The solution to chain rattle

[Desert FLyer]

Installed an accusump oil pressure accumulator on my 2007 S4 with 45k miles. The car used to have slight chain rattle every once and again. I have been running the accumulator for the past 3 weeks and I have not experienced even a HINT of rattle. According to my VAG-COM I am getting nearly normal oil pressure just prior to start. Can't be happier! I will post pics as soon as I get home from training.

-TK

[Tropicgreena4]

that is good news! which model did you go with?

[jr1415us]

I see a future DIY post in the works!

[2.7taudi]

I have this on my car too.


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[svra42.8]

subscribed!

[Desert FLyer]

Its going to be about a week and a half for the the pictures. Im currently in Dallas, TX at Simuflite getting training on the new company jet. Its a fairly easy install but the wiring can be a pain.

[kelseysautobody]

very interested in this... subscribed

[ilko]

Can't wait to see the install!

[dparm]

Interesting. Keep us posted.

[vdubjetta02]

Yes, please post as much info as possible

[Mr.Wrong]

In for more info and DIY, subscribed.

[Slow4]

Is this chain rattle at start up or chain rattle during drive?

[dparm]

Is this chain rattle at start up or chain rattle during drive?

Seeing as how he said he's getting higher oil pressure right before starting, I would assume he means at startup.

OP, post your VAGCOM readings, oil info, installation notes, etc.

[cplus1]

in...

[LJH]

I saw a post about the Accusump a few weeks ago but never chimed in but I have a question. So, over the last year I have taken to cranking the engine a couple revolution on the starter but not letting it fire. My theory, which may be flawed, is that I am building oil pressure and getting the tensioners to apply tension to the chains before the motor fires and goes to @900RPM so it is more gentle on the guides. Does anyone know the RPM that the starter turns the motor at? Our car pretty much only gets driven on the weekends so it sits in the garage all week and the first start of the week does usually, but not always, produce a second of chain rattle. Since I have started this practice I do not get any chain rattle at all on the initial start up. Once the car has been driven she is quiet on start up for the remainder of the weekend.

Thoughts?

Cheers,
Jim

[dparm]

A lot of that is also a function of the polarity of the oil, its viscosity index, and ambient temps.

My car has sat for 3 weeks at a time and started right up with no rattle. Then again, it has never rattled.

[BCsniper]

^^^That's because you still have low mileage and have always been good about using good oil. Not all previous owners were so kind.

[dparm]

^^^That's because you still have low mileage and have always been good about using good oil. Not all previous owners were so kind.

68k. Certainly on the low side but some of those miles have been pretty hard, and we know of problematic cars with far fewer miles. I agree mine is not a typical DD.

[Black3.2]

even though i am at 73k mils and never once have i had the chain rattle pop up, i am still interested to learn more about this product and see a DIY

[dparm]

even though i am at 73k mils and never once have i had the chain rattle pop up, i am still interested to learn more about this product and see a DIY

http://www.accusump.com/

[b spot]

Did you go with the smallest model and use the electric switch to wire it into the ignition?

Did you use their connection kit or fab up your own?

[BCsniper]

68k. Certainly on the low side but some of those miles have been pretty hard, and we know of problematic cars with far fewer miles. I agree mine is not a typical DD.

Who was it that said (it might have been you) that running the motor hard is really better than babying it all the time.

[dparm]

Who was it that said (it might have been you) that running the motor hard is really better than babying it all the time.

I've probably said it, though there's a line between stretching its legs and being abusive. Puttering around town at low RPM and lots of short trips will dilute the oil with fuel and won't let it come up to temperature to burn off contaminants. It also helps rings seal if you give it some throttle (and do some engine braking).

[Desert FLyer]

I probably should have waited to post this thread until after I returned from Dallas. Sorry guys. I bought my car used before I knew ANYTHING about the platform. While my leakdown tests are near new spec I suspect the PO wasn't the greatest with oil changes. I used the 1 qt sump and used their connection kit. If you listen closely once the key is in the on position you can hear the sump discharge if you have the windows down.

[MattboyR32]

subscribed!

[howsyouraspen]

I probably should have waited to post this thread until after I returned from Dallas. Sorry guys. I bought my car used before I knew ANYTHING about the platform. While my leakdown tests are near new spec I suspect the PO wasn't the greatest with oil changes. I used the 1 qt sump and used their connection kit. If you listen closely once the key is in the on position you can hear the sump discharge if you have the windows down.

Sump discharge = good.
Burning discharge = bad.

Good find. I'm def gonna watch this post. I predict Accusump stock to go up soon.

[04 S4]

In for a DIY

[Black3.2]

Sump discharge = good.
Burning discharge = bad.

Good find. I'm def gonna watch this post. I predict Accusump stock to go up soon.

now that is really funny

[Nitro1]

now that is really funny

Can someone clarify as maybe I missed something:

OP, are you suggesting that the accusump can be a preventative method to possibly stop or prolong the life of the timing chain guides?

Or...are you suggesting that the accusump is just a remedy for the normal chain rattle at startup and this is just s solution to get rid of the rattle that is supposed to normally be there (within reason of course)

Thx

[ilko]

Can someone clarify as maybe I missed something:

OP, are you suggesting that the accusump can be a preventative method to possibly stop or prolong the life of the timing chain guides?

Or...are you suggesting that the accusump is just a remedy for the normal chain rattle at startup and this is just s solution to get rid of the rattle that is supposed to normally be there (within reason of course)

Thx

It's both.

[Nitro1]

It's both.

Ok....so, this is intriguing. I'm just trying to understand as I thought the following:

The tensioners are going bad from dirty oil gumming up the tensioners (not frequent enough oil changes), or lack of oil getting to temp or getting through the system BEFORE driving the car hard.

If these are the two (rumored) causes of the timing chain tensioner failure, then how can pumping the oil through the system before starting the motor help at all?

--The oil would still be dirty (or) the tensioners have already begun to gum up from a previous owner (How does the accusump help here?)
--The oil would still be cool before driving the car hard (you still want the engine to come to temp)

[mbgt72]

Ok....so, this is intriguing. I'm just trying to understand as I thought the following:

The tensioners are going bad from dirty oil gumming up the tensioners (not frequent enough oil changes), or lack of oil getting to temp or getting through the system BEFORE driving the car hard.

If these are the two (rumored) causes of the timing chain tensioner failure, then how can pumping the oil through the system before starting the motor help at all?

--The oil would still be dirty (or) the tensioners have already begun to gum up from a previous owner (How does the accusump help here?)
--The oil would still be cool before driving the car hard (you still want the engine to come to temp)

Scoured cylinder walls are attributed mainly due to inadequate/improper warm up and infrequent oil changes (old oil obviously isn't going to lubricate and cool as efficiently etc).

Timing chain issues are attributed mainly to lack of oil pressure at initial start up in the timing chain guides that add pressure to hold the chains in place. Poor OCI add to this problem as the oil breaks down and doesn't pressurize in the guide as well/as quick.
So when the engine starts and the guide isn't tightly pressed against the guide (due to lack of oil pressure since the engine isn't on - which is why cold starts is when the symptom is most prevalent), the chain can "slap" agains the guide. This quick slap adds to the deterioration of the guide and guide mechanism. Eventually they fail all together and other parts can often go with it as that stress is then applied additional throughout the system.

Personally I don't know enough about the problem to say that this is an adequate solution or not. But it certainly is an interesting approach and appears to address the main problem which leads to further issues down the road. Obviously if a guide is already in poor shape, the damage is done. But anything to pressurize the system temporarily before engine start seems like it would be a very beneficial step.

[Nitro1]

That was a great explanation. Thanks....So OP, which one on the website www.accusump.com should we be buying?

Edit: Nevermind...I saw your post 1qt.

How much to install?

[howsyouraspen]

Yeah, thanks mbgt. That was an informative post. I really am looking at getting one of these accumulators.

From what I understand from the website, there is a manual, and an electronic way of activating this thing? Also curious about mounting. Can it be remote, or need to be in the engine bay?

[Hyde]

Can't wait to hear more info ...

[peterk81]

Subscribing for parts list and install instructions.

[dparm]

Dirty oil is not necessarily the problem, its that the oil is too thick at startup, hence my suggestion to go for something with a very high viscosity index that pumps easily. M1 0w40's VI is 185, much higher than most other 5w40s. There are very few oils suitable for our car that are above 180:

M1 0w40: 185
Lubro-Moly Synthoil Energy: 181
Renewable Lube 0w30: 193
Renewable Lube 5w40: 188
Lucas 0w30: 186
Redline 0w40: 197
Royal Purple 0w40: 182
Mobil Delvac 1 ESP 0w40: 186

[Xyber]

Subbed!

[vdubjetta02]

Is this something that can be easily installed?

[Desert FLyer]

Im in the process of creating a PDF with parts list, prices, and instructions. I will be in Dallas until the 21st for training and once I return to Indy I will post the whole DIY with pics.