Dreaded coolant reservoir leak... and then some...

[TideMD]

Recently noticed white residue on the outside of the engine coolant reservoir, so got a plan together for some maintenance work this weekend - replace the leaking tank, replace belts, throw a fresh filter in the Bend Calibration flex-fuel adapter, check catch can... then go have some driving fun.

Got the faulty coolant tank removed and found just a small amount of watery residue in the OCC. All was going well until I got to the point of swapping out the belts. Realized the standard procedure for releasing load from the water pump belt wouldn't work because of the VTT CBC device installed roughly a year ago. And thank goodness I decided to check down in the crank pulley.
Most of the 8 CBC/pulley bolts were noticeably loose with turning them by hand. So... tack on extra time to deal with that.

Removed the CBC and found that it was significantly worn at the face where the bolts/washers lock down. Also, all but 2 or 3 of the 8 CBC/pulley bolts were stretched enough to be obviously thinner diameter through the mid-portion of the bolt. Found some replacement bolts last minute around 9pm (after having my mind blown by a clerk at the local hardware store trying to tell me 5/16" bolts were "close enough to work, because we're out of that exact match"... not even exaggerating there).
Anyway, now it's time to get this stuff back together... hopefully!

[Mike.]

that looks like a sticky situation. Well I guess crusty now, but hell, at least you caught it now

[TopJimmy]

That's pretty gnarly…second one I've seen chewed. It seems that using loctite is a requirement for the CBC bolts since any looseness allows the washers or threads to chew into the aluminum plate.

At least your catch can looks normal. As it gets colder in the fall and winter I notice my catch is more watery than oily. E85 really cranks up the catch but 93 makes very little.

[mapster37]

looks like the cbc was severely over tightened

[Kilabyte]

Originally Posted by mapster37

looks like the cbc was severely over tightened

Or under. Looks like once the bolts got a bit loose the lock washers dug into the face because of vibration.

[TideMD]

Originally Posted by Kilabyte

Or under. Looks like once the bolts got a bit loose the lock washers dug into the face because of vibration.

Yeah, I'm not sure what the root cause is here. Installed the CBC myself and torqued each bolt to 25ft-lb, per VTT install specs. Went through the tightening sequence 3 times with torque wrench to verify each bolt. And used Loctite.

It's hard to see from the pics, but hands-on inspection of the CBC looks like it shifted clockwise over time with the washers digging in and the bolts coming to rest firmly against the leftward edge of each bolt slot.

It was rather shocking to find and then realize I've noticed no issues with the car recently. You would think the slightest play in the crank pulley would cause some noticeable vibration or noise.

[Silverlining_m2]

Originally Posted by TideMD

Recently noticed white residue on the outside of the engine coolant reservoir, so got a plan together for some maintenance work this weekend - replace the leaking tank, replace belts, throw a fresh filter in the Bend Calibration flex-fuel adapter, check catch can... then go have some driving fun.

Got the faulty coolant tank removed and found just a small amount of watery residue in the OCC. All was going well until I got to the point of swapping out the belts. Realized the standard procedure for releasing load from the water pump belt wouldn't work because of the VTT CBC device installed roughly a year ago. And thank goodness I decided to check down in the crank pulley.
Most of the 8 CBC/pulley bolts were noticeably loose with turning them by hand. So... tack on extra time to deal with that.

Removed the CBC and found that it was significantly worn at the face where the bolts/washers lock down. Also, all but 2 or 3 of the 8 CBC/pulley bolts were stretched enough to be obviously thinner diameter through the mid-portion of the bolt. Found some replacement bolts last minute around 9pm (after having my mind blown by a clerk at the local hardware store trying to tell me 5/16" bolts were "close enough to work, because we're out of that exact match"... not even exaggerating there).
Anyway, now it's time to get this stuff back together... hopefully!

This makes me not even want to install my cbc honestly.

[Info@mad-us.com]

Ouch. Time for pinned crank hub.