Vibration at idle

[English_Mike]

I have a '88 5.0 that has an annoying 'vibration' at idle which can be felt through the bodywork. I have replaced plugs, leads, dizzy cap, rotor arm, starter coil, all to no avail. I do also think that the motor lacks power - not dramatically, but noticeable to me.

I am stuck for clues here in England and I will get conned by our mechanics over here!

Any help greatly appreciated!

[pearce9906]

check out to damper pulley (harmonic balancer), they tend to spin apart or start seperating. This puts one helluva vibration in the car. Check it out and make sure it looks normal. Good luck, let us know how it turns out.

[goodyear1984]

does the engine rum like crap? does the vibration get worse when u rev it up>?

[English_Mike]

Originally Posted by goodyear1984

does the engine rum like crap? does the vibration get worse when u rev it up>?

The vibration doesn't get worse above idle, but I have noticed a reduction in power and a mis-fire when pulling hard through the gears during gear changes.
I will check the harmonic balancer as our previous friends advice (when I can find out where it is! No workshop manuals here worth a damn!!).
The motor always fires up first turn.

[pearce9906]

The harmonic balancer is the big pulley on the front of the crankshaft. Do you think the vibration is coming from the motor (i.e. the front of the car) or could it be coming from the rear or midsection of the car, I've known of the exhaust laying against the unibody chassis and vibrating the crap out of it during idle.

[English_Mike]

Thanks for the advice my friend.

The vibration is most definately from the front end, so checking the harmonic balancer will be my first port of call at the weekend!

[English_Mike]

Originally Posted by pearce9906

The harmonic balancer is the big pulley on the front of the crankshaft. Do you think the vibration is coming from the motor (i.e. the front of the car) or could it be coming from the rear or midsection of the car, I've known of the exhaust laying against the unibody chassis and vibrating the crap out of it during idle.

I have checked the harmonic balancer and all looks fine.

However, I have found a earthing strap hanging from the firewall which has a washered end on it which looks like it should be attached to something like the bell housing!
I did have a new clutch fitted and wonder if the guys forgot to re-attach it.
Could this be the problem?
Where should it attach?

[mpj76]

Not sure how a ground strap would cause vibrations like you describe. How did you check the balancer? It is the solid piece BEHIND the pulley. Just wondering. Checking the little bolts for tightness wouldn't be good enough. Those dampers are actually two pieces with a rubber piece sandwiched between. That rubber can break down over time with heat and chemical exposure. Especially if you have a power steering leak. Also check tightness of fan to pulley bolts. Any loosness there will rapidly destroy your water pump as well. Sometimes an aging belt run accessory such as alternator or smog pump will start annoying vibrations. A quick test is to remove the belt and see if the vibration is still there. Do this for a short time only so you don't overheat the engine as the water pump won't be spinning. At least that will help you pinpoint it. Bearings going out in the distributor will also cause vibration.