General tick tick timing slip

[manic_monkey]

Well, i finally the engine put back together and she started first time! so thanks to everyone for their advice and help

but then.... the engine started making a ticking noise, like noisey tappets. so i turned it off, and went and had a look around. the timing had slipped out by about 4 teeth! I rotated the engine about 8 times after tensioning the belt and the timing kept coming back ok, so im at a loss to how it happened.

Was the tapping likely to have been the valves? I guess this is going to be expensive?

 

[id12586]

What a pity mate

You've probably bent some valves
And yes. Will cost... :bang:

 

[jug]

4 teeth is asking for trouble, but you may be lucky. yes the ticking was the pistons hitting the valves, but it does not mean the valves have been bent. get the timing sorted, and then try again. if it then runs ok but the power sems down, do a compression test. if compression seems low it means the valves have been damaged enough to lose compression, and you should sell it to some poor sucker. fingers crossed it wont come to that and you'll be lucky.

but whats just as important is figuring out how it could slip 4 teeth. when trying to find out what happened it helps if you can say one cam was put out (meaning it slipped on a cam) or both were out (meaning it slipped on the crank). also did you check the tension after it slipped? did the belt seem to have gotten looser?

 

[manic_monkey]

Cheers Jug. Will give it a check over as soon as i can and try an find out where the slippage is. The engine seemed to slow just before i shut it off, so im fearing the worse . Dont suppose you know what psi reading i should be getting when testing the compression?

EDIT: Im an idiot. I turned the crank to align the cams, and the cams were fine, but it seems to be out on the crankshaft by 1, maybe 1.5 teeth. belt tension was the same, but the belt has moved to the edge of the pulley.

I think it might be time to call in the proffesionals

 

[jug]

i'd loosen off the tensioner, slip the belt round the crank pulley back where it should be, and then tension again. if the timing was only about by a couple of teeth it cant have caused any valve damage.

 

[manic_monkey]

well, i found what caused the timing slip. it appears that putting the car in gear, doesnt stop the crank moving. This confuses me as on my old clio, it would lock the crank tight. Anyway, if the crank wasnt locked off, pulling the belt to tension it must've moved the crank.

But i still havent found a way to lock the crank in position while i tension the belt. Help!

 

[jug]

if you stick it in 5th and have the handbrake on then the crankshaft can still move a bit, so you need to have a mark made so you can check once the belt is on. but the better way to do it is to jam a screwdriver in the flywheel teeth. personally i just stick it in 5th and use a tippex mark to check, but it only takes a minute to jam a screwdriver in the flywheel so do that if you prefer.

 

[manic_monkey]

well, i got it timed up, and it appears to be staying in time after a couple of minutes running.

I checked the compression, and cylinders 1-3 came back at 150psi, and cylinder 4 was 180psi!! doesnt seem good to me. could it maybe be an excess of oil in cylinder 4? ( i oiled the bores while rebuilding the engine. )

oh, and i still got a llittle tapping sound. it doesnt seem to be fast enough to be valve contact ( i reckon its somewhere around 120 - 150 bpm). i thought initially it might be a tappet, but i thought they were hydraulic and didnt make that sound?

 

[jug]

oil in a cylinder can increase compression (this is how you test for ring leak), but only if the cylinder is already losing compression. a heathy cylinder wont see any benefit from the oil since it is already sealing sufficiently. however it is expected than an engine with a good few miles will in fact be losing compression on all cylinders, so maybe your test result is simply due to oil increasing compression.

i would take it for a good drive to let oil get circulated around the engine, that should stop the tapping if it is just a dry tappet (hydraulic tappets will be noisey when dry).

the compression test may also show more even results after more use of the engine. although even if it tests the same again, i wouldnt worry about it, at least its even enough to run fine.

go give it an italian tune up and see how it performs

 

[manic_monkey]

Cheers Jug. Thanks for all this help by the way, its been invaluable
and i might finally have my car back on the road! (then i can stop driving this 1.2 clio )

Only thing bothering me now, is that the engine seems to labour a bit and slow by a couple of hundred rpm after running for a few minutes. i dont remember if it used to do it before the head gasket failure though.

 

[jug]

you mean the idle rpm drops as it warms up? if so thats normal, on a cold start it should hit 1100-1600rpm depending on temperature, but once warmed up it should drop down to approx 850rpm and be stable at that rpm.

 

[manic_monkey]

you mean the idle rpm drops as it warms up? if so thats normal, on a cold start it should hit 1100-1600rpm depending on temperature, but once warmed up it should drop down to approx 850rpm and be stable at that rpm.

thank god for that! I though it might've been part of the ECU resetting process, but most of the engines ive worked on in the past have been 2 stroke motorbikes, so im real paranoid about seizures.