Engine Overheating
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Busman36
- Posts: 5
- Joined: Sat Jul 26, 2014 11:46 am
Engine Overheating
My 73 thing is overheating after driving it a short while. Is there anyway to check the cooling fan and belt without having to remove the engine?
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Busman36
- Posts: 5
- Joined: Sat Jul 26, 2014 11:46 am
Re: Engine Overheating
It gets so hot that you can't leave your hand on the hood release handle for more than a few seconds. That can't be normal.
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Marc
- Moderator
- Posts: 23741
- Joined: Thu May 23, 2002 12:01 am
Re: Engine Overheating
You can grope the fan (engine off) to see if it's blocked by a rag or paper towel left in the engine compartment. That will make a characteristic whirring/roaring sound at higher RPM.
The standard belt for a 12V Beetle is a 9.5x905La, which is fine for their 30A generator. It's inadequate for a 50A or larger alternator, and will slip causing overheating - a glazed appearance on the flanks of the belt is visual indication this is happening - which is why alternator-equipped cars should use the 11.3x912La belt.
Things come with a 38A generator. IMO they too should use the larger belt, so if you go shopping for a replacement get the 11.3x912. It fits fine with the same pulleys.
On the subject of pulleys, the 38A generator is longer and requires a different fan hub, sheetmetal, and pulley to squeeze it into the space allotted for the 30A. It's unique in that the half closest to the generator is made of cast iron...and it's also obsolete. If a "normal" generator/alternator pulley is fitted to a 38A generator the belt will be misaligned. Not by enough to cause it to be thrown, but it will wear unevenly and be more prone to slippage. If you have this problem and can't locate a cast pulley, the alternative is to remove the crank pulley and put spacer rings of the appropriate thickness over the crank to move the pulley back in line with the generator. http://www.cbperformance.com/ProductDet ... tCode=1915
Chromed pulleys are a bad idea, belt slippage is more of a problem with those.
The standard belt for a 12V Beetle is a 9.5x905La, which is fine for their 30A generator. It's inadequate for a 50A or larger alternator, and will slip causing overheating - a glazed appearance on the flanks of the belt is visual indication this is happening - which is why alternator-equipped cars should use the 11.3x912La belt.
Things come with a 38A generator. IMO they too should use the larger belt, so if you go shopping for a replacement get the 11.3x912. It fits fine with the same pulleys.
On the subject of pulleys, the 38A generator is longer and requires a different fan hub, sheetmetal, and pulley to squeeze it into the space allotted for the 30A. It's unique in that the half closest to the generator is made of cast iron...and it's also obsolete. If a "normal" generator/alternator pulley is fitted to a 38A generator the belt will be misaligned. Not by enough to cause it to be thrown, but it will wear unevenly and be more prone to slippage. If you have this problem and can't locate a cast pulley, the alternative is to remove the crank pulley and put spacer rings of the appropriate thickness over the crank to move the pulley back in line with the generator. http://www.cbperformance.com/ProductDet ... tCode=1915
Chromed pulleys are a bad idea, belt slippage is more of a problem with those.