i recently installed one of the spair 2 ltr engines i have into my gtv.
i installed the motor last week and today started it up.
the engine ran as normal and i set the timming, and got the engine up to operating temperatures
and noticed a very light rattle coming from the engine when reving, which seemed to be when the engine was decelarting.
we took it for a drive around the block and the noise got worse and worse
it sounds like the timming chain is lose and rattles against its housing.
i think it is the tensioner that is broken or lose.
has anyone experienced this sort of thing before?
cheers, brad
Hi Brad,
Set the engine up so that it is on #1 TDC firing(cam cover off) so the cam lobes face to the sides IE away from each other.
The timing marks on the cams should line up with the line on the bearing caps.Loosen the bolt that clamps the cam tensioner and rotate the inlet cam in the backward direction(21mm spanner) so that the chain tightens up and the cam tensioner takes up the slack,if it does not then you will need to fix that.When it is all tight do up the clamping bolt again and position the engine with #1 on TDC again as before and check the timing marks lign up,if not you will need to adjust the cam gears to get it correct.While you are there you can check out the valve clearances etc.
If that is all OK and the noise is still there then it may be the lower timing chain?.
See how you go.
Cheers
Andrew
Sounds like chain to me.
HAd a 105 Berlina that rattled, just needed the tensioner loosened at idle and then retightened, I would follow the suggestions and have a look.
Follow the manual to the tee with timing chains - always dangerous if something is not just right.
Catch ya
Shane
As shane says LOOSEN THE TENSIONER AT IDLE.
Never start or rev the engine with the tensioner loose,it pulls the tensioner in and slackens the chain this allows the cam to open valves out of sync and you can bend them against the pistons
suggest you do as alfagtv152 ...or with the engine off and all timing marks aligned, loosen the bolt for the tensioner, place a screwdriver between the shoulder of the tensioner and the head and move the tensioner outwards, retighten the tensioner.
replace the cam cover and start the car let it warm up
With the car at idle loosen the tensioner again, with a warm engine it should self tension.
Again dont rev the car with the tensioner loose. If there is still a lot of noise after doing this I suggest a new chain. If it does need a new chain connect the new chain to the old one and pull it through, unless you want to replace the bottom chain, then of course you will have to remove the front engine cover
Check the sides of the head were the chain travels down a lot of cars i've had over the years have had score marks where the loose chain touches against the head
thanks for the help guys :),
but... i took the car to my local alfa mechanic to see what he thought about the noise
he seemed to think it was not the timming chain, and 1 of 3 things: a bearing, loose flywheel or a broken crankshaft :o
iam confident it isnt a loose flywheel as i used locktight and tightend to 112 nm.
so its either a broken crankshaft or a damaged bearing, iam hopeing the later.
he said an old freinds race motor made a similar noise, and it turend out that it was a broken crankshaft.
the noise is a mix between a knock and a rattle and is noiser when the engine decelerates.
i know it is almost imposible to diagnose the issue without seeing/hearing the engine run but does anyone have an idea what it could be?
cheers, brad
i would still check the above as you dont want to waste ur money
I am not saying this is the cause but the flywheel bolts may have been done up to tension but they can also bottom out in the crankshaft (happened to me) and not be actually providing the rated tension on the flywheel at all after which then rattle loose.
Bearings usually make more noise under load ie. going up a hill and under acceleration but your noise is the opposite. Never had a broken crankshaft so I don't know what that sounds like.
thanks md,
never thought of that,it could be the case as i used a early flywheel on a late model engine. i will have to check this out.
can t give you any further advice on the noise but I can definately hear the sound of money leaving your pocket :-(
thanks md your guess was correct!
the noise was hard to detect were it was comming from but to my suprise it was both the timming chain and flywheel!
the timming chain was a bit loose from old age, will need replacing
when i took the engine out and took the flywheel housing off i took attention to the flywheel.
i could move the flywheel around without the crank moving, about 1mm either side of the bolts.
i didnt investigate as to why. but i put the original flywheel and bolts from that engine back on and all was good!
thanks for the help! :)
cheers, brad
hi sportiva.
thanks for the help
but problem is sorted.
now i have a problem with the shifter >:(
Brad
I removed the my last post when I realised you had it sorted and any suggestions I had were pointless
you and I must have been posting at the same time
I posted then read your post saying things were sorted then removed mine about 30 seconds later
It is good that noise issues are fixed
now what is the problem with the shifter