camshaft - repeating problem - clio 172 ph1

[mortster]

Hi,

had my 172 ph1 from new back in 2001, had most of the usual problems, but this particularly problem seems to re-occur

at 20k miles (in 2003) the cam lobe cracked on the inlet camshaft (cylinder 3), a new camshaft was installed by renault dealer (walker, stourbridge), they couldn't really explain it, although they did mention oil pressure, seemingly pointing the finger at me for running car low on oil, but this has never happened, i check the electronic meter, and the dipstick regularly, tbh the car has never needed any oil topups, and i always change oil every 6k miles.

fast forward to 2009 (44k miles) and the same thing happened, got a local independent guy to do the work (ex. renault tech) and it was the inlet camshaft again, cracked lobe on cylinder 3. So had a new camshaft in again ! he cannot explain why it's re-occurred either (i was running the car on fully synth silkolene 5-40 (the stuff everyone recommends)) - he reckons he checked all the valves, and valve tops, and all checks out ok, he also 'pressed' out the tappets for me, oiled them etc..

He reckons renault had a faulty batch of camshafts, but as far as i can tell, no-one else in the cliosport club has had this same problem, so whilst i would like to believe this explanation (perhaps the new camshaft is better quality!) i don't think it's the right one.

Any ideas guys ? it's a shame as my 172 is mint, having had it from new i've always kept her in tip top condition, i'd hate it to happen again...

Recently i've connected an rstuner to the car, and no faults are showing, only ones in memory where injector 4 fault, and air con link fault, but these are not 'present' errors, and i presume they might be logged from when guy was doing camshaft work recently.

Please any advice would be great

 

[mortster]

 

[Fred@BTM]

jesus i've not seen that on an F4R before!

i have however seen a 60K mile engine that was 15valve from new!

 

[Alastair.]

wow thats a first

 

[mortster]

jesus i've not seen that on an F4R before!

i have however seen a 60K mile engine that was 15valve from new!

any ideas fred, what might be causing it ?

 

[Fred@BTM]

the cam lobes are pressed on, that looks like a heat treatment problem when the cam was manufactured - so your dodgy batch thing rings true

are you replacing it with a NEW cam or a 2nd hand part?

 

[mortster]

a new cam, the thing i noticied though is that the part no. has changed from when i got a new cam back in 2003,

the part no. in 2003 was 7700115267
the part no. we just put in was 8200032853

perhaps just a normal renault numbering change, if u get a chance fred could you check those numbers out for me ?

 

[Fred@BTM]

i'll have a nose now

2nd hand cams go for peanuts, like £30 a pair

 

[mortster]

thanks fred, this camshaft set me back £270 !! if i knew for sure it was badly manufactured then next time (if it happens again lol!) i will change over to some better aftermarket cams i think.

 

[Fred@BTM]

inlet cam - 7700115267
exhaust cam - 8200032853


catcams 420's are stock cams (in simple terms) made from billet (aka 1 piece)

 

[mortster]

that's odd, really odd, as i'm sure the mechanic said it was the same camshaft as before... Fred, can I tell by looking at the faulty part he removed if it's inlet or exhaust ?

 

[Fred@BTM]

yep, inlet cam has 4 small holes and one large hole in one end, exhaust is solid (should have a stud sticking out the end)

 

[K-Tec Racing]

were all the followers and lifters checked,

it looks like 1 valve is pressing hard on the lobe causing fatigue

are the bearings blued around it?

have the installed length of the valves been checked?



Andy

 

[mortster]

ok fred, here's a photo of my fault camshaft, both ends, and a top down view of the cam, is the crack lob on cylinder 3 ?

is this an inlet or exhaust camshaft ?

something doesnt seem to add up here, with what the mechanic has told me.

 

[Fred@BTM]

eh? how can 1 valve press hard on the lobe?


that's an exhaust cam

 

[K-Tec Racing]

if the valve spring went coil bound etc...

 

[mortster]

thanks for all the advice guys, rang the mechanic, and it was the exhaust cam shaft he changed, only link to the problem in 2003 was it being on the same cylinder, no 3.

so at 20k miles my car had new inlet camshaft, and at 44k miles it's now had a new exhaust camshaft. Perhaps this does point to a problem with the manufacturing of the original camshafts on the car then (it's a Y plate 2001).

Will keep you posted, it runs like a dream now

 

[mortster]

were all the followers and lifters checked,

it looks like 1 valve is pressing hard on the lobe causing fatigue

are the bearings blued around it?

have the installed length of the valves been checked?



Andy

he reckons the valves were checked, and all ok.

no blue colouring on the camshaft at all.

i just hope to god the camshafts in early mk1 cars had a problem

 

[K-Tec Racing]

thanks for all the advice guys, rang the mechanic, and it was the exhaust cam shaft he changed, only link to the problem in 2003 was it being on the same cylinder, no 3.

so at 20k miles my car had new inlet camshaft, and at 44k miles it's now had a new exhaust camshaft. Perhaps this does point to a problem with the manufacturing of the original camshafts on the car then (it's a Y plate 2001).

Will keep you posted, it runs like a dream now

not something we have heard of but very usefull info never the less

if you need anymore help please let me know

Andy

 

[mortster]

Thanks Andy

 

[Chrisjk]

i just hope to god the camshafts in early mk1 cars had a problem

I don't! Mine is one of the 1st ph1 (w reg) and from what i can make out has never had a problem like this.

 

[Andyman]

Is that not a lot of wear where the cam sits in the journal for a car on 44k?

Reason i mention, had my re-grinds removed due to wear and where the cams sit in the journals looked the same as that where by on another set of stock cams i have on 60k they look un-grooved and mint.

Possible oil starve due to blocked oil well, knock on result heat build up thus cracked it?

Just a guess

 

[mortster]

Is that not a lot of wear where the cam sits in the journal for a car on 44k?

Reason i mention, had my re-grinds removed due to wear and where the cams sit in the journals looked the same as that where by on another set of stock cams i have on 60k they look un-grooved and mint.

Possible oil starve due to blocked oil well, knock on result heat build up thus cracked it?

Just a guess

the cam does seem quite well grooved where it sits in the journals, it's certainly not smooth. how would you go about diagnosing a blocked oil well ? how could it be fixed ?

whilst i'm happy to sit here with rose tinted spectacles, hoping for a problem with the fabrication of the original cams, i do have this nagging feeling that something else is causing the issue.

 

[mortster]

taking another look at the camshaft, the area where it sits in the journals for both cylinder 2 and 3 is more worn than 1 and 4 (far left, far right), you cant feel any grooves at all there, but for the other 2 there is scoring which you can feel when you run your nail along it.... does this point to anything ?

 

[mortster]

I don't! Mine is one of the 1st ph1 (w reg) and from what i can make out has never had a problem like this.

I know, sorry didnt mean it to come out like that
trust me, if you had the problem you'd know about it, farmer giles time.

 

[stan*]

Looks like a manufacturing fault to me.

If there had been any wiping/coil bound issues you usually see on the lobe where they have picked up.

Odd, never seen this before.

 

[mortster]

all the lobes themselves are smooth and look fine, no pitting or scoring or any noticeable wear etc, also no blueness anywhere, so i do think they are getting well lubricated, done a bit of googling today, and everything seems to point to poor heat treatment of the original camshafts in my car....

 

[Fred@BTM]

that looks like a heat treatment problem when the cam was manufactured

glad i paid attention in metallurgy lessons

 

[mortster]

glad i paid attention in metallurgy lessons

blimey all they taught us at school was maths, geography and french !

 

[mikekean]

How did you come to notice there was an issue with the car for the mechanic to diagnose the crack came lobe?

Ive just encountered the same issue on my car and my was making a tapping noise which sounded like a faulty tappet, is this the noise you had aswell?

Thanks

Mike.