Tapping noise at 3000rpm- but not when cold.

[AC993C2S]

Noticed a distinct tapping noise in the pass side when I hold the throttle at 3000 rpm. This only happens when the engine is WARM. It almost sounded like pinging, but it is not. Took the car to the local shop today and he told me that the Dealer normally uses "0" weight oil and that I should be using something heavier. The dealer just did a 30k.

My thought was lifetrs, but he ruled that out. He said that his suspicions are the wrong oil weight from what he thought was "right" becasue the tapping is most prevalent when the engine is warm.

There is no noticable tapping noise at idle.

Bringing car in tomorrow to have existing oil drained and re-filled with heavier oil weight per his recommendation.


This sound right to you?

[cowtown]

Did the noise start right after the 30K service, or was it present before that?

[AC993C2S]

I bought the car from the dealer...and cant say that I noticed the noise when I test drove the car. I didnt take possession fo the car until after they did the 30k. Now, it could have been there and I just didnt notice b/c of excitement...

I always read about tapping when engine is cold...but never when warm. Its not loud, but noticable. If I hold the throttle at 2900-31--rpms and slightly rev higher or lower, you can hear the rate change with the RPMs.

Again, only when fully warm...and mainly while in gear.

[AFJuvat]

Yes, that sounds right.

Mobil-1 15W-50 for Florida. - serves you well all year long.

The 993 lifters get a little noisy on the 0W-40 that Porsche uses.

AFJ

[kang]

I find it interesting that you only hear this noise at a constant 3000 RPM load with a warm engine. I would think there would be plenty of oil pressure to pressurize the lifters at that RPM, even if you’re lifters are starting to go. On the flip side, if your lifters were starting to go, you’d hear them tapping in a lot more situations than just a constant 3000 RPM.

Do you hear the noise when you are driving at a constant 3000 RPM, or just sitting in a parking lot, holding a constant 3000 RPM? There is a substantial difference on the load on the engine in these two circumstances.

Do you hear lifter clatter when you do a cold start, say first thing in the morning? When using a heavier oil, say 15W-50, this clatter can be quite loud, as it takes a while for the lifters to pressurize. When using the factory specified 0W-40, this clatter is minimal or even absent. With bad lifters, it could go on for a while.

Yes, your car can be a bit nosier with 0W-40 than 15W-50, but that doesn’t mean anything is wrong.

As for the oil weight, the factory does specify 0W-40. Some say this is so the dealers only have to stock one kind of oil, but I say hogwash. Porsche is not so cheap as to only want to stock one kind of oil at the dealer. Most dealers have several kinds of oil in stock.

Joel Reiser, of the PCA, has mentioned on the PCA tech board that some 993’s have had problems with lifters due to using the heavier oil, like the 15W-50. The 0W-40 pressurizes them much quicker and the lifters like that much better. He recommends 0W-40 except in extremely hot climates or lots of track driving.

Some old school experts recommend 15W-50 because that is what they have always done. They fail to take into account improvements in oil technology. Some manufacturers recommend 0W-20 these days. This is not because engine building technology has improved; it is because oil technology has improved.

As far as deciding what oil to use, I rate the various opinions like this:

Factory > Joel Reiser > Various Experts (Steve Weiner) > everyone else

Both the factory and Joel Reiser recommend 0W-40 for your climate.

Make your own decision.

[AC993C2S]

Replaced oil with 15w50...sounds MUCH better!

[DB_NC_95C2]

may I ask (used search to find this thread) about 15w50 Mobil 1 in the N.C. climate ?
My SC that was just totalled loved that weight it seems, so I'm looking at a 993 C2 and hoping it's also the right weight for it. (I have 4 5-qt jugs of the stuff)

Thanks

[dmwallace]

DB,

There's a huge thread in the 911 forum about oil for our cars; you can do a search on user name cnavarro and find it.

FWIW, I replaced Castrol Syntec that the dealer used with Swepco 15w-40 in my car.

Regards,
David

[Bill Verburg]

Originally Posted by kang

As far as deciding what oil to use, I rate the various opinions like this:

Factory > Joel Reiser > Various Experts (Steve Weiner) > everyone else

Both the factory and Joel Reiser recommend 0W-40 for your climate.

Make your own decision.

Some seem to forget that oem oil recommendation
for temps mostly > 50F
were
for mineral oil
15w-40, 20w-50, or straight 40

for synthetic oil
10w-40,15w-40 or 15w-50

for temps mostly between 14F and 50F
mineral
15w-40,10w-40 or 10w-30
synthetic
10w-40, 10w-30 or 5w-30

Current factory recomendations have little to do w/ current owners concerns wrt longevity, the factorys recs are ephemeral and based on political/regulatory/commercial environment as much as engineering principles. They don't actually care what happens once the cars are more than a few years old, it is actually to their benefit to have to rebuild frequently.

I have experienced lifter rap on cold starts w/ 15w-50 synthetic, but not w/ 10w-40 synthetic. I prefer the 15w-50 for track use in the summer. JMPO

call be a dinosaur