924Board.org

[timstar92404]

I still have a cold start problem on my car (and hot start), cold start meaning when the car sits till engine is cool and I start it it iddles too low at around 600 rpm or even lower and the engine vibrates too much for around 5 mins or more until the temp goes over the white area and then it iddles at 950-1000 rpm.


when the car iddles really low , 600 or less (400rpm) there is a pretty clear ticking noise comming from the cam. Does this mean my camshaft is worn out and needs to be replaced.

I was reading the faqs and it says a worn out comshaft is a common thing that cause rough idle. it wouldn't be the cause of the low idle though right?

if my camshaft is worn and ticks do I need to replace it ?
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78 924 sold.
85.5 944

[CBass]

Ticking coming from the top end would be a good sign of a valve being out of adjustment. Get a set of feeler guages, and the procedure should be in the haynes manual.
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'81 931 in various states of assembly

[Ozzie]

Could be just low oil pressure at low idle and oil hasn't got up the top yet.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[Smoothie]

Agree with the above and I'd suspect valve noise first, but jumping spark can be suprisingly loud and's easy enough to mistake for a valve click. Have a look at the plug wires in the dark and/or with insulated pliers lift each wire off the valve cover (or whatever other metal they might be touching) and see if the clicking stops.
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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[Gram]

If the cam followers need adjusting you'll be able to replace the cam cover gasket, and fix that oil leak (if it isn't the oil sensor).
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'82 924 NA Euro (hers)
'98 Audi A4 TDI (ours)

[timstar92404]

the ticking only occurs when the rpms are low (with my cold start problem) when it iddles at 600 or lower like down to 400-500 rpm the ticking becomes louder.

when the iddle goes up to normal at 950 rpm the ticking stops.
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78 924 sold.
85.5 944

[Paul]

Don't worry about the ticking, worry about why the idle is dropping to 600. Are you really expecting the motor to be quiet when it's running way below it's recommended idle speed?

[Lizard]

it is possible that the AAV isnt opening all the way, there was a post about how to fix it within the past couple of days. that is where I would start, as for the ticking I personally wouldnt worry about it overly. as stated though the issue could be jumping spark, to test this start the car in pitch black and when cold and you will see the spark JUMP and if you see that happening then you need to replace the spark plug leads
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3 928s,

[timstar92404]

thats why I can't figure out my cold start problem.

I already checked my aav and according ot the instructions on this site I took it out put it in the freezer (in a bag) and after one hour it was almost halfway open maybe a little less (40 percent open). With the engine cool it is barely open like 15 percent open.

I don't know if replacing it will fix the problem because to me it looks like its fine or mabye it should open up faster or a bit more?



aside from the aux air valve what else could be the cause of my low idle from cold start? the iddle goes to normal after 5-8 mins or whenever the temp neeedle gets over the white area of the temp gauge.



could it be the warm up regulator? I haven't checked haynes yet to see how you test this.
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78 924 sold.
85.5 944

[Lizard]

yes it could be the WUR, however you need special tools to be able to check that piece.
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3 928s,