Cerbera 4.2 sump - Helicoil

[cruty]

Hi,

Could anybody tell me the size of the sump plug for a 1997 4.2 Cerbera. As the thread on my sump is past its best and have been advised to use a helicoil, but not to sure on the size.

Thanks in advance

[jensena]

I've heard that a Renault Sump plug is used when the thread has gone. I dont know which one, but this info may help point you in the right direction in your search.

[cruty]

cheers,
I'll see what I can find out.

[trackcar]

I drill and tap the old bolt to take an 8mm bolt through it, then threadlock the original bolt in the sum. Drain oil through the 8mm bolt and you never have thread problems again. Getting in to helicoil the old alloy sump thread is a right royal pain.

[cruty]

Cheers for that, but just to clarify you would drill and tap a new hole into the sump to accept an M8 bolt and for the old sump hole you would just seal it using the original bolt and threadlock.

If this is correct where would you drill - I have the later sump with the dip stick at the front of the engine.

thanks

[raceproved]

M16 if I remember correctly. Hope this helps.

[griff2be]

cruty said:

Cheers for that, but just to clarify you would drill and tap a new hole into the sump to accept an M8 bolt and for the old sump hole you would just seal it using the original bolt and threadlock.

If this is correct where would you drill - I have the later sump with the dip stick at the front of the engine.

thanks

I think what Joolz said was he would drill and tap the old sump plug to take an 8mm bolt in the centre, then threadlock the old plug back into its original hole. To drain the oil you remove the 8mm bolt

[trackcar]

griff2be said:

cruty said:

Cheers for that, but just to clarify you would drill and tap a new hole into the sump to accept an M8 bolt and for the old sump hole you would just seal it using the original bolt and threadlock.

If this is correct where would you drill - I have the later sump with the dip stick at the front of the engine.

thanks

I think what Joolz said was he would drill and tap the old sump plug to take an 8mm bolt in the centre, then threadlock the old plug back into its original hole. To drain the oil you remove the 8mm bolt

yup that's right.
Sadly the sump plug is right in line with the lower chassis rail so you have to drop that side of the engine to get in to take the next helicoil size up, with corresponding bolt .. if the original alloy thread / original heliciol is pulling through then you won't be able to just re-helicoil back into the same thread you'll have to drill up to the next size and re-helicoil that .. a right PITA.

[cruty]

Thanks for the reply's

At present the original thread is still intact, but is definitely starting to go as, as you can only tighten the bolt to the point where the oil is very very slowly weeping out. any tighter and the bolt will just spin. Therefore before I take the bolt out, I would of like to of ordered the correct helicoil size so I could do the job in one hit, but presently I'm not sure of what Helicoil size would be best to tap into the original thread - any ideas??

thanks again

[trackcar]

That possibly won't work .. chances are it's already helicoiled from the factory (most are), and the reason you can't tighten the bolt is because the existing helicoil is pulling out of the alloy sump. You'd need to drill out the existing hole to take the next size up, with corresponding bolt, that's the reason i threadlock teh bolt in place and do the 8mm bolt trick through the middle of it, it's 10 mins work as opposed to 4 hours.

[cruty]

OK, thanks for the info on the helicoil direct from the factory, I didn't know that. It does now make sense to go the 8mm way. Will have a go over the weekend.

Thanks for the help