Valve lifter problem? (Oil pressure? Journals? Oil pump?)

(Sorry for this being so long, but I'm trying to tell everything so you can try to make the whole picture of the problem)

I have a Audi A6 1996 with 2.6L V6-engine, with hydraulic valve lifters. The car has been driven for about 85k miles (

Reply to
Tero Patana
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Theory time.......... sounds like debris is in the oil pan and at higher rpms, the oil pump sucks at a greater volume and the debris clogs the oil pump strainer. Then the oil pump pumps less oil to the lifters and that noise develops.

Testing time....... See if my theory is correct by installing an oil pressure gauge and observing readings while conducting the same high rpm tests.

Or drop the pan to check and possibly change the oil pump.

Are you using good oil filters? which brand?

later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris

Reply to
dave

This is very possible, I just wish this could be proven fact, and also given a good solution to get rid of the debris.

This is one of the next things to try (I wonder why the repairman didn't test this at first??)

I was told that this engine needs quite much labour (=cost) to open the engine. So far, the costs have been quite nice, and almost nothing has been done, so I wouldn't want to spend any more money at guesses. I wish there was some way to make certain what is the problem.

Don't know, since the repairman has acquired them. Should be ok, but this was one of the questions which I intended asking him next time I'm visiting him.

One of the thousand quesses, was that if the filter has too small flow holes (or what you call them?), then the oil flow "chokes" when it needs to flow more. One quess, but I don't believe too much in this one.

-Tero

Reply to
Tero Patana

Ever replaced the Belt and Belt tensioner?? I suspect your problem lies either here or in the oil pump.

"Tero Patana" escribió en el mensaje news: snipped-for-privacy@paju.oulu.fi...

Reply to
JP Roberts

Not sure about the tensioner, but the belt is changed 10k miles ago (~16k km).

Can it be the pump, if the other V-brach works (or at least seems to) correctly?

Reply to
Tero Patana

Tero, Sounds like the "Orange Filter of Engine Death" to me - paper element cannot handle the high oil flow and implodes - sucking chunks of paper into the oil passageways in the engine. I've only heard of this with older 200/5000 turbo engines, but the filter that may have been the culprit was thrown out with the oil/filter/lifter change, right? Unfortunately, the people who I have heard this happen to have had to undertake a major motor rebuild to get the fluff out of the system. When the engine was flushed, did you look to see what came out in the flow? Given that the engine is so new, and the onset of the noise so instantaneous, it's a wonder why your repair guy didn't drop the pan - maybe it's time to change the repair facility before they change anything else on spec. Cheers! Steve Sears

1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Uni> > >From: Tero Patana snipped-for-privacy@mail.student.oulu.fi
Reply to
Steve Sears

I had some noise at tilt, and some detonation under load at around 1950 rpm - on my 1.8T, and it all disappeared when I had the belt, tensioner and the V-branch pulleys replaced. Since your car has over 140 thousand km in the counter, you should already have had those replaced quite some time ago, so I'd suggest your doing this before any further attempts at replacing the pump.

Also, since it seems to be the case that the noise occurs under engine load - as you mentioned - this might indicate that there could possibly be a bad belt tooth causing detonation because of excessive timing advance at certain times when the bad belt tooth sent the wrong ignition timing. Because it's a six cyl. power loss might not be so noticeable as it would on a 4 cyl. engine.

My two cents,

JP Roberts

Reply to
JP Roberts

edited

get some oil pressure readings at different rpms and/or while that lifter noise is occuring

later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris

Reply to
dave

I wasn't around when the engine was flushed, so didn't get to see the oil. I guess that the filters aren't the cheapest around (nor the most expensive), but I suppose I will ask the repairman about the filter. They are experienced with Audis, so I assume they shouldn't have done a mistake that stupid. I really hope this isn't the case, since rebuilding the engine doesn't sound too cheap solution. In addition to stupid car tax regulations here, there is some limits how costly repairs are reasonable to do for cars that old.

Around here, there's two choices. Either the local Audi dealer, which costs like hell, or private repairs, which cost moderately cheaper, and in fact, in many cases do better job than the dealer. This one seemed to be better than average experienced with Audis, so I wish I could rely on their expertise.

Thanks for the tips Steve.

-Tero

Reply to
Tero Patana

Hmm.. given my great knowledge about English, what you mean with V-branch pulleys? When I was talking about V-branch before, I meant the other half of my V-engine. I recall 1.8T is not V, but straight.

But if the belt is changed under 16 thousand km ago, I suppose it shouldn't be problem yet?

What indicates that it is not timing nor ignition problem, is that when they removed the valve lifter gasket, no oil came there when the engine was running.

So most probably the problem is somewhere in the oil flow chain, the pump, the filter, the journals etc... or maybe not :(

Any comments or suggestions are appreciated, since the real cause is still unknown. I just personally suspect the oil flow chain.

Thanks for comments,

-Tero

Reply to
Tero Patana

Just talked with the repairman, they had installed oil pressure gauge, and measured the pressure while the problem was on. I don't know what the readings were, but he said they were ok. If I talk to him again, I might ask the readings, if he did wrote them down or is able to memorize them. (Why I used _if_ instead of _when_ :) )

Next thing he suggested to try, is to open up the motor and try to find what and where the clog is.

One guy suggested, that the... isolating thing between the engine and the cover, which mostly keeps oil from spilling out, whatyoucallit?.... might be worn so, that it partially blocks the oil journal. If the engine is opened, it will be replaced the same time so it might correct the problem. (or then again, it might not...)

Reply to
Tero Patana

Did they change tensioner and idlers, and possibly the water pump at that time? I have had the timing belt(s) changed on my 2.5tdi V6 recently, and I believe there were about four idlers and the tensioner that were replaced at the same time, plus the water pump as a precaution. The idlers alone were about EUR 550, and the waterpump about 80, IIRC.

I doubt that this is your problem though.

Cheers, Thomas

Reply to
Thomas Tornblom

You drove the car 85K miles and only changed the oil once?

Um, I seriously hope that you bought this car used and have only had it a couple thousand miles. I wouldn't leave *any* oil in an engine longer than 10K miles, and I tend to change my own vehicles at 3-5K.

In any case, in response to your question, I'd be interested to know actual oil pressure as measured at various places around the engine. I dunno if you've got a sludge problem or actual engine wear, but I'd be betting on one or the other.

nate

Reply to
Nate Nagel

It says:" I don't know what oil's there have been before, but when I bought the car, I applied Mobil 1 0W-40 synthetic oil."

So I guess that could be read as if I don't know what oils the previous owner(s) did use, but when I bought the car, I (almost) immediately changed the oils.

Yes, I have driven now with this car almost exactly 10k miles, with these oils 6-7k, as I said in the post, the oil change was due in near future. The Mobil 1 recommends around here something like 6-7k change interval. I also change filter every time when the oil is changed.

I try to get that information. Could someone tell what is "sludge", since my English-inHead-dictionary doesn't recognize that word, and my Webster is at work. Engine wear shouldn't be the issues, since it looks to be in good condition (AFAIK), if you don't look at the debris inside the engine.

-Tero

Reply to
Tero Patana

I think that what you are calling "debris" is what I'm thinking of as "sludge." Catchall word for that black goo and/or hard crusty stuff found inside an engine's oil system when something hasn't been right with it.

nate

Reply to
Nate Nagel

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