2000 S4 No compression in any cylinders

[MinionB5S4]

- If anyone could point me in the right direction it would be greatly appreciated..

- Backstory: I was driving home and when I got there I realized the top of my motor was making almost a "ticking" sound, it was not obnoxiously loud so I drove to work. On my way the car started dropping RPM's, I continuously downshifted to raise them and they kept falling until the car shut off completely. My friend was following me and he said no smoke came out the back end. There was nothing leaking from the head or block, and my oil was still full.

- I had the car towed to a local Foreign Car Shop to have it looked at and was told there is no compression in any cylinders and it would be cheaper to swap a motor in. I am just wondering what could cause this dilemma, and if my best option is to forget even looking into it and just throwing a used motor in.

- Any response is greatly appreciated, thank you in advance,
Matt

[Monty23]

Most likely something failed with you cam timing and your valves got mangled from contact with your pistons.

[bOOOOstedAudi]

You could have a crack in the block

[jpurre]

Normally I would say head gasket, but since there was no smoke from the tail pipe that kinda rules that out. If it were timing belt failure related, it would have stopped immediately. Very hard to say. I think you can pick up a used working engine for around a grand.

[Kaane]

Verify on your own. I had a shop years ago tell me my motor had no compression and they just wanted to F me over and motor was fine.

[MinionB5S4]

Thank you all for replying so fast! I'm definitely going to have to verify by my own what's going on before rushing into anything. I just haven't heard of a motor blowing up without anything leaking or smoking or banging excessively so I was skeptical.

[rdcyclist]

The quick way to check a cam timing issue would be to pull one of the upper timing belt covers (easily done with just a screwdriver) and see if the belt rotates when the motor is turned over by the starter. A timing belt issue could manifest itself with what you describe if the tensioner failed and allowed the timing to skip a tooth at a time. The initial ticking would be one tooth and the valves lightly touching the pistons. From there you get catastrophic failure. It would probably be easier to just replace the motor if this is the case.

[bwizard]

Bent valves I'm sure

Sent from my S4's talk to text broke in my garage.

[MinionB5S4]

So every valve in that case is trashed and if it is that an entire used motor would be the easiest fix? Sorry for all the questions

[erykv1]

depending on the damage (piston related or not) you could swap heads and get away with it possibly but its hard to tell without a tear down.

when was the last time your timing belt / associated components were replaced??

[MinionB5S4]

Previous owner said it was done by audi at 85k (with receipt) I'm now only at 109k. Either way I'll have to take it apart and really look at it.