Monday 22 August 2016

Vauxhall Zafira B 2.2 16v Direct. Timing chain and water pump problems

I've just replaced the timing chains and water pump on my 2005 Vauxhall Zafira B 2.2  16v direct. I was very dubious about attempting this on account of not being fully sure of my own diagnosis and the sharp intakes of breath from local mechanics and refusals to even attempt it.  Main dealer obviously out of the question as the last time I ventured in to one they decided to charge 35 quid labour to change a bulb, once bitten and all that..Online research seemed to indicate 4 figure bills for similar jobs. I am aware that failing timing chains and tensioners were a known issue and there were recalls however this engine has done 85k and is 11 years old.
 
Its not really worth me writing this haynesesque style but I thought I'd share a few things I found out as I couldn't find much specifically related to doing this on a Zafira. Firstly its a Z22YH ecotec engine the same as in the 2002 onwards Vauxhall Vectra,Signum and I believe Astra. Secondly it's as near as fk is to swearing the same basic engine that GM have been putting in all manner of jalopy worldwide since about 2000. As such instructional youtube  vids for most 2.0l and 2.2l  Vauxhall, Opel,  Pontiac,  Saab and even the odd Fiat and Alfa romeo will all be relevant and give general guidance if you aren't sure where the last bolt is that's still holding the damn water pump on. It also means that aftermarket parts are readily available and can be a lot cheaper if you do your homework, cross reference and search by part numbers.
  
Symptoms were rattle which has gradually been getting worse over the last few months, coming from the timing chain side, I was also getting occasional misfire under load at higher revs  and consequently the engine emmisions fault light coming on every time it did.(Note a) Initially I replaced the usual service part suspects so spark plugs, air filter had been ruled out over the previous few weeks and oil and filter change was within the last 3 thousand miles. Eventually it got a little quieter and began overheating. At this point it was blowing water from the expansion/filler tank limiting journeys to 10 minutes or less. I suspected at this point that the rattle had been the water pump failing, possibly the impellor blades as there was no visible water leak from the casting itself. I could tell that no water was being pumped around the engine at all by feeling the radiator which remained cold versus the rest of the hoses which quickly got up to pressure cap releasing hot

As the water pump is driven off the timing chain, or more accurately the balance timing chain and the engine is notorious for chain tensioner issues I knew replacing just one part was probably not going to be an ideal solution. I could have forked out fifty odd quid for the timing locking tools and just tried replacing the pump (glad I didn't) but instead opted to buy the kits needed for both timing chains, a new water pump plus oil, filter etc so I could change everything. The parts cost about £250 from various motor factors on ebay. Both timing kits were aftermarket incidentally, FAI branded TCK3 and TCK5, they contain everything you need, chains sprockets seal gasket tensioners guides and bolts where nececessary
 The better how to videos I found show the engine out (Note b) but I completed this without any real difficulty with the car parked on the road in front of my house.
All covers off
View from under wheelarch with splashguards removed

 On a Zafira the job requires removing the front wheel and the front half of the splash guards under the offside wheelarch and the covers between the bonnet and the windscreen/bulkhead. This looks like a bigger job than it is (4 bolts and few clips for cable routing and windscreen washer tubes) This gives much improved and necessary access to the back of the engine. You need to fetch the air filter housing and airflow meter off and the left hand engine mount  so you can get to the timing chain cover. You need to take the exhaust manifold off to get to the water pump and thermostat housing. If you undo the thermostat housing block complete it will move back far enough to swing the water pump cover and rigid pipe out of the way, without having to disconnect any hoses or even unplug the temperature sensor.


Once I'd got the timing chain cover off I was not expecting to see what I did. The balance shafts and water pump drivetrain was worn to the point where there were no teeth at all on the exhaust balance shaft sprocket or the crankshaft sprocket so the chain would have just been hanging loose and largely stationary around what was left of a spinning crankshaft sprocket.
No teeth left..
Tension was non existent as the chain had gained enough slack to fully extend the tensioner and then some, the guides had deep worn in grooves and an inch or so was broken off the end of one entirely.  The water pump sprocket and inlet balance shaft sprocket were badly worn. Bear in mind I had been running this engine (albeit very gingerly and under 3000rpm for short periods) for probably 50 or more miles in its final overheating and therefore non spinning waterpump or balance shaft state.
All the old parts
The camshaft chain and sprockets were still intact although very obviously worn (put up against the new chain it had stretched a good link and a half).

 The only thing you can't do with the engine in the car is pull the balance shafts out completely, they only come out as far as the steel box section in the engine bay even with the engine dropped as far as it will go onto the front subframe.
View from the top with air filter box and engine mount removed
This was enough for me to be able to get a fairly hefty pipe wrench on what was left of the gears to hold them while I undid the bolts. Tightening the new ones to the correct torque requires a bit of care so as not to damage anything, I stopped the whole drivetrain moving using a spanner as a sort of t-bar between 2 of the 3 bolts holding the water pump sprocket on, but there are probably several other equally or more effective ways to do it.
    
There is absolutely no need for any timing tools if you replace everything.  Before you take the old camchain off turn the crankshaft so the keyway in it is pointing up(tdc), the exhaust cam timing mark is pointing at about 10 or 11 oclock and the inlet cam mark is about 1 or 2 oclock. The keyways in the camshafts, balance shafts and the marks on the new chains and sprockets are then self explanatory, I'm not saying it would be impossible to go wrong but if you're confident enough to be thinking about attempting this I'd say its highly unlikely. In any case you will spin the thing over a couple of times by hand to make sure there are no nasty surprises once the new chains are on.

Note a
 If you are wondering  (which you might very well be if you are reading this) the fuel pump and fuel pressure regulator problems that are fairly well documented don't show these symptoms, the engine will literally just cut out randomly with the spanner light on rather than misfire. When that started happening to me a couple of years ago it was the fuel pressure regulator sticking.
 
Note b
A well worded Youtube search will give loads of results but I found this one particularly helpful for the chains and this one for the water pump.