bent connecting rods

OmanDriver · Dec 14, 2016

Hi everyone,
Hope you're all having a very great time,
Guys, I need I help. I own clio RS 197, It was running perfectly, I took it for normal service at the dealership, when I took it back there were some knocks from the engine. Long story short, they open the engine and found one connecting rod is bend.
The technicians says it can't bend for no reason even though it happens at their workshop.
So, my question is, what is the reason for a connecting rod to bent? I've done 100K KM on the car, all service on time at the dealership, I drove 1600 KM before taking it to the service and it was running perfectly with no any noise.
How long does it take the rods to bend? they're trying to convince me that the rods " begin " to bend long time and when the received the car after doing the normal service it totally bend and knocks started. is it possible ?

Discussion is going on about that's who's fault and who should fix it.
Please advise.

One more question, which oil is recommended for Clio RS 197 ? is it similar to all other Renault cars ? because they said they are using the same oil for all cars

Budgie · Dec 14, 2016

Did the service include cambelt change?

If not, and all they did was an oil change etc, then it's one of those things unfortunately and they can't really be held responsible. If they did the cambelt, i'd say you've got a case in blaming them...,

Con rods don't bend over time IMO, there is normally a quick reason they bend. Either the pistons have hit the valves( in which case they would bend too), or water has got in and water doesn't compress like air/fuel.

Jonz · Dec 14, 2016

Budgie has it spot on, rods won't bent over time, they bend instantly as a result of a major failure such as pistons hitting valves due to cambelt failure or improper fitting.

197. · Dec 14, 2016

What's the condition of the valves and head like? If they're fine, it sounds like a case of liquid making it's way into the combustion chamber

dynodan · Dec 14, 2016

Rods only really bend through seeing too much pressure, on NA engine's this is nearly always due to water entering the cylinder OR incorrect valve timing.

If the valves have contacted the during a in-correct cambelt change, then it will only usually be 1 cylinder that affected and there will be signs of damage to the valves on that cylinder too.

Most other circumstances happen at high RPM/load and result in broken rods/valves/pistons.

OmanDriver · Dec 14, 2016

Budgie said:
Did the service include cambelt change?

If not, and all they did was an oil change etc, then it's one of those things unfortunately and they can't really be held responsible. If they did the cambelt, i'd say you've got a case in blaming them...,

Con rods don't bend over time IMO, there is normally a quick reason they bend. Either the pistons have hit the valves( in which case they would bend too), or water has got in and water doesn't compress like air/fuel.

No, just normal service. I replaced the cambelt on 80K service
not sure what happened all what I know is the car was running perfectly until I took it for service and it came back with a bent connecting rod

OmanDriver · Dec 14, 2016

Jonz said:
Budgie has it spot on, rods won't bent over time, they bend instantly as a result of a major failure such as pistons hitting valves due to cambelt failure or improper fitting.

What could it be happened ? What if Renault symbol engine oil used in the Clio 197 RS, can it bent the rods ?

bloke · Dec 14, 2016

something dodgy, rod won't just bend. time to kick up a fuss.

MicKPM · Dec 14, 2016

Wow!

So the car went in for a service without issue and it came out with a knocking which was diagnosed as "bent conrods"?

Something really not right there and you really should seek a second opinion IMHO. Have you physically seen the rods yourself and confirmed that they are indeed "bent"? I don't trust people at all with this kind of thing and It is stupidly hard to bend one of these components - even a piston/valve collision at 7krpm would struggle to effect deck height.

OmanDriver · Dec 14, 2016

MicKPM said:
Wow!

So the car went in for a service without issue and it came out with a knocking which was diagnosed as "bent conrods"?

Something really not right there and you really should seek a second opinion IMHO. Have you physically seen the rods yourself and confirmed that they are indeed "bent"? I don't trust people at all with this kind of thing and It is stupidly hard to bend one of these components - even a piston/valve collision at 7krpm would struggle to effect deck height.

exactly my dear friend,
I've seen physically seen the rods myself and confirmed one of them is bend.
They've also cleaned the injectors? Is there any possibility that "careless" cleaning injectors could bend the rods ?

STEVE.M · Dec 14, 2016

OmanDriver said:
exactly my dear friend,
I've seen physically seen the rods myself and confirmed one of them is bend.
They've also cleaned the injectors? Is there any possibility that "careless" cleaning injectors could bend the rods ?

Are pistons & rods removed from engine,or still assembled in the block with one piston not at the same height at TDC?
Does the top of the piston with the bent rod have a clean washed look to it,with no physical damage?
You have not mentioned how long the car was with the garage,when it was by date & how long you have owned the car.

OmanDriver · Dec 14, 2016

STEVE.M said:
Are pistons & rods removed from engine,or still assembled in the block with one piston not at the same height at TDC?
Does the top of the piston with the bent rod have a clean washed look to it,with no physical damage?
You have not mentioned how long the car was with the garage,when it was by date & how long you have owned the car.

I wasn't at the workshop, I was on the workshop office, so I didn't see the engine but the rod shown to be damaged. The bent rod is clean with no physical damage.
I own the car since March/2016, I was done 78K km by that time. on 80K service I've replaced all the cambelt and brake pads and well full serivce at the dealership, the car has full history at the dealership nothing done at local workshop
the car was there from last week sunday ( sunday is a working day in my country ) 4th Dec, knock noticed on Tuesday 6th, engine open yesterday 13th December

npt · Dec 14, 2016

I'd guess someone's had the car out a test drive, and driven it very hard resulting in rod failure I'm afraid

197. · Dec 14, 2016

npt said:
I'd guess someone's had the car out a test drive, and driven it very hard resulting in rod failure I'm afraid

Must be more to it than that I reckon, although completely plausible as these are known for weak conrods

bloke · Dec 14, 2016

i've never heard of a rod just bend, look at it logically, it couldn't.

STEVE.M · Dec 14, 2016

OmanDriver said:
I wasn't at the workshop, I was on the workshop office, so I didn't see the engine but the rod shown to be damaged. The bent rod is clean with no physical damage.
I own the car since March/2016, I was done 78K km by that time. on 80K service I've replaced all the cambelt and brake pads and well full serivce at the dealership, the car has full history at the dealership nothing done at local workshop
the car was there from last week sunday ( sunday is a working day in my country ) 4th Dec, knock noticed on Tuesday 6th, engine open yesterday 13th December

I`m sorry,but your reply is clear as mud.Please have another go.
I was working towards frost damage,but as you live in Oman,probably not,current overnight temp 50 degrees F.
Did you rersolve your gearbox issue?

OmanDriver · Dec 15, 2016

STEVE.M said:
I`m sorry,but your reply is clear as mud.Please have another go.
I was working towards frost damage,but as you live in Oman,probably not,current overnight temp 50 degrees F.
Did you rersolve your gearbox issue?

I live in Oman, temp 50 degree C.
Yes I resolved my gearbox issue at 80K service at the dealership

I took a photo of the bent rod

bloke · Dec 15, 2016

No way has that 'just happened' what's the piston crown like?

I'd be looking for who to beat to death with that if it was me.

Budgie · Dec 15, 2016

bloke said:
No way has that 'just happened' what's the piston crown like?

I'd be looking for who to beat to death with that if it was me.

In the Middle East, that's a valid customer service technique.

dann2707 · Dec 15, 2016

No one picked up on the injector cleaning bit?

Totally depends on how they were cleaned. If they've been removed and water/fuel has dribbled into the inlet then that aughta do the damage.

I'd be asking how they've cleaned them.

... · Dec 15, 2016

Having seen many bent rods in race engines that has impacted something at high RPM , the piston and valves on that cylinder are likely toast as well unless it did the head gasket and dumped a shed load of water in

thats had a huge load through it , so either water(hydraulic damage) and piston would look fine or the piston is toast

OmanDriver · Dec 15, 2016

dann2707 said:
No one picked up on the injector cleaning bit?

Totally depends on how they were cleaned. If they've been removed and water/fuel has dribbled into the inlet then that aughta do the damage.

I'd be asking how they've cleaned them.

It could be, I've done research about cleaning injectors but couldn't really find something that could help to use it against the dealership.
can you please share some links ?

bloke · Dec 15, 2016

dann2707 said:
No one picked up on the injector cleaning bit?

Totally depends on how they were cleaned. If they've been removed and water/fuel has dribbled into the inlet then that aughta do the damage.

I'd be asking how they've cleaned them.

takes more than fuel dribbling in to hydraulic an engine.

STEVE.M · Dec 15, 2016

OmanDriver said:
I live in Oman, temp 50 degree C.
Yes I resolved my gearbox issue at 80K service at the dealership

I took a photo of the bent rod

Would you have believed this was from your engine if they handed it to you?

It`s actually from a VW that suffered head gasket failure.Notice how the piston crown has been washed.
You need to see the rest of your engine,and identify it as YOUR engine.
Thinking in a different direction,were the plugs replaced or removed and gaps adjusted?
The head could have been full of oil,or if the engine was pressure washed,water.
I`m actually surprised they would strip out the block,as opposed to just remove the head and see the pistons were at different levels at TDC.

Travelman868 · Dec 17, 2016

OmanDriver said:
Hi everyone,
Hope you're all having a very great time,
Guys, I need I help. I own clio RS 197, It was running perfectly, I took it for normal service at the dealership, when I took it back there were some knocks from the engine. Long story short, they open the engine and found one connecting rod is bend.
The technicians says it can't bend for no reason even though it happens at their workshop.
So, my question is, what is the reason for a connecting rod to bent? I've done 100K KM on the car, all service on time at the dealership, I drove 1600 KM before taking it to the service and it was running perfectly with no any noise.
How long does it take the rods to bend? they're trying to convince me that the rods " begin " to bend long time and when the received the car after doing the normal service it totally bend and knocks started. is it possible ?

Discussion is going on about that's who's fault and who should fix it.
Please advise.

One more question, which oil is recommended for Clio RS 197 ? is it similar to all other Renault cars ? because they said they are using the same oil for all cars

If it's the cambelt then there would be damage to piston and properly the head as well. It is NOT wear that bent a con rod, that's impossible and they do not wear over time.
I would write to the garage and see if they will put that in writing.

SKIDDERWOLF · Dec 17, 2016

I bend a rod in my Alfa 156 after stupidly :grimacing: driving through deep water, The first picture looks very much like my con rod did after I took the engine apart. After stripping and replacing the big end bearings and changing the cam belt the engine ran again but as others have said on here there must be considerable force being transmitted to achieve the bend.

STEVE.M · Dec 17, 2016

OP has gone AWOL.

STEVE.M · Dec 17, 2016

SKIDDERWOLF said:
I bend a rod in my Alfa 156 after stupidly :grimacing: driving through deep water, The first picture looks very much like my con rod did after I took the engine apart. After stripping and replacing the big end bearings and changing the cam belt the engine ran again but as others have said on here there must be considerable force being transmitted to achieve the bend.

I`m not sure I would trust a crankshaft once this had happened.

SKIDDERWOLF · Dec 18, 2016

I drove the car for another year before it failed its not for rust and sold for spares. As the car was not worth much it was worth a try. Don't think I would be doing it again .

... · Dec 18, 2016

STEVE.M said:
I`m not sure I would trust a crankshaft once this had happened.

Having snapped a stock zetec crank I would not be worried on a road car.
It takes alot to do it .

The next one was billet to make sure I didn't do it again

bloke · Dec 18, 2016

STEVE.M said:
I`m not sure I would trust a crankshaft once this had happened.

you'd kill the gearbox waaaaaaaaay before the crank.

NorthloopCup · Dec 18, 2016

bloke said:
you'd kill the gearbox waaaaaaaaay before the crank.

Lies. They're indestructible! 😂

I've got a bent rod out of a 13ltr at work. I'll have to upload a pic of that bad boy!

bloke · Dec 18, 2016

NorthloopCup said:
Lies. They're indestructible! 😂

I've got a bent rod out of a 13ltr at work. I'll have to upload a pic of that bad boy!

just remembered you're commercial aren't you? give me mo, you might appreciate vid of old detroit v8 two stroke i found ages ago...

NorthloopCup · Dec 18, 2016

bloke said:
just remembered you're commercial aren't you? give me mo, you might appreciate vid of old detroit v8 two stroke i found ages ago...

Yes mate I am. From the same stables as Guy Martin too.

bloke · Dec 18, 2016

NorthloopCup said:
Yes mate I am. From the same stables as Guy Martin too.

eh? so you're goofy and bit on the ugly side as well:tonguewink:

NorthloopCup · Dec 18, 2016

bloke said:
eh? so you're goofy and bit on the ugly side as well:tonguewink:

No, I'm a good looking guy with a great haircut, but I originate from the same area as Guy, work on the same stuff as him and also share his work ethic. Maybe you could try the latter? Flol! 😂

bloke · Dec 18, 2016

NorthloopCup said:
No, I'm a good looking guy with a great haircut, but I originate from the same area as Guy, work on the same stuff as him and also share his work ethic. Maybe you could try the latter? Flol! 😂

i heard young children scream when you smile at them, is that true?

you should appreciate this, it's one of those clips you just end up loving, the accents, body filler, foul language, roar of the engine and copious amounts of easy start go so well together...

(got it wrong sorry, was a commer knocker)

STEVE.M · Dec 18, 2016

bloke said:
eh? so you're goofy and bit on the ugly side as well:tonguewink:

Dumb all over & a litle bit ugly on the side.
:smile::smile::smile:

NorthloopCup · Dec 19, 2016

bloke said:
i heard young children scream when you smile at them, is that true?

you should appreciate this, it's one of those clips you just end up loving, the accents, body filler, foul language, roar of the engine and copious amounts of easy start go so well together...

(got it wrong sorry, was a commer knocker)

Well my little girl doesn't so I'm going to say you've been fed misinformation. Lol!

That video is hilarious as well!!

bent connecting rods

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