Possible stat issues, may have resolved smoking issues. Any ideas

[SDHA4SLine]

Hi,

Got a confusing one here...

Had a long trip up to Crewe today and as usually lots of blue/grey smoke every time I touched the go pedal

On the return trip my coolant temp gauge was constantly up and down between 60 and 70 degrees. Normally it's solid as a rock a 90 and I assume this is a faulty thermostat stuck open?

It was the same when cruising at 70-80mph and when stuck in today's giant M6 traffic jam now I don't know if the rad fans are very quiet but I couldn't hear it kick in whilst stuck in the jam. Now to add complexity to the issue, very strangely no smoke from exhausts all the way back, anyone have an idea why this may be?

Worth noting that before today it didn't matter if car was cold or hot, the smoke was always there when under load.
Also had the coolant temp senser and thermostat replaced in last six months using genuine Audi parts so not too worried if my problem is one of these because of the two year guarantee.

Any advice/ideas appreciated.

Regards
Steve

 

[Charlie Farley]

Have you tried running any diags on the car steve, if not then maybe it may be wise too do so as it may just show up a problem part or area that is the root cuase of your problem.
just because you may not have any warning lights ping up on the dash , it doesnt followm that you dont have a problem.
My turbo issue only showed up when i ran vag-com, i knew there was a problem but nothing obvious pinged up on the dash.
maybe worth a go even if it is just to eliminate certain parts .

rob

 

[SDHA4SLine]

Yeah that's 1st thing I'm gonna do when I get the chance though if it is the thermostat I don't think it'll show up as its mechanical isn't it? More confused by the fact the smoke has stopped when it appears I have an issue

 

[novril]

Was the needle moving quickly? A stat would cause the temp to be low when moving quickly and then slowly warm up when moving slowly. Any fast movements would indicate temp sensor fault. This could be affecting the fuelling, hence the difference in smoke.

 

[SDHA4SLine]

Was the needle moving quickly? A stat would cause the temp to be low when moving quickly and then slowly warm up when moving slowly. Any fast movements would indicate temp sensor fault. This could be affecting the fuelling, hence the difference in smoke.

Depends on what you call quickly but I would say no it was gentle up and down. This morning it hardly registered at all and the smoke was back.

just popped out at lunch tme slow town traffic and it crept up to 70.

Regards
Steve

 

[SDHA4SLine]

ive found someone local to me from the forum to do a vcds scan will update when I have a chance to meet with him

 

[SDHA4SLine]

Turns out a piece of the thermostat housing had broken off and wedged itself inside the thermostat jamming it half open.

Fixed under parts warranty

Although the part not in stock so I will have to have one of the demo cars for the next 24hrs, hope its a good-un