Warm start rattle solved on my car!

[crc]

there are other check valves and spray jets throughout the oiling system.iN addition to the one that CRC pointed out in the sump there's a check valve and a spray jet in the head is well part number 4 in the link below.

http://www.jimellisaudiparts.com/sho...chString=valve

It seems to me that if a little bit of broken piece of plastic or grit or debris of some sort can wedge itself between the wall and sprung cylinder of the check valve it can cause it to remain open and drain the oil out of a given section of the motor thus causing trouble. over time the springs lose some of their strength making it easier for debris to gain a purchase in between the two walls.

According to the engine study guides there is also a check valve in the oil pump (understandable) and oil filter housing (don't think that is accurate). Anyone with start up rattle want to replace their oil pump on suspicion so we can test the theory? :)

[Ritt]

Anyone know if you need to remove the front clip to do this? I'm not seeing how to remove the bottom bolt on the flapper with out doing this... Just trying to get my ducks in a row before I tear into this.

[SprintBlueWorld]

Anyone know if you need to remove the front clip to do this? I'm not seeing how to remove the bottom bolt on the flapper with out doing this... Just trying to get my ducks in a row before I tear into this.

To take the intake manifold off? Noo. Flapper comes off with the intake manifold.

[thejsando1]

Yes, I get both, and mine last about a second longer for each one. The oil valves and jet replacement haven't seemed to cure either one.

Even if replacing the valves doesn't fix it, I guess it is still a good preventative maintenance measure to take that isn't all that expensive. I'm gonna order the parts and replace the valves next weekend.

Do you know anyone else that's had that sound on start up?

[breal]

There are multiple connectors and a few hoses that hold the manifold down if you didn't disconnect them. JHM has their manifold spacer install video on youtube that lists everything that needs to be done.

[2004B6S4]

this is an interesting thread, I like the theory but personally I'm very skeptical that it helps chain rattle. so much so that I skipped this when I replaced my valley pan gasket, but I wish the best of luck to anyone who tries it. I definitely recommend replacing the oil cooler o-rings. Mine were leaking so bad that, after cleaning the whole area really well and then leaving for a couple hours, I'd come back and find more oil had leaked out from around those o-rings. and this was after draining the oil and not running the engine at all. I imagine it must have been leaking pretty bad when the oil was under pressure. anyways the cleaning sure is a hell of a big job. here are some before and after shots of mine:


a couple tips - when you remove the oil filter housing, and when you remove the valley pan cover, be prepared as oil will spill from both! if it doesn't spill out of the valley pan and you can actually see the check valves then that's probably an indication that they are bad. mine spilled a bunch out of the front side and then it still had puddles of oil sitting on top of the check valves.

Also I saw some people discussing the possibility of the car having additional check valves. I may be wrong but I think there are only the 2. I'm saying that based on the ELSA chapter on check valves, which you can see here:


and they don't show any for the oil filter housing either:



I have a suspicion that some of the people who thought this fixed their problem, were just fooled by the fact that topping off the oil quiets down the rattle. I've noticed any time my oil is getting low I'll hear the rattle a lot more frequently, both during cold starts and sometimes warm starts. Before I realized this there were several times I started hearing the rattle, got all worried about possible timing tensioner problems, and then within a week or 2 later my low oil light came on. Then after I topped it off my car would start up perfectly smooth and quiet 90% of the time (it still occasionally has a very short rattle on cold starts regardless of the oil level). Took a few times of that happening before I noticed the pattern, now if I hear chain rattle I know it's probably time to top off the oil.

p.s. if anyone else is interested in getting the elsawin manual you can download it as a torrent. definitely very awesome to have access to that, but I still find myself using online DIY's a lot since it's sometimes necessary to modify the procedure when you're working without all the vag special tools. it's also helpful to have feedback from regular people that have done the job

[breal]

This diagram shows two, one in each head, listed as #4.

[breal]

Here is where I'm at...bent my torx socket so I'll have to wait 2 days before I can continue. Both of the valves in the valley seemed to function correctly.

[blai76]

If the rattling experienced is the result of one these valves failing, couldn't you easily diagnose that by pulling fuse 28, which I assume prevents startup but still turns the crankshaft, so you could lubricate everything first and retry? If it then doesn't rattle, doesn't it absolutely mean it was rattling because it was not retaining oil in one of the potential areas? Perhaps it's been said already; I couldn't completely read through this insanely long and fascinating thread completely, just yet.

[Jborch8]

If the rattling experienced is the result of one these valves failing, couldn't you easily diagnose that by pulling fuse 28, which I assume prevents startup but still turns the crankshaft, so you could lubricate everything first and retry? If it then doesn't rattle, doesn't it absolutely mean it was rattling because it was not retaining oil in one of the potential areas? Perhaps it's been said already; I couldn't completely read through this insanely long and fascinating thread completely, just yet.

bump

[breal]

Well, I'm dead in the water again. Snapped the "impact" T30 that I just got in today on the first try using a hand ratchet, along with two bent normal torx sockets.

[SprintBlueWorld]

Well, I'm dead in the water again. Snapped the "impact" T30 that I just got in today on the first try using a hand ratchet, along with two bent normal torx sockets.

Ouch! So your breaking these tools trying to remove the check valve in the heads? These don't just pull out as they do beneath the valley pan? This is groundbreaking stuff as far as this DIY goes.
Per crc's post there's one more yet to be tried in the sump. Again I'm thinking debris from internal engine parts ie flaking valve covers bits of gasket or brittle plastic can hang these valves.

[breal]

Ouch! So your breaking these tools trying to remove the check valve in the heads? These don't just pull out as they do beneath the valley pan? This is groundbreaking stuff as far as this DIY goes.
Per crc's post there's one more yet to be tried in the sump. Again I'm thinking debris from internal engine parts ie flaking valve covers bits of gasket or brittle plastic can hang these valves.

I was just poking around looking for any hidden check valves. I did not find anything, so I guess the BHF is without the valves in the heads. Nothing groundbreaking unfortunately, and now I have spare valves.

[2004B6S4]

scary $hit is right! I'm surprised this is the first I'm hearing of these bolts, after reading so many threads about scored cylinders. I think I may try and remove just the top half of the IM without unbolting the whole thing, just so I can get rid of these screws and clean out the IM real well. I'll remove the whole thing again if I have to but it would be nice to not have to disturb the new gaskets I just installed below the bottom half of the IM.

I know JHM rebuilds these professionally, maybe Jake will be nice enough to share some technical info like the torque specs and sequence?


edit - I just searched a little harder and came up with a little bit of info. I found 1 post (http://www.audizine.com/forum/showth...=1#post6639963) by a guy who said that a bolt came loose from the manifold and got into his #5 cylinder, destroying the engine!!! Poor guy. After reading that I don't think I'm gonna drive another mile without getting in there and removing these bolts! I'm still amazed that this isn't a more commonly discussed issue on the forums but I'm very glad that Jake brought it up!

Also I found a picture that may show the bolts in question but I'm not sure these are the ones, so hopefully Jake or someone else can verify if this is correct. I also found a thread that had a couple comments about resealing the intake with rtv, which is what I kinda assumed would be necessary. But there was no mention of torque specs for the bolts that hold the IM together so I'm still looking for that.

so I have 3 main questions for you, Jake, if you would be so kind as to offer the expertise of you all over at JHM:
1. What is the torque spec of the bolts that hold the upper IM to the lower IM?
2. What is the correct sequence for these to be torqued in? I made a little diagram that will hopefully make this easy to answer, I circled these bolt holes in blue and took my best guess and numbered the bolts in the sequence that I would think would be correct, can you tell me if I am right? (note this isn't my picture, I yanked it from a different thread and just added the numbers and circles with ms paint)
3. Please verify, are the bolts circled in red the ones that you were talking about which should be removed?

[TarlCabot]

the bolts that need to be removed are circled in red, they will also be in the same spot/location on the top half...

[mistral cytz]

Wait, so Audi designed these cars with screws on the intake manifold that come loose on their own and can randomly drop inside the engine???
Can someone verify this or post a pic of where they are in more detail? I've had my manifold off twice and don't know what we're talking about here? Watched JHMs intake spacer install CD twice and don't remember anything mentioned about these..

[mistral cytz]

We have opened up manifolds that had some missing. They can most definitely come all the way out on their own.

If some manifolds had them missing where did they go? How common of a problem has this been with cars being damaged from these bolts? I'd assume every Audi 4.2 engine with that style intake manifold could suffer the same problem do you would think lots of horror stories would be out there..

[Tinpusher]

A couple of years ago my indy had and RS6 engine rebuild going on and he showed me a screw (maybe 1/2 inch long) crushed into the top of one of the cylinders. Not sure if they ever figured out where it came from.

[mistral cytz]

A couple of years ago my indy had and RS6 engine rebuild going on and he showed me a screw (maybe 1/2 inch long) crushed into the top of one of the cylinders. Not sure if they ever figured out where it came from.

Yeah this could be the cause of many engine failures on 4.2 V8s over the years and I doubt getting away with scored cylinder walls would be the worst case scenario. I'd say if a metal bolt fell inside a cylinder it would be just a bad expensive outcome. I guess I'll be taking off my manifold again soon... If anyone has info on how to separate the intake manifold and how difficult it is to get it back together and sealed, I'd really appreciate it.

[TarlCabot]

if your worried about pulling it back off just for the bolts....

IMHO... it is a lot easier to just pull the top half back off, remove these bolts and then reseal with silicone when putting it back together, just be careful to get a good seal putting the halves back together and NOT breaking the flapper arm...

[mistral cytz]

Can you confirm that I can pull the the manifold apart by just removing the top half while leaving the base of the manifold still in the car? I'm not sure If I would have to remove the throttle body by looking at it sitting on the motor and if the whole manifold has to be removed to do this. Also, what do you use to separate the intake, a butter knife and razor blade? Cast aluminum can be pretty easy to crack if I pry on it too much.,

[TarlCabot]

yup, just a little tight to get to those bolts so you don't have to get to the flapper arm (pic above), two vacuum lines and remove the bolts that separate the two halves, not the ones that bolt it to the head, the few that i have worked on came apart with very little effort, just pried with a screwdriver and they popped apart, original seal/silicone hopefully will stay on the bottom half and you can just apply a nice new thin layer before putting them back together to get a good seal

absolute worse case scenario i guess you could just go ahead and pull the whole thing back out

[mistral cytz]

yup, just a little tight to get to those bolts so you don't have to get to the flapper arm (pic above), two vacuum lines and remove the bolts that separate the two halves, not the ones that bolt it to the head, the few that i have worked on came apart with very little effort, just pried with a screwdriver and they popped apart, original seal/silicone hopefully will stay on the bottom half and you can just apply a nice new thin layer before putting them back together to get a good seal

absolute worse case scenario i guess you could just go ahead and pull the whole thing back out

Okay I'm not sure I follow what you're saying regarding the flapper arm and two vacuum lines but after going out to look at my car it looks pretty tight to get it apart and I may just pull the whole thing out to be safe.

[TarlCabot]

Okay I'm not sure I follow what you're saying regarding the flapper arm and two vacuum lines but after going out to look at my car it looks pretty tight to get it apart and I may just pull the whole thing out to be safe.

one vacuum line on the back (top) and one on the front (top), the 2 bolts holding the vacuum diaphragm that works the flapper arm, the rod going to the arm actually pops out like a ball socket, it is plastic and could break... that's why i recommend just pulling the 2 bolts that hold it to the top half and just leave that in the car. I know B6's are super tight to get there, B7's fortunately have like about an extra half inch of room there so its not so bad :/

here is a close up, you can see the 2 bolts on the top left of the picture.... this is a B6

[mistral cytz]

one vacuum line on the back (top) and one on the front (top), the 2 bolts holding the vacuum diaphragm that works the flapper arm, the rod going to the arm actually pops out like a ball socket, it is plastic and could break... that's why i recommend just pulling the 2 bolts that hold it to the top half and just leave that in the car. I know B6's are super tight to get there, B7's fortunately have like about an extra half inch of room there so its not so bad :/

here is a close up, you can see the 2 bolts on the top left of the picture.... this is a B6

Okay thanks for clarifying and great pics!

[2004B6S4]

If I remember right I think I've read that with most cases of cylinder scoring they never determine the actual cause. it would make sense that these screws are often the cause but the shop doesn't think to separate the manifold to check. I guess if that happens they should at least find pieces of the screw inside the cylinder, though

[Gosser]

If a screw fell in the cylinder and you ran your car for many miles before investigating, then I doubt there would be much left of the screw, there would probably be marks on the piston too.
I thought everyone chalked up the scored walls as high revs while the engine wasnt at operating temperature.

[breal]

Finally got my engine bay back together. Have a rough idle on first start up that I'll diagnose tomorrow. I'll report back over the next week with any start up noises.

[Mr. Corey]

Finally got my engine bay back together. Have a rough idle on first start up that I'll diagnose tomorrow. I'll report back over the next week with any start up noises.

More photos of this awesome engine bay please!!!!

[JimmyBones]

Looks great man.

What did you use to paint the intake manifold and ignition coils/wiring harnesses?

[Priest]

Looks nice :-)
Sorry to post and ask in here. Anyone have genuine Audi S4 4.2 ecu map for tune? Could be 2003-2004 year. Thanks

[breal]

Both are automotive paint. The manifold was professionally done, ignition stuff was me. Curious to see how well they hold up.

I ended up having a vacuum leak from the front of the manifold. Took it off and redid the gasket. Give it another shot tomorrow.

[pandapod]

I did this to my car a couple weeks ago...i usually get a cold "rattle" and sometimes a warm start "rattle", but it doesnt sound like any other rattles i've heard, hence my quotation marks (my rattle is barely audible and i dont even want to call it a rattle). Regardless, replacing the check valves did not fix anything (probably because stock check valves were 100% functioning)

[breal]

Week and a half in and no more noise at startup. Kind of surprising since the valves seemed to be working. I'm happy regardless.

[Tugboatguy]

Week and a half in and no more noise at startup. Kind of surprising since the valves seemed to be working. I'm happy regardless.

They may have moved freely to the closed position and still leaked by at the seat.

[breal]

I'll be cleaning up the car for some photos soon hopefully. I'll post some pics in the photo thread afterwards.

[SquiddyB6S4]

If it helps any, guys, springs wear out from changing position over and over again. Just because a check valve can be moved does not mean that it is functioning properly. I have not held a worn out BHF check valve in my hand yet, and certainly some check valves do not have high mission critical preloads, but it is at least possible that although it is working, it is so weak that it does not properly shut. Also possible that the valve seat is simply worn out, which is honestly much more likely, as old valve seats rarely seal completely.

Just my two cents on the topic. Also, I always figured that if and when I undertake a timing service, I would go ahead and replace the oil pump itself, both for cheap insurance over time and to bring operating pressures back to original specification. It's a basic rebuild part for any engine.

[alcatranz518]

Found this morning after doing the flapper cleansing and wanted to share. I split the intake since after I did the cap cleaning the rattle was still present. Very glad I did as I found something that could have been a HUGE disaster. So just in case, here's what I found for all you. Hopefully this is another surprise the toad of a P.O. left me and not something the manifold does over time. (She has 141k on the clock).

If you look at the pics below, there's (4) gold T30 screws circled in red on the upper and (4) gold T30 screws circled in red on the lower intake manifold plenum halves that when I separated the intake, I found them not only loose but extracted about 1/16" out of the threaded holes. After a brief but much needed anxiety attack I tightened them back down and torqued them to about 20 in-lbs with (blue locktight as well) then conducted a thorough cleaning throughout the entire intake manifold.

BTW...that partial polish job on the upper intake plenum ports was properly finished and done to the lower, I didn't leave it like that. Just wanted to take the pic before I got too involved ;)

[mistral cytz]

Found this morning after doing the flapper cleansing and wanted to share. I split the intake since after I did the cap cleaning the rattle was still present. Very glad I did as I found something that could have been a HUGE disaster. So just in case, here's what I found for all you. Hopefully this is another surprise the toad of a P.O. left me and not something the manifold does over time. (She has 141k on the clock).

If you look at the pics below, there's (4) gold T30 screws circled in red on the upper and (4) gold T30 screws circled in red on the lower intake manifold plenum halves that when I separated the intake, I found them not only loose but extracted about 1/16" out of the threaded holes. After a brief but much needed anxiety attack I tightened them back down and torqued them to about 20 in-lbs with (blue locktight as well) then conducted a thorough cleaning throughout the entire intake manifold.

BTW...that partial polish job on the upper intake plenum ports was properly finished and done to the lower, I didn't leave it like that. Just wanted to take the pic before I got too involved ;)

Those bolts were only used during the casting process of the aluminum from the factory and serve no purpose so you could have just removed them all like I did. Mine were all still tight besides 2 at around 50k miles, although one was 50% backed out :( so I can imagine what yours were like at 141k miles! Either way, since you torqued them and used locktight they should never be a problem again but for those of you who do this, feel free to remove all 8 bolts and toss them for peace of mind.

[Gosser]

x2 what mistral said.

However, those bolts actually do not pose any harm. They are long enough that they cannot completely back out. There is a thread somewhere that illustrates the interference before they can become free.

But remove them for peace of mind, or lock tight them in.