Engine Wobble/Shake at Idle (only when AC off)

[Fred44]

I've had a few threads about this, but have just discovered something new and it made sense to start a new one; especially for people in future finding it on a search.

 

Car has the BLT engine and shakes/wobbles at idle really quite badly.

 

If I turn the aircon on and then let the car idle its about 90% better.

 

What does that mean?

 

Previously I thought the aircon didnt do anything, and it doesnt if you turn it on as its shaking. But today I found if you have the AC on all the time it virtually fixes the problem!

 

Thanks for any advice in advance because this is what people were asking about before.

[MoggyTech]

Caused by low emissions settings for the idle fuelling. Some are worse than others. The AC adds a considerable load to the engine, so ECU gives more fuel and the shuddering stops. Even turning on heated rear window and headlights will make a difference.

 

The easy fix is with VCDS. Engine at full operating temperature, adjust idle from 850 to 900 RPM, this fixes it for most cars, but on some, you have to lower the idle to 800 RPM for some strange reason.

 

JFYI this problem is sometimes made worse after a cambelt change. If this is the case it's worth having the timing offset angle checked with VCDS.

[Fred44]

Mine shakes the entire car :(

 

Checked the timing and it was a 0. Tried a few like 0.5 1.0 -0.5 and -1.0 but most made it worse.

 

I will have a look at the idle speed, thanks for that idea!

[Fred44]

You know it ****es you off when your on the drive past 2am adjusting your idle.

Had some strange results but dropping idle by about 40 rpm seems to have taken a bit of an edge off.

So a bonus!! But still frustrating.

What would you usually set timing to?

Mine is at +0.5 at the moment.

[Fred44]

I thought the idle speed had made it better.

 

On the way to work I was wrong, its as bad as ever :(

 

Any other suggestions on this?

 

Has anybody ever had the map for idle fueling changed or cant it be done?

[Chillie]

Does it get better when the car warms up?

[Fred44]

If anything it gets worse.

 

For about the first 3 minutes form cold its perfect (even with AC off) then starts, then sometimes is so bad the car physically shakes.

[Chillie]

Not entirely sure then, 

 

Engine wobble could be a misfire in one or more of the cylinders though that might result in the car having trouble starting, I've read that a flywheel fault can cause engine wobble too.

 

What happened before the car started doing it? or was it completely random when it started to happen?

[bluecar1]

does it improve if you push the clutch in? if so DMF possibly shot

[Fred44]

Its always done it a bit.

 

DMF is new (it was doing it before)

 

A lot of things I'm reading/hearing suggest injector.

 

Phoned the dealer expecting it to be about £90

 

£630 for ONE injector  -  WTF!!!!!!

Edited 29 July, 2013 by Fred44

[Chillie]

Go onto the GSF car parts website, put your reg plate, find injectors and choose your engine code, comes in around £450, but if you hand in your old injectors you get £150 cash back or around that figure

[spud31]

Its not injector its the warm up fuelling map.

I bet its worse when temp guage around 70-75 deg?

My ibiza does this ( same engine) but as soon as past this point gets better.

Do check with VCDS that car fully warming up to 90deg as mine wasnt until i changed thermostat that made big difference.

[Dean-]

Its not injector its the warm up fuelling map.

I bet its worse when temp guage around 70-75 deg?

My ibiza does this ( same engine) but as soon as past this point gets better.

Do check with VCDS that car fully warming up to 90deg as mine wasnt until i changed thermostat that made big difference.

 

Exactly like mine...

 

From Startup (Cold) Its brilliant until that temp needle starts to move. If i then stop it shakes horribly. If i go for a long drive to get the engine to temp the shaking then is non existent unless I let the car idle for a while.. (Maybe this is due to the engine cooling down again)?