mike@fmc

Never had issues with overheating or coolant, until this morning on the way to work. Warning light came on, temp was barely above the fat 1/3 mark (typical driving temp), oil was cool (28 F outside). I parked it and popped the hood - res. cap was on tight, but coolant was "burping" from the reservoir back down the top (inlet) hose, like some weird heartbeat. Coolant level was up, and had leaked some from the bottom of the res. Will check tonight on my way home...

Is there a way to check the water pump and timing belt to get an approximation of its age? The guy I bought the car from 3 years ago said it had been done a year ago, so I am assuming that means back in 2004... I don't drive the car much, maybe 15K miles since I have had it. But now I wonder if the water pump is bad, and if he really had it changed. Any thoughts?

DaveInSaltLake

of knowing it's done right. I do a timing belt service on all of my C4s. I might consider running on an old belt if I had solid proof it was done properly....but it's pretty rare to find that kind of documentation.

If you're a gambler you might try changing out just the thermostat.

4Driver4

There is no visual check.

A6Gary

First, you'll need to remove the front cover, the serp belt, serp belt tensioner, and then the TB covers. You can then visually inspect the belt for cracking, rips, or any other obvious wear/damage. Then inspect the water pump for any coolant leaks, which would be an indication of a seal and/or bearing failure. But this process won't tell you if the water pump bearing (or the tensioner and/or idler) are on the verge of failure, which are the primary cause(s) for a TB failure while rotating.

If you expended time for this effort, it wouldn't take too much more additional time to replace everything, provided you have the two special tools (#3242 & #3243) to maintain the camshaft/crank timing. As DaveInSaltLake says, you could spend a few hundred bucks for peace of mind.

DaveInSaltLake

while racing an Audi in the Virgin River Gorge on I-15 in southern Utah. (check it out on GoogleEarth). Turns out his water pump with about 86k miles seized and blew the serp belt, which, in turn, trashed a few other things on the front side of the engine. A $500 towing bill and a $1200 repair bill later he was back on the road. I told him he was luck that his water pump was driven by the serp belt and not the timing belt.

A couple hundred bucks in parts and a couple hundred bucks in labor would have prevented all that mess.

austinado16

Unless it completely grenaded, at which point you would have known something was going on because the timing belt would be skidding on the locked up water pump pulley....noise and smoke.

You may have a thermostat that's failed though. It could be sticking closed, and in your current outside air temps you wouldn't necessarily notice that on the temp gauge.

Thermostat can be replaced without removing the timing belt. Bleeding cooling system takes some effort, but we've discussed it at length here recently, so search the archives.

If you do a timing belt job yourself, it is not possible to get the cam timing correct unless you use the cam sprocket puller to break both cam sprockets loose. The sprocket MUST be allowed to rotated as you tension the timing belt. If the sprockets are not loose and allowed to rotate, as you tension the t-belt, the cams will be pulled out of time. Doesn't matter if you have the cam holding bar on or not, they will be pulled out of time.

kc100csquattro

It took awhile for the symptom to get worse but slowly notice residue in my coolant and oil. Finally discovered head gasket was the culprit. I'm in the process of changing the head gasket. Hope yours is not this bad but your diagnosis seem similar to mine.