Rough idle - vibrations!

[mark.r.cullen]

For those with a 1.0L Arouser, how does it idle?

This one's idleing seems to cause the car to vibrate for a few minutes. Seems okay once it's warmed up a tad though. Doesn't look like the revs are hunting around either, but will check later on today.

Is this just a characteristic of the little 3 cylinder engine at idle?

 

[HalfOfZero]

My Arouser idles just under 1k, seems ok. Then again this morning I had literally no fuel in the thing n it sounded a bit juddery lol

 

[mark.r.cullen]

Yeah, it idles at about 800-900 I think. Just seems a bit rough. Once going it sounds absolutely fine though. It's probably due filter and fluid changes, so that may help.

My own 4 cylinder diesel *feels* smoother at idle though. Not to be confused with sounding smoother Diesel clatter!

 

[lunalupi]

3 cylinders....? The only 3 cylinder I'm aware of is the 1.2 in an Ibiza...

 

[mark.r.cullen]

For some reason I was under the impression that the 1.0L was a 3 cylinder engine? Is it a 4 cylinder? :-O

edit - DUH! Forgive my idiocy. 4 cylinder 8v engine. Blimey. lol

 

[foto2021]

VW Group has a 1.2 litre 3-cylinder petrol engine that can be found in the Polo, Ibiza and Fabia. But I don't think it was ever fitted to a Lupo/Arosa.

However, the Lupo/Arosa 3L models had a 1.2 litre 3-cylinder diesel engine. The 1.4 TDi also has 3 cylinders.

 

[mark.r.cullen]

My bad. Well as it's a 4 cylinder then I think it may be running a bit rough at idle. I'll change filters and fluids first though and see if that helps at all. Also read that cleaning the throttle body can help? Not sure how to do that, but the way everyone talks about it; it sounds like it should be easy

 

[foto2021]

My Arosa 1.4 MPi also has a lumpy idle. I don't want to spend a lot of money on it as it passed its MOT and it runs OK, but I might try new spark plugs.

When I bought it, the car had only done 2800 miles since a full service (receipt supplied) but I have replaced the air and pollen filters and found they were extremely dirty. So I suspect they were never changed at the "service" and that the spark plugs probably weren't either.

 

[Boo]

I would suggest to do the plugs 1st really. Chances are its idling because its not firing properly.

 

[lunalupi]

If the plugs don't help it may be the HT leads - it's not massively expensive to replace them, but more than doing spark plugs so try that first

 

[foto2021]

I agree with lunalupi. The plugs are quite cheap. The HT leads cost about three times more.

I'm going to buy some plugs just as soon as I can work out which ones - the ones recommended as suitable by eBay sellers aren't always right for the car.

Another possible cause of lumpy idling is a petrol/air mixture that is too rich.

 

[HalfOfZero]

So to clarify, 1l Arosa is 4 cylinder?

 

[lunalupi]

Mk1 uses NGK BUR6ET for a basic spark plug.

And yes, the Arosa is 4 cylinders - take off your engine cover and you can see the 4 plugs and leads underneath

 

[HalfOfZero]

Mk1 uses NGK BUR6ET for a basic spark plug.

And yes, the Arosa is 4 cylinders - take off your engine cover and you can see the 4 plugs and leads underneath

The engine bay is something I tend to never look at..

I just quint my eyes a little n pretend it says "CUPRA, WITH A MILLION HORSEPOWER" on it.

But it doesn't.

 

[foto2021]

So to clarify, 1l Arosa is 4 cylinder?

Yes, the 1.0 litre Arosa is a 999cc four-pot.

 

[mark.r.cullen]

The engine bay is something I tend to never look at..

I just quint my eyes a little n pretend it says "CUPRA, WITH A MILLION HORSEPOWER" on it.

But it doesn't.

Haha!

I picked up new filters, oil and plugs for the beast yesterday. I'm not sure when they'll actually get fitted though. So far I've just been spending my days at home attacking it with polish, as it's not actually being driven by anyone yet.

Will let you know though, thanks!

 

[mark.r.cullen]

Have changed air filter and got father to help change the spark plugs. Air filter was a bit black, but not too bad. Spark plugs he said looked a good color (orangey coppery, as opposed to black or white) so it seems to be burning fuel good.

It does seems smoother at idle. Still vibrates a fair amount revving to about 2-3k rpm at a stand still though. Maybe just engine mounts or something?

Still got fuel filter, oil filter and oil change to be done. Possibly tackle the fuel filter later today...

 

[mark.r.cullen]

Changed the oil, oil filter and fuel filter.

Changing the fuel filter doesn't even need the wheel off if you're at standard ride height, though the clips were a royal PITA! I just got under the car with a pair of pliers and got the clip nearest the back off fairly easily, I struggled with the other clip as it was a bit hard to get at, but then realised I could cheat. I simply unclipped the fuel line from the chassis, unscrewed the filter and then you can easily pass it out through the wheel arch. The clip was off in a few seconds using the pliers. I am fairly sure the fuel filter had probably never been changed, or hadn't been changed for a very long time. It was very hard to blow air through compared to the new filter.

I also cleaned out the throttle body. That was fairly straight forward, though I couldn't get some pipe (crankcase breather?) off of it, so had to do it basically in-situ. It didn't seem all that bad to be honest. I've seen far, far, far worse cleaning out the air intake pipework / EGR / manifold on my Furby

After the fuel filter and throttle body clean (even after throttle body adaption with VCDS) the idle was acting a bit strange. It was idling at 1200RPM on first start, and it would very, very slowly drop down to 800-1000RPM, but whilst actually driving If you went over 2000RPM and then pressed the clutch in, it seemed to get stuck idling at 2000RPM for a few seconds, then it would drop down to 800-1000RPM!

After driving the car around for 50-100 miles it seems okay again now, though still likes to idle at about 600RPM when warm. Seems happy enough idling there though, so I would guess it is nothing to worry about.

And after all this, it seems less rough at idle, smoother to drive, but it still vibrates the car quite a lot revving to about 2500-3000RPM in neutral (or in gear). Might try new HT leads at some point. Maybe engine mounts. I am pretty sure it needs a new clutch cable and / or clutch too... (see http://www.seatcupra.net/forums/showthread.php?t=323951)