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Water pump or not

6K views 5 replies 4 participants last post by  Paparazi 
#1 · (Edited)
I was a VW technician a few years ago so I kind of know the answer before I ask it. However, what is your opinion.
My car; a 2007 EOS with a 2 litre Turbo engine TFSI BWA code. Has covered just 18,000 miles since new. It has had around 6 VW service stamps and a couple of indy's in that time but I can't see any evidence of a cambelt change.

My plan is to fit a genuine cam belt but I really don't feel it will need idlers, a tensioner and a pump....yes I know about the consequences and that's why I am changing the belt purely on age. The belt I can pick up for about £26 but the kit is another £100.

So my feeling is; at 18K and about 5K each year whilst in my ownership, I am being foolish just changing the belt, or, should I push the boat out and fit a pump as well?

Martin
 
#2 ·
Tough call on the water pump since your car has such low mileage. Smart after nine years to do the timing belt no matter what, because I'm sure age is a factor in belt condition.

Given the amount of labor involved, I'd still probably replace the water pump (and the rest of the parts) when doing the belt. I'm always a big proponent of "while you're in there" parts replacement because I hate tearing things apart again for something I could have easily replaced. That way you know you're good until the next belt change, which could be a while if you continue to accumulate miles at a slow rate.
 
#3 ·
I went through similar thinking on MY07 TDi at about 40K. The local motor factor had an after market German made cam belt and roller kit for a fair price. I either went to EuroCarParts or GSF (?) and the kit was about £65 (belt only about £25). As the car was below 60K I decided NOT to replace the water pump until I had checked for any bearing wear.

At 40K the roller bearing was like new. When spun it, it still had that stiffness you get from a new well greased bearing. Although I replaced it, I wish I had just replaced the cam belt. There was no evidence of water leaks or end play on the water pump either.

For DIY you need a couple of tools which you can get cheap on auction sites and it is not that big a job if you are careful after everything is locked up. The bigest problem I had was thinking the new belt was too small because it was real pig to get on.

Your cam belt is well over time on age wear and I would definitely change that, but I bet when you take the old belt off and fold it back on the toothed side you won't find cracks or fraying.

I came across a lot of confusion on cam belt replacement intervals and I never did get to the bottom of it but I suspected some are made with different materials. They call them 'Poly belts' which makes me think they may not have degrading rubber in them but synthetic plastic.:confused: Some newer engines and belts seem to have much longer service intervals up to 80K. It may not be just the belt material that determines life, but the wrap and tensions which could be different for newer engines.

If I repeated the excercise on my TDi I would do the belt at 40K, then belt, roller bearing and pump at 60K. I do low mileages and cam belt age determines service life over mileage if I follow VW recommends. PS: I always put an egg cup full of soluble oil in the coolant mix and I've never had a water pump failure. Water pumps usually fail when the carbon seals leak water forwards to the bearing which then fails fairly quickly. Soluble oil helps lubricate the pump seal.
 
#4 ·
Hi Vox,

My experience with using soluble oil in engine cooling systems for water pump lubrication in the 1970's resulted in a severe case of dermatitis after coming into contact with used coolant that had been in the engine for several months. I subsequently discovered water/soluble oil cutting fluid mixtures were very prone to bacterial contamination even at the normal high temperatures of radiator coolant which I expected to kill any bacteria that might be present.

Modern soluble oil formulations may be less susceptible to this problem however I am now convinced changing the water pump at the same time as the timing belt is good preventative maintenance practice especially when the pump is included in a reasonably priced timing belt replacement kit. The timing belt in my Toyota 3L diesel is changed every 100,000km and I replace all the fan belts at the same time. I use a basic 50/50 Ethylene Glycol/Water coolant and replace it every two years. After nearly 550,000km, I have never had a water pump failure or coolant leakage from the water pump seal and inspection of the cylinder head and block waterways after my timing belt failure did not reveal any corrosion or crud build-up - see post #11 on the link below which shows the aftermath of a timing belt failure:

http://www.vweosclub.com/forums/showthread.php?t=10562
 
#5 ·
Yes, chemicals can be a problem for many, particularly if they have had very little exposure. My hands now seem immune or resistant to most things. Most garage technicians wear gloves. I started wearing gloves a few years ago using the synthetic household type which seem to hold together with oil unlike latex. I would think used diesel engine oil has the most potentially harmful content to aggravate skin. :eek:

I discovered another benefit to adding a small amount of soluble oil on a car with a small but persistent cyl. head leak. Glycol Antifreeze mixes can contain many additives including a detergent which causes 'foaming'. Foaming is bad in a coolant churned around by the water pump and soluble oil can stop it dead. I carried out experiments with several brands of Glycol mix, shaking each one in a bottle. Half of the sample produced a lot of foaming which reduces their effectiveness to cool when in contact with the block and cylinder head. The best in the sample was a very expensive BMW own brand pre-mix, but then it was recommended for a motorcycle engine with marginal cooling capacity and frequent but normal temperature over swings.
 
#6 ·
Well I think I have made my decision to change the pump and belt. The parts will be either genuine VW or Contitech (Contitech are the OEM supplier in most cases) I wouldn't fit any of the lesser brands: FAI/Bosch/Febi Bilstein/ and although GATES make good belts I imagine that there pumps are badged brown box supplied.

Thanks for your comments....I already have a 20 litre container of G12+ I use for my Vanagon Westy.
 
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