Chain service. Unable to prime engine afterwards. Advice please.

[jjrichar]

I pulled the engine from my 4.2L Allroad (pretty much identical to the S4 engine) a few months ago to do the timing service as well as a bunch of other stuff.

Engine is back in the car, and I've attempted to prime the engine by cranking it using the starter for about a minute in total. No oil is making it to the oil filter housing. Not a drop.

While the engine was out, I did a bunch of other stuff, which included the intake manifold and the check valves in the valley, as well as the oil pipes in the oil pan that go from the pump to the oil cooler and back to the gallery that then goes vertically to the valley. The oil pump or sieve didn't come out. The entire oil gallery has been emptied as a result.

My assumption was that cranking it will immediately suck the oil up and fill the OFH and remainder of the gallery reasonably quickly.

I'm assuming the oil pump is turning, as with the coolant pump removed, I can see that shaft that goes to the coolant pump is turning when I crank the engine by hand.

Advice from someone who has experience in this area would be much appreciated.

[neilpaku]

Good timing (no pun..). I just put my engine back together. I ran 4 cycles of 15s cranking it over with the idea of priming the lubrication system. When I started the engine, it ran for 15s before the oil reached the timing mechanism sufficiently to trip the timing adjuster (it seemed like hours, listening to all that clanking going on : )
So my experience was that it did not pump up quickly - at least quick enough for me. However, it's all good now. Here's a link to the excruciating sound of the timing mechanism flogging away - enjoy! http://www.youtube.com/watch?v=yhpnopr-hwU (also some more info in the "Got cracking on the guides" thread)

[jjrichar]

Neil, thanks for the reply. I actually did start mine, and this is when I realised I had a problem. It only ran for about 1 second prior to me shutting it down. The noise was shocking. It sounded like the most god awful chain rattle from the back of the engine. Is that what you heard?

Interestingly, when I do an oil change, I always prime it for about 10 secs to fill the oil gallery. When I then start it, it sounds like it was going only seconds ago. The only thing that I can think is different is that the gallery prior to the check valves remains full when you do an oil change, and this allows the pump to prime more effectively because the pump is completely full of oil when priming. I'm thinking of removing the valley pan and front check valve and filling it from here to get some oil into the pump prior to priming.

[neilpaku]

Yes, sounded exactly like that. Have a listen to that video I posted. You can just catch at the end when the oil pumps up and the noise stops. It was about 15s. Don't worry about that killing your engine - it won't if you keep your foot off the gas.
Could be worth a shot if you have the valley off already to top it up with oil, but if not, I wouldn't bother.

[badger.]

Mine didn't sound like that at all.

http://www.audizine.com/forum/showth...1#post10631602

[neilpaku]

Yours sounded good. Might have been the difference between my 15s and your 30s priming cranks? (and that I did my priming cranks a week or two earlier : ). Anyway, it's all good now - no rattle cold or hot. I found out the hard way about the finicky power steering fluid - it was a bit low so the pump was growling a bit - I topped it up but then it started cavitating and shot bubbly oil everywhere. So, after a day of sitting the bubbles have dissipated and I siphoned out the overage. Hopefully it'll run this time without fussing.
I was reading that thread though with amusement because I bought that o-ring but determined that it was not needed on my engine/adjuster because although there was a recess on the adjuster (or the block), there was no matching hole on the other part, so I didn't install it. This engine is a BHF from a later production date than the car (2004) and has been opened before, so who knows what was supposed to be in there. I'm not going to worry about it unless I start getting odd noises again.
Car is still up on blocks because I'm waiting for the rear engine undercover to arrive.

[Bonz099]

There has to be a better way to prime this engine than to let it run scavenging for 15+ seconds while your asshole is puckering in the hopes that nothing breaks. What about removing the oil filter to pour some oil in the center tube before starting to help it?

[kevinye77137]

There has to be a better way to prime this engine than to let it run scavenging for 15+ seconds while your asshole is puckering in the hopes that nothing breaks. What about removing the oil filter to pour some oil in the center tube before starting to help it?

Exactly... I do this all the time when changing oil

Sent from my SM-G920V using Audizine mobile app

[neilpaku]

I'm sure I'll do that next time : )
Man, this engine is a bucket of bolts : )

[jjrichar]

UPDATE:
Well, I got the thing to prime properly. I just hadn't done it enough. Started a treat afterwards.

Like Badger described, plugs out and the fuel pump fuse pulled works well. It rotates freely using the starter like this with little load. My guess was it cranked at about 120 RPM (twice per second). I looked at the crankshaft at the front while my wife cranked it and this was my best guess. Having talked to a pretty helpful Audi tech who I know, and him talking to the Audi master techs where he works, they said up to 15 secs worth of rattle is normal. Strangely, he said they wouldn't attempt to prime an engine prior to start, which did surprise me.

This 15 secs at about 1000 RPM initial idle speed is about 250 rotations, about 2 mins when cranked with the starter. I would definitely suggest what Badger said he did, allowing it to cool after each 30 secs or crank.

The most exciting thing. Cold start this morning and it sounded like a new engine. Happy days.

[badger.]

UPDATE:
Well, I got the thing to prime properly. I just hadn't done it enough. Started a treat afterwards.

Like Badger described, plugs out and the fuel pump fuse pulled works well. It rotates freely using the starter like this with little load. My guess was it cranked at about 120 RPM (twice per second). I looked at the crankshaft at the front while my wife cranked it and this was my best guess. Having talked to a pretty helpful Audi tech who I know, and him talking to the Audi master techs where he works, they said up to 15 secs worth of rattle is normal. Strangely, he said they wouldn't attempt to prime an engine prior to start, which did surprise me.

This 15 secs at about 1000 RPM initial idle speed is about 250 rotations, about 2 mins when cranked with the starter. I would definitely suggest what Badger said he did, allowing it to cool after each 30 secs or crank.

The most exciting thing. Cold start this morning and it sounded like a new engine. Happy days.

Good stuff Glad to hear you were successful
It's a sigh of relief after such a major undertaking to not pucker up on every start.