Zetec Rattle

[nelmo]

Jees, never heard of stretch bolts - I don't think they are as the Haynes manual doesn't mention them and it doesn't even say they have to be replaced. Considering they're about £50 a set (£80 for ARP), I'm very glad of it...

[brumster]

A quick search does indeed suggest they are stretch bolts :

 

https://workshop-manuals.com/ford/focus_1999_08.1998-12.2004/mechanical_repairs/3_powertrain/303_engine/303-01b_engine_1.6l_zetec-e_(zetec)-1.8l_zetec-e_(zetec)-2.0l_zetec-e_(zetec)/description_and_operation/diagnosis_and_testing/general_procedures/in-vehicle_repair/removal/disassembly/assembly/engine/

 

With stretch bolts it is sometimes possible to re-use them (ARP are like this) but you need to specifically measure how much the bolt has stretched from original spec, and adjust the tightening procedure to compensate. ARP give you the details for this; Ford don't (which probably means don't reuse). Coupled with what you are describing, I really wouldn't risk it. These puppies really do take a hammering. It's one thing to do half-measure fixes on kit cars like "Oh, that wheel arch isn't on quite square but, pffft, I'll live with it" but with engines, I never cut corners, it usually not worth it in the mid to long term. Put some ARPs on it anyway, that way you have some reuse in the future (measure them before you install and keep a note)...

[nelmo]

Where does it say stretch bolts?

 

Although it does say use new ones, which the Haynes manual doesn't mention...

 

EDIT: ah, it seems the fact that the tightening process says 'torque + 90deg' means they are stretch bolts...jees, more expense...

Edited September 14, 2018 by nelmo

[brumster]

Nothing with engines is ever cheap if you're doing it right (14 valves down, head gasket, head bolts, timing belt, tensioner, new tensioner bolt because I don't trust the old one now, new cam cover gasket.... )

[Matt brown]

Just get the ARP ones not cheap but will also give you the option to rev upto nearly 8000rpm

[cb750]

If you use the ARP bolts you should use the ARP assembly lubricant and make sure the holes have enough chamfer to take the bolt head radius

[kevin the chicken]

They usually come with a sachet of lubricant and fitting instructions.

[nelmo]

If you use the ARP bolts you should use the ARP assembly lubricant and make sure the holes have enough chamfer to take the bolt head radius

Yeah, that's why i didn't bother - chamfering 8 holes would probably take me ages and it's taken me long enough to get this far.

 

Surely there would be other factors in allowing an engine to rev higher other than just these bolts?

[theduck]

Nope, oe bolts are the weak link. Assume rods are the next weak link in the chain but my understanding is, as matt mentions, they are ok for 8k rpm

[theduck]

Of course to make that worthwhile you need a cam that makes power at those revs...

[cb750]

None of my arp bolts came with the lubricant!

Edited September 16, 2018 by cb750

[theduck]

Thats not good, pretty sure they are meant to. All of mine certainly did.

[Matt brown]

Mine did to and deans

[nelmo]

I AM AN ENGINEERING GENIUS!!! Yup, it's official, I am the greatest mechanic in all of...er...my road.

 

Ok, sorry but I'm very excited - big end bearings replaced, car back together and, amazingly, it works! Rattle is gone, all is rosy (although I've only done a 10 mile road test so it could still go pear-shaped).

 

Apologies for getting so excited - for you guys, this is all in a weekends work - this was my Everest, well outside my comfort zone.

 

Many thanks for all your comments and advice...much appreciated.

[tractor]

well done Neil now you have delved into the depths of your engine and fixed the problem its not as difficult as some people think eh