Cold starting problem

[Mark-RS]

Before I bought the car I was told it had a cold start issue that would be fixed before I bought it.

I have the paperwork for the problem, but it seems the issue was never actually resolved as the car still fails to start first time from cold on occasion.

If you keep trying after several times it will eventually fire but runs like a dog for 30 seconds or so before it idles smoothly.

The fault was apparently traced to a temp sensor which was making the car think it was at 94 degrees all the time. The sensor was replaced and the issue supposedly fixed.

Since buying the car this issue has returned. I have also noticed that the rad fans seem to want to run at full speed all the time.

Also now the engine management light has come on after a poor start yesterday. It's not the EPC light, but the little starter motor looking thing.... After some research it's linked to running poorly ? Bad fuel ? Emisions etc.... Which would make sense if it runs like crap for a while on most start ups ?

Here are a few pics of the paperwork.... And faults...

Basically looking for some advice. The garage that did the work is a near 3 hour drive from me so it's out of the question to take it back to them. So I need to try and sort it myself as cheaply as possible.

Thanks guys. Appreciate your time.

[Shoppinit]

Could be the temp sender again. They fail often. If it was replaced with an ebay special it wouldn't surprise me at all that it failed again quickly.

A Vagcom would really help in this situation. Have you got one?

[Mark-RS]

No Vagcom yet, but I do have a friend who has a reader and a phone app that he says should be able to read codes and clear faults. Is this the same sort of thing ?

[Ajc]

It probably won't be throwing up a code , But if the reader can show engine temp then it may be of use .
Where abouts are you ? , Maybe someone local with Vagcom can plug it in for you .

[Mark-RS]

I'm in northants area. Anyone local ish ?

[Shoppinit]

It'll be throwing a code because the MIL is on. Probably just misfires though. Still, without checking who knows?

An OBD2 reader that can do live readings might help. If it's just a code reader then it'll be of limited usefulness.

[kvxxy]

This sounds like pretty much the exact issue I had a while back. Turned out to be a coolant sensor. Replaced it with a oem part and it cured the problem. It’s only £40 from TPS as well. The previous sensor fitted was a cheap one, it was corroded in as well and was a pain to take out. Like shopp said, avoid the eBay specials.

[Mark-RS]

Is it easy for me to get to ? To pull out and look at ? Going to try the car on this phone app in the next day or so to see if it will return a live reading of the temp.

I'm hoping I can do it myself as the garage charged the previous owner just shy of £300 for doing it... Or not doing it, as seems to be the case.

[Shoppinit]

It's an easy job. 300 seems a bit excessive. There's no point looking at it. You can't tell anything visually.

You could try displaying the coolant temp on the AC controls. Might not tell you anything useful. See FAQ.

[Richard J]

There may be more than one temp sensor. Also engine speed sensor is crank sensor and can cause similar starting issues particularly on warm engine.

[Ben_r1]

My rad fans were also always running flat out. I replaced the coolant temp sensor and sorted the issue. Was relatively cheap from Audi too, just be sure to get the seal and a new clip that holds it in.

Changing it however was an absolute pita, there is minimal room to work with, the plug refused to come off after several attempts I broke the clip and the sensor was corroded in tight. Obviously if yours has been done previously not an issue for you.

[Mark-RS]

Where exactly is the sensor ? Back left hand side of the engine ?

[Shoppinit]

For FAQ's sake.

[Mark-RS]

Ah....

I see what you did there

[Mark-RS]

The scanner we had didn't work. It didn't show any signs of life at all. Tried it in his BMW and it worked fine... There isn't a switch to activate the port by any chance ? he has another one, different one we are going to try tomorrow.

And TPS is trade only it seems ? Any other options for a quality sensor ?