Alternator pulley gone missing!

[Pat]

Driving home today pulling 1.5 ton of trailer+horse and heard a bit of a bang under the front. Still driving fine, but shortly afterwards I noticed the battery & warning lights were on.

Only about 1.5km from home so I kept going. Right towards the end the temp gauge started going up and was around the 3/4 mark when I stopped.

A quick look showed the alternator pulley was missing off the shaft(!), the serpentine belt just flapping around, and audible bubbling noises. A small amount of coolant also visible but no obvious source.

So.... How the hell does the pulley just come off the alternator (the serpentine belt was replaced about a year ago, and I checked the pulley at the time).

And secondly, what damage am I likely to be looking at? Could the lack of coolant circulation mean I've cooked the engine/head in just a couple of km (albeit towing a trailer uphill)?

Not happy...

 

[Old.Tony]

In either the YD25 or V9X, the belt that drives the alternator also drives the coolant pump. Losing the pulley from the alternator causes the belt to no longer function, which means the coolant pump and fan stop.

Without a functioning coolant pump, there'll be very little flow through the radiator (convection might allow a small amount) and the block temperature will start rising dramatically, particularly with 1.5T behind you and even moreso that you're climbing a hill.

The engine needs to be looked at by a trusted mechanic. It's likely they'll do a pressure test on the coolant system to determine if there are any leaks in that, which might indicate a cracked head or damaged head gasket. You'll obviously need a new alternator unless you can nab a pulley from somewhere, but the shaft may have some damage as the pulley came free and may not be suitable for use on the car any more (but if you want to make yourself a 1500W wind turbine, you have the important bit right there).

It might even be solvable with a product like Chemweld or Liquid Copper. I was at the drive day after the Bathurst 6 Hour (this Monday just gone) and the owner of two of the Porsches they had there (who also owns one of the few Mosler racing cars in the world, plus "a few" sprint cars) told me about Liquid Copper and how he uses it in ALL of his cars. I haven't tried it, I've used K-Seal which then required me to replace the radiator and flush the coolant system, but he swears by the Liquid Copper product and another owner said he does it too (this guy only had a McLaren 720S, the poor bugger).

https://www.supercheapauto.com.au/p/rislone-rislone-liquid-copper-block-seal---510g/290751.html

 

[KwakaZX10R]

My wife's R51 Pathy had the same thing happen not long ago.....the pulley sheared off the thread from the alternator shaft! I found the pulley sitting on top of a cross member......thankfully my wife was not far from home when it happened.

Long story short, a new alternator was required and of course, being a Nissan, it was the most expensive alternator of the bunch.

I had a dude from Lube Mobile come out to do the work, rather than worry about a tow - he was awesome and did a great job!

 

[landmannnn]

I had a tow home when it happened to me.

 

[Pat]

Seems like a common problem that simply shouldn't occur if the alternator was designed properly!

So I now have a nice shiny new pulley which has been firmly attached with a rattle gun. Needless to say not from Nissan who wanted over NZD600 plus GST for the pulley alone...wtf!

After a precautionary bleed of the cooling system watching for a while before giving it a blast around some local hills all seems good. Temps are normal, no coolant loss, and holding pressure OK.

Will keep an eye on it, but hopefully I dodged a bullet this time. Next time I'll pull over straight away and the wife and her damn horse can walk home.

I dunno about chemweld etc, if I absolutely had to then yes, but I'd prefer not put it in my Nav (let alone my Porsche or McLaren)

 

[BarneyB]

In either the YD25 or V9X, the belt that drives the alternator also drives the coolant pump. Losing the pulley from the alternator causes the belt to no longer function, which means the coolant pump and fan stop.

Without a functioning coolant pump, there'll be very little flow through the radiator (convection might allow a small amount) and the block temperature will start rising dramatically, particularly with 1.5T behind you and even moreso that you're climbing a hill.

The engine needs to be looked at by a trusted mechanic. It's likely they'll do a pressure test on the coolant system to determine if there are any leaks in that, which might indicate a cracked head or damaged head gasket. You'll obviously need a new alternator unless you can nab a pulley from somewhere, but the shaft may have some damage as the pulley came free and may not be suitable for use on the car any more (but if you want to make yourself a 1500W wind turbine, you have the important bit right there).

It might even be solvable with a product like Chemweld or Liquid Copper. I was at the drive day after the Bathurst 6 Hour (this Monday just gone) and the owner of two of the Porsches they had there (who also owns one of the few Mosler racing cars in the world, plus "a few" sprint cars) told me about Liquid Copper and how he uses it in ALL of his cars. I haven't tried it, I've used K-Seal which then required me to replace the radiator and flush the coolant system, but he swears by the Liquid Copper product and another owner said he does it too (this guy only had a McLaren 720S, the poor bugger).

https://www.supercheapauto.com.au/p/rislone-rislone-liquid-copper-block-seal---510g/290751.html

So was Richey Rich saying he adds Liquid Copper to his vehicles as a precaution? Not as a temporary fix for a cracked head or blown gasket?
(Like adding an oil conditioner or a fuel stabiliser as part of routine maintenance....)

 

[Old.Tony]

So was Richey Rich saying he adds Liquid Copper to his vehicles as a precaution? Not as a temporary fix for a cracked head or blown gasket?
(Like adding an oil conditioner or a fuel stabiliser as part of routine maintenance....)

He adds it to the coolant as a precaution, and then races the vehicles. As in, on a race track. His Mosler is the one that burned up on the top of Mt Panorama at the 6 Hour event in 2018. He told me he's rebuilt the car, crashed it again, and it should be ready to go on the track again within the next week.

The amount of money these guys spend on vehicles is staggering.