1998 Audi A4 - Chain Noise

[NPASC_mike]

Original issue was no compression, no start. Found valves carbon-ed up plus a huge intake leak let a ton of debris in. Once head was off, found bad rings, and wrist pins, lots of piston slop, Serviced head, replaced pistons, rings, rod bearings. ( mains looked fantastic.) cam bearings looked great too. Have double checked all my clearances.. AGAIN, and still get a low oil pressure when hot, and a VERY noisy chain tensioner even after a start up ( actually, right at startup for about 10-15 seconds it is the quietest)

1998 A4 Turbo, quattro
New Valves , pistons/rings/ rod bearings, oil pump and chain tensioner. All Timing belt components are new. Tried several oils and swapped filers.

Going to lunch now and have a DRINK! ( no German beer thank you)

Not much of an Audi guy, but WHAT am I missing?????
Be back in a while, Thanks in advance for any input. Putting on a manual gauge after lunch.

[ricmorin]

You may have checked but the oil pickup screens on these are known for plugging.

[NPASC_mike]

All new. .. beer didn't help me think of any more solutions either.. maybe time for rum. I'm am half tempted to put the old chain tensioner back on to see if it makes noise too. I never heard this car run until after the repair, Kid states " it ran fine and made no noises" prior to the no start condition. Which after seeing the rods and pistons even I know that wasn't true. Ugh..

(edit) did find a couple of tiny particles on the screen on the new tensioner. Nothing that would make me say.. Wow there's my problem. installing old tensioner now.

[NPASC_mike]

Old tensioner, same noise, 95 psi at cold idle. Purrs like a kitten for first 20-30 seconds running then starts to ratteling. Calling it a day

[steven kiser]

since you said head i'm going with it's a 1.8, correct? if the head was planed or twisted when it came off the cam may be binding. i've seen this before. if valve stem length isn't correct it will make noise. another issue i've run into is the lifter sticking in the bore. these heads are known for cracking and although some are acceptable at certain points. if the head does twist you will have issues and one could be the cam or lifter binding. the kid could be correct when he tells you that there was no noise before it came apart. if the head was planed with the cams out then throw it away and find another. i've seen heads bowed at the cam level and flat at the block side. the time frame before the noise sound consistent with a cam or lifter issue. as soon as there is a temp change the issue arises.

[ricmorin]

OK. Have you confirmed oil pressure when the noise starts?

[NPASC_mike]

1.8 turbo yes sorry.

bottom of the head was well within flatness spec. Even made sure to untorque it in order also during removal. Noise is definitely in the top end but now not so sure its the tensioner even though it appears to be coming from the back of the head. Put old tensioner on last night to see if noise changed, which it didnt.

At stone cold startup 94-95 psi then drops off during warmup. noise starts approx 15-20 seconds after startup. ( oil pressure is still almost 90-95) by the time engine is at 160 deg F im down to about 20-25 psi at idle 50-55 at 2500 rpm which is within "spec". I have a manual gauge hooked up as these wonderful cars have nothing but an idiot light.

I am second guessing my cam timing now, Engine runs like a top, but is it possible on these to be one tooth off somewhere and still be able to roll the engine over by hand and not make valve to piston contact? Pulling plugs and going to scope out the tops of the pistons to check for contact marks with the valves. Be back soon.

Steve, if there was a problem in the top of the head as you decribed, wouldn't I see some sort of abnormal wear pattern in the cam and or bearings? hot spots, blueing, scoring etc. I see none of that but I admit I never checked the cam bores for alignment.

Its just 8:30 am here now, be in the shop in a few minutes. Thanks for the replies.

[NPASC_mike]

No marks on the pistons, Valves are all the original ones in the original locations, They merely needed cleaning. The sound is like that of several rockers that are backed WAY off.
going back in to triple check timing.

[NPASC_mike]

Timing is perfect. Does anyone know what the valve lash spec is? I cannot find it in Mitchell

[FRONTLINE]

When you say tensioner do you mean tha cam adjuster in the back of the head? I have done tons of those for noise. prefer one from dealer.

[Tim Martin]

My DVD version of On Demand says that "Valve lifters are not repairable or adjustable. Replace faulty lifters. Irregular valve train noise is normal when starting engine."

Go figure.

[NPASC_mike]

Yes that's all mine says too Tim. None of the appear to be "faulty" even when I had them out. none are stuck in the bores. But If after a warmup, I snatch the valve cover off and rotate cam so Lobe is up, I can push down on them and the spring right back up . Shouldn't they be somewhat hard to push down if I just ran the engine 3 minutes prior?

Yes Frontline, speaking of the cam chain tensioner, which I assumed is was that making noise, however last night, I put the old tensioner back on. same noise.
Except now its quiet at Idle, and as soon as I come off idle even a cpl hundred RPM,s it sounds like a screwdriver in bicycle spokes.

Do these have any Balance shaft issues??

[NPASC_mike]

Ordered Lifters, I hate shotgunning but why not now? I'm in over my eyebrows on this car now. Be a week or two before they get here. My next post will be a picture of happy customer, or a pair of audi tailights in the Bering Sea . Happy Turkey Day everyone.

[steven kiser]

deadliest catch........ sounds like the lifters bled down. be sure to soak them before installing. i haven't ever soaked these by the book so i don't know the exact procedure. i've always just tossed them into a can of 10w. i also use a cam lube when installing them. make sure the bores are smooth and the top of the valve isn't battered. now is the time to take your time and examine all. it's possible that since there was carbon buildup causing the valve travel to be less removing and restoring the valve travel caused it to damage the lifter. a thought is fluttering around in my cranial cavity here. were there shims in the lifter cylinder?

[NPASC_mike]

Same method I use, For this job I even got a tin set up so I could keep the order in which they were installed. ( soaked in castrol 5w30 for about a week.)

It's funny you mentioned the shims, I was surprised not to find a single one during teardown. I know valve length is critical on these.

I have been using Lucas as an installation lube for years, never had issues. What you say about the valve travel makes sense. Tried to save the customer a few hundred bucks where I could. I generally am pretty good at covering the "what if's" end estimating the job accordingly. I'm not going to end up making a dime on this job, All I know is I want it to be right when it leaves. I guarantee any other shop in town would have just given it back to him and said, "Hey, it runs now, noise? what noise?"

Heading home to NY in a few weeks to be with Family, hopefully the parts will be in before then, I will post an update after lifter installation.

I've been evicted from the kitchen so gonna go to the shop and clean..lol

[steven kiser]

your luck's getting evicted from the kitchen. as rule i do all the big meals as most of the regular. my wife is irish and salt is the only seasoning she uses. i spent two hours Wednesday night prepping and got up at 5 am (ya i know, later than usual) rubbed the bird down. no tina, i really mean putting spices on the turkey.

i had told everyone that the meal would be hot and on the table at noon. i didn't want to be dicking around when the pat's were on t.v. well food was ready but my wife sent two of the children on an errand. 1:15 we all sat down and the food was turd cold and had to be nuked. we had my wifes aunt over from the assisted living home and it was great. my sister in law's mother in law lives at the same place and it was a big secret that ann was coming to my house. if the other found out all hell would break loose. well being the pain in the butt i am i was sitting at the table and told ann i would give her twenty bucks if she would tell the other one she was full from the turkey at my house. ann isn't firing on all 8 and virginia got all upset because ann just might say it. i upped the anti and the kids got involved. virginia was really getting pissed. later she asked if she remembered not to tell edna. ann said she wouldn't. i told her that if she wanted to come over for christmas it would up her chances if she told edna. well before the ambulet came to get her i had to sit down with her and tell her i was just joking and we already made arrangements for her to come for christmas.

i spent most of the day in the basement with my dogs, watching football. i took the quiet time to completely tear down my 22 rifles and clean them. one was so full of grit i had to really scrape it down and let the assembly soak in solvent. it was a gun i purchased used 20 years ago and just put it away. that's another story.

now i have to add (to keep within the post) that with this type of lifter i will use a 10 weight oil. i put the lifers solid side down in a pot, pour oil in to cover the lifters by at least two inches and put the pot on a hot plate trying to keep the temp around 250 degrees for ar least five hours. i use molly lube for installs. old school and i've been using it for years. iuf you can get your hands on tuff oil i would throw that in as well. again it's just what i've been using for years and it works. i'm sure there are a lot of chemicals out there that work just as well but being a virgo i'm sticking with what i use. again, i kind of feel that changing my way of doing things is like trying to reinvent the wheel, i'm sure there are better way's but not for me. i don't think i could comfortably do it another way.

[NPASC_mike]

All in All, Sounds like a much better day than mine, Unfortunately, not much family here other than Dad and his Wife. 23 lb bird for 4 of us, and ALL the trimmings, every single morsel homemade from scratch. But the shop is Sparkling this morning and I know everything is in its place, Here's hoping I can keep it that way longer this time LOL.

Hot plate was something I completely forgot about, excellent Idea. When these get here I will give your method a shot, Even though I am like you, Why change something if its worked for years. ( until now I guess LOL) I've always used whatever oil I was planning on running to soak them, But I suppose hot 10w would surely find its way into every lifter. Sounds like a very universal and fool proof method.

Enjoy the rest of the weekend, Will update after installation.

[liljoe]

I'm wondering if a passage in the head might have gotten plugged up at some point?

[liljoe]

How did this one turn out?

[NPASC_mike]

Lifters finally arrived yesterday, Hot soaked them and then still let them sit overnight. Installing them as I type ( well, really I'm taking a coffee break) Going to let them bleed down till after lunch then fire it up. Its just noon here, so...