Strange Occurance
03-11-10, 04:40 PM
#1
Strange Occurance
Ever since I bought my 88 NA convertible, it has had a bad vibration any time the engine revs between ~5,000 - 6,500 rpm.. between 6,500 and 7,000 rpm the vibration disappears however. I have driven the car for 30,000km like this, and it now has 97,000 km, so whatever the issue, it isn't causing any immediate harm.
Today I changed the Alt belt and the Air pump belt, and instead of re-installing the power steering belt, I figured I would go for a quick run without power steering to see what it was like in this car.
When i drove the car without the power steering operating, the vibration was gone!!(or minimized to the point I didnt notice it)
Does anybody have any idea what could be causing the vibration if it dissapears with less load on the front pulley?
Without the power steering attached, the engine revs much smoother and the engine feels a little happier lol (if that makes sense)
BTW if i decide to leave the car without P/S are there any concerns with continuing to use a rack that is normally used with P/S? I figure I will put the belt on every so often to make sure the system doesnt seize up or anything like that.
Thanks for looking.
Today I changed the Alt belt and the Air pump belt, and instead of re-installing the power steering belt, I figured I would go for a quick run without power steering to see what it was like in this car.
When i drove the car without the power steering operating, the vibration was gone!!(or minimized to the point I didnt notice it)
Does anybody have any idea what could be causing the vibration if it dissapears with less load on the front pulley?
Without the power steering attached, the engine revs much smoother and the engine feels a little happier lol (if that makes sense)
BTW if i decide to leave the car without P/S are there any concerns with continuing to use a rack that is normally used with P/S? I figure I will put the belt on every so often to make sure the system doesnt seize up or anything like that.
Thanks for looking.
03-11-10, 04:46 PM
#2
The P/S pulley or idler pulley could be bent, or the bearing could be going out in the pump. I've had a bad water pump cause similar problems (vibration at about 4-5k RPM, but no higher). Driving without the P/S belt on can work, but I don't think you really need to put the belt back on every now and then. The pump should be able to sit for a long while and not sieze up.
03-11-10, 04:55 PM
#3
RR88 thanks for the quick reply lol 6 minutes!
I 'eye check' the pulleys every time I open the hood lol.. they seem to be rotating fairly smooth.. no side to side movement or wobbling.. and I've replaced the idle pulley bearing recently.. maybe I should remove the pump and inspect the internals? or is taking it apart not the best idea?
I 'eye check' the pulleys every time I open the hood lol.. they seem to be rotating fairly smooth.. no side to side movement or wobbling.. and I've replaced the idle pulley bearing recently.. maybe I should remove the pump and inspect the internals? or is taking it apart not the best idea?
03-11-10, 05:05 PM
#4
You could, but I'll warn you that taking out the pump is not as easy as it looks. The hub underneath the pulley is usually REALLY on there, and breaking it loose it tough with the shaft spinning freely. I've swapped mine out with a reman unit, but I don't know easy it would be to just change the bearing.
If you can live without P/S, pull up a search for de-powering the steering rack. That might be another option if the pump is the problem.
If you can live without P/S, pull up a search for de-powering the steering rack. That might be another option if the pump is the problem.
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