Gut Check

'03 TDI ALH Wagon, as my "tag" suggests...

~220k miles, on third timing belt. I did the last change; the current belt in the car was put in at 150k. About 20k miles later I had to have the pump resealed due to seepage (sent out to DFIS) so the tension was taken off but the belt not removed.

It's got low (but not zero) A/C output right now, presumed RCV problem (but COULD be a grendaded compressor -- although it engages ok and makes no noise -- just not much pressure differential.) The blend doors have been fixed (that was a *****, incidentally.)

Recently the O-ring sealing the CTS started leaking fairly profusely, and was replaced along with the sensor since the temp gauge was showing mildly less than full 190 although the car was definitely up to full temperature. The O-ring was in utterly terrible condition which was a bit surprising since I had changed that sensor several years previous (along with the O-ring.) The "reads a bit low" temperature needle thing was something I had seen before so the sender got swapped instead of just replacing the O-ring; the temp gauge now smartly goes to 190 and stays there as expected once the car starts to warm up. Post that and cleaning up the mess the leaking coolant made I've got a small coolant leak that is appearing on the bottom of the flange under the crank pulley -- one drop, and some splatter on the (metal) DG belly pan. The obvious implication is that it's leaking from the water pump, either the O-ring seal or the bearing. Neither is reasonably accessible to inspect and of course both are bad with the potential for a catastrophic bearing failure that lunches the timing belt system thus, if it's coming from there the belt and associated hardware has to come off. The plastic coolant flange outlet area at the block is dry and has no staining. There is also a very small coolant level loss which makes sense; perhaps 1/8" or so in the reservoir (a few ounces) over a couple of thousand miles. Belt condition, tensioner and such looks ok on inspection to the degree it can be seen from the top with the top cover off as it has whenever the oil has been changed.

The only other issue the car has is a very tiny seep of gear oil that is likely coming from the output flange seals. It's been there a decent while and not material (it doesn't impact level in ~30,000 miles to any measurable degree as my finger still finds oil right at the fill plug) but you can see it on the belly pan as a very small (fraction of an ounce) oil spot after a few thousand miles post-cleaning. If/when the clutch needs replaced I intend to deal with it at that time since the transaxle will be out of the car.

So here's the question: I'm materially beyond halfway to the timing belt interval, so the obvious thing to do is change the belt and associated hardware, plus the water pump. The FIRST change (a looong time ago) was done by a dealer and done "right" (no evidence of paint marks, etc) and the other one was done by myself with parts from one of our known good vendors here.

What, other than the "standard" timing belt kit, would you change? There is no evidence of leakage at either the crank or camshaft seals I can see.

ID recommends BOTH the cam sprocket and engine bracket be replaced on the third belt change due to apparent reported issues of the cam sprocket not holding (!) and engine bracket threads stripping -- and maybe the engine mounts (all three) due to routine deterioration.

I've also seen reference to a potential coolant leak location that is apparently hidden under the IP and is *not* the plastic thermostat flange. Where is this potential spawn of trouble location, if I may ask, since it sounds like it's in a place that *could* lead to the nice red drop of liquid appearing on the bottom of the crank housing and thus be misleading me highly as to where the leak is coming from...... (and since I can't see the water pump from either the top or bottom with all the guards and such in place, it's impossible to know if I have coolant tracking coming from there.) I'd be at least a bit peeved if I went to do the belt job 20k miles early and find on tearing it all down that the water pump was perfectly fine and I still have a leak!

Thanks in advance.

For the RCV, DanG advised me to remove the RCV and just run the AC full on since the refridgerant showed signs of metallic stuff. That was in 2013 IIRC and my AC is still working.

http://forums.tdiclub.com/showthread.php?t=283967

For the coolant leak, if you had a leaky IP, you may need to replace the seal on the metal coolant pipe. See JETaah's post 19 and MoGolf #41.

http://forums.tdiclub.com/showthread.php?t=132193

Eh, if that pipe O-ring is leaking I'm gonna be quite bent -- that looks like a ****** of a job for a $2.50 part failure...... and yeah, I DID have a pump leak a few years ago. I caught it quick, but....

Will get an inspection mirror in there and see if that's where it's coming from.

Well, it's NOT leaking from that hard pipe -- I can't see where it goes into the block even with an inspection mirror but there's exactly zero coolant tracking down the FRONT of the block near the bottom where you can see it with the belly pan off, and there IS coolant inside the flange where the crank pulley is for the belt. That means it pretty much has to be leaking from the water pump unless I missed something ridiculous since there's just no other place where it can be coming from on the front end of the motor that wouldn't leave a trail somewhere on the outside.

Ordered a timing belt kit; it may be ~20k before I should have had to do it, but it is what it is and I can't see any other source where it could be coming from.

Could be the o-ring seal around the water pump or the water pump itself then. Thanks for the heads up on changing the camshaft sprocket. I had not heard that recommendation before. Added to my list for my next tb change (due for me in about 25k miles / 15 months, I am at 335k now). I also read that Oilhammer recommends changing the oil pump chain tensioner around 300k miles.

Yeah, I think it has to be one of the two, and the leak rate has accelerated in the last few days, so I've strongly urged the kid to park it until the parts get here. Lost ~3-4oz (enough to light up the low coolant lamp on a cold start) with a run to and from work that's no more than ~20 miles and left a modest puddle under the car overnight on the garage floor.

Unfortunately the best I can do on inspection allows me to see the top of the pump's gear with the cover off, which doesn't tell me anything useful.

That I can't find any evidence of a leak on the block above the crank pully opening marks the source of the leak as almost-certainly either a failed O-ring around the pump or the pump's shaft seal. The latter particularly concerns me because the true underlying problem could easily be the bearing getting loose (although I don't hear any ugly noises coming from that general area when the car is running.) If it IS the bearing in the pump then the risk of a no-warning catastrophic failure exists -- that would be bad considering that there's really nothing else wrong with the car other than the questionable AC compressor and I don't feel like having to do a head job.

One of our top mechanics on this site tells us the timing belt tensioner is designed to only be engaged once. My tensioner has been tensioned 3 times, but I've always set a bad example.

Might want to prepare to change the cam seal. When I did the TB on the daughter's wagon I discovered that it was leaking (and the PO had recently done the TB! - that TB job was due to a failed/failing WP- idiot didn't replace the rollers, which were clearly rusted up from the leaking WP).

I wonder whether the cam sprocket replacement suggestion is based on the older spec'd torque values? Seems that it's more commonly accepted to tighten to higher torque values and that higher torque values might keep them from slipping (which is what the concern is, what people are trying to do to avoid when replacing the gears).

The kits from the 'reputable' places all come with a cam seal. I don't see evidence of leakage (and didn't on the last change either) but of course I can't see the seal area as well with the sprocket on as I will be able to once it's off. If it's leaking I'll change it but I'm not changing it if it's not. There's no evidence of a front crank seal leak (that one's VERY visible as it drips from the bottom if it's leaking and is easily seen before you take it apart) either.

Those kits with the cam seal, sprocket, extra bits, are for high mileage cars. You're kind of on the line. If your car has had an easy life, no major events (mine has), doesn't use oil, I'd go one more change then go for the extra kit. Nothing wrong with doing it now though.

Yeah, if you're not leaking then don't bother. Seems that it's almost a hit or miss as whether a new install will leak or not.

I'm one of those "change all the rollers" guys and always have been. It's not worth having to do it AGAIN if one fails early. The top one is easy to get to -- the lower small roller, not so much.

Ditto on things like the water pump but in this case it's not optional. I've already got non-stretch bolts in the IP pulley slots, so that's a non-factor, and I'm not changing the mounts this time around.

The car has never been in the salt belt and I've never had trouble getting anything apart on it, or on any of the others I've owned here, which helps. Hell, I ever got all the harmonic balancer bolts out last time without damage -- but I DID replace them (and will again; that's a nasty little 'screw you' if the round out on you.) The belt looks ok as do all the other components looking at them from the top and were the car not to be leaking coolant I'd have certainly said "run it until 100k", but since it has to be done it is what it is.

I will expect to do the front crank seal, oil pump chain and tensioner on the next go-around though -- and maybe the cam and lifters. Other than a bit of lifter noise on a cold start for a few seconds all is quiet and well.

I'll say just one thing: extra parts recommendations to replace parts you never knew were in danger, and that recommendation coming from a place that sells parts need to be taken with a grain of salt. Caveat emptor.

Take the cam sprocket for example. If you take a dry clean paper towel and clean off the cam nose and the inside of the cam sprocket mating surface, then bolt it down correctly, there will be no slip. In fact, you will have to crank on the puller until you hear a hard crack when they finally come apart. Problems with cam sprocket slippage will always come from bad installation technique.

Cheers,

PH

You have had hands and eyeballs on the car and for some time now so that counts. I followed along with all of the recomended replacement parts because even though I had receipts for certain repairs when I purchased my Golf, this was my first VW and I had reason to question everything upon disassembly when I had lifter failure. I replaced the cam sprocket just to alleviate any potential problems and the engine mount bracket because the threads in it were toast. I did not replace the engine mount as it looked okay upon inspection. I replaced the crank seal even though it wasn't leaking because it came in the timing belt kit I purchased. I didn't replace the cam seal because the new head I was installing came with it installed already. The two things I didn't replace when I had everything apart were the drive belt tensioner and roller and the valve cover but that was just me being cheap and I have since rectified both issues.

In the end it mostly comes down to how much money you have to spend and how much downtime and inconvenience you can swing. I work for a dealer and had other means of transportation so I was not as limited as some might be.

Hoh hoh.... if you have a coolant leak that "might" be coming from behind the timing belt cover, better check into it quickly.

This one was. From the shaft seal on the water pump, not the O-ring. That's very bad because a leak from the shaft seal will quite-quickly trash the bearing, at which point the pump fails and we know what comes with that on these engines. The bearing in the water pump was still good but it sure wasn't going to stay that way for very long.

The cam seal was also seeping a bit, so I changed it for one of the ones that was laying around in-package The original was still in there and one of those teflon monsters but I replaced with a spring-style so let's hope I didn't get it "exactly wrong" on the shaft (and get a nice leak out of that as a result.)

Everything else looked good; tensioner was still ok, all the rollers still smooth with no slop and the belt itself was fine. The cam looks great; no reason to be changing that out at this point. Gotta love that Rotella-T oil; it definitely does the job....

Don't have it all back together yet (will later this evening) but a $1,000+ bullet was dodged on this one. If it was driven daily and topped up whenever needed it might have run for a long time, but one couple-week parked "go on vacation" thing so the coolant could gum up in there in the bearing and...... boom.

BTW has anyone ever figured out a way to drain the block on these damn things before pulling the water pump? It's my nemesis on these jobs -- guaranteed to make a BIG mess.

I am fairly certain that the WP on the daughter's wagon, that the PO replaced (and failed to replace everything else other that it and the WP!) was an O-ring failure. The edges of the block where the WP goes in to showed rust staining. I was very nervous about purchasing this car, fearing that the engine could have suffered a failed TB (injection deviation was really good, and I took the gamble based on what it showed me- compression tests later confirmed that the engine's very healthy). When doing this work I noted a leaking cam seal, so that was replaced: first and only one I've had reason to replace.

Problems just never seem to get better by ignoring them!

Yeah, I was expecting that the O-ring failed, but nope -- while it had a hell of a set the circumference was dry, and the shaft and gear was dripping once I got the covers off. That's the ugly failure on those and I'm real glad I tore it down when I did - who knows how long it would have run before the WP shaft locked up.

I was surprised to find the cam seal leaking. It wasn't leaking BADLY, but it certainly wasn't going to get better with time.

The only other thing I saw was that it has a minor EGR leak; when she's got an extra $100 laying around to toss on a new valve I'll take care of that, but that's just a mess-maker rather than a "aw crap" situation. And it's weeping a bit from the valve cover, but has been doing it for a while -- since you can't replace the gasket separately that's a bummer and I'm not buying a valve cover at this point.

Is the EGR weeping at the hole? I broke down and committed to cleaning the intake on the wife's car because I though that the EGR valve was shot (lots of oil). Turned out that the O-ring was the culprit! I'd bought a new EGR valve and was going to put it on her car but ended up going on my car as I did its intake sooner than hers but I used it on my car because I wanted to speed up getting its intake all cleaned up and the car running again.

Valve cover leaks... many times just pulling, cleaning and then dabbing some RTV in the key spots can take care of them. Daughter's wagon was over-seen by an ape who figured that he needed to get even more torque on the valve cover so he used heftier bolts! (I had to chisel the stupid things off!) The same ape had had the engine freshly washed down when I bought it; later discovered all the leaking; I finally get this all nicely taken care of and then the daughter decides to drive the car with the oil light on -> blown turbo oil feed line! (compliments of the same ape- didn't use the hold-down brackets- grr!)

UhOh said:

Is the EGR weeping at the hole?

Click to expand...

Yep. Not badly, but it is.

Oh, and a pressure test on the cooling system before putting all the rollers back on (no, I am NOT going to go get another big roller stretch bolt if it was going to leak on me!) revealed.... hisssssssssss from the coolant ball. Guess where? Yep. Seal removed for now, will get a new ball. This is #3 by the way and the other one was replaced because it was nasty. I thought they put a stop to the crappy manufacturing and leaking low coolant probe penetrations a LONG TIME ago? Nope!

The leak may well have saved her from a coolant migration disaster as without it there would not have been a reason to check it for another year or two. That could have been bad.

Valve cover leaks... many times just pulling, cleaning and then dabbing some RTV in the key spots can take care of them.

Click to expand...

Yeah, I'm going to try that; I have some and may as well. A previous attempt didn't stop them however, but it did help.

Back to it....

Oh, one other "PS" that I don't remember seeing around here before. Contrary to popular belief it IS possible to get the pendulum bracket out of a Jetta without removing the engine first

I'm either getting better at this or luckier (I'll take either) -- first time I've done a timing belt and had the timing come up in the upper half of the graph right out of the box -- no fine-tuning needed.

Well done!

I had beginner's luck on my car. I think I'm about mid-upper and have not touched the timing since I did that TB almost 40k miles ago. My car starts instantly. Runs extremely well. Churns out 50+mpg tank after tank. Also had pretty good luck on the daughter's wagon (fastest starting TDI ever!), though I was a bit above top: as shop up in CA felt it necessary to adjust (and it really didn't do anything for an issue that it's having; sigh...).