No engine compression

[Scottyp172]

I have just fitted higher lift cams to my 2002 clio 172 and everything went well. It was running fine in the garage. I was replacing another couple of problems with car and when i completed these it was ready for road again. I started it and just as i was about to leave garage the car lost total engind compression?
Any ideas what could have happened anyone?

 

[MicKPM]

What exactly were these "Other couple of problems" that your corrected? Does it appear to 'spin' faster when trying to start it?

Personally, I think timing is the most likely issue and either the bottom sprocket or cam/dephaser pulleys are just spinning due to incorrect torque being applied to the bolts.

Mick

 

[Scottyp172]

The other problems were just inner cv boot and exhaust. Mechanic just Stripped engine back down and all 16 valves are bent and rockers are nackered! What could have been the cause of this? Whats my best option to do with it?

 

[Alex H]

Cambelt snapped? Fitted wrong?

 

[Fred@BTM]

incorrect fitment by the sound of it!

what cams did you fit? did you use all the correct torque settings AND the 3 reanult tools?

 

[mx1_champ]

probs span on one of the pulleys

 

[sideways danny]

probs span on ALL of the pulleys

EFA

 

[mx1_champ]

yeah thats more like it haha... crap design

 

[Scottyp172]

No belts have snapped, and yes correct tool was used. And was torqued correctly. So dont have a clue about what could have happened!

 

[Scottyp172]

It was piper cams that were fitted.

 

[Jonny1*2]

Belt failure maybe? Piper cams should be fine on standard internals. It's either the guy who did it, or renault that should foot the bill tbh. Parts come with a year garantee. Good luck proving it though :S

 

[bmh.01]

Pulley(s) slipped. Put money on it. New crank bolt and pulley nut/bolt used?

 

[Scottyp172]

No no new crank bolt and pulley nut/bolt used.
Have just bought new valves and rockers. Everything else seems to be ok.
Should i replace anything else?

 

[Alex H]

Should i replace anything else?

The garage you're using.

 

[bmh.01]

Fingers crossed the bottom end is ok too. Lack of new bolts is probably the cause if everything was done to spec, the crank pulley bolt is a stretch bolt 100% not sure about the others.

 

[Scottyp172]

Well the mechanic im using has just made his astra vxr to a stage 5 without a problem so i very much doubt it would b him! And he has 12 years of working for BMW aswell

 

[Scottyp172]

Yea everything has been stripped back down and the valves and Rockers were the Only things damaged

 

[sideways danny]

Fingers crossed the bottom end is ok too. Lack of new bolts is probably the cause if everything was done to spec, the crank pulley bolt is a stretch bolt 100% not sure about the others.

No, it's actually not a strecth bolt. A stretch bolt gets longer by design when torqued, the crank pulley bolt simply has a limitation on how much it's allowed to stretch and be re-used. I check the length on every bolt and it's rare to find one stretched. Infact most of the time i only have to replace them when the hex head is damaged/rounded from previous bodging

 

[bmh.01]

Well the mechanic im using has just made his astra vxr to a stage 5 without a problem so i very much doubt it would b him! And he has 12 years of working for BMW aswell

Both of which are designed nothing like a renault, he's already fell foul of mistake no.1 with the F4R.

 

[Scottyp172]

So what is he doing wrong?

 

[bmh.01]

You have to be careful with it as the crank, cams and their associated pulleys aren't keyed like a lot of other cars do its a floating setup. Which leaves you open to pulleys spinning if they haven't been tightened correctly or the bolts renewed, now i'm not pointed any fingers but its his mistake at the end of the day. Also the floating setup opens up the whole "issue" for potential timing issues.

The renault manual specifically states to renew all the fixings (barring the measure the crank bolt but brave imo to reuse full spot for the cost), if he's done everything else to the book then thats the only thing he's done "wrong" persay.

 

[bmh.01]

http://www.getflat.co.uk/3286A.pdf
http://www.getflat.co.uk/3200A.pdf

Don't know if he's already got these but he needs them if not.

 

[Hutchie]

i wouldnt care the crank is keywayed, why not put a woodruff key in like the diesels?

 

[mx1_champ]

i wouldnt care the crank is keywayed, why not put a woodruff key in like the diesels?

diesels use floating pulleys to

 

[Scottyp172]

Thanks for all your help folks,much appreciated. I shall let you know how i get on with it.

 

[MicKPM]

Because the way the timing belt run is tensioned requires for all sprockets to rotate freely. I liked the F7R method but when you've done a few F4R's and K4M's you soon get used to the way things are now.

 

[bmh.01]

i wouldnt care the crank is keywayed, why not put a woodruff key in like the diesels?

The 774 is keyed too, don't know about the 197/200?

Seeing as the S/C'd cars tend to slip crank pulleys without them got to wonder if Renault found them to slip on higher torque engines. Or whether its just down to the extra load of a rotrex.

 

[Fred@BTM]

So what is he doing wrong?

and yes correct tool was used

there's one problem, there's 3 tools in total

crank pin
cam "horseshoe"
cam pulley locking tool

 

[Fred@BTM]

Well the mechanic im using has just made his astra vxr to a stage 5 without a problem so i very much doubt it would b him! And he has 12 years of working for BMW aswell

doesn't matter if he's number 1 mechanic for Alonso, if he doesn't know about F4R engines there's a 95% chance he'll f**k it up - FACT

 

[Alastair.]

18mm crank pulley bolt should always be replaced, ive seen what happens if you dont

 

[bmh.01]

Because the way the timing belt run is tensioned requires for all sprockets to rotate freely. I liked the F7R method but when you've done a few F4R's and K4M's you soon get used to the way things are now.

You don't need them all to rotate though do you? As long as 2 of the 3 do then thats enough to equalise the tension in the belt. As said at least the megane engine is keyed on the crank, don't know how many more.

 

[Bassplayer]

The main problem with bottom pulleys is that they have to be tightened by degrees. Most people try to use a degree wheel, yuk! That is where I reckon the problems start. As for the F4R being so "unique" the ford Zetec cams aren't keyed either... amongst others.

 

[MicKPM]

You don't need them all to rotate though do you? As long as 2 of the 3 do then thats enough to equalise the tension in the belt. As said at least the megane engine is keyed on the crank, don't know how many more.

No you need them all to spin if you're doing the job properly as you are supposed to 'spin' the newly fitted setup 5 or 6 times in the direction of normal rotation to check the tensioner mark is bang on prior to final assembly and not moving all over the place.

 

[bmh.01]

Well how do you do that on a 774 with a keyed crank pulley? The tension should eqaualise as long as the cam pulleys are both floating, one fixed point shouldn't be a problem in my head.

 

[sophiesdad]

Well how do you do that on a 774 with a keyed crank pulley? The tension should eqaualise as long as the cam pulleys are both floating, one fixed point shouldn't be a problem in my head.

on these you lock everything up as though the job is complete , and rotate 2 full cycles , then recheck , and adjust if needed.

 

[GRitch]

So what is he doing wrong?

his job?