engine by anything other than the crankshaft... the issue with rotating via cam is that not only can it damage the tensioner but it can stress the belt teeth as they groan their way around the crank sprocket doing a job they were never designed to do ... the damage may not be immediately obvious but down the road in a few ten thousand miles you may experience stripped belt teeth because of this previous stress .... better safe than sorry belts=cheap, heads=expensive

GoFaster said:

When is the last time the timing belt was changed?

If you haven't changed the timing belt during your ownership period ... it needs a new one anyhow. And a new tensioner, and a new water pump.

Set the timing correctly with the existing belt before you change any of that stuff to establish whether carbon in the cylinder is stopping the piston.

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I've got a full timing belt kit sitting on my bench right now. I was intending to do it this weekend.... But...

And, this is where I realize this series of unfortunate events started way back last September. So, in September, I bought the full timing belt kit (high mileage) from IDParts, the full timing belt tool kit from MetalNerd, and a used cleaned intake off of ebay with plans to do the belt over Thanksgiving. Was planning it around 300,000 miles to get the maintenance schedule back to a nice round number.

But, first, I broke my elbow ice skating at the end of October. Simple mental lapse. Caught an edge and went down hard on the elbow. Recreational skating, didn't have pads on.

Second, I broke my elbow again 3 days after surgery. Slipped inside my home on a puddle of mystery fluid on the floor. Feet swept out clear from under me and back down hard on the elbow. So I knew I wouldn't be doing any timing belts for a few months. That was early November. I didn't bother opening up any of the boxes of parts and tools.

Third, finally ready to do the timing belt this weekend at 310,000 miles, I opened the MetalNerd box, and 3 tools were missing. No cam shaft lock, no injection pump pin, and no offset 10 mm box end wrench. Now my rhythm was totally off, but I decided to tackle the intake anyway, and the rest is history.

Brett

jimbote said:

this ^^ never turn the engine over via cam sprocket no matter how many times you watch the tdiclub tb video ...bad practice and your belt should probably be replaced now too ....

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Yep, Fully aware this is ill advised. But, I'll probably do it again some day. LOL

Brett

GoFaster said:

Set the timing correctly with the existing belt before you change any of that stuff to establish whether carbon in the cylinder is stopping the piston.

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My thinking, too. Question is then how to do that. I like the idea to pull the cam so the pistons can travel.
Brett

KLXD said:

Safest way is to remove the cam so the valves are closed then you can get the crank to TDC. Also be able to see if carbon is holding valves open or if pistons are hitting chunks.

Remove all plugs for easier turning and better feel.

I don't think you necessarily damaged the belt system. It's a bad practice as I've said for years but many do what you've done. Even the instructions on this very site say to rotate using the cam.

Click to expand...

Yes, I was thinking about cam removal. Just wasn't sure of the process, or if there may be some alternative thoughts anyone might have. But, I think that is likely the way to go. I really don't want to pull the whole head.

The cam lobes and lifter surfaces are beautiful, by the way, after 310,000 miles. Brilliant mirror shine to everything upon first inspection. I was expecting worse, but it's really nice under the cam cover.

Amsoil used during my ownership starting at 220,000 miles.

Thanks,
Brett

Brett San Diego said:

This is where I'm at. I need suggestions on how deep I need to go. If the timing is off, what's the best way to rescue it? I need to get back to #1 TDC, but the engine won't turn. Also possible that there's a mass of incompressible carbon in the cylinder. Am I looking at head removal?

Click to expand...

I had a similar event a couple years ago. Different circumstances, but I knocked some intake crud into cylinders 2 & 3. I didn't even realize I had done it until I tried to start the engine and it make a loud "thud". After that, it wouldn't start. It's a bit of a sickening feeling on a Sunday afternoon...lol.

I ended up removing the cylinder head, and although it wasn't really part of my original plan, I also replaced the cylinder head. The cam journal on the TB end was all chewed up, and I decided I'd just replace the whole works.

In any case, there was a gooey black mess in the two center cylinders. That was the dry crud from the intake plus the diesel fuel that had been injected on to it when I was trying to start the car. The crud was holding the valves open slightly which was preventing the engine from starting.

I'm not saying that you have to remove the head, I'm just stating what I did. Mine had spun at starter speed and made what I thought was an ugly thud, so I was concerned enough to pull the cylinder head.

Another member on here suggested that if I had kept turning the engine over that it eventually would have cleaned the valves off and started.

jimbote said:

the instructions on this site are wrong and need to be amended... continental warns against rotating the engine by anything other than the crankshaft... the issue with rotating via cam is that not only can it damage the tensioner but it can stress the belt teeth as they groan their way around the crank sprocket doing a job they were never designed to do ... the damage may not be immediately obvious but down the road in a few ten thousand miles you may experience stripped belt teeth because of this previous stress .... better safe than sorry belts=cheap, heads=expensive

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I agree and was in no way advocating it and my post years ago was the first I've seen here saying it shouldn't be done. Just saying guys, even "Gurus" have been doing it.

Moot point in this case anyway since he's got the new parts.

Rembrant said:

I had a similar event a couple years ago. Different circumstances, but I knocked some intake crud into cylinders 2 & 3. I didn't even realize I had done it until I tried to start the engine and it make a loud "thud". After that, it wouldn't start. It's a bit of a sickening feeling on a Sunday afternoon...lol.

I ended up removing the cylinder head, and although it wasn't really part of my original plan, I also replaced the cylinder head. The cam journal on the TB end was all chewed up, and I decided I'd just replace the whole works.

In any case, there was a gooey black mess in the two center cylinders. That was the dry crud from the intake plus the diesel fuel that had been injected on to it when I was trying to start the car. The crud was holding the valves open slightly which was preventing the engine from starting.

I'm not saying that you have to remove the head, I'm just stating what I did. Mine had spun at starter speed and made what I thought was an ugly thud, so I was concerned enough to pull the cylinder head.

Another member on here suggested that if I had kept turning the engine over that it eventually would have cleaned the valves off and started.

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This is what you call a learning opportunity.

maxmoo said:

This is what you call a learning opportunity.

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I learn most of my lessons the expensive and/or painful way Max.

I quite like the saying that one of the members on here had in their signature line: "I've learned so much from my mistakes I'm planning to make some more".

Can't fix it unless you broke it , right?

I have decided to pull the head. After thinking about it a long time, I figured I may be able to find out which cylinder is the problem, but I thought it unlikely that I could rectify the situation with the head in place. How would I remove a chuck of carbon jammed between the valve and seat by going through the intake port? Or how would I remove a chunk of carbon that is now probably mashed onto and stuck either to the cylinder head surface or piston crown? So the head's coming off. When I'm already planning on replacing the timing belt, it's actually not that much more work than I've already done removing the intake and timing belt. Mainly just the exhaust manifold/turbo has to come off.

Wish me luck. At the moment, I'm planning on cleaning the offending carbon out, and reassembling with the same thickness head gasket and hoping for another 100K miles out of this head. That's about 4 years. So I'm thinking (hoping) it'll be about $100 now for another 4 years, then maybe it'll be time for a new/rebuilt head. Or maybe I'll get more out of it. Rolling the dice a little, I realize. We'll see if there's more compelling reasons to rebuild the head now when I get it off. I already do see that my quick assessment of the hydraulic lifters was off. One of them has some pitting. It will get replaced. I don't want to take the big hit now. I've got some spring skiing I want to do with the epic snow pack in the Sierra this year.

Brett

inevitable

Yep. You own that head removal. Hard way to get there, but it's funny how you eventually end up realizing there is no way around the hard way.

Take your time and double check things when reassembling, you know. It's not dead, and you don't want it to get that way! Just needs a "deeper cleaning". Then post your triumphant ending.

dubStrom said:

Yep. You own that head removal. Hard way to get there, but it's funny how you eventually end up realizing there is no way around the hard way.

Take your time and double check things when reassembling, you know. It's not dead, and you don't want it to get that way! Just needs a "deeper cleaning". Then post your triumphant ending.

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It was a minor triumph getting the head off, so here's the triumphant beginning. The intake valve on cylinder 4 was at maximum lift as I scraped away the carbon in the port. A huge amount of carbon got into the cylinder and squished between the piston and head as I turned the engine by hand. (I did not dare try starting the engine.) Image below. No chance of fixing this without head removal.



The cylinder walls, valves, and pistons look great at first glance. I have confidence in putting this back together as is and getting another 100k miles out of it. I'm very fortunate. This engine actually went through a timing belt failure at 224,000 miles. I was driving to Oklahoma from San Diego. About 1 hr past Amarillo on I-40, we stopped at a really nice rest area complete with tornado shelters. Anyway, upon returning to the car, it would not start. After very extended cranking, it did start, but ran super rough. I hopped out and saw the timing belt cover seemed to be dancing around and shut it down immediately. Probably ran for 10 seconds. I got it towed to a shop back in Amarillo. The belt had sheared the teeth. The tech decided to just throw a new belt on and hope for the best. It ran like a boss. They said drive it back to CA, and so I did. That was 90k miles ago. No issues since.

Brett

P.S. Why didn't anyone tell me that the punched holes indicating head gasket thickness are visible outside the engine? I thought they were covered up between the head and block. I could have ordered parts a week ago and been ready this coming weekend to start putting things back together.

Brett San Diego said:

P.S. Why didn't anyone tell me that the punched holes indicating head gasket thickness are visible outside the engine? I thought they were covered up between the head and block. I could have ordered parts a week ago and been ready this coming weekend to start putting things back together.

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I don't remember you asking

VERY good thing you went with the head removal. If you didn't plan on it, I would definitely grab a new belt, tensioner, idlers, water pump, etc while you have it all apart. From the sounds of it, all of that was skipped 90k ago, so I wouldn't let it go much longer or you may be pulling this head again!

Brett San Diego said:

P.S. Why didn't anyone tell me that the punched holes indicating head gasket thickness are visible outside the engine? I thought they were covered up between the head and block. I could have ordered parts a week ago and been ready this coming weekend to start putting things back together.

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As often as I curse Volkswagen for the things they did/do, I would think that hiding the headgasket thickness info between the head and the block would be a particularly hateful thing to do.

Don't know where you ordered your parts from, but I just did a quick check of both IDparts and Cascade, and they both provide info on how to determine what head gasket you need.

http://www.idparts.com/head-gasket-alh-engines-p-621.html

https://www.cascadegerman.com/product/038103383alh/

gone postal said:

I don't remember you asking
VERY good thing you went with the head removal. If you didn't plan on it, I would definitely grab a new belt, tensioner, idlers, water pump, etc while you have it all apart. From the sounds of it, all of that was skipped 90k ago, so I wouldn't let it go much longer or you may be pulling this head again!

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Yes, my original DIY project was to swap in a fresh used intake and do the timing belt. Wasn't planning on pulling the head any time soon, but here I am.

Brett

This is the current state of #4.



All cleaned out, and everything is ready to go back together, but the head gasket and reassembly parts aren't due until Wednesday.

Brett

Making progress. My parts pile is getting smaller as things go back on the engine. The head is on. Timing belt and serpentine belt are in place. Engine turns without obstruction. Engine mount is back in place. What's left is exhaust manifold/turbo, intake manifold, EGR, intake hoses, connecting coolant flange and vacuum pump to the head, injector pipes. It's also getting a new valve cover and PCV valve (finally). I bought them probably a year ago, and never got around to putting them on. Hoping to have it back on the road this weekend.

In the end it'll be around $200 in extra costs above the timing belt and intake manifold parts that were my original project. Had to buy a head reinstallation kit and head gasket, and also a turbo oil feed line since I destroyed the one on there trying to remove it.

Brett

It's aliiiiiiiive. After everything was buttoned up and double checked, I primed the IP by pulling vacuum on the injector return line. When it didn't start upon the first few extended cranks, I cracked the #3 injector line and cranked it. There was fuel flowing. I closed it back up, and next crank, it started and ran beautifully. Timing was spot on with VCDS.

I had a little hiccup, though. There was a major oil leak from the camshaft seal that I had replaced. After locking the cam and IP again and removing the cam sprocket, I noticed the new seal wasn't even close to sealing the camshaft (1-1.5 mm gap all around the shaft). When I put the new seal in, I didn't like the fit. I couldn't push it in. I had to loosen the #1 bearing cap, put the seal in place, and tighten it down. But it just didn't seem right. I didn't notice the gap around the shaft. After some checking on what came with the kits from IDParts, I realized I put the crankshaft seal in for the cam shaft seal. Quick swap with the proper seal and all was good in the world. It took me 3-4 tries to nail the injection timing the second time around, but no problem. Just a little extra time.

The car is rejuvenated. Power is back. Cruise control maintains speed on hills again. It's a joy to drive again. I'm hoping fuel economy does something good, too.

Brett

Congratulations on a good recovery!

Good for you!

I'm declaring victory on this repair. I just completed an 800-mile road trip from sea level in San Diego to 8,000 feet and back. The engine ran beautifully. Only exception was the intake hose from the turbo blowing out of the connection to the hard plastic hose to the intercooler in the right wheel well. It was under load on a hill climb about 3.5 hrs into the drive, and this was after driving it all week to work, too. I must not have gotten the wire clip seated properly. Fortunately, the factory supplied jack lifts the car pretty high, and I was able to get underneath and get the hose fully seated and clipped. No issues the rest of the way.

For the first half of the trip plus a couple of days of commuting to work before the trip, I logged 43.9 mpg. This was the uphill climb to 8,000 ft over 400 miles, AND this was with cross bars and a ski box on top. In December, driving the same route but with a severely clogged intake (and ending three hours farther north), I logged only 38 mpg. I still have half a tank upon returning, so I'll record mpg after I burn the full tank in a few days. But, given that I got 43 mpg on the return in December, this time it may be pushing 50 for the downhill run.

edit: I typically set my cruise control at 66-67 mph indicated when on the highway.

Brett