Let me first introduce myself. I have finally bought an audi 1999 A4 2.8L Quattro and i'm happy to join the forums.

I bought the car from someone who had it just sitting for 3 months I started it up and ran fine. It had a cracked radiator with no coolant. Then I had my dad do a timing belt rebuild replaced timing belt, water pump and new oem radiator.

Well when I start the car it makes a funny knocking sound (like a diesel) and seems to tame a bit after idling for a min or two. When I shut it off and turn it back on, I have to hold the ignition for about 10sec before it struggles to start up.

I would apperciate any help or suggestions!

 

Um..... do you have an oil light on? Have you taken it to Autozone or something like it to get it scanned for codes incase they pulled the lights?(its free)

 

Sounds like low oil to me as well. Many of the audi models and many year ranges can be picky about oil levels. even though the dipstick may not appear to be very low t can still cause that sound out of the engine. I have experienced this on two of my older cars. You said it was new to you.... you did the water pump/t-belt... did you do an oil change as well? always good practice on new used car purchases... unless it was a dealer purchase and they can provide service records.


check and possible change the oil.. the cost of an early oil change is much less than a new engine....

 

Off topic but did you replace your t-belt tensionor as well? THats what fails on these cars. Most of the time before the belt does. If that happens your screwed!

Josh

 

Thanks for the responses guys.

The dipstick level is on max just added 1/2 quart with no luck. I have not changed the oil, I was planning on changing it a lil later on. Just figured out that at around 2,500rpm it backfires twice. So i'm starting to think timing might be off. I have a vag-com and will see if it threw any codes tomorrow. And yes I replaced the tensioner also.

 

It could be the oil but the late starting points towards incorrect timing setting.

 

If this knock started after the t-belt change I would say that's your problem. I must of over looked that at 1st. Hope you have not bent any valves. [:@]Have you tried to manually turn the motor to see if the valves are hitting?