jophish

Hey all,

So, this has been going on for about two weeks with no sign of letting up. When it's cold in the morning (usually 20 degrees or less...which it usually is at 6 AM in VT this time of year) the car has some real issues starting up. It'll turn over fine and rev up fine but then the idle immediately drops down to below 1K and the engine runs very rough. I've noticed that the vacuum on reading is around 0 when this rough idle is happening.

After a few minutes, the problem corrects itself and the car runs and starts as normal. I can turn it off and turn it on again later and it will start fine. Only after sitting for 10 hours or so will it have some trouble starting again.

Sometimes revving the engine corrects the problem when it starts rough...sometimes it doesn't. When the weather is warm, it starts and runs just fine.

I've known I've had a vacuum leak in the engine somewhere for a while, but it has never adversely affected how the car performs. I've done a little digging and these symptoms seem common to several problems, some larger than others.


Some clarification would be great,


Thanks in advance

jophish

Update:

Outside temp was 26 degrees this morning. Car started up fine and had no issues. Only difference between today and yesterday was that I filled the tank yesterday night.


hmm...

4Driver4

What engine is in the car?
Have you checked for codes?
Replaced the coolant temp sensor?

jophish

Engine is the 1.8T

Only code returned so far has been system too lean, bank 1...this has always been there and i've always attributed it to a vac leak

I replaced the coolant temp sensor about a year ago, the guage was intermittent...since then it hasn't had any sensor issues

GTA_Driver

The gauge is using a different sensor from the one that provides temp for the ECU.

You may need to look into the other one. Intake temperature readout via VAG-COM.

Reggie

If you suspect vacuum leaks get a good indy shop to find it. Turbo engines are noted for them