help my 4age enjoys eating cambelts

[shihad]

motor is 4age bluetop with twin sidedraughts
last week while the car was with a friend the carbs made a funny noise and died.On further inspection the cambelt had jumped 3 teeth and it left a rip down the middle of the cambelt about 5cm long.The cambelt was replaced and it was put down to a freak accident (perhaps a stone?).so Today (saturday) I attempted to drive home to Gisborne from Dunedin the car lasted an hour and a half before it happened, the exact same (*&^&(*^*&)^&*^%*&^*&(%^*&%^&%$^&$*^%&$^%&$ thing.the carbs made a funny noise (no warning no big bang) car died and im left in the middle of nowhere.i get the car towed back to Dunedin (a mere 170) and had a quick look at the cambelt see the photo a nice little rip in it.car doesnt run because timing is so far out.

something is obviously causing the cambelt to slip and cutting a nice 5cm line in it.
cams were checked and were not considered tight by mechanic
before it happend i noticed temp gauge behaving odd it was jiggling about a mm each way (maybe unrelated)
will put up more photos with all the covers off tomorrow.


anyone ideas?




sorry image is huge

[thegreatestben]

I'd pull it down and inspect all your pulleys, it's only got one tensioner so you might as well replace that too for piece of mind.

Looks like something went through the middle where it's badly damaged and caused it to split a few cm each side of the impact to me

[pc]

was it run with or without a cam pully cover?

[jondee86]

I'd be looking down in the lower belt cover to see if there is some
loose part lying down there... bolt, nut or stone etc.

Cheers... jondee86

[shihad]

was it run with or without a cam pully cover?

cam pully cover was on just took it off for photo

it's only got one tensioner so you might as well replace that too for piece of mind

was replaced with cambelt first time last week

[IH8TEC]

your not doing it up way too tight aye you?

[shihad]

cambelt was changed in march because oil was leaking onto the belt by a mechanic. it lasted till this problem started last week.cambelt was then replaced last week by a different mechanic and lasted about 200km before same problem so i doubt thats the issue.

[strx7]

looks like a classic case of the old cambelt eating gremlin to me.....

[l1ttle_d3vil]

yeah check all your pulleys, make sure everything is normal/smooth etc. check your bottom crank pulley keyway too, they get eaten out heaps and timing goes out / cambelt gets loose.

[Lloyd]

Belt wasn't loose when it came off. Driving down the road normally, then engine sounded like there was carb issues and it stalled. Belt was still tight but out 6 teeth on the crank

[sergei]

I had similar damage when little tab where tensioner pivots had fallen out. Tensioner was still in place as it was held by bolt.

[mjrstar]

i'd be making sure that both of the cams, oil pump pulley and belt tensioner all move freely with the belt off and then look at fitting a new belt. i guess the belt replacement was done as a 'slip on/slip off method without looking at the timing too much..
take it for a run then remove the belt cover and inspect.

I little off topic but i recall getting a wtarpump for my 1g wiich had a slightly different casting which i had to grind off to gain clearance to fit it. Have you got any Non OEM parts in front belt area.

[85AW20v]

Also check that the keyway on the bottom pulley hasn't broken or slipped. would explain the jumped timing.

[crispy'86]

HHmmm check movement on the crank pulley for the cambelt, check tensioner see if that is noisy/ has been replaced or if it had been said it was replaced. Check the bolt for tensioner actually stays tight. Did the water pump get replaced at same time?? We had a similar problem with a 4a corolla that stopped. Cambelt had chewed teeth off the belt and punched a hole in the rocker cover 4afe engine, turned out one of the water pump bolts had worked its way out, from previous water pump replacement., got flicked round by the belt, punched hole in the rocker cover and ended up sitting beside the tensioner

[shihad]

from what i heard the tensioner bearing was buggered and it caused tensioner spring to drop out and land between crank cog and cambelt.

[crispy'86]

Yeah now you say that, i've heard of that happening. Always wondered how the spring could just fall out, knew there had to be a reason for it