Peugeot vclic engine noise

[cypriot]

Hi all,

This is my first post. I read and learn too many things in this forum up to now.


I recently bought non runner (non starter) 2008 Peugeot Vclic EV 50cc scooter.

Mechanic diagonised and told that cylinder and piston need change because of damaged cylinder wall and piston.

I chose good quality 47mm piston 80cc bbk for replacement.

Mechanic also replaced all vacum and fuel houses, new cdi, new inlet, new performance filter instead of stock airbag and filter.

Anyway it is now easily start without having any trouble.

It has good engine power also.

But there is a noise coming from engine mechanic told that it is crankshaft rod bearing (conrod big end bearing) faulty.

As I know valve gaps adjusted .003 or .004 (not sure)

I have short video of running engine please advise to me what is the cause or whiçi parts I should check before taking apart engine for replace crankshaft.



youtube.com/shorts/O2kBoss3uBU?feature=share


Thanx in advance for your help

[GrumpyUnk]

Given how poor YT audio is in PC speakers, the engine sounds fine to me. If it does have rod bearing problems, it will likely get worse, but you will hear it. I would use 15W40 in the crankcase, personal choice being a diesel rated as it has additives removed from auto oils. (ZDDP) The valves will tap a bit, and that's what I heard.
tom

[cypriot]

Dec 26, 2021 8:00:42 GMT -5 GrumpyUnk said:

Given how poor YT audio is in PC speakers, the engine sounds fine to me. If it does have rod bearing problems, it will likely get worse, but you will hear it. I would use 15W40 in the crankcase, personal choice being a diesel rated as it has additives removed from auto oils. (ZDDP) The valves will tap a bit, and that's what I heard.
tom

Hello Tom,

Thank you for your reply.

After bbk install mechanic erkek put 10w 40 engine oil.

I suspect it might need second gasket between cylinder and crank case.

On Tuesday I will have time to visit mechanicer garage.
I insisted noise caused by not proper adjusted valves or worn valve quides or piston and cylinder head clerance.

he told that he will dissassembly valve cover to prove me that ticking sound not from valves.

I think if it was faulty big end rod noise should be more like "knock" but not "tick"
Like in my bike video.

Btw if big end bearing faulty he should noticed it while he install 47mm / 80cc bbk.

If he didnt noticed or he noticed and not told me before it is his fault.


I dont think that he noticed faulty big end bearing and didnt told me.

What do you advise to check before taking apart engine?

Cypriot

[jloi]

could it be possible wrist pin noise. I agree with knock for rod noise. I don't hear anything on u tube either. what does noise do with rpm increase ?

[cypriot]

Hello,

I just watched boatian bt49 (vclic clone) video which has only 5 kmh or miles on clock and it has the same or very similar noise. Watch espacially after 3:30 seconds which guy started scooter with kick start.

I dont think


I think on Tuesday I should focus on check with mechanicer ;

1- valve adjustments,
2- piston cylinder head clerance, conrod bearing gap, wrist pin.

I hope it will be something easy and cheap.


Cheers

Cypriot

[cypriot]

youtu.be/dLTgiH7puNY

Here is a link of boatian

[GrumpyUnk]

My thought is a big end bearing failure would have more of a 'rap' sound than I heard. What I heard was normal valve clearance tappy-tap. It likely will increase as the engine warms up. The cast iron cylinder will not expand as much with temperature change as will the cylinder head. The head carrying the rockers and cam will expand more than the cylinder, increasing valve clearance as the engine warms. In theory any way.
I bet if you get the engine to full operating temperature, it will be a bit louder with the valve clearance noise.
If the crankshaft bearings are failing, it will make noises that you cannot ignore. Connecting rod 'big end' bearings or the actual crankshaft bearings will all make nasty sounding noises when they start to fail. Once they start, it is a cascade of damage. There is not enough room between the inner race, the ball and the outer race to allow for any particles of metal to get in there without causing damage. The damage messes with the race surface, raising bits and lowering(maybe) other bits, the raised ones causing MORE damage as they try to rolll the damage out of the way. Very similar to the way dirt roads will get sections of 'ribs' with depressions in between, due to the reaction of vehicle tires to a pot hole, which will launch out of a pothole, raise a bit higher than normal, and then come down hard on some spot after the hole, bounce up again, and come down a bit further on, rinse repeat, and you get 'washboard roads'.
tom

[cypriot]

Dec 27, 2021 9:55:13 GMT -5 GrumpyUnk said:

My thought is a big end bearing failure would have more of a 'rap' sound than I heard. What I heard was normal valve clearance tappy-tap. It likely will increase as the engine warms up. The cast iron cylinder will not expand as much with temperature change as will the cylinder head. The head carrying the rockers and cam will expand more than the cylinder, increasing valve clearance as the engine warms. In theory any way.
I bet if you get the engine to full operating temperature, it will be a bit louder with the valve clearance noise.
If the crankshaft bearings are failing, it will make noises that you cannot ignore. Connecting rod 'big end' bearings or the actual crankshaft bearings will all make nasty sounding noises when they start to fail. Once they start, it is a cascade of damage. There is not enough room between the inner race, the ball and the outer race to allow for any particles of metal to get in there without causing damage. The damage messes with the race surface, raising bits and lowering(maybe) other bits, the raised ones causing MORE damage as they try to rolll the damage out of the way. Very similar to the way dirt roads will get sections of 'ribs' with depressions in between, due to the reaction of vehicle tires to a pot hole, which will launch out of a pothole, raise a bit higher than normal, and then come down hard on some spot after the hole, bounce up again, and come down a bit further on, rinse repeat, and you get 'washboard roads'.
tom

Hello,

Thanx for your reply.

I think first try adjust valves 0.003 again when engine cold.

Then 0.002 if ticking noise not stop.

If still there is a ticking noise I think I should add second gasket between cylinder and crank case in order to have little more clearance between piston - cylinder head or valves.


What do you advise to me?


Cypriot

[cypriot]

Good morning mates,

I just came back from mechanicer.

My scooter running very quite. He adjusted valves before I went there.

As I understand he tried to convince me that crankshaft need replacing because big end bearing damage and get more money from me.

Because I insisted noise is caused by valveş he adjusted them without waiting me visit his shop.

Anyway I will only pay for new spark plug and carburetor enricher (old one not working as it should, it was to slow to closed extra fuel.

Anyway I will get scooter this afternoon and wait fairings to paint and install them on motorbike.

Thanx for your help.

[GrumpyUnk]

Lots loess costly than a crankshaft replacement... Hope it works well.
tom