Titanium Grey S4 Avant

[UrS4boy]

F60 Idle Switch and N71 Idle Stabilization Valve info

Also check the throttle pot switch is actually closing, it needs to for the ISV to work.

Well, to be pedantically technical , it's not the G69 throttle potentiometer per se. It is the F60 idle switch that the ECU reacts to and starts controlling the N71 ISV.

G69 / F60 Throttle valve position potentiometer /idle switch information:

http://forums.quattroworld.com/s4s6/msgs/20405.phtml

N71 ISV info:

http://forums.quattroworld.com/s4s6/msgs/21853.phtml

[newsh]

That's why I called it the throttle pot SWITCH

[geneandbolly]

Don't use carb cleaner, wash it out with GT85 or WD40.

Carb cleaner is way too aggressive.

Also check the throttle pot switch is actually closing, it needs to for the ISV to work.

Those products won't clean the grime out of the ISV - have used all three of those mentioned products and none of them made any difference to a dud ISV in my experience ..

[newsh]

Brake cleaner is also ok but carb cleaner melts plastic

[hunker7]

My bad luck isn't over. By the looks of it she spun shell bearing so knocking is pretty bad. Next job is taking off the head and seeing what's going on. What do I need for head bolts, spline?

[Error404]

Head bolts are XZN or Triple Square as they are sometimes called.
What makes you think you spun a bearing? Would be pretty unusual for a seasoned engine to spin a bearing, plus they will often block the oil gallery through the crank causing catastrophic failure
Taking head off won't help you check the bottom end. Take the sump off and check mains and big ends. I would cut open and check the oil filter first and see if you have any debris in the oil system.

[hunker7]

Head bolts are XZN or Triple Square as they are sometimes called.
What makes you think you spun a bearing? Would be pretty unusual for a seasoned engine to spin a bearing, plus they will often block the oil gallery through the crank causing catastrophic failure

Thanks

Fuel got into the sump, and made oil pretty thin, and also because it sounds like this?

[Error404]

Oh dear.

[hunker7]

Oh dear.

...and then it doesn't start properly, and there is a crack in exhaust manifold

[newsh]

Are you sure the noise isn't just the exhaust manifold leaking? Didn't you do a stud repair on the cylinder head? Maybe the repaired stud has come loose?

[Error404]

As I suggested above I would first start by cutting open the oil filter and check the filter media for debris. I do this on my oil change anyway
If there is particles in there you can take the sump off and check the main and big end bearings. Don't run it again, if you have spun a bearing next thing will be a rod through the block.
Badly cracked manifolds can sound appalling sometimes, you might be lucky and find that is your nasty noise

[hunker7]

Crack on the manifold is tiny, no way it sounds that bad. I'll remove oil filter then, and check for metal particles in that.

Why would it not start though?

[diesel des]

Does it still turn over ok. Maybe so much petrol in the oil the tappets sent pumping up right?

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[hunker7]

Does it still turn over ok. Maybe so much petrol in the oil the tappets sent pumping up right?

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Level is just above maximum so it's not huge amount, but enough so when I remove dipstick oil drips off it

[bikerjim]

How did the petrol get into the sump? I presume from an injector leak?

I haven't read further back than this page so forgive me if this has been covered. Obviously a leaky injector will cause bad starting but I guess you could have hyro-locked a cylinder? Hopefully not though!