It is not a fact that it will destroy an engine. It is possible for damage to occur in some cases. I had mine let go at 7000rpm in 4th ( The bush on the tensioner pulley was worn causing the belt to creep off the pulley and got shredded, either that or it was a faulty belt!!!!! ) and it did NO damage. A clean break is less likely to do damage than a belt which has jumped teeth. The cam pulleys if not driven and left free to rotate, will stop very easily with the valves closed, and therefore less chance of damage due to piston/valve contact. I was convinced I had destroyed my engine and bought a replacement before discovering my good luck!

[Edited by ustolemyname??stevieturbo - 5/2/2002 12:44:34 AM]

 

if they snap do they take valves with them???

 

Yep

Engine out,both heads off i'm sorry to say!!!!!!!!!!!

Darren

 

ey up....

Hope this is you just been inquisitive... and you've not blown your scoob....

Skinny wheels...

 

BIG TIME

 

no i havn`t blown it, i was wondering weather or not to do it cos i have no record of it being done.(don`t read jap)

this weekend me thinks!!!

skinny wheels-hows the car coming along?

 

Not bad mate just bought a spoiler... similar to yours but not the same..... oh and a front splitter just need em spraying up.....

Its only the first day of the month tommorrow and ive nearly spent me wages already... never mined...

Dan

 

Hi Jonny,
Its a 36000 ml replacement item from memory.
If it goes the valves kiss the pistons so it is an expensive sight.
Let me know if you need to source a belt at the right price.

 

I'm new to this and done't want to put anybody's back up.....BUT...
I've spoken to Subaru technical about this and they said if the belts go it doesn't damage the engine, it has a fail-safe on the engine......i'm not saying it true but if Subaru say so then it's got to have some credit....

 

I build the engines at Prodrive and i can say that it definitely does bend valves when the belt goes. Seen it a few times now.

Not nice and usually expensive.

Luke

 

thanks for that guys
harvey-mine has 57k on it so do you think its a good idea to change it now?

 

Hi Jonny,
What evidence is there of last belt change & at what mileage?
If there is no evidence then why not?
What is the visual condition of the belt?
Is it genuine Subaru or after market? If after mkt then at least one change has been done at sometime.
A new belt is a fraction of the cost of repair if a belt lets go.
Can I help you get the best deal on a proper belt?

I would like to know more about this fail safe balloney.
No disrespect to the guy repeating the myth but where does it come from, names etc.
When a belt goes then the cams stop turning so if valves are down(open) then they can be hit by the piston(s) as they will continue to rotate for some time and certainly until drive is disconnected.(clutch)
When a piston hits a valve something goes and this is usually a bent valve(s)

 

I spoke to Subaru in Aylesbury (didn't get the guys name), i was just finding out about costs of clutches (ouch) and cam belt replacements. I mentioned that mine was needed doing at some point soon and i didn't want to the cam belt to break as we all know what the consequences of that are, but then he said that the engine had a fail-safe on it. But as Luke builds Prodrive engines ...maybe he knows a bit more..... I've spoken to a company in Uxbridge called "power plus engineering" they do cambelts and clutches cheaper than Subaru...does anyone have any experience of them in Sooby's ? i had an RS Turbo done by them years ago and they were good then.....any comments ?

 

Like I said "IF the valves are open" You have to be very lucky not to do damage. For the cost of a belt it is not a worthwhile risk.

 

I had a BMW that let go it's cam belt... this was also a valve piston connection affair and cost a fortune.. I was told by the guy that towed me in that some cars have a fail-safe.. when the cam and crank sensors deviate the electrics are cut and engine dies...

I thought at the time 'big deal' the engine also dies because the cam ain't spinning.. and it wasn't a lot of use to me as, surprise surprise I was travelling along in top gear so the momentum of the car cranked the engine over via the gearbox... OUCH!

If only I'd been quicker with the clutch!

 

The cams on the quad cam are able to stop very quickly in the valves closed position. In a normal stright engine there is usually always a position when the cam is stopped there will be valves held open. With the subaru however, each cam can come to rest with the valves closed ( because are so short and only operate 4 valves each ), and if free to rotate this will more than likely be the positon they stop at ( if you ever remove a belt you will see what i mean ). While free spinning it is very unlikely there would be enough momentum for them to actually continue rotating and open the valves. So providing the belt does break there is a good chance the cams will stop quite quickly ( unless dragged by the broken belt ) and even if the engine continues rotating no harm will be done. When mine broke ( or shredded to be more accurate ), there was less than 10000 miles on it. Still not totally sure if the very slighly worn bush caused it to go or not ( faulty belt ??? doubtful ). But for peace of mind, change them at 40-50K max or so anyway.

 

i've had cam belts go on a renault 21 (very low revs) and
a lotus elite (medium revs) both times resulted in bent
valves (no piston damage though)... but shiming the
cam followers on the lotus an absolute nightmare...
upright engines not too bad a job... on a scooby... gulp

my scoob my98 came with a 'non' standard owners manual (maybe euro/saudi/middle eastern) it has cam belt change on every 60k as opposed to 45k as in a UK manual.... anybody know the reason for the discrepency ? other than Uk subaru con/rip off

 

steve, does this mean that on one side (either), all the inlet valve open at once, and all the exhaust valves open at once?

also, anyone know the cost of a subaru belt?

thanks, ian.

 

I am just saying that for each camshaft, for approx ( guess )180 deg rotation, it is not acting on the valves. ie. the valves are closed. Unlike a normal engine where the camshaft will always be holding valves open at one point ( maybe more ). It is just because it is only operating 2 cylinders instead of 4/6 etc.
That is why it is possible for it to break with no damage. The cams will rotate and not have enough momentum ( if undriven )to open the valves and will probably just come to rest closed.
Of course situations will arise where damage will occur, i think i was just very lucky that time. If you change the belt and see the pulleys with no belt attached you will see what i mean.
Subaru look around £120 + vat for a belt, Best ive paid was about £70 for a Gates belt - 5834XS

 

steve, see what you mean, thanks for info mate
going to change mine over the summer, was last done on its 45000mile service as it should, now on 70000. i know it doesnt need doing till 90000miles, but id rather be safe than sorry, considering it it modded and i thrash the **** off it

cheers, ian.

 

Dealer list for my last belt was£105.87 + vat. Guess they like me as I only paid £95.28 + vat.Shopping around for after market can save a good bit on these prices, Hope that helps you Ian.

 

thanks harvey

when i do it ill fit a genuine subaru belt. are there any other parts worth replacing at the same time e.g tensioner etc?

 

You can check the tensioner but unless it has been abused should be OK. Obviously check the powersteering/alternator & air con belts while you are at it.
At the same time I did thefuel filter, air & oil filters, new sump washer, 4no plugs &rocker gaskets, including the rubber inserts (half moons) but that was because I sometimes had a burning oil smell on stopping but never any oil on the floor. Hot oil was going onto the exhaust in minute quantities. Took a tip from someone else to sus out.

 

thanks harvey. i checked the other belts the other week when oil/filter plugs etc were changed, they all look fine, and are subaru belts.
like you say, when i do the cambelt, ill check the condition of the tensioner etc...

cheers, ian

 

You may have a shock if you do need to change the tensioner as I'm having mine changed next Monday. The cost of the tensioner alone is £194+vat plus they want around 2 hours labour to fit! I dont think I'll be getting any change out of £350. They also said for me to change the belt at the same time but it was only replaced 12000 miles ago (1 year), does anyone think its really necessary as its going to cost another £120 on top?

Stuart

 

It is usually not reccomended to re-tension a belt after it has already been used. Having said that I have done so many times with no problems, and i reckon yours would be fine too.
I havent really seen any of the older tensioners give problems, althought the new pivoting hydraulic tensioner seems to cause bother not sure what year they started using them 99 maybe?
The only thing I would check is the bush that the tensioner pulley pivots on for wear. This is what i think caused my car to **** a belt ( i doubt the belt was faulty, althought there was very low miles on the belt ). I got a friend to machine me up a new one with virtually no play in it, and its been perfect ever since. Having said that I have took apart other engines where the bush looks to be worse/same as my original, and they have been running fine, but its still worth a look in case it might cause the belt to creep forward off the pulley from not runnning true.

 

What make was it mark? Sounds like a bargain.

 

cant remember the make mate but it was identical to the genuine subaru one i took off ,all timing marks and writing on belt were the same, midland impreza asured me it was top quality and that they use these belts in all there cars .

 

got my belt from midland impreza £40+vat very good quality.








[Edited by mark_wrx - 5/8/2002 9:59:18 PM]