General Conroe change fiat Ducato

[Steady1234]

have a fiat Ducato 2012 and we believe it needs a piston and con rod
Just one ,
Engine is out , can the piston be fitted from the bottom? I know usually you would fit it from the top, but we are pretty sure this is the issue and it just needs a piston and rod , if we are correct and the bore is good don’t see the point off removing all the cams and head and all the other bits , any advice would be appreciated thanks

 

[brokendonkey]

are you just planning on sticking the piston in with the old rings fitted?

 

[Steady1234]

are you just planning on sticking the piston in with the old rings fitted?

Was going to buy a piston with Conrod I assume it will come with rings , vehicle has only done 19000

 

[bugsymike]

I would say very unlikely with modern engines.
Even if it were possible, when a piston and new rings are fitted it is foolish not to check the gaps are correct before spacing the rings correctly and sliding the piston in the bore using a ring compressor to prevent broken rings.
What makes you sure it is only the piston?

 

[Steady1234]

I would say very unlikely with modern engines.
Even if it were possible, when a piston and new rings are fitted it is foolish not to check the gaps are correct before spacing the rings correctly and sliding the piston in the bore using a ring compressor to prevent broken rings.
What makes you sure it is only the piston?

Engine had an injector out , a lot of water got into the engine when it sat with injector out , into that bore , the guy tried to start it and it hydro locked, I have taken it on I would assume conrod is slightly bent? The van runs spot on no misfire, runs and drives lovely but has a loud tapping noise, difficult but it does seem to come from that area, as long as there’s no damage to bore or rings I could put the original rings on , thanks for your replies so far

 

[Kahcorp]

The bottom of the bore is cast with no machining which creates the problem of getting the ring compression tool to seat properly. You could give it a go but you must have a plan B as you will probably be going down the correct route to engine rebuilding.
You should be able to purchase an individual ring set. Here I purchase individual 1 piston ring set x 4, 6 or 8

 

[Steady1234]

The bottom of the bore is cast with no machining which creates the problem of getting the ring compression tool to seat properly. You could give it a go but you must have a plan B as you will probably be going down the correct route to engine rebuilding.
You should be able to purchase an individual ring set. Here I purchase individual 1 piston ring set x 4, 6 or 8

If I buy a conrod and piston complete it should come with the rings I? Would you fit this as it is or would you fit the rings off the original piston, ?

 

[Kahcorp]

If it's new it won't come with rings. If used then probably with rings so just go with it. Make sure the ring grooves are very clean. Oil ring is easy to remove off a used piston the other two not so easy if you are not experienced.
There is a good chance you will break the rings. If you have a look at the oil ring (3rd ring) you will see it is in 3 pieces. The thin pieces are what will get you if you get the other two rings in.
You will also have to be inventive with the compression tool as there is not much room with crank in the way.
I have never tried to do this so it's just my experience rebuilding the correct way that is giving me thoughts on the issues you may come up against.

 

[bugsymike]

The last engine I was able to fit pistons from the bottom with cylinder head still on a Wartburg Knight three cylinder two stroke with the bottom of the bores tappered to allow them to enter without ring compressors. It also involved all three pistons attached to the conrods and crankshaft at the same time so a lot of care was required.
I honestly think the correct way with yours is head off and fit the pistons from the top, apart from anything else you may find the knock/noise is from the top end, possibly a damaged valve stuck in a guide or hydraulic tappet etc.
Thinking about it, if it had a hydraulic lock on that cylinder it could quite possibly rammed the valve back up against it's hydraulic tappet/cam follower causing it to fail. Many modern diesels break the valve gear first with 16 valve twin cam engines.
With the head off you can measure the piston height compared with it's partner which would show if con rod is bent.
On the earlier 2.5 and 2.8 Sofim engines if a cam belt failed the valves on at least one piston would come in contact and definately bend the con rod, also given the design of the bottom end there was no way the pistons could be fitted from underneath, which I suspect you will find with your later engine, although my knowledge of rebuilding the Sofims finished at the 2.8s.

 

[Steady1234]

The last engine I was able to fit pistons from the bottom with cylinder head still on a Wartburg Knight three cylinder two stroke with the bottom of the bores tappered to allow them to enter without ring compressors. It also involved all three pistons attached to the conrods and crankshaft at the same time so a lot of care was required.
I honestly think the correct way with yours is head off and fit the pistons from the top, apart from anything else you may find the knock/noise is from the top end, possibly a damaged valve stuck in a guide or hydraulic tappet etc.
Thinking about it, if it had a hydraulic lock on that cylinder it could quite possibly rammed the valve back up against it's hydraulic tappet/cam follower causing it to fail. Many modern diesels break the valve gear first with 16 valve twin cam engines.
With the head off you can measure the piston height compared with it's partner which would show if con rod is bent.
On the earlier 2.5 and 2.8 Sofim engines if a cam belt failed the valves on at least one piston would come in contact and definately bend the con rod, also given the design of the bottom end there was no way the pistons could be fitted from underneath, which I suspect you will find with your later engine, although my knowledge of rebuilding the Sofims finished at the 2.8s.

The last engine I was able to fit pistons from the bottom with cylinder head still on a Wartburg Knight three cylinder two stroke with the bottom of the bores tappered to allow them to enter without ring compressors. It also involved all three pistons attached to the conrods and crankshaft at the same time so a lot of care was required.
I honestly think the correct way with yours is head off and fit the pistons from the top, apart from anything else you may find the knock/noise is from the top end, possibly a damaged valve stuck in a guide or hydraulic tappet etc.
Thinking about it, if it had a hydraulic lock on that cylinder it could quite possibly rammed the valve back up against it's hydraulic tappet/cam follower causing it to fail. Many modern diesels break the valve gear first with 16 valve twin cam engines.
With the head off you can measure the piston height compared with it's partner which would show if con rod is bent.
On the earlier 2.5 and 2.8 Sofim engines if a cam belt failed the valves on at least one piston would come in contact and definately bend the con rod, also given the design of the bottom end there was no way the pistons could be fitted from underneath, which I suspect you will find with your later engine, although my knowledge of rebuilding the Sofims finished at the 2.8s.

Hi bugsymike, I the valve or cam follower I’d damaged will it be apparent, I don’t know where this knock is coming from I’m just assuming it is a rod or piston, I suppose the first thing to do would be to get the cam cover off to see if anything can be seen?

 

[jackwhoo]

You cannot fit piston from below

 

[brokendonkey]

use the rings off the piston you are taking out.

if its the 2.3 like this one,
link
it looks like you will get away with sticking it all in from the bottom if you take the main girdle off and the crank out,
lube the bore and your new piston assembly up with some thick gearbox oil and clamp it with the compressor then tap it in with the handle of your mallet.
pistons often have a mark or a dot etc.. indicating which way is forward.

id probably strip it down one day then leave it till the next to fit it back up so all the oil can dribble out, saves it going on your face. LOL.

 

[jackwhoo]

Engine had an injector out , a lot of water got into the engine when it sat with injector out , into that bore , the guy tried to start it and it hydro locked, I have taken it on I would assume conrod is slightly bent? The van runs spot on no misfire, runs and drives lovely but has a loud tapping noise, difficult but it does seem to come from that area, as long as there’s no damage to bore or rings I could put the original rings on , thanks for your replies so far

If it had been hydrolocked before attempted start the starter motor would not have been able to rotate the engine.
I do not believe the starter motor powerful enough to bend a Conrod.

Your best option is head off if you want to check and check bore for corrosion-that would be my major concern

 

[brokendonkey]

if its already out of the van, then stand it upside down and take the sump off and have a look and a measure.

 

[bugsymike]

Hi bugsymike, I the valve or cam follower I’d damaged will it be apparent, I don’t know where this knock is coming from I’m just assuming it is a rod or piston, I suppose the first thing to do would be to get the cam cover off to see if anything can be seen?

With the cam covers off you may see a valve with excessive clearance or something else that doesn't look right, that's the route I would take.