Guys,

I have 2004 turbo cab that I bought new. Only has 25k miles on it -- is pristine. Just took it to Rennwerke to do the coils and sparkplugs since I hadn't had it done and the car is old. They have done fabulous work on my 1955 356 cab and are wonderful guys.

Heading to Rhode Island late at night, I averaged around 90, pulled over for some food and stopped the car. Upon restarting, i heard a loud "knock knock knock knock knock" noise coming from the engine. Have never heard anything like it. It was quite loud and regular - probably a half second apart. I shut down the engine, started again and still had the knock. I pulled away, clenching my teeth, and stopped again. The knock disappeared and has not come back.

Any thoughts? If it were a bad rod, would it go away like that? Bad pump? Bad gas (I filled it with 93 but you never know). Wonder if it could be tied to the overhaul I just had for the spark plugs / coils?

Thanks for any insight.

marty

 

Not sure if this is material - also had oil changed as part of service. And mechanic had reported engine looked great as part of spark plug / coil replacement.

 

Is it just somewhat of a pronounced ticking noise (from inside the cabin) right when you start the car? My own 996TT will occasionally make a ticking sound, which I suppose could seem loud, for a few seconds upon starting up, but it always goes away within about 5 seconds. This seems to happen more regularly if I don't drive the car, but I've never associated it with any serious problem and the car hasn't given me any issues as a result.

 

Have you checked the oil level after they filled it? Possibly be low?? Knock would stop once starts to flow through engine. Google "Tufoil" I always add one quart with oil between changes? Worked really good on older cars.

 

+1 on checking the oil level. I read that the IMS problems were caused by not keeping the oil level up to the full mark.

Engine ticking noise is normal, knocking is not.

 

Thanks for the suggestions. Oil had all bars lit (eg completely full). The knocking was hard knocking ... I'd been driving for about an hour, pulled over to stop for a break and restarted the car a few minutes later ... which is when the knocking started. It then went away.

I'll let everyone know if it comes back...

 

Sounds to me like it is oil related. If your oil level is not low, then perhaps the wrong type of oil was mistakenly added. If it happens again, I would change the oil and make sure the right stuff is added. In fact, if it was my turbo, I would just change it again now.

 

Thanks for the feedback everyone. I'll see if the oil is the issue.
martin

 

If you tell me the car's a manual I'm going with a clutch/transmission rattle.

My 03 does this when its engine and drivetrain is really hot.

I pull into a parking space or pull onto a gas station forecourt next to a pump island and it sounds kind of bad but the noise goes away when I push in on the clutch pedal. When I release it the noise does not return until the next time.

Another possibility is a piece of combustion chamber deposit broke loose and was being pounded to dust.

That the noise went away and not other symptoms have come up the noise was most likely nothing serious. But no doubt a bit scary.

Sincerely,

Macster.