Noisy top end

[croker]

Hi Guys,
Can anyone suggest what may be the issue here in the video you can hear rattling on the r/h top end of the engine. Also, the r/h exhaust is smoking where as the left hand one isnt. So I am guessing valve clearances maybe? http://youtu.be/6BFzAyw48PU

[doublegarage]

Very hard to tell from the video. But a couple of thoughts:

- It sounds 'external" - not in the boewels of the engine but either inside the valve cover or possibly at the front of the engine on an "accessory" component like water pump or distributor.
- have you serviced the car - always worth doing first - so, valve clearances, timing, belt tensions, cam chain tensions etc.
- You could probably home in on the source with stethoscope, either homemade (eg long screwdriver) or a real automotive stethoscope (cheap and they work)

Please follow up and tell us how you get along.

-Richard

[croker]

So I checked the chain tension and valve clearances today. The chains were slack. The r/h chain when moved up and down turned the outlet camshaft.
I think I have corrected the tensions. The left hand one didnt move the camshafts at all but was noticeably slack.
Reading the service manual, it states measure the deflection of the chain. Is this the TOTAL movement or just pulling up from where the chain sits (you can push it down as well as up). I adjusted them to 7mm movement upwards from static (not pushing down then up) I didnt have a 44 lb spring balance so I judged it by hand
Then I checked the valve clearances with the following results..
cyl in out
1 .12 .35
2 .11 .40
3 .11 .27
4 .25 .35
5 .15 .30
6 .15 .40

Cylinder 3 was the lower compression cylinder.

What do you make of this?

[croker]

further checking and i find the timing marks on the 1-3 cyl cams like this

and on 4-6 like this

Timing mark on the pulley on the 3-4 pointer.

So, How do I correct this? Can I slacken the chains and remove the cams and sprockets to realign the markings??? I loosened the tensioner to its minimum but it doesnt seem to slacken the chains enough so do I have to undo the camshaft caps?
I have never worked on a 4 cam engine with chains so a step by step guide would be really appreciated.

[The Dutch Dino]

Your valve clearances are off. The should be 0,2mm+/-0,05mm and 0,4mm+/-0,05mm for a fiat 2400 dino.

Did your cams look worn? If not, adjust the clearance.
And if your chains were very loose, they can hit the cam covers. Check if the cam covers do not have markings on the inside from the chains. That might cause a nasty rattle also...

[Dario]

Hi, it's not difficult but takes some patience. I did mine a couple of times like this, but maybe there is a better way. A good description can also be found on the shop manual for the 246 engine, and also on the yahoo dino group
-Place the engine on TDC PM 3-4. Make a note of where the distributer is oriented. Release tension on chain, hold camshaft with vicegrips and undo bolt holding the sprocket. The lock tab washer must be replaced. I stuff a big rag down the engine to avoid things dropping in. Remove the metal dowels holding the sprocket (they are threaded for our convenience) and remove the sprockets. At this point, you can also remove the camshafts and replace the valve shims.
-Work on each side one at a time. Make sure the engine is in TDC and turn the camshafts with the markings lined up. Vicegrips work nicely to turn them and hold them in place. Place the chain over the sprockets and push them onto the camshafts. Tension the chain by hand and check to see if there is a hole on the sprocket that lines up with one on the camshaft. If there is, the one on at 180° will line up also. If you are lucky, and both camshafts line up, then push the dowels in and hand-tighten the bolts after mounting the lock washers. At this point, I tension the chain and rotate the crankshaft by hand a couple of times to make sure the marks line up correctly. If they dont, undo the bolts, remove the dowels and look for another hole. You should be able to get them perfect.
-Holding the camshaft with the vicegrips, I tighten the bolts to 80ft.lb and bend the tab on the lock washer.
-Do the other cylinder bank, replace distributer. If engine fails to start, distributer may be 180° off. Remember that the notches on the camshaft driving the distributer are 90° off from the distributer due to the coupler. I had to put some silicone oil sealant behind the lock washer to prevent oil from pushing through into the distributer but that may have been my mistake in misplacing the o-ring.
I would preventively order a couple of extra tab washers, the oil seal to the distributer, and a couple of studs for the camshafts if you decide to remove them. They strip easily if you over tighten the nuts. Also, depending on your chain tensioners, you may with to pre-load them (if you can) by pushing back on the tensioner and looking it down. Then, when you are ready to tighten the belt, just release it slowly and it will spring to place.

Good luck,
Dario

[croker]

Thanks Dario, that really helps. Great step by step... Unfortunately, the previous person to mess with the cams didnt use a new tab washer and on the first tap with a screwdriver it snapped off and fell into the engine!! So now I dare not turn the engine. I have tried fishing with a magnet but no sign of it.
So I guess I will be stripping the engine?!

[The Dutch Dino]

Oh oh... I think w've all drop something somewhere sometime...
Judging by your valve clearance, compression, misaligned cams, it may not be a bad idea to pull the engine. Which is not that difficult if you have an engine lift.
And refurbish that engine a bit, clean the carbs while you are in there. Etc.
Keep us posted and enjoy the wrenching.

[Dario]

Bad news! Did you drain the oil? I would try to drain the oil and then pour it down where the chain is, while wiggling it, a few times. With two pans, you can drain and pour until maybe it comes out with the fluid. Did you try to look down to see if you can spot the piece?

Good luck!

[Barnfind]

Hello.

What about this little fellow? Is there anything that can be done with it? Looks like another tensioner, but I have found no literature about it..

I have chain noise. I have tensioned the chains. They were not too slack, by the way, so I'm wondering if this "thing" also plays a role.

Thanks..