2004 Cayenne light knocking

[Supra-p!g]

Received the oil on Friday. Planning to change oil tomorrow. Is it a good idea to start the car and let if warm up before draining the oil? I haven't started it for 9 days since I noticed the light knocking, and thought it would be better to change the oil prior to driving it again. Just curious if warm-up is really necessary.

[JFP in PA]

Unless the car is exceptionally cold, no, it is not necessary to start it.  You should, however, plan on letting it drain completely.

[Supra-p!g]

Thanks! Last time I didn't start it either, but only drained the main oil pan. I plan to drain both tomorrow and fill the with the DT40. I just drain, replace the crush washers, and then refill until the oil level is at max on the dipstick. Then I start the car and let it run for a minute, and then top it off. Is anything else that I need to do? I don't want to damage anything.

[wizard]

Oil filter change?

[JFP in PA]

12 hours ago, Supra-p!g said:

Thanks! Last time I didn't start it either, but only drained the main oil pan. I plan to drain both tomorrow and fill the with the DT40. I just drain, replace the crush washers, and then refill until the oil level is at max on the dipstick. Then I start the car and let it run for a minute, and then top it off. Is anything else that I need to do? I don't want to damage anything.

 

That process should be fine, if you also change the filter.

[Supra-p!g]

20 minutes ago, JFP in PA said:

 

That process should be fine, if you also change the filter.

Right, I do replace the filter. There is also an oil line on the right side, but I don't think I'll bother. I'll change the oil again in 5K miles. Thanks. We'll see if this quiets the engine a bit. 

[Supra-p!g]

Since these engines have lube problems at startup, why hasn't anyone tried using an Accusump installed on a modified oil filter fitting? 1 quart of oil before cranking may eliminate this issue.

[Supra-p!g]

1 minute ago, Supra-p!g said:

Since these engines have lube problems at startup, why hasn't anyone tried using an Accusump installed on a modified oil filter fitting? 1 quart of oil before cranking may eliminate this issue.

 

Or a pre-oiler togther with an accusump.

[wizard]

Wow ! 

 

You sure appear to be advancing rapidly in the mastering of how to carry out an oil change.

 

I'd stick to well-proven basics if I were you.

[lewisweller]

1 hour ago, wizard said:

Wow ! 

 

You sure appear to be advancing rapidly in the mastering of how to carry out an oil change.

 

I'd stick to well-proven basics if I were you.

 

[JFP in PA]

3 hours ago, Supra-p!g said:

Since these engines have lube problems at startup, why hasn't anyone tried using an Accusump installed on a modified oil filter fitting? 1 quart of oil before cranking may eliminate this issue.

 

Pre oilers would not do anything to address abnormal cylinder liner scoring and wear as the oil would simply just wet the bearings and not the cylinder liners.

[Supra-p!g]

I'm wating for the oil to drain. A few observations:

 

1. The oil is black -- I just changed it maybe 800 miles ago.

2. There is pungent smell of gas/oil coming from the old oil -- maybe running too rich, which could account for the backfire sound I heard when letting off the throttle at idle. Injectors, or coils failing?

 

[JFP in PA]

If I were you, I would be saving a sample of that oil to send out for analysis.  And if there is substantial fuel intrusion into the oil, the next question becomes why?

[Supra-p!g]

I'll save it and send for analysis. The previous oil change didn't seem to smell like this. Also, the torque figure for the oil plugs -- is it 21 ft/lbs, or 37? I've seen both.

 

The main plug came out easily, I didn't torque it that hard, the second plug was likely done at the dealer, it took some effort to remove.

 

I bought two new oil plugs last time, but just realized that I only have one new oil plug crush washer. Can I reuse the old one since I likely didn't torque it enough? Well, I really don't have a choice since I only have one new washer today.

[Supra-p!g]

Something I still don't understand is why I can only get 7 quarts in and it's at the full mark. I pulled both oil plugs and let it fully drain. Replaced filter as well. 9.25 quarts is written on the inside front panel under the Mobil 1 sticker. Is this normal for a Cayenne S?

 

Seems like not enough oil, but looking at the records the previous oil changes required 9 quarts. Could there be 2 quarts left in motor or faulty dip stick? I ended up with too much oil last time when I added 8 quarts.

[Supra-p!g]

A bit of strange info: the last receipt I have from the previous owner's oil change listed the oil qty filled at 6 quarts. Could 2 quarts get trapped somewhere in the system if something is plugged?

[wizard]

Did you measure how much oil actually came out after draining?

 

In a petrol (gas) engine, the oil should not turn black anywhere near that quickly. 

 

Under normal circumstances, that would be excess (unburnt) gas getting into the combustion chambers.

 

Leaking injectors?

Edited November 14, 2016 by wizard

[Supra-p!g]

9 hours ago, wizard said:

Did you measure how much oil actually came out after draining?

 

In a petrol (gas) engine, the oil should not turn black anywhere near that quickly. 

 

Under normal circumstances, that would be excess (unburnt) gas getting into the combustion chambers.

 

7.8 quarts came out, but it was a but overfilled last time. Still need to start and drive the car, so more will probably be added.

[Supra-p!g]

I replaced the oil and now the light knocking sound is gone. Valve train is also quiet. Only concern is the sound of intake air coming in, and high pitched buzzing noise that lasts a few seconds right after cold startup. Maybe the starter got wet when coolant pipes went out?

[Supra-p!g]

Just an update: I had the Cayenne inspected at a highly recommended independent Porsche shop here in Denver. They said that my engine has no signs of scoring and overall it's the quietest and cleanest motor they've seen in a while. They scanned the car as well and no faults were recorded besides the "Air Suspension Warning" -- (I installed a Turbo Instrument Cluster from another vehicle). 

 

The car has no noises at all as I heard before with the Mobil 1 0W40 (aside from the injector noise). The DT40 motor oil made it very quiet, and it look clean as the day I put it in, even with 1500 miles on it since I change to DT40. In comparison, the Mobil 1 0W40 came out black and nasty after only 800 miles. Could the Mobil 1 have cleaned out any sludge that was in the motor?

 

Also, I just received my oil analysis packet from Blackstone. Should I send them the old black old that I took out, or wait for the next oil change?

[JFP in PA]

Glad to hear you are making progress.

 

It is almost impossible to say why the old oil was so black.  I would send them a sample of the DT40 when you drain it as it will give you an idea of where the engine is now, so you know where you stand going forward.

[lewisweller]

10 hours ago, Supra-p!g said:

Just an update: I had the Cayenne inspected at a highly recommended independent Porsche shop here in Denver. They said that my engine has no signs of scoring and overall it's the quietest and cleanest motor they've seen in a while. They scanned the car as well and no faults were recorded besides the "Air Suspension Warning" -- (I installed a Turbo Instrument Cluster from another vehicle). 

 

The car has no noises at all as I heard before with the Mobil 1 0W40 (aside from the injector noise). The DT40 motor oil made it very quiet, and it look clean as the day I put it in, even with 1500 miles on it since I change to DT40. In comparison, the Mobil 1 0W40 came out black and nasty after only 800 miles. Could the Mobil 1 have cleaned out any sludge that was in the motor?

 

Also, I just received my oil analysis packet from Blackstone. Should I send them the old black old that I took out, or wait for the next oil change?

Some good news then! Result. 

 

Shortly after I got my ctt back from the indy that did the head gaskets I could here a thud type noise from bank 1 which sounded quite unsettling, I would suspect it was a bad hydraulic lifter. By the time I drove it a few km's to the garage noise was gone and never came back. Weird. 

 

Last oil change the 5w/40 fully synthetic oil came out very black and thin. The oil filter was very dirty with lots of bits of crud and what I think was small gasket bits materials rubber and other sediment maybe left over from the head gasket job that flush out in the last 5000km but no metal. 

 

New oil is a cost effective 10w/40 semi synthetic which I'm not absolutely sure is the best oil for this particular engine, but my decision was based on the climate here which is between 18oC and 50oC. So a thinner oil is really not required for those not so cold starts. I intend to change my oil every 4-5000km. 

 

I guess the moral of the story is strange noises don't always spell impending engine failure, but don't ignore it. I was taught at college that black oil shortly after an oil change signifies that the oil cleaning properties are good, good quality oils will absorb and retain carbon better than cheaper oils. 

No idea about the detergent properties of mobile 1 compared to DT40? Which is the best multi-grade oil for a 115k km ctt running in a hot climate? 

Any thoughts gents. 

[JFP in PA]

DT40 brings both excellent film strength, and one of the highest levels of ZDDP that you can find in an over the counter full synthetic, as most of the larger oil compounders have bought into the low SAPS oil formulations that supposedly help with converter life (which is at best speculation) by significantly reducing (or even eliminating) ZDDP from their formulations.  The new anti wear compounds, usually other metal salts such as titanium, simply do not offer the level of wear protection that ZDDP has done for decades.

 

As for your question about which oil for a hot climate, I would use the 10W-40 full synthetic with the highest level of ZDDP I could find.  10W-X oils inherently have better film strengths than 5W-X oils, which will offer better component protection in the heat.  Gibbs had a full synthetic 10W-40 oil that they promoted for "hot rods or restored muscle cars" that would be an excellent choice, as would some Motul offerings in the same weight range.  I would also keep an eye out for diesel oils like Shell's Rotella (which is available as a 15W-40).  Because diesel engines are very hard on oil, and do not carry catalytic converters, their oils still carry high levels of ZDDP.

[lewisweller]

2 hours ago, JFP in PA said:

DT40 brings both excellent film strength, and one of the highest levels of ZDDP that you can find in an over the counter full synthetic, as most of the larger oil compounders have bought into the low SAPS oil formulations that supposedly help with converter life (which is at best speculation) by significantly reducing (or even eliminating) ZDDP from their formulations.  The new anti wear compounds, usually other metal salts such as titanium, simply do not offer the level of wear protection that ZDDP has done for decades.

 

As for your question about which oil for a hot climate, I would use the 10W-40 full synthetic with the highest level of ZDDP I could find.  10W-X oils inherently have better film strengths than 5W-X oils, which will offer better component protection in the heat.  Gibbs had a full synthetic 10W-40 oil that they promoted for "hot rods or restored muscle cars" that would be an excellent choice, as would some Motul offerings in the same weight range.  I would also keep an eye out for diesel oils like Shell's Rotella (which is available as a 15W-40).  Because diesel engines are very hard on oil, and do not carry catalytic converters, their oils still carry high levels of ZDDP.

Thanks for the information. 

I do like the idea of using a 15w/40 or 50 fully synthetic oil if there is such a grade available here. Will need to do some reading up on ZDDP. Knowledge is king. 

[Supra-p!g]

16 hours ago, lewisweller said:

Shortly after I got my ctt back from the indy that did the head gaskets I could here a thud type noise from bank 1 which sounded quite unsettling, I would suspect it was a bad hydraulic lifter. By the time I drove it a few km's to the garage noise was gone and never came back. Weird. 

 

The Indy also said that I likely was hearing lifter noise when I heard the intermittent thud sound.

 

Head gasket? How can you tell if that is going bad besides water in the oil, or water out the tail pipes? I have none of that, and no smoke ever, but black carbon buildup on exhaust tips. I can see old oil stains (maybe it puddled in that area at some point) in the middle bolt on the side of the right hand bank where I heard the lifter noise.

 

Thanks,

Mike

 

 

 

Edited December 2, 2016 by Supra-p!g
SP