MKIV 2004 Golf - Engine rough at idle and power lag

[telemeister]

Hi all,

I recently had an engine overheating problem which was caused by a cracked impellor in the pump. The mechanic replaced it and replaced a number of other things including the timing belt (kit), thermostat, radiator cap, by-pass hose and ignition leads. (2004 MkIV Golf)

Driving it home from the mechanic (less than 500 yards), I noticed the engine seemed to run a little rough at idle. I took it for a good run today (about 70kms up the freeway) and noticed a number of problems which were not present prior to me taking it to he mechanic.

Firstly, the engine runs a little rough at idle (it isn't really rough, but gently shudders). When I put my foot on the accelerator I get a very long lag before the engine kicks in (several seconds). In second gear the engine becomes jerky after the gear change until the revs raise above about 3000ish (not entirely certain though). Finally, I was accelerating in 5th gear up a long gentle hill (increasing from 100kph to about 110kph) when the engine became very jerky. Jerky enough that I backed right off and moved to the far left lane.

Obviously my first thought is that the mechanic has stuffed something up, but I've not got a lot of idea what it might be. Can anyone give me an idea of what might be happening and whether you think it might have been caused by the mechanic?

Cheers

[Jmac]

Hi there, Best thing before to do is take it back and ask your mechanic to look at it and give him the benefit of the doubt 1st.Dont want to bag him as it sounds like he has done the right things for your overheat condition, most guys would miss the thermostat. Anyway 1st thing would be get him to check it , explain your problem, and hve it scanned.
Hope it gets rectified soon, chime in ifyo need more help
Cheers
Jmac

[telemeister]

Thanks Jmac,

Will definitely take it back on Monday. Im pretty upset about it as I had a fair bit of trouble dealing with them (more the guy behind the desk than the mechanic, who is pretty good). What do you think the most likely cause(s) of the problem is, given the work that was done?

[Speed]

Firstly, do what Jmac says.

Is it a 1.6, 2.0 or 1.8T? Don't believe you stated.
If its missing maybe one of the new leads has popped off.

[telemeister]

Thanks Speed,
Definitely taking it back tomorrow, I just like to do a it of research to improve my general knowledge of things like this (which is pretty woeful!).

Sorry, I forgot to mention it is the 2.0L engine.

[VDUB-BUD]

Possible he disconnected the battery and needs an Idle Speed Adaptation .?

[telemeister]

Hi all,

Thought you might like to know that the problem was caused by faulty ignition leads - they were apparently arcing! Mechanic fixed the problem (under repair warranty) and replaced the plugs while he was there.

Thanks for the replies, I'm very happy to have my Golf back
Cheers all

[Speed]

My guess wasn't too far off.
Glad to hear its all sorted and back to smooth driving!