147 snapped timing belt

[prova]

Hi there ..... I bought my son an Alfa 147 for his first car. He is only 17 and will go for his license in January. We bought the car through an auction in Melbourne a few months ago and we were both pretty stoked with the purchase and I've been having a nice time driving it around! It came with a full service history and the current kms are around 225,000. We have had the car checked for a rwc and having been buying the bits we need (just front pads and rotors) and items needed for a service mainly the timing belt, etc which we knew it needed.

Just making arrangements for the car to be serviced, etc and the belt went this morning whilst trying to start the car in the garage. The engine did not fire but was only turned over with the starter. I would appreciate any advice .... mainly - will the engine be damaged, bent valves, etc from being turned over by the starter only?

If so it seems fitting a complete used motor with new belts, tensioners, water pump, etc is the best way forward?

Cheers and any advice greatly appreciated. My (our) first foray into more modern Alfas - not off to a great start!

[Neil Choi]

Hey there, being there exactly same, bought a 156 TS and drove around for a week and was planning a week out from doing a cam belt, as it happens belt stripped the teeths, bent 14 of the 16 valves. Another second hand head, new cam belt, balance belt, tensioner, water pump, may as well get the auxiliary belt and tensioner as well.  A few special tools needed, ie long 15mm ring spanner, that tensioner tool, maybe cam locks and something else I forgot. 
Easier to just replace head if you can.  Though maybe logical to replace whole motor, given the bottom end has done 225k km.
Smaller job for head replacement only.
Whereabouts are you.

[prova]

Thanks mate for posting a reply so quickly. We are in the Geelong region. Do you think the starter would bend the valves? The balance belt has very worn teeth ... I think it has taken out the timing belt .... really annoyed with myself and I should have been way more cautious! I suppose you still keep learning life (car) lessons even when you get older!

[Neil Choi]

If and when you take the bottom cam belt cover, at the crank, off, just use a 5 mm allen key socket to undo all those allen bolts, you will find black strips of cam belt teeth in the bottom cover, scoop them up and save them!!!  As you crank with starter, it drives the crank and the crank stripped the belt because the teeth were worn and delaminated from the belt.
Oh you will obviously need a head gasket kit as well the stuff in the above list.  And a special torque wrench which shows a final torque up in angles.  There is a procedure for doing up the head, instructions are usually with head gasket kit. 
I feel for you as I have been there before, but I actually enjoyed the learning experience since I am going to keep break the thing.

[johnl]

Do you think the starter would bend the valves?

Even at cranking speeds it's very likely that some valves are bent. The only way to find out is to lift the head off. If you find only a few bent valves then it may be cheaper to replace just those, instead of replacing the whole head. It would depend on how much damage you find, and whether you are paying someone to do the work or doing it yourself, how much valves will cost and how much a second hand head would cost, etc. etc.

With the head off you would be able to easily see badly bent valves (in a still assembled head), but a slightly bent valve may be hard to see. Turn each camshaft and see if any valves obviously don't close properly. Individually check each combustion chamber for valve leakage by closing all the valves in that combustion chamber, then invert the head and fill the chamber with kerosene or petrol. The fluid shouldn't leak into the ports, if it does then a valve stem is bent and so the valve can't close fully (or less likely the valve and / or valve seat has a damaged sealing surface).

The balance belt has very worn teeth ... I think it has taken out the timing belt .... really annoyed with myself and I should have been way more cautious! I suppose you still keep learning life (car) lessons even when you get older!

At least one reason why I deleted the balance shaft belt when I replaced my timing belt. It's never happened to me nor have I ever seen it, but I've heard too many sad stories involving balance shaft belts breaking and taking the camshaft belt with it (I don't know, it may have only ever happen very rarely, but each time the story gets retold and retold...). I found that deletion of the balance shaft belt results in a barely noticeable increase in engine vibration.

Regards,
John.

[prova]

Thanks John appreciate your thoughts and advice. I am going to give myself a few days to think of the best way forward. I did speak with a friend who is a mechanic (but not an Alfa specialist) and he suggested using his probe camera to look at the valves through the spark plug openings? I will post an update when something happens. Thanks again, Ren.

[colcol]

When the valves give the piston a big enough thump, you can cause the bearings on the bottom end to go out of round, causing failure a few weeks after you have fixed the top end.
Some of these cars have turned up cheap on ebay after a timing belt failure, without the bottom of the engine being checked for any further damage, Colin.

[Mick A]

Hi Ren,

Ignore this rubbish being posted about the bottom end being damaged, if it happened at cranking speed there will be no problem with bearings or conrods.

Your simplest way to check for damage is to fit another belt temporarily and do a compression check.

But I will almost guarantee some bent valves unfortunately.

You can buy a good second hand head from any Alfa wreckers, and it is the most cost effective way to get the car back on the road.

If the engine wasn't using oil or blowing smoke and drove fine, there is no need to go replacing it.

I suggest you call and speak with an Alfa specialist about your options so you have something solid to go by.

Mick.

[johnl]

Ren
Mick is correct, lifting the head off isn't the only way (as I stated it was) to find bent valves. A compression check will also do it, but whether it's worth going to the trouble and / or expense is debatable. I also agree with Mick re the likelihood of damage, I'd be very surprised if no valves are bent. The cranking engine wouldn't have been rotating very fast, but the force of the piston pushing against the protruding valves would have been considerable due to the starter motor torque, geared ratio of the starter motor / ring gear and the geometry of piston and con rod motion approaching TDC.

Regards,
John.

[Cool Jesus]

I have a spare engine out of a 2005 147, only travelled about 25K kms which I no longer need. PM me if you need more info. Feel for you too, real disheartening for you both.

[johnl]

....and he suggested using his probe camera to look at the valves through the spark plug openings?

Ren,
I would say it's not a complete waste of time doing that, but close to it. The probe would only show a severely bent valve, and it only takes a very small stem bend to cause the valve to leak. All may look fine through the probe, but still not be...

Regards,
John.

[prova]

Thanks to everyone for posting ... much appreciated. Just so annoyed at myself for driving it around. We live a half hours drive from our mechanic in Geelong and the cars next trip was to get its belt done .... bugger!

Cool Jesus I'm going to PM you.

Cheers all, Ren.

[prova]

Hi Cool Jesus I sent a PM to Colcol (sorry Colin) that was intended for you but have now resent it regarding the engine you mentioned.

I'm going down the path of replacing the complete engine with a lower Km used engine. I will fit a new timing belt kit and water pump before fitting the replacement engine. Is there anything else I should renew whilst the engine is out of the car?

I found this on Ebay ... not in Vic but pretty cheap even with freight calculated in. http://www.ebay.com.au/itm/ALFA-ROMEO-147-ENGINE-PETROL-2-0-4CYL-AR32310-09-01-12-10-01-02-03-04-05-06-/201633783547?hash=item2ef24f5efb:g:MK4AAOSwXrhXmVVV How confident do you think I can be in regards to the stated mileage, condition, etc? Also if i get an engine from a Selespeed model I imagine I would have to swap over my existing manual clutch, clutch cover, etc but are the flywheels common to both semi auto & manual cars? Anything else I should consider in regards to buying an engine from a Selespeed model?

Thanks again, Ren

[psproule]

My son's $350 not running 156 TS had spun the timing pulley on the crank and bent every single valve. We simply dropped in one of the many available $500 wrecker motors, fitting fresh belts, pulleys, clutch and a few coolant lines in the process. Was cheaper than buying a head plus gaskets was going to be. If you buy from a reputable wrecker it will have warranty. Maybe spin it over on the starter for a compression check before fitting it to be sure. And whip the rocker cover off and check the cam lobes are all good. We buy our parts from Alfaworkshop in the UK. Cheaper than AU and fast.

Pat

[Cool Jesus]

+100 for Alfaworkshop, they are excellent.