1998 A3 1.8t agu. Odd tick over?

[Mark Greenall]

I just bought a a3 1.8t 1998 as a bit of fun. Bought cheap with full service 165,000 miles.
When I picked it up it was warm and tick over fine, the next morning started it cold and it ran lumpy. Once warm it was fine.
I noticed the temp gauge took a while to come to 90c compared to my b5 a4, I changed the cts it's a blue 4 pin not green?, now it's fine cold a slight drop every now and then. But once warm it idles near 1100 rpm but runs a bit lumpy dropping a few revs? Do you think the new cts is not good it's non genuine I think from gfs. What else might it be? Does anyone know of anywhere near Leeds with vagcom.
I have a saab 93 2.0 low pressure turbo 155bhp it's a convertable and must weight alot but it's way faster than the a3, do you think the a3 should be as quick?
Thanks

 

[16Klappe]

AGU's do odd things, I wouldn't worry about it until it decides not to start.

Otherwise you will go on a wild goose chase spending money and replacing parts with nothing to go on.

Who cares about the SAAB, if you think the A3's down on power put it on a dyno and get it fault checked.

 

[Mark Greenall]

I don't like the saab it's a rattling piece of **** it was the bhp comparison which made me ask the question that's all.

 

[Joshstan]

If the temp is slow to rise and drops every now and then stick a new thermostat in I chased this problem for months with my old agu and changed the thermostat and all was good
Pig of a job though about half hour of pure contorsionism
My tip is remove the tray under the inlet manifold and the dipstick tube CAREFULLY as they like to break and go at it with a mix of 5mm Allen key and shallow 10mm socket ( I cut one down) on the smallest ratchet you have access to

 

[Mark Greenall]

I will buy one today and fit it, will let you know the outcome
Thanks

 

[16Klappe]

And here we go, down the garden path of throwing money at an AGU with a lumpy idle...

Enjoy.

 

[Mark Greenall]

Well I gave £550 notes for it with full audi service and audi care plan, so if I must spend a couple of quid finding the issue so be it. I'm not going put up with it until it strands me miles away. I think it's vac pipes or stat.
Thanks

 

[Joshstan]

Giving the throttle body a clean also did wonders for me

 

[Mark Greenall]

Do u need to do an adaption after? Looks simple 5 Alan bolts?

 

[Mark Greenall]

Cheers guys I fixed it. It was vac pipe under inlet had a 2 inch split car fly now and has better mpg

 

[Joshstan]

That'll do it good job buddy very common that one

 

[Mark Greenall]

Thanks again I thought it must have been down on power. Your a star

 

[Mark Greenall]

Oh dear my oil light came on last night at about 80mph I topped oil up it came back. I recovered car home and haven't started it since. Oil pick blocked I reckon? I'm an engineer by trade so going to do it myself this weekend. Anything I should be careful of? Any advice great fully received
Thanks guys