for what it`s worth as i am on 997 m96 3.6L i had valve lifters knocking after AX runs consistently - so i installed x51 pan and went to heavier 5w50 oil and it stopped completely. now i use 5w50 for winter and 50/50 mix of 5w50 and 15w50 oils for summer. seems to work fine for DE and AX.

 

In our experience the weight of the oil can be a "band aid" for one symptom and lead to others, especially using heavy weight oils in VC+ engines.

The brand of oil and its elemental composition is the key, not just the weight.

Fact is most people reading this have 1/2 of their lifters no longer properly functioning due to debris blocking their oiling passages. Using a flush makes it worse, it flushes all the other debris right into the lifters as they are the final portion of the pressurized oil delivery system.

 

so let me understand

1- there is nothing you can do unless you open the engine ?
2- what are the consequences of stuck lifter ? aside of the noise ?

 

1- This remedy requires intervention. Remove the cam covers, remove the cams. The lifters basically fall out.

2- Noisy lifters are lifters that are collapsed. The M96 engine loses roughly 20% of it's net valve lift if a lifter is collapsed. This results in uneven idling, poor chamber filling, reduced power and most notably a reduction in fuel mileage.

I have literally performed an upgraded lifter retrofit and the car piked up 10 MPG on its return trip home over what it averaged while being driven 450 miles to our facility for the work to be carried out.

Noisy lifters won't lead to big booms, but they can lead to broken lifter cradles from the excess side loading of the lifter traveling further before contacting the valve. The collapsed lifters always lead to excess valve lash, which is what creates the noise.
They never stick "open", always "closed" (or collapsed)

 

Thought I would jump in on the use of "BMW lifters" as I think I was the first to post on this a couple of years ago. The original lifters for a 3.4 VarioCam engine (actually all VarioCam engines including the Boxster) were part number 996.105.041.50, and were used on both the intake and exhaust valves. These lifters were made by INA and were also used in several BMW engines including 2000 X5 V8's.

In 2002 when Porsche introduced the 3.6 VarioCamPlus engine the lifters were changed. The intake lifters were completely redesigned and the exhaust lifters were revised (I don't know how as they function the same as the old lifters) and had a new part number 996.105.041.72. Porsche also superseded the lifters for the VarioCam engines to this new part number and at some point in time stopped distribution the old lifters/part number. I don't know what specific changes were made in the design between the old part number 996.105.041.50 and the new part number 996.105.041.72. Perhaps Jake Raby can shed some light on this. However the new exhaust lifters were more expensive than the old ones (the new intake lifters were much more complex and were much much more expensive).

When I was fixing the intermix on my engine I discovered that more than half of my lifters were "collapsed" and started to look at alternatives for replacing them. I did a lot of searching on the internet trying to find an inexpensive source for lifters. In searching for the old part number I could not find any source at all but saw some references to BMW's. Found several sources for the new part number. Being persistent I found a website and catalog for Febi/Bilstein for lifters, including ones made by INA. I found the new part number. Took a look through the BMW section of the catalog and found that the 2000 X5 V8 listed a lifter with both a BMW part number (11 32 1 748 884) and the old Porsche part number. Then found a source for the BMW lifter that at that time was only $12.02@. I talked with them and they were not sure of the fitment for the Porsche. I ordered 24 of them and they were exactly the same lifters as the ones I had taken out of my engine.

So yes the BMW lifters will fit a VarioCam engine (and I am guessing they would fit the exhaust side of a VarioCamPlus engine) and are still readily available under the BMW part number. Unless someone can explain why the superseded lifters are "better" than the old lifters, I for one am happy to use them.

 

For those who are interested, Pelican Parts lists the new Porsche part 996.105.041.72 for $47.75@. If you search under the old part number it will redirect you to the new part number. But if you go to the BMW section and search for the BMW part number 11 32 1 748 884 they have them for $18.25@

 

It is interested to hear that poor MPG might be an indicator of 'dead lifters'. I heard some 996 owner complaining about bad MPG and I was surprised as I get great MPG on my car but it only has 30k miles on it.

I hope someday someone will post a DIY on this cam removal procedure.

At least it doesn't seems to be fatal to then engine.

phil

 

I think I'm having the same problem with one or more of my lifters on my 99 c2. (104k miles) A mechanic friend of mine agrees, but I haven't taken in to my local indy shop yet. How many hours labor do you think would be required for a competent p-car mechanic to replace all lifters? Also, the noise I'm hearing seems to come from the left side only. Should all of them be changed, if just one is bad, or just one side is causing the problem?

I read an interesting post that Doug wrote about what's involved in changing them out as a DIY. I'm comfortable changing spark plugs, but this may be a little beyond me.

-Jason

 

What's poor mileage? I'm getting 18 and just got 19 last refill.

 

He must have the proper cam timing tools to carry out this job. It is not difficult, but procedural. I have prepared an in depth article that covers this and it is available to those shops in our network.

Most 996s in good tune and health will get 23MPG and maybe as much as 23 on the open road. With MPG in the 16 range I'd say your engine probably does have worn vario cam components or lazy lifters or both.

Collapsed lifters effect MPG because MPG is a direct reflection of efficiency. Cylinders that have lazy lifters actuating their valves see poor chamber filling and uneven firing. The MPG shows these issues more than anything else, even when the collapsed lifters aren't audible.

 

My car goes 21 to 22 MPG. I drive mostly to work and back. On city and highway.

To me this ticking is anoying...
Well mayby I'm just too meticulous with my cars

 

Given the complaints to Mike Miller of Bimmer Mag. about BMW engine lifter noise I'm not sure BMW lifters are the way to go.

While the Porsche lifters with the new part number are expensive they might be better lifters, be quieter and last longer?

Sincerely,

Macster.

 

I don't disagree with Macster that the newer lifters might be better/longer lasting than the old ones. I wish we could all find out what the design/difference is. However with 24 lifters the price of the old ones is only $438 plus tax while the new ones would be $1,146 plus tax. WOW!

I know that Flat 6 was offering their rebuilt, modified lifters for about $500 a year ago. Not sure if Jake still offers them.

Jake, it would be great if you could explain the difference in the designs and confirm if you still offer the modified lifters.

 

Jake, what choice of oil would you recommend to prevent this issue, or delay, or reduce severity?

 

Thats easy, Flat Six Oil.

We still offer the updated lifters, but we use them so fast that we can't keep them in stock these days. Between elective update work, repairs and engine builds our shelves stay depleted.

It is imperative when changing lifters to have the lifter carrier measured for taper and excess wear at the 6-12 O clock positions. Not doing this spells certain death to lifters at around 8K miles at the wear eff3etcs the lifter rotation during operation and increases wear dramatically. We've learned this the hard way during test work and even in one of our updated engines.