VW Cabriolet start up problem

For a friend of mine with a 199X Cabriolet:
The car starts and goes over 3000rpm at idle. Sometimes it will drop
to close to normal idle very briefly then it goes up again. Once it's
overheated, the engine stops. You would have to wait a few minutes
before you can start it up again.

What could be the problem?

Thanks for the help,

"liu" > wrote in message
...
> For a friend of mine with a 199X Cabriolet:
> The car starts and goes over 3000rpm at idle. Sometimes it will drop
> to close to normal idle very briefly then it goes up again. Once
> it's
> overheated, the engine stops. You would have to wait a few minutes
> before you can start it up again.
>
> What could be the problem?
>
> Thanks for the help,

You say "overheated"? If it is overheating, check the engine cooling
system and repair that first.

On 06/02/2011 09:02 AM, liu wrote:
> For a friend of mine with a 199X Cabriolet:
> The car starts and goes over 3000rpm at idle. Sometimes it will drop
> to close to normal idle very briefly then it goes up again. Once it's
> overheated, the engine stops. You would have to wait a few minutes
> before you can start it up again.
>
> What could be the problem?
>
> Thanks for the help,

look for head gasket leakage. there may not be oil in the water, just
gas in the coolant - a chemical test will tell you. or bubbles in the
expansion bottle.


--
nomina rutrum rutrum

>
> You say "overheated"? If it is overheating, check the engine cooling
> system and repair that first.

I saw smoke coming from engine area and then the car stopped.

We added carburetor cleaner / gas treatment, and checked the engine
oil level. Don't see any problem. The car just starts at extremely
high RPM idle. We dare not even drive. I wonder if driving it would
break the "lock" and go back to normal.

> look for head gasket leakage. *there may not be oil in the water, just
> gas in the coolant - a chemical test will tell you. *or bubbles in the
> expansion bottle.
>
Thanks for the pointer. You meant water in the oil? If that's the
case, only the professional can fix it, then! I will let him know.

In article >,
liu > wrote:
>For a friend of mine with a 199X Cabriolet:
>The car starts and goes over 3000rpm at idle. Sometimes it will drop
>to close to normal idle very briefly then it goes up again. Once it's
>overheated, the engine stops. You would have to wait a few minutes
>before you can start it up again.
>
>What could be the problem?

Just about anything. Pull the codes and tell me what you see.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 06/02/2011 12:28 PM, liu wrote:
>
>> look for head gasket leakage. �there may not be oil in the water, just
>> gas in the coolant - a chemical test will tell you. �or bubbles in the
>> expansion bottle.
>>
> Thanks for the pointer. You meant water in the oil? If that's the
> case, only the professional can fix it, then! I will let him know.

on some cars you get coolant in the oil, others oil in the coolant.
they're easy to diagnose. the harder ones are where you just get
combustion gas in the coolant. if you've had overheating, and the idle
control system is freaking out, that could be gasket and bubbles in the
coolant. [idle control is heavily dependent on coolant temp. if the
computer's temp sensor isn't fully bathed, readings go awry, and idle
speed with it.]

but as scott says, check for engine codes too.


--
nomina rutrum rutrum

jim beam > wrote:
>
>but as scott says, check for engine codes too.

Could be omething as simple as a vacuum leak or as serious as a
cracked block.....
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Thank you all for more information.
>
> Just about anything. *Pull the codes and tell me what you see.
> --scott

Where to pull the codes? Do you need to drive it to Autozone or a
similar store to get the reading?

Thanks,

In article >,
liu > wrote:
>Thank you all for more information.
>>
>> Just about anything. =A0Pull the codes and tell me what you see.
>
>Where to pull the codes? Do you need to drive it to Autozone or a
>similar store to get the reading?

I'd take it to a real mechanic, if you don't have a scanner. Because
the next step is going to be to look at the ECU parameters if there aren't
any codes set, and you are going to need a scanner for that (and a better
one than the ones the kids at Autozone have).

Without the scanner you basically can do only very limited diagnosis on modern
cars, because you can't tell what the engine control system is doing.

With the crappy Autozone-grade scanners you can see if any error codes have
been set, but beyond that you can't really see anything. Sometimes that's
enough to tell you what is going on, sometimes it's not.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."