Should I proactively replace my stock alternator at 200K miles?

CBR.worm

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'06 Infiniti G35 w/ 200K miles. I am resealing the timing cover and replacing the water pump and associated parts for the first time, due to a small oil leak at the bottom edge - it's not dripping yet, but it is getting the front of the motor grimy and I'm sure it will get worse. While I have the alternator off, should I replace it with a new OEM one?

While the alternator is off the car, it would be very easy to replace. This car isn't worth much, but it is fun and in good shape. I plan to drive it until something catastrophic happens, or until it becomes unreliable. I'm replacing the idler pulleys, the radiator, and other pieces that I had to remove to get the timing cover off, also the primary timing chain, chain guides, crank sprocket, tensioner, and gallery gaskets. I read so many horror stories on the internet about the VQ35 tensioner and guide issues and gallery gaskets, but I have no visible wear on anything other than the crank sprocket. No signs of impending doom. I've got the new OEM parts, so I'm going to put them on.

I expect to do a couple of cross-country trips this summer, and while I don't want the car to ever leave me stranded, it would be worse if I was thousands of miles from home. I don't expect the OEM alternator to fail in the next 10 or 20K miles, but it might and I would prefer to not have to touch the serp. belt-driven components again for a long time.

I don't know what the lifespan on these is. It is a Mitsubishi branded alternator. I would think that I have probably used up most of its life, but I really don't know. The mechanical parts on this car seem to last forever.
 
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Some of the logic in a vehicle "thinks" engine is running when alternator is providing output. If yours happen to be one of that vehicle some system will take the down the engine aka cut the spark/fuel when alternator stops providing output.
 
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Some of the logic in a vehicle "thinks" engine is running when alternator is providing output. If yours happen to be one of that vehicle some system will take the down the engine aka cut the spark/fuel when alternator stops providing output.
I've never seen that before. That would be extremely stupid engineering.
 
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The regulator failed during one of the moves early in my career. We were towing a U-haul trailer with my '65 Comet at the time. We were driving at night and my battery was pretty old, though likely fully charged.

After about an hour the headlights were getting a bit dim. So we stopped at a closed roadside garage. That was in the days when garages repaired cars and the mechanics left for the night. I thought I might need a boost to get going again in the morning but planned to continue my trip (we were about about 100 miles from home). We slept in the car.

Shortly after dawn, the car started just fine and the regulator immediately when into "overdrive" so I turned on all the electrical loads to hold the charging back a little. I thought of bonking the regulator with a wrench but suspected it would go into "off" again so I drove it home and replaced the regulator that afternoon.

Oh for the good old days of unreliable cars.
 
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Near the beach in Delaware
'06 Infiniti G35 w/ 200K miles. I am resealing the timing cover and replacing the water pump and associated parts for the first time, due to a small oil leak at the bottom edge - it's not dripping yet, but it is getting the front of the motor grimy and I'm sure it will get worse. While I have the alternator off, should I replace it with a new OEM one?

While the alternator is off the car, it would be very easy to replace. This car isn't worth much, but it is fun and in good shape. I plan to drive it until something catastrophic happens, or until it becomes unreliable. I'm replacing the idler pulleys, the radiator, and other pieces that I had to remove to get the timing cover off, also the primary timing chain, chain guides, crank sprocket, tensioner, and gallery gaskets. I read so many horror stories on the internet about the VQ35 tensioner and guide issues and gallery gaskets, but I have no visible wear on anything other than the crank sprocket. No signs of impending doom. I've got the new OEM parts, so I'm going to put them on.

I expect to do a couple of cross-country trips this summer, and while I don't want the car to ever leave me stranded, it would be worse if I was thousands of miles from home. I don't expect the OEM alternator to fail in the next 10 or 20K miles, but it might and I would prefer to not have to touch the serp. belt-driven components again for a long time.

I don't know what the lifespan on these is. It is a Mitsubishi branded alternator. I would think that I have probably used up most of its life, but I really don't know. The mechanical parts on this car seem to last forever.
Bring it to a rebuild shop and ask them to replace any worn parts.
 
Joined
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ottawa
'06 Infiniti G35 w/ 200K miles. I am resealing the timing cover and replacing the water pump and associated parts for the first time, due to a small oil leak at the bottom edge - it's not dripping yet, but it is getting the front of the motor grimy and I'm sure it will get worse. While I have the alternator off, should I replace it with a new OEM one?

While the alternator is off the car, it would be very easy to replace. This car isn't worth much, but it is fun and in good shape. I plan to drive it until something catastrophic happens, or until it becomes unreliable. I'm replacing the idler pulleys, the radiator, and other pieces that I had to remove to get the timing cover off, also the primary timing chain, chain guides, crank sprocket, tensioner, and gallery gaskets. I read so many horror stories on the internet about the VQ35 tensioner and guide issues and gallery gaskets, but I have no visible wear on anything other than the crank sprocket. No signs of impending doom. I've got the new OEM parts, so I'm going to put them on.

I expect to do a couple of cross-country trips this summer, and while I don't want the car to ever leave me stranded, it would be worse if I was thousands of miles from home. I don't expect the OEM alternator to fail in the next 10 or 20K miles, but it might and I would prefer to not have to touch the serp. belt-driven components again for a long time.

I don't know what the lifespan on these is. It is a Mitsubishi branded alternator. I would think that I have probably used up most of its life, but I really don't know. The mechanical parts on this car seem to last forever.
If you do get one....get a rebuilt by denso.
Good as a new one.
 
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