Knocks on acceleration and cruiseing on my new (to me) 106

[dezroze]

Hi, I have just bought a 106 1.4 roland garros and noticed a problem with the drive.

When you are accelerating the drive is smooth and the engine is fine when idling however when you take you foot off the accelerator the car bangs as thought something is loose, it is a little unsettling to drive for long especially in traffic, can anybody help with any advice, im praying its not the gearbox as i dont know much about cars but ii know that is expensive!?

Thanks guys

 

[jonnyfishing]

Try checking:- 1) Exhaust mounting rubbers
2) Engine/gearbox mountings

 

[dezroze]

Jonny, thanks for your comments

I have looked at the exhaust and it seems to be connected properly with no movement and the engine mounts all seem to be attached to engine and chassis fine.

I took it for a drive this morning and I can best describe the problem by saying that when idling the engine runs fine, finding a gear is fine, accelerating is also fine. The problem is when you take your foot off the accelerator to stay at a cruising speed without pressing the clutch the car jerks a lot, it feels like something is loose in the drive chain, excuse my ignorance I am not much of a mechanic.

Any thoughts?

Thanks for your help!

 

[jonnyfishing]

You don't say what year or c.c. your 106 is.

Does the jerking feel like an engine misfire ?

If so,I think you will need a diagnostics check to point you in the right direction (possibly the throttle position sensor faulty) but don't just guess, sensors are quite expensive and cars have several different ones.

 

[dezroze]

Its a 1.4 injection roland garros 1993

Im not sure, i doesnt really feel like a misfire its more like a loosness in a driveshaft or something, is that something that happens??



I am going to double check the mounts tonight.

Thanks

Chris

 

[jonnyfishing]

Hi Chris,

Place a piece of wood on the jack and jack up the engine about 2 inches then check the mounts for splitting, sheared off nuts,studs etc.
I assume that you have checked the wheel nuts and driveshaft nut are not loose(both sides).If you can't find anything wrong I think you should let someone with a little more knowledge and experience take a look.

 

[johnwr]

Try checking the rear front subframe bolts are tight, I have seen a P205 with both rear bolts missing, and it makes a banging noise when you decelerate when the subframe hits the body.
Hope this helps johnwr