sump thread helicoil wreakage in 1HZ ............... new helicoil or oversized plug?

[garfield83]

Hi all,

recently my 1HZ started to leak oil from the sump plug such that I had to put a bin underneath (probably about 50ml per day). Having experienced a decrease in resistance when tightening the sump plug during recent oil changes, I took out the plug and drained the oil. Then I saw something coily in the sump hole and started to mug around with a screwdriver. After a while a pulled out a long coil (5 cm) which I guess was a helicoil from a previous repair (I bought the vehicle second hand).

After taking the coil out current sump hole diameter is 13.35 mm, the diameter of the original sump plug is 11.8 mm.

Now the question is whether I can/should simply put in a new helicoil without further enlarging the hole. Or would it be better to re-thread the sump hole for an oversized plug ........... probably >14mm. I am uncertain about the latter not knowing how much usable metal is around the sump hole thread. The engine is 1HZ, model year 1993. The plan is to leave the sump on the engine while doing the repair ........ which may rule out re-threading because of impossible exact drilling.

Any suggestions/experience???

Thank you.

Cheers

 

[roscoFJ73]

Have you priced another sump? Not exactly hard to get these days used.

 

[garfield83]

Hi,

The engine sits in a Coaster, so a pita to get it out. Also no hoist/ramp available. Thus try to avoid taking the sump out.

 

[doug720]

Kits are available to install oversize drains plugs.

Google Search

 

[roscoFJ73]

Now the question is whether I can/should simply put in a new helicoil without further enlarging the hole

I think this would be the best. You will have to avoid overtightening, maybe add some tape to help it seal. If it fails, go the next size up. The usable metal is about 2mm on the sump I have in my shed

 

[roscoFJ73]

Inside sump pic. I guess they would have used 1mm each side for the existing helicoil?