Stumped....

B6/7 S4/RS4
#81

Extremely strong work gentlemen. Really enjoy following this sort of thing. Thanks for sharing.

#82

^^ Thank you for contributing your knowledge and assistance.

I made an observational assessment of how my guide failed/cracked and wanted some input on my train of thought. I didn’t get much response from the AZ crowd for whatever reason but I am hoping to get a good guage here…I understand the basics of the car and how things work so excuse the “Joe Schmo” approach on things:

[QUOTE=Teamaker]How long from the start of the rattle did you drive the car until you decided to replace the timing components?
[/quote]

[quote=me]You talking about cold start up rattle, warm start up rattle or rattle under load?

In my opinion, these are three different rattles and all three can be heard if you train your ears to them.

** start up cold rattle **

I’ve stated this numerous and numerous times, this is normal on cars that have 60K+.

Why? Because of wear and tear to mechanical parts such as the adjusters, guides. These parts expand under heat and contract when cool; they are also moving parts or attached to moving parts therefore “slack” will play a part. If you’ve ever pull-started a chain saw or looked at the chains on a bike, there is natural slack…incorporate this idea into an engine with some wear on it. When you start the engine up, it cranks thereby re-tightening hence the short lived rattle or “muffled slapping” of the chains on the guides. As stated previously, if your cold rattle is less than two seconds (id say a second) then you’re ok…if you’re doubting the “two second rule”, physically count out one-thousand one, one-thousand two, etc; a second is actually quite a long time.

** warm start rattle **

Very similar to my “theory” on cold start except the engine is warm. I can understand the concern for this because everything should already be tightened therefore no slack. Things of concern when warm start happens are the mechanical adjusters.

Are the keyholes on the adjusters (can’t remember “engineering” nomenclature for this) worn that much where this “slack” can play a factor?

** rattle under load **

I am speaking from my personal experience for this explanation. Some time around late spring of last year, after I upgraded my piggies to proper downpipes, I began to actually hear “chain rattle” under load, specifically on a gentle incline of a road, at speed (45+). At first, I thought this “rattle” meant that I needed to check my oil because it sounded like I was low on oil.

  • note * my low oil lamp did not come on but I’ve come to know when my car is low on oil, personally ** note **

  • note 2 * the times when my min oil light came on, the sound of the rattle was VERY noticeable prompting me to pull over immediately * note 2 *

  • note 3 * i also had an educated guess that my valve stem seals were going bad due to the slowly increasing number of oil top offs I had to do, not to forget about the blowing of blue smoke durin engine decels (hard and soft); I would make it a habit to check monthly which changed to bi-weekly, then it became weekly…hence I knew when my oil levels were low by sound * note 3 *

The “rattle” became more noticeable under load on steeper inclines and gentler inclines at 25 or 35 or at speed. I kept putting it off as my engine being low on oil but when the oil levels weren’t short upon inspection, that’s when I began to question and fear that I might be due for a timing change within the next 20-40k miles. It wasn’t until this year, as posted a few pages back that nothing was “seriously” wrong until the “clicking/clunking” noise from my valve cover could be heard.

Back to the “rattle”, this “rattle” is a lot different than the start up rattles. This “rattle” would actually sound like a chain rubbing against a plastic object, like an actual muffled rattle and was consistent with throttle application.
[/quote]
Thoughts?

#83

I have a very long response I’m working on. I would say what you posted is very close to how I have observed it works.

The guys on another site just keep getting the chain rattle more and more wrong as time goes on. When you have a broken guide you won’t hear any rattle. If anything the broken guide can lead to premature adjuster failure.

#84

hahaha show your kids ‘this is why you can’t go to private school’

#85

Private school is overrated.

#86

Sometimes yes, sometimes no. Kind of a broad statement.

#87

Everything is overrated till you have kids. My guess would be you don’t have kids.

#88

;D

I do actually send my kid to a private school; technically, its a day care that teaches kids from toddler age up to fourth grade. The “school” utilizes the Montessori style teachings and teaches it to the kids…personally, I think its an over-glorified day care but I have noticed that my kid is a little more advance in regards to academics than the average kindergartener. Seriously though, I am pretty much paying TWO mortgages, my house mortgage and my kids private education versus spending that money on car parts, haha.

Personally, I think private school IS overrated and the success rate is 50/50, depending on child and their learning environment. As stated previously, I currently have my son enrolled in a kindergarten class at a Montessori-styled private academy and the only differences I can see is the smaller student:teacher ratio allowing more one-on-one time if the children struggles. They are currently learning academics that is preparing them for first grade whereas the public school kindergarten class is getting the basics of what Jr K was teaching (observance from family friends with their kids currently in kindergarten).

Public schooling is always playing catch up, primarily due to the bigger student:teacher ratio and the concept that each student retains their education differently. Eventually, the public school system will catch ALL the kids up and there is an established base line for education…generally somewhere around the 7-8th grade levels and continues through the 12th grade in High School. This is what my wife fails to see, as she is ALWAYS boasting the pros of private schooling, even though she personally attended public school her entire life (ironic no?).

#89

Thoughts?
[/quote]
This is very well thought out. There are more then one kind of rattle as well. The chainsaw is a great example.

#90

Having been to both private and public schooling at both the elementary and high school levels, my experience was that private school was about 2-3 years ahead of public schools.
I went to public in grades 2-5 and when I went to private in grade 6, I had some catching up to do. I just barely passed the entrance exam. I then went back to public school for my last year of high school and I was bored out of my mind. They were teaching things I learned 2-3 years prior. I then went to engineering in Uni and the first year in math and sciences was yet again a bore. Only in the 2nd year did I begin learning new things.

All in all, I think it depends on the private school. Some are more sport oriented, others are more academic oriented, and yet others are just posh oriented with nothing extra to offer other than sending your kids to a school where other people are also rich and like to stick together.

#91

I think the benefit of private school is pretty simple

  1. concentrated classes and perhaps better education (debatable all day on the second part)
  2. more interesting experience (because families with money can afford more interesting trips/excursions, the schools do a few more interesting things)
  3. nicer surroundings and resources - private tennis courts, ice rinks, sports fields, beautiful buildings etc…very different
  4. making connections with wealthy, connected people (this to me is the biggest thing)

There’s also a huge alumni benefit…i.e. ‘you went to Ridley? Me too!’ that helps with people you may not have even known, but feel you are ‘approved’ because you’re like them. This helps in job interviews etc.

Of course the pricing is retarded and only for the wealthiest (or those fortunate enough to get scholarships). A high quality private school around here will cost a parent $30,000 to $60,000 per year. Not kidding. It makes University seem a bargain.

#92

I went to public schools my entire life and in different parts of the country (Washington, Georgia, Connecticut and Florida). I have to say that curriculum differs vastly from state to state and the type of area you live in.

With that said I think public schools are fine unless your in a low income area or an over populated area. We currently send my step daughter to a private catholic school here in NYC and i think its a joke. I knew so much more at her age and learned far more than she has. And she is smart girl. The curriculum is just bad. They are more worried about passing some bullshit state test than teaching them. By fourth grade we knew all 50 states and capitals and where geographically everything is located. She is in 8th grade now and couldnt tell you anything outside of NY.

And as bad as i think her school is in curriculum i wouldnt dare send her to a public school in the city. That would be a disaster.

#93

UPDATE:

Sorry to interrupt the school talk but I have a set of news today, one good and one really really bad. I’ll start off with the good…

I now have a “cold air intake” system!! Haha, I performed the airbox flapper mod.

http://tapatalk.imageshack.com/v2/14/09/08/5ed6e0a209393ec320e8db29e163e0de.jpg

http://tapatalk.imageshack.com/v2/14/09/08/6e32acdb85d481f78561938fe04a410c.jpg

Now I’ll have “cold air” on demand without having to wait for the actuator to activate under high load!

Now, onto the bad…

In the process of changing out the valve stem seals, we discovered that I have three bent intake valves.

Some pics of the valve stem seal replacement:

http://tapatalk.imageshack.com/v2/14/09/08/a0149e3ada879c98a5224cad6f1078e6.jpg

One of the special tools required to remove the seals

http://tapatalk.imageshack.com/v2/14/09/08/0da320517e9e5f49c8e603ffc3b789a2.jpg

http://tapatalk.imageshack.com/v2/14/09/08/143a3a8fbda8481a36833ce452f9885a.jpg

Also, for those interested…the back of the engine with guides removed and engine in car:

http://tapatalk.imageshack.com/v2/14/09/08/8cc8c0a4a7f868add1644e75fe02e143.jpg

http://tapatalk.imageshack.com/v2/14/09/08/a943814fe0eb3a85a4f23fb36dc3e160.jpg

Enough space to fit my entire head/shoulders through

http://tapatalk.imageshack.com/v2/14/09/08/7428c3c95ecb304a08a21b04ff9c0733.jpg

Main driver for the engine

http://tapatalk.imageshack.com/v2/14/09/08/9067a3511531f0fc74996e7bf5722237.jpg

And now, cracking into the heads

#94

Are you assuming you have bent valves because of the valve stem seal wear?

Not that it’s any better, but maybe your guides are just really worn and you can get away with replacing the guides.

#95

At first it was a worse case assumption during the process of extracting the valve stem seals in cylinder one. It wouldn’t hold the 90psi’s that was being put into it, like you can actually hear the air escaping from one of the valves (the tape on the valve inlets also bubbled up when you poked it).

Jimmy found this to be odd so he peered down the inlet and noticed the middle intake valve were not fully sealed. He then performed the test again on cylinder three and again same result, to which he found very odd. A triple check by spraying some carb cleaner into the inlet to see if the valves would hold the solution yielded negative results…both middle intake valves eventually drained into the cylinder. It was at that point that I caved and accepted the idea that I had bent valves, leading us to break down the heads and PHYSICALLY look.

As of now, we have discussed several solutions to fix the problem. I opted to have Jimmy replace ALL the middle intake valves versus spending mad ludacris money on rebuilt heads and valves.

#96

A few more pics:

http://tapatalk.imageshack.com/v2/14/09/08/24c6cb665019379a134413486fb39b13.jpg

Passenger side cylinder head removed

http://tapatalk.imageshack.com/v2/14/09/08/f372cbd260e99e446c3f4f94e0c75f4f.jpg

Top view of passenger side cylinder head; don’t mind the fluid…it was intentional (click Here for an explanation of why)

http://tapatalk.imageshack.com/v2/14/09/08/779d1cdedf7218096178eba5f481ce45.jpg

Bottom side of pass-cyl heads; glimpse of valves.

It’s hard to see with the naked eye but up close, you can see middle intake valves in cyls one and three are affected. Not pictured is cyl 8s valves, the intake valve is “a c*nt hair off” as Jimmy so eloquently puts it.

http://tapatalk.imageshack.com/v2/14/09/08/52382b6bc735a593499b5dfb9c306cd5.jpg

Front end view with both cylinder heads removed.

http://tapatalk.imageshack.com/v2/14/09/08/cf38203db73a21046c00d27778d13c2c.jpg

Top-down view of headless engine…note the amount of space with things removed.

Next image is not for paranoid owners:

http://tapatalk.imageshack.com/v2/14/09/08/8c2649dd638aa76f33293f1fbf34f7a9.jpg

Moderate scoring in cylinder 6

Yup! For all those terrified of the timing GUIDES (not chains)breaking or cylinder scoring…it WILL happen, just matter of when NOT if.

#97

Have him check the guides too, otherwise replacing the valve will be pointless.

Have you had a comp test/leak down done before the issues arose?

#98

The timing guides?

He’s already removed all the guides and was waiting to finish the valve stem seal job before putting them back on. A comp test/leak down was completed back in late June a few days after I found out about the clicking noise and everything was ok. Prior to that incident, I had the initial purchase compression test done by a dealership but I don’t remember what those numbers were except that they were good.

Cylinder Leakdown Readings:

#1: ~2%
#5: ~4%
#4: ~3%
#8: ~4%
#6: ~38%
#3: ~5%
#7: ~5%
#2: ~7%

Jimmy can explain the percentage readings better than I can but from what I remember, anything between the green zone (1-20%) is very good compression, anything between the yellow or red is very bad.

EDiT:

Cylinders #1 and #3s near perfect leak down readings is what baffled. Both of those cylinders should’ve held the air when pressurized but for whatever reason, they were leaking. Its why Jimmy performed a follow up test with the carb cleaner, spraying it into the valves from the manifold inlet; if it held the liquid after a period of time then it would mean the valves had a good seal but this wasn’t the case.

Both him and I wanted to make sure that it was JUST the intake valves so I okayed the break down of the cylinder heads to physically inspect for any more damages. It was DEFINITELY one of those “oh shit” moments.

#99

The valve guide, is the part the valve stem slide through (gold/bronze colored) and the stem seal sits on top of.

Those can get worn out and cause the valve not to seat properly and will wear stem seals. If you put a brand new valve in a bad guide it will do the same exact thing (bad valve guides will need replaced)

Not timing chain guides…
since you have the heads off there is a procedure in the bentley to check the valve guide wear tolerances.

#100

Ah, I see what you’re saying now. Jimmy was talking to me about it this morning and I was completely clueless as to what he was trying to explain; I sorta grasped it but it just added more to my confusion. He just called back to inform me and then reading your post, a light bulb went off.

He took my cylinder heads to a machine shop to get it looked at so we’ll see where we’re at later on tonight.