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My alternator belt failed this afternoon while driving in the heat. I had spare belts, but was only about ten miles from home and figured I would try to go for it. I turned off the A/C and the fan to lessen the drain off the battery. The car ran fine. In fact, better than fine. I made it home fine.
I've noticed during the last few months that the car tends to back off somewhat noticeably when I take my foot off the accelerator. Haven't had time to consider what the cause may be.
Funny thing is that with the alternator not drawing off the engine the car did not back off but coasted SMOOTH when I pulled off the gas. Funny huh? It might be my imagination, but I don't think so.
1994 944 266k miles Regina
fuel pressure?
failing alternator?
normal?
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When you lost the belt you also lost the efffective load of the A/C also and the electrical loads of everything else. I'll bet the shut down of the A/C was the biggest power saver. When I had the diesel I really knew it when the A/C was running!!!!!
--
'96 965, 16' wheels, Michelin Pilot Sports, rear 18mm bar + Koni, 204HP cams, 126K. Put 200K on '85 745 TD.
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I only lost the alternator belt.
Running the fan off the battery, the A/C was poor (?).
I shut the A/C down and cut the fan.
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The point I didn't make clear was my thought that shutting down the A/C was your biggest load reduction. With the belt back on, see if you get similar results when you shut the A/C and fan off.
--
'96 965, 16' wheels, Michelin Pilot Sports, rear 18mm bar + Koni, 204HP cams, 126K. Put 200K on '85 745 TD.
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Thanks, I read you. I understand your point.
The funny thing about this simple failure was the whole experience of realizing the alternator belt failed.
All of the sudden the car ran very smooth and effortless, and when I glanced down at the instruments the status lights were all glaring at me. I knew it was an alternator belt, and wished that I had a analog meter that showed whether it was charging properly. When I backed off the accelerator to slow down and check under the hood, the car did not 'lurch' back the way it normally does, but smoothly deccelerated. I figured the alternator must take a lot off, and that maybe it was an indication my alternator was at the end of it's useful life and causing an abnormal amount of load to charge the battery. The pulley on the alternator spins freely and quietly with no play in the shaft.
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Hi
With the A/C off, it would make a difference. Belts are not a real efficient means of transfer, with friction losses.
Gets you wondering how you could trim little losses and maybe add up to something measurable. Synthetic Engine oil is supposed to be a start, as is Synthetic Auto Fluid. Is there a synthetic lower friction diff lube?
I suspect that tweaking wheel bearings would have to make a difference, as well as caliper slides to ensure brakes don't drag. I even read that polishing the car makes a difference to drag. What about U-joints?
An alternator with new bushes certainly runs smoother. Whether it's worth the money to have them changed regularly is the question.
regards
Alan
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Alan Clarke, Australia
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I'm thinking Redline makes a synthetic differential lube ---check their stuff at www.Redline.com
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"V" belts do have inefficiencies. The flat serpentine belts used on the newer cars are pretty good. The flat toothed belt used for driving the cams was/is the most efficient system available.
--
'96 965, 16' wheels, Michelin Pilot Sports, rear 18mm bar + Koni, 204HP cams, 126K. Put 200K on '85 745 TD.
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Dear Hovonogila,
Good p.m. At 266K miles, the alternator could show some wear. When were the bushings last changed?
When was the last time, you changed the crank pulley?
If these parts are worn, the face of the alternator and crank pulleys may not be parallel with the face of the engine block. That could accelerate belt wear and/or put a strain on the alternator's bearings.
Fuel pressure should be 43 pounds/square inch.
These Volvos are not very aerodynamic, so speed "bleeds-off" quickly, when you take your foot from the accelerator. I happen to like this, as it minimizes the need to use the brakes. Think of it as "air braking".
Yours faithfully,
spook
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The bushings were changed with aftermarket last year and it appears they are holding up.
The crank pulley is ORIGINAL.
The faces appear parallel with each other. Not perfect, but very close.
I like my "flying refridgerator". That's the comment a friend used to describe my white sedan.
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Dear Hovonogila,
Good a.m. and hope this finds you well. To be sure your crank pulley is in good working order, take some white-out (correction fluid) and draw a line from the inside of the pulley (near the crank bolt head) out to the edge of the inner hub. From there, continue the line across the flat face of the pulley, to the edge.
Drive the car for 15 minutes. If the section of the line on the pulley face is still "connected" to the section of the line inside the pulley hub, the pulley is fine. If the line sections are not "connected" - if the line on the pulley face is, say, 30 degrees of arc away from the hub section line - then the pulley has failed.
The rubber insert in these pulleys will fail, as a result of heat and oxidation. When that happens, the outer section will start to turn around the inner section.
The pulley no longer transmits energy from the crankshaft to the accessories.
Eventually, the pulley will fail completely: the sections may actually separate.
Hope this helps.
Yours faithfully,
spook
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