f.talat

Hi I bought a 2000 A4 Quattro 2.8L last week and now the it's overheating. I got it checked and they said the main water pump needs to be changed. I drove it about 300km frequently replacing the coolant and put in a stop leak in the expansion tank and recently when i get to 60 kms/hr the transmission goes to 5th gear and the car jerks. The car is driving fine in tiptronic mode though with no jerks and with perfect gear shifts, is it the spark plugs, new transmission oil or some sensor gone wrong?

AudiMick

You may regret putting stop leak in your car as it's probably going to make it much more expensive to fix.

If the water pump is leaking park it. If the pump fails the timing belt will shred and wreck (as in scrap) your motor. The pumps on these cars are replaced as part of the timing belt service every 65-75K miles. It's a huge deal on these cars and why the repair history is important.About 5-7 hours work and $400 or so DIY. Up to $2000 at the dealer.

Check the fluid level on your transmission, has to be done a certain way whilst monitoring temperature. Don't take it to AAMCO and don't power flush it. Definitely don't add any "magic" liquids.

f.talat

Thank you for your input, I looked online at other forums and I guess the correct terminology is that the car is misfiring. Because when it is happening the "check engine" light starts blinking. Should I replace the spark plugs or the vacuum hose?

AudiMick

Neither, get the codes read to narrow down the cause.If the CEL is flashing that means don't drive it.

The codes will help determine a diagnosis what is happening, even then it's not always a perfect diagnosis.

Don't throw parts at it. The water pump and this problem suggest neglect.

4Driver4

Given all the issues you posted, the thing you should replace is the car.
Sorry, just telling it like it is.

AudiMick

If the pump is failing maybe timing has skipped hence the misfires.

f.talat

Alright thank you just ordered the water pump and belt online. The pump should solve the overheating problem and the belt hopefully the misfiring. If not I'll change the coilpacks and sparkplugs.

AudiMick

Wait up!

Pump, timing belt, tensioner, thermostat. That's the minimum parts you should replace.

5 hours if you know what you are doing. Double that if you mess up. There are special tools to line everything up, buy, borrow or rent them.

For a DOHC check the cam seals and tensioners otherwise she will leak oil like sieve.

Flush, flush, flush to try to eliminate the stop leak.

There are no alignment marks if you mess up then valves meet pistons.

Top up with G12 . Then bleed, bleed , bleed to get all the bubbles out.

Not being negative here, but plan ahead. Expect 13 year old fasteners to snap off in the block if you re-use them. Ask me how I know, and my A4 was a babied always garaged West coast car.

4Driver4

Disagree. This is not even minimum. Idler and tensioner roller are critical.

Bobby Kinstle

And if you are leaking oil check the suction pump too. It clogs up and pressure builds up and that causes the oil seals to fail.