coolant pump failure = timing belt failure?

Hey:

thinking of buying an '02 Golf w/ 147K km on it. talked to the dealership that serviced it. it has had its regular oil changes of synthetic. the timing belt and tensioners were done at 100,000 km - but the coolant pump was not. Should I plan on making it til the next timing belt change on this pump?, if the pump goes while driving and leaks coolant into the timing belt, how long will it take to ruin the timing belt?, will the car overheat first or is it possible for the timing belt to go immediately after a failed coolant pump?

The pump can jam without warning and the sprocket with it. The tooths on the belt will be ruined almost instantly against the jammed sprocket -> CATASTROPHIC RESULTS. Change it

I would suggest waiting until the next tb change for water pump replacement. Although it is theoretically possible for the wp to take out the tb upon failure, it is not very likely. If it were to fail it most likely would be as a leak, and not an exploding wp. Keep your eye on the coolant expansion tank level.

For a point of reference, my '01 Golf is at 153k miles and still has its OE wp. I will replace it later this month when I do my tb at our gtg.

I would like to think that the pump could go to 160,000km and beyond without problems.

I also believe in the Tooth Fairy.

Is the Tooth Fairy TDI- certified?

weedeater said:

I would like to think that the pump could go to 160,000km and beyond without problems.

I also believe in the Tooth Fairy.

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I'm not sure what you are saying. Do you think it needs to be changed before 100k miles/160k km? Since that's the interval for the timing belt, I'd be quite surprised if the water pump needed to be changed first. Most folks I've read posting on this subject seem comfortable with 100k mile replacement of the wp.

In any case, my OE water pump is OK at 153k miles and will be replaced at the timing belt change @ ~160k miles.

Water pump failure means T-belt failure, which means you get to pull the head off the engine. Replace it now.

These water pumps fail one of three ways: leakage out the weep hole, which is not very common unless you count a wee bit of seepage. Next way the plastic impeller comes loose from the shaft, which means instant overheat and usually engine damage. Then the worst way, which is the most common, is the bearing fails, which allows the shaft to pivot and mashes the pulley into the water pump housing, which means immediate catastrophic engine damage. In many cases, the ones I have taken apart with a failed bearing were STILL totally dry, the seal held up even with the shaft cocked at a 25 degree angle.

Never put a new timing belt on these without a new water pump, you are asking for disaster. They are cheap, quick, and easy to replace when you're in there replacing the belt.

3800rpm-
When the dealership did the tb at 100k km, did they put in the 100 k km, 130k km belt, or the 160k km belt? In other words, when is the next one due?

oilhammer-
Since you basically go through the same labor for the tb, would you advise just replacing both at this time? Would 3800rpm's answers to the above questions make any difference?

I agree that it makes sense to replace the wp with 100k miles belt replacement. But in my A4, the original timing belt replacement was 60k miles, which was too early to change the wp, IMO. I don't know if the interval for tb change was 60k or 80k miles for the '02, but even 80k miles is pretty soon for a wp to need to be replaced.

Your thoughts?

hey guys, great comments here, thanks.

so i am also wondering when the next TB would be due as well - don't know what belt they put on - I will call them back and ask them - i'm so new at this that i didn't even think of asking although i did think of it last night -

i agree that with the risk involved and the ease of replacing it while doing the TB - I will do it all at once when it is my car. But for now - if I get the car - I'll probably drive it til about 200K km then replace everything to be safe. and i'm pretty sure the '02 belt was a 80,000 mile (128 km) one....

I think I will rest assured that by watching for leaks, watching the coolant pump reservoir and immediately coming to a stop if the engine overheats that i'll be safe until my next TB change.

BTW, could a ticking sound coming from behind and below the motor when cold be an indication of a problem with either of these things? just made the sound when i started it up cold. it was not noticible during the drive or after the drive........

I will not replace a timing belt without the water pump. It is an all-inclusive price, and it is non-negotiable.

oilhammer said:

I will not replace a timing belt without the water pump. It is an all-inclusive price, and it is non-negotiable.

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The way I see it I treat every motor as if it's my motor, replacing a timing belt without a water pump IS NOT UP FOR DISCUSSION, this means all inclusive kit or I simply can't help you.

I like sending people off knowing that the motor is 100% reliable for the next 100,000 miles no exceptions. I will be the first to say that if I do a timing belt and one of the components goes bad I don't charge for replacement of the failed part. Yes you will have to get the car to me and we will work out the details of getting new parts under the sellers warranty, after that I want to be the one to put it back together and also find out what happened.

With that said thus far NOBODY has had to bring a car back due to a failed component. This is a tribute to the TDI parts sellers here, grant it I get a lot of kits from www.dieselgeek.com but the others are also doing a great job at providing well researched top quality components.

My advice is to get your car to a TDI member and have the car gone over top to bottom. The water pump can in fact be replaced from the top of the motor. It still takes about 2 hours of labor so for a few more $$ you could do a complete inclusive kit install...My vote is to redo the belt, the last thing I want to see is you posting that the belt ate itself and the dealer telling you to pound sand. It will be the best $600 you have ever spent and to top it off you won't have to do it again for another 100K no ifs ands or buts about it!

DB

Is there any way to replace a water pump without changing the timing belt easily?
I'd rather not have to drop another 800 on having the timing belt replaced when I did it 5000 miles ago.

Oilhammer and DB-
No one disagrees that the wp should be replaced at the tb as a standard practice.
This is an oddball case, so the questions are:
1) should this guy spend another few hundred on another tb/wp now,
OR
2) can he wait until 200K km/125k miles to do both
OR
3) can he replace the wp without doing all the labor and replacing the parts (stretch bolts, etc) needed for the tb job? DB, it sounds like you are saying this is possible. Is that correct?

3800rpm- I think your plan for option #2 is a good one.

tditom said:

I'm not sure what you are saying. Do you think it needs to be changed before 100k miles/160k km? Since that's the interval for the timing belt, I'd be quite surprised if the water pump needed to be changed first. Most folks I've read posting on this subject seem comfortable with 100k mile replacement of the wp.

In any case, my OE water pump is OK at 153k miles and will be replaced at the timing belt change @ ~160k miles.

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I'm an optimist. I would like to think that the WP will safely go beyond 100kmiles for everyone. But I think that doing so is taking an escalating risk for each 1kmile above 100k. Since a pump failure can take out the motor it is not a risk I would chose to take.

In the old days of 40kmile belts, one could go two belt changes per WP. With 60kmile belts you could toss a coin and decide to do it or not. With 80k and 100kmile belts they should be done with each change because chances are pretty good they won't make it to the 2nd change.

As to changing it now or later, I think it depends on the parts that were used. The '02 had an 80kmile interval. He might go to 200kkm/125kmiles and just do it anyway.

i guess what i'm really wondering is: if the coolant pump fails, will I be able to catch it b4 it takes out the TB???

tditom: you summed up my options nicely - i'd rather not change the pump (and that would mean TB would be done too) after buying the car, but on the other had i obviously don't want to run the risk of wrecking the motor i guess in the end it's a toss up and a decision i'll have to make.

weedeater: i'm an optimist too, but the thoughts of buying this car and having a waterpump blow, and etc... don't settle well either

Drivbiwire and oilhammer: i couldn't agree with you more but i'm trying to get an idea of what the "chances" of this stock pump failing between 147K km and 200K km..........?

what i'd really like to do is buy the entire kit from dieselgeek.com and try to do it myself or have someone help me or take it to reputable shop (definately not the dealer!) and get charged labour alone.

I guess the ultimate question is how long do these factory coolant pumps generally last? How many of you guys have had them blow catistrophically before 130,000 miles???

in any event i'm still bargaining with the used car dealer (frustrating because he didn't know what Vag-Com is and said the TB wasn't an issue and i don't need to change it ever! yeah i know - complete BS! - hard guy to deal with ) and might take it somewhere for someone to check over............

happy drivin'

Not on the right subject, just my two cents, but being in Ottawa and having recently purchased a Jetta, I can highly recommend to you to check out the market in Montreal. TDIs tend to be a bit cheaper there in my experience and it is only a couple hours drive away. The disadavantage is that you have to pretty careful about rust. Try www.lespac.com (TDIs come up there pretty often from private sellers) or the MTL newspapers (particularly Journal de MTL and La Presse).

How many of the engine mount bolts were replaced?

Were the idler pulley's replaced along with the stretch bolts that hold on the main idler?

You may or may not catch the water pump, roll the dice hope you get lucky.

Yes QUITE a few pumps have in fact taken out peoples engines. Somtimes it gives a bit of warning sometimes it doesn't.

Did the dealer replace the serpentine belt? If not you need to!

Too many if's with a half a$$ job, I don't trust it and I would not bet $6,000 on it if it were my motor. So do the math $600 (Parts and Labor) is a GREAT deal for a 100,000 mile insurance policy. Its a no brainer if you ask me what you need to do.

DB

ssg: are any of those publications in English - i cannot read French that well... and do you know of good TDI mechanics in Ottawa???

Drivbiwire: yeah i hear what you are saying. i agree it would be a great insurance policy. how long would it take an experienced TDI shop to install the TB kit from dieselgeek??? - so i have an idea of the labour costs......

Just to lengthen the thread...

Although the Dieselgeek kit is superb, he's in the U.S... In Canada many of us buy our supplies from Brian Harrison:
http://www3.ns.sympatico.ca/roseland/VWPartsA4.htm The only thing not included in his DeLuxe kit is the serpentine belt... you have to add it...

You asked for publications... well... that Drivbiwire fellow who's been kind enough to enlighten you has also put together the following (please download it, so you know what's involved)
http://pics.tdiclub.com/pdf/a4timingbelt.pdf

And when he says "thus far NOBODY has had to bring a car back due to a failed component" - well, he's only done about 1300 timing belts (actually more by now...)

Many independent shops won't be thrilled to install a kit of parts that you brought in... and will not warranty the job...

All the best,

Yuri.

I just wanted to report that I did my timing belt at this past weekend's MI gtg. I followed the DB tb replacement instructions for the most part. Thanks, DB and crew, for the great write up. It was very helpful.

I found this comment in the write-up very interesting:

This is a picture of the water pump. If you have 120,000 miles or more consider replacing it. It's only a few bolts and a
gallon or so of coolant.This is a great time to do the job if you have high mileage.​

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It was the only reference to the water pump in the whole 120 page procedure, and hardly sounds like the mandate now being given in this thread. I'm just wondering if there have been a bunch of water pump/timing belt failures since the write-up? I understand not wanting to take unnecessary risk, but the original poster's situation doesn't seem to fall into a clear category of high risk to me.

For the record, my OE water pump with the plastic impeller showed no signs of stress fractures when I changed it during the tb procedure (at 154k miles).

3800rpm- I don't know if you ended up buying the car, but I would feel pretty safe letting it go to 200K km if I were you.

One of these days I will re-write the procedure to include all the latest 2003 Upgrade revisions. The water pump issues stemmed from the model years 1999.5->2002 where the OEM water pumps showed a LOT of stress in about 1 out of 3 pumps. This means leaking via the upper and lower weap holes. The later models seem to be doing better 2002+ however even these pumps with 80,000->100,000 miles have in fact showed some signs of weaping/gassing in the vent holes. The pumps are not failing but the gassing and coolant residues in the holes are an indicator that the pumps mechanical seal is in fact losing it's battle. Once the seal starts to leak the coolant destroys the sealed greased needle bearings and you get the "Whooosh-Whooosh" sound...if you are lucky.

Once VW issued the 2003 upgrades, it's suicide for the motor to try and push the water pump to 200,000 miles. Frankly I can't see the pump lasting that long no matter how good it looks at 80,000 or 100,000 miles when it's inspected during the first timing belt change.

Whenever I pull a pump I spin the shaft and feel for play. Regardless of model year you can always feel sufficient play in the shaft (except a new pump) that may cause unseating of the mechanical seals contact faces.

I personally won't touch a car unless the water pump is replaced. It's not worth the risk to me so this ultimately protects your engine as well.

DB

it's suicide for the motor to try and push the water pump to 200,000 miles.

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Note that I was using km, not miles, in the previous post.

I did compare my OE pump with the replacement in regards to shaft play. OE was as tight as the replacement.

To reiterate- the original poster had a special circumstance that the wp wasn't changed when the tb was done at 60K miles. With the car now at 90K miles, he was asking whether to go another 30K miles on the OE wp before changing both wp & tb. I think we are all in agreement that it only makes sense with 100K mile belts to replace the wp as standard practice.

DB, can you comment on if it is possible to replace the wp w/o removing the engine mounts?

Hey guys:

Well it's fitting that this thread is active today after a couple weeks of no activity because I BOUGHT A TDI YESTERDAY! pretty excited about it, I love it already. i find myself already looking for excuses to drive it. . I just want to point out that the information I got on this forum has been beyond valuable in helping me find a used car in good condition that has been taken car of. I learned what to look for and what to ask about and what to have a mechanic check for....... Thank you all!!!! Now it's time for me to learn how to maintain it and work on it....

anyway it's a 2000 Golf w/ 220,000km (~140,000 miles) - runs like new (at the moment anyway ). The situation is sort of the same as my original post - TB was done (and supposedly all bolts, idlers and tensioners) at 150K km. it had the 160K km (100K mile) belt put on it so will be good til about 310,000km. however, still original WP! I'm not going to ask everyone's thoughts becuase it's already been discussed here - but just to let you guys know my original concern has now become a reality..... do i roll the dice, or fork out more money i don't have just to be on the safe side??? I'll decide soon what to do....

tditom: how many miles were on your OE water pump when you pulled it and noticed no shaft play?

Congratulations!!!
In this case, I think you should replace the wp as soon as reasonably possible. Hopefully DB (or someone else) will advise if this is possible to do without pulling everything off (motor mounts and such) to get to it. If you can find a tdi guru to do it, you are better off. Or if you feel up to it, use those timing belt .pdf instructions and do it yourself. Better yet, attend a gtg and have someone knowledgable guide you through it.
good luck

Yes it is possible.

FIRST set engine at TDC and insert the cam lock tool!!!

Now:

Relieve tension on serpentine belt and slide belt off of the harmonic balancer, Remove the serpentine belt tensioner (3 bolts), the harmonic balancer (Big serpentine belt driving pulley), lower timing belt steel covers. Release tension on the timing belt, pull the cam pulley.

Drain the coolant by removing the lower oil heat exchanger coolant line, drain the radiator.

Now pull the three water pump retaining bolts. Extract the water pump and install new one.

Put engine back together and reset ALL THE TIMING SETTINGS as if you just installed a new timing belt.

Total time for me is around 2 hours like I posted before it's almost as much work as doing a complete timing belt.

If there is ANY DOUBT WHATSOEVER that the engine mount bolts were re-used REPLACE THEM NOW!

DB

3800rpmDiesel said:

....
tditom: how many miles were on your OE water pump when you pulled it and noticed no shaft play?

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154K miles. Plastic impeller looks fine too.

Originally Posted by 3800rpmDiesel .... tditom: how many miles were on your OE water pump when you pulled it and noticed no shaft play?

tditom said:

154K miles. Plastic impeller looks fine too.

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__. My timing belt was done at ~88k miles -- that's uurmmm, a fair old number of kilometers. I changed *every* part that touches the belt (rollers, bearings, tensioner, tensioner bolts, water pump etc. -- all parts except the toothed gears on the cam, crank and fuel pump) along with coolant, "stretch bolts", cam seal and serp belt. So far as could be told, all the removed parts were in perfect condition -- no drag or roughness in any bearing, no visible wear on the belt, serp belt looked pretty good, no leaking gaskets and cam seal looked fine. Looking at the water pump, there was no weeping from the bearing hole and there was no sign of any loose bearing; however, there was a fair amount of erosion on the impeller vanes.

__. Since I put a 100K (OK, OK, I know that one -- it's 160Km in those French measurements, right????) mile belt kit on, that would have meant that I would have been trying to make that pump live for 189K miles (i. e. that's what mathematicians call a great big lot of Km's, there eh?) if I hadn't changed it. With this in mind and considering what I held in my hand and looked at, I'd never change a belt without changing the pump. A lot of people will get away with it, but it's far too big a gamble for me.
'

mrGutWrench said:

...I'd never change a belt without changing the pump. A lot of people will get away with it, but it's far too big a gamble for me.

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I concur. With 100K mile belts available, it only makes sense to replace it all at the same time now a'days.

But I think their are alot of people who were in my shoes where their first tb was required to be replaced at 60K miles and we replaced everything but the wp with a 100k mile kit. It wasn't standard practice at the time of the change out (2003) for us to automatically replace the wp too. (look at the A4 tb procedure I referenced earlier) The guy who changed my tb at that time (GeWilli) didn't mandate it. So I'll bet there are quite a few others out there who are approaching the 160K mile mark with their OE water pump. After looking at my OE pump w/ 154K miles on it, I'm only saying people shouldn't go around fretting about it.

I agree - I'm not sure it's anything to fret about - I'll change my TB before it's due so i can get the WP too, but I'm not in a panic to do it now. I am not disputing the fact at all that it should be done at the same time and I"m not disputing the fact that the WP could blow and take out the engine.

BUT:

I'm sure there are lots of people out there who are not even aware of this (ie, potential for WP to take out TB that ruins motor) who just take their car to a dealer all the time and never get the pump changed out when the TB is done. All dealers I've talked with said they don't change it unless it's leaking or looks problematic. So I think if WP's were taking out peoples engines (by way of WP instantly taking out TB) wouldn't we be hearing a lot more about it? I'm just not sure how probable this scerario we're talking about actually is..... I'm sure that it does happen but how common is it?

What if I put it this way: how many of you have actually seen a WP blow, instantly take out the TB, and then it blows the engine - all within a few seconds while driving? how many cases do you directly know of?

It be interesting to know how many people had WP's blow that didn't take out the TB?, How many out there have over 200K miles on their original WP?

I hope were not beating this issue to death, but it is one that has very costly implications, but I'm just wondering how often it really happens?

3800rpmDiesel said:

... How many out there have over 200K miles on their original WP?...

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Did you mean km's?