Hello, This is a 2000 A4 1.8T

I recently replaced the head, head gasket, timing belt, water pump, thermostat, upper and lower temp sensors and the fuse for the aux fan.

Since then the car has been hard to start ( 3 or 4 turns of the key about 15 seconds each turn ) before it finally sputters to life. The engine accelerates smoothly with no pings tick or knocks. It will idle all day long with no issues. There is some condensation and water dripping out of the exhaust pipe as most cars do.

I'm pretty sure i bled the coolant system properly as i have heat and coolant circulates as it should. I've noticed i have to bleed the heater core outlet hose each time in order to get heat though.

My biggest problem is when i actually drive the car. After a short trip ( 1 or 2 miles ) it overheats. There is no coolant in the tank until i loosen the cap and it all comes rushing back only to disappear again when i replace the cap.

As far as i can tell the head gasket doesn't leak, there is no burning coolant smell, no puddles, and no milky oil.

I've dumped a bunch of money into this and i'm getting nowhere.

Any help would be appreciated. Thanks.

 

sounds like you have air in the system.... try running it with the cap off and add more when it goes empty and keep adding, until it boils over and then turn the car off and let it sit a few minutes and try again. thats how i ended up bleeding my system the last time i did it.

 

I did as suggested. Not getting better. I suspected i was getting air in the coolant somehow as i was getting bubbles from the return line. I also suspected coolant was getting into the cylinders. I was right on both counts for when i removed the valve cover I noticed milky oil and when cranked without plugs or injectors the cylinders were still getting wet.

I suppose i somehow managed to blow my new head gasket or perhaps the machine shop didn't level the head... who knows.

I will try tightening the head bolt and hope for the best.

I'm assuming air from the cylinder into the coolant is preventing proper circulation?

Anybody have theories on this?

 

Update,

I tightened the head bolts and reassembled everything.

The car started on the first turn. No issues after a nice long run other than occasional loss of power. I am unable to explain that as it doesn't happen all the time.

Sounds like the turbo is sucking air when i mash the gas, but like i said it's intermittant.

It does not overheat anymore, but a long trip and some stop and go traffic will commence shortly for a true test.

 

Ben,

Did you use new bolts for the heads? Those are torque to yield bolts and they don't stretch right when you reuse then.

 

I used the old bolts. If it becomes an issue I will order new ones.

Also my turbo leak was a rubber hose not properly attached. A screwdriver later and it's all better.

Thanks to everyone on this forum, it helped me.