Cause of loud shuddering/car shaking at tickover only?

[McTavish]

I've got a strange symptom that I can't diagnose.

When the car reaches operating temperature the car starts to shudder and knock at tickover, but slowly increasing the revs causes this to disappear.

Tickover varys only marginally vary whilst the shaking occurs

I thought maybe the targa panel was shaking in its frame but it feels more prevalent from the chassis, centre console and through the floor with intermitent knocking. All symptoms disappear when on the move.

I can't hear anything from outside the car but it is becoming more prevalent and concerning!

Anyone experienced similar or have ideas?

Edited by McTavish on Monday 10th December 22:41

[DavidY]

I'd agree with Quinny, but also check the gearbox mount

davidy

[Barreti]

Can you actually see if the engine mounts have gone - you can only see the top edge can't you. Is there a way to test them?

Asking on behalf of the OP really as I changed mine earlier this year.

[thenick]

Bit of a long shot but I had this problem a while back and discovered it to be my exhaust pipes resonating at operating temp idle (would die off above idle). I have some tail pipe extenders on so it would pronounce the effect and made the whole car shake which was a bit odd until I noiticed the pipes wobbling up and down when standing behind the car while it was idling. To fix it I just tightened up the rear hanger a bit and replaced the rubber the hanger goes in to and its never done it since!

Edited by thenick on Tuesday 11th December 16:54

[McTavish]

Thanks for the comments. I don't think its the exhaust causing the symptoms, I've recently replaced it and the car was shaking prior to this.

I've ordered a pair of gearbox mounts from RPI today, I've already got a pair of engine mounts to fit as they are noticably cracked. Hopefully this will solve the issue.

As an aside when purchasing the gearbox mounts from RPI's ebay shop, they do cite on their shop page, symptoms of body shake and vibration from age hardened mounts as opposed to oil softened.

Think I'll leave this job for the New Year