Johnny G Pipe

Lately the old girl is moving around more at idle, just a mild but clearly noticeable side-to-side shimmy.
I've also had a problem with hunting idle in cold wet weather for a while, and I'm pretty sure she isnt pulling as strong at low revs. High revs she still pulls as hard as ever. Maybe a few more pops than ususal from the G pipe too. Hmm..
Does this suggest anything in particular to anyone? The engine has never been out, so she has all her original factory features.. so maybe its just shagged 20 year old car syndrome..

I was wondering if it was time to replace the good ole ignition leads, but I thought ignition problems more likely to show at high revs when the system is under strain?

Thanks in advance..

boxsey911

Mine produced a fair old shimmy at idle in the middle of last year. It was straight after I had taken one side of the inlet manifold off. As it hadn't done it before I decided that must be the cause so stripped it down again, re-seated it and took extra that all the hose clamps were tightened up. The shimmy disappeared.

Although mine had a clear cause to the event it still might be worth you spending 10 minutes going round all the inlet hose clamps and tightening them up.

crg53

It sounds to me like you have 1 cylinder that is not firing at idle, could be electrical or fuel; if you are getting more pops from the exhaust than normal, that would be unburned fuel in the exhaust system being ignited.
When was your spark plugs and wires last replaced?

springer3

Check the compression. Billions are wasted every year trying to get poor running cars to improve, when the underlying cause is a bad cylinder. You might as well get the bad news before spending a lot of money on ignition and fuel system parts. If the compression is OK, the problem will be easy to find and fix.

Oracle

The shimmy was solved when I replaced the motor mounts as the engine was hanging...

911Jetta

Like Oracle said, check to see how much sag you have with your motor mounts...

Johnny G Pipe

Thanks folks,
Maybe I am running on 5 at idle, but I would have thought that scenario would make it run rougher than it is. A non car person would never notice the shimmy, just my sensitive buttocks..

I'll have a look for a how-to for compression testing, as I suspect it wont be that easy! I guess the lower spark plugs are the easiest to access with the tester. This is when we curse the boxer layout..

How much engine mount sag is normal? I'd wondered about engine mounts, but there wasnt anything linking mounts to shimmy on a search.

Indycam

A compression test is easy . I would do the top plugs . You can get the top plugs out without much work vs the bottom plugs .
I would try and find the suspect cylinder before doing a full compression test .
Disable the spark to one cylinder at a time and see if you can find the suspect cylinder .

Is your motor running on one or the other spark ?

hawk911

I thought maybe you had put a smokin V8 in the car and not remembered

newsboy

You could do a check on the drive belt for your secondary distributor.