I have an 02 Audi A6 with a 4.2L with 155,000 miles on it. It started overheating. It would idle fine at the correct temp but as soon as I went to drive it would begin to overheat. Coolant was seeping out of the expansion tank for a short time after I turned the car off. There is no heat inside the car (bad water pump or clogged heater core), even with the car 3/4 hot (never let it pass that). I am wondering if that is a related problem or if it is separate. The existing timing belt was replaced 60,000 miles ago. I ordered a timing belt kit. I also ordered the cam locking tool and the crank locking pin. I've changed a tb in a VW several years ago so I thought why not.
My parts will all be here tomorrow and I am anxious about messing up the timing. Could someone please tell me how I know the timing is TDC before I remove my old belt? I cannot see any marks on the cam pulleys or on the crank. Do I simply rotate the engine until the cam locking tool fits and then put the crank locking pin in? I am most likely over thinking this. Any help/encouragement is greatly appreciated.
Also, would the car overheat like described above if the electric coolant fan doesn't come on? The radiator is not clogged.

Thanks!

 

Hey Jason, I am going through a similar issue with my 2001 A6 Avant Quattro at the moment.
As far as the heating issue and the electric fan, diagnosing my problem, I disconnected the fan from the fan switch sensor on the lower radiator hose and jumped pins 3 and 4 on the plug to get the electric fans to run in the "high" mode. I drove a around the block a few times but the temp still went one notch above middle. I then pulled the inlet hose to the heater core enough to expose the pin hole to bleed the system but nothing came out. I then pulled the hose completely out and I found very little flow going into the core. Now in my case I still got heat in my car, so in my case I suspect that my thermostat is stuck. If you expose the bleed hole on your vehicle (I wonder if it would be the same on the 4.2 as mine is a 2.8), if you get a stream from yours then it could be that your core is clogged. I hope this helps you.

 

Thanks man. My problem was my water pump. It had plastic fins that cracked and was just laying in the block. I got it all out back together tonight. Who ever did the last timing belt change got the timing off. I scratched my head for a couple hours wondering if I was going to trust the marks I made on the cams or the cam lock bar. I chose to trust the cam lock bar and crank pin. My paint marks don't match but the A6 runs SO much better. Not sure why anyone would ever do a timing belt without those tools.
If you end up changing your thermostat use the right tools. Big, but doable job. Have a good one.

 

Glad you were able to find the problem. Yeah, waiting on the bar and pin before I do the thermostat. Never like doing a job rushed or without having the correct tools. Make sure to bleed the system, get any air pockets out.

 

Hey Jason my name is Rick and I was wondering which timing belt kit did you go with? I have a 02 A6 4.2 and mine is in the shop as we speak getting the timing belt water pump, valve cover gaskets and crank seal gasket. I'm looking to do some things with the car but I'm having a hell of a time finding anything for it. It's as if this particular motor configuration got forgotten about. Any help would be greatly apprecieated

 

Hi, I'm new to this forum. I have a 2011 plate Audi a4 2,0l TDI se 170 bhp my timining belt is coming up for replacement and I was wondering who would know what locking tool I would need to do the job ?? I bought one for my old golf but not sure if it would work on the Audi as my golf was a 1.9l TDI??? Many Thanks for your time