997.2 3.8 Engine Failure
#811
Three Wheelin'
#812
I had a 2008 BMW 535 and , reliability wise, it was a disaster. Under warranty they replaced a turbo and waste gate, vanos solenoid, high pressure fuel pump, injectors, fuel pressure sensor. At 40K miles it was really falling apart. It also had a second rate factory paint job. Never drive a BMW unless it is covered by a warranty. Luckily, I had the standard suspension with all season tires so I did not have to deal with runflats, bent rims and destroyed tires. When the engine was running well it was great but the dealer had the car often and I was left driving 328 loaners with runflats. I guess they need to have a strong warranty while their cars are being leased.
#813
I had a 2008 BMW 535 and , reliability wise, it was a disaster. Under warranty they replaced a turbo and waste gate, vanos solenoid, high pressure fuel pump, injectors, fuel pressure sensor. At 40K miles it was really falling apart. It also had a second rate factory paint job. Never drive a BMW unless it is covered by a warranty. Luckily, I had the standard suspension with all season tires so I did not have to deal with runflats, bent rims and destroyed tires. When the engine was running well it was great but the dealer had the car often and I was left driving 328 loaners with runflats. I guess they need to have a strong warranty while their cars are being leased.
#814
Now back from a holiday that made internet access difficult (and that I was reluctant to broadcast to all and sundry) I am ready to finish the report I will make available on bore scoring soon.
Regarding warm up - I think the best way is to start the engine and drive off but not on full throttle and full revs until everything has warmed up. The M96/7 engines have the top and bottom of the cylinders free to flex and more bore clearance (especially when they go oval in the thrust direction) and the pistons are moderately oval - so can take earlier full throttle.
The 9A1 Gen 2 has fatter and tighter pistons, more rigid top and bottom cylinders and a comparatively massive lump of alloy cast into the bottom of the cylinder that will take longer to warm up than the upper cylinders - so needs longer to expand all the way down to the bottom.
Also the M96/7 KS cast pistons had the hard ferrous coating (that resists scoring) and the Mahle replacements (later 3.4's Cayman 3.4 S, 3.6 and 3.8 engines had forged pistons with a plastic coating. The Gen 2 9A1 also has forged pistons but a different coating (ferrotech) which we have tested in Lokasil and found netter than plastic coatings but not as durable as the old ferrostan hard iron coating - and this may influence the way the 9A1 piston reacts to running tight especially if (as we have proposed) the bores are closing in on some cylinders and some engines to squeeze the pistons near to their operating clearance limits.
Baz
More soon,
Baz
Regarding warm up - I think the best way is to start the engine and drive off but not on full throttle and full revs until everything has warmed up. The M96/7 engines have the top and bottom of the cylinders free to flex and more bore clearance (especially when they go oval in the thrust direction) and the pistons are moderately oval - so can take earlier full throttle.
The 9A1 Gen 2 has fatter and tighter pistons, more rigid top and bottom cylinders and a comparatively massive lump of alloy cast into the bottom of the cylinder that will take longer to warm up than the upper cylinders - so needs longer to expand all the way down to the bottom.
Also the M96/7 KS cast pistons had the hard ferrous coating (that resists scoring) and the Mahle replacements (later 3.4's Cayman 3.4 S, 3.6 and 3.8 engines had forged pistons with a plastic coating. The Gen 2 9A1 also has forged pistons but a different coating (ferrotech) which we have tested in Lokasil and found netter than plastic coatings but not as durable as the old ferrostan hard iron coating - and this may influence the way the 9A1 piston reacts to running tight especially if (as we have proposed) the bores are closing in on some cylinders and some engines to squeeze the pistons near to their operating clearance limits.
Baz
More soon,
Baz
#815
Rennlist Member
Thanks Baz. Appreciate the information. Most of us bought these baby's used and stuff like this is scary! I warm up my C4S idling in the driveway until temp climbs just over 100 deg (2-3 minutes) so I know there is warm water running around in there. Then I drive it easy until it reaches operating temp. I look forward to your report.
#816
RL Community Team
Rennlist Member
Rennlist Member
Thanks Baz. Appreciate the information. Most of us bought these baby's used and stuff like this is scary! I warm up my C4S idling in the driveway until temp climbs just over 100 deg (2-3 minutes) so I know there is warm water running around in there. Then I drive it easy until it reaches operating temp. I look forward to your report.
#817
I think that the experts have conveyed to us that it is the oil temperature that is an indicator of when the engine is fully warmed up, not coolant temp. It takes my 997.2 engine about 12 to 15 easy miles on the freeway to get oil temp up. The water temp shoots up very quickly.
#818
RL Community Team
Rennlist Member
Rennlist Member
2009 C2S..
I posted this before. Car was parked outside all night with ambient temp 32 degrees F when I started it up. Data from Durametric. Oil temp lags water temp by about 4 minutes once water temp hit 180... some of that 4 minutes it looks like I was at a red light.
https://rennlist.com/forums/997-foru...tric-data.html
Click on pic for larger.
Peace
Bruce in Philly
I posted this before. Car was parked outside all night with ambient temp 32 degrees F when I started it up. Data from Durametric. Oil temp lags water temp by about 4 minutes once water temp hit 180... some of that 4 minutes it looks like I was at a red light.
https://rennlist.com/forums/997-foru...tric-data.html
Click on pic for larger.
Peace
Bruce in Philly
Last edited by Bruce In Philly; 05-20-2019 at 06:02 PM.
#819
I think that the experts have conveyed to us that it is the oil temperature that is an indicator of when the engine is fully warmed up, not coolant temp. It takes my 997.2 engine about 12 to 15 easy miles on the freeway to get oil temp up. The water temp shoots up very quickly.
#820
Rennlist Member
As a separate followup, we had Ceratec tested to see exactly what it is. As we figured, it a super concentrated moly additive. Here are the test results:
https://www.speediagnostix.com/new-o...lysis/cera-tec
As I've told many of you who have emailed me, I wouldn't use this product with any oil other than Liqui-Moly's oils, because of fear of additive clash.
The standard A40 additive package used by most manufacturers has 0 to 50ppm of moly.
For comparison, DT40 has 600ppm and DI40 has 300ppm of MoDTC (moly).
Based off multiple research papers I've read on hypereutectic bores, increased levels of ZDDP and Moly are the key to reduced wear.
#821
Rennlist Member
#822
Spot on.
As a separate followup, we had Ceratec tested to see exactly what it is. As we figured, it a super concentrated moly additive. Here are the test results:
https://www.speediagnostix.com/new-o...lysis/cera-tec
As I've told many of you who have emailed me, I wouldn't use this product with any oil other than Liqui-Moly's oils, because of fear of additive clash.
The standard A40 additive package used by most manufacturers has 0 to 50ppm of moly.
For comparison, DT40 has 600ppm and DI40 has 300ppm of MoDTC (moly).
Based off multiple research papers I've read on hypereutectic bores, increased levels of ZDDP and Moly are the key to reduced wear.
As a separate followup, we had Ceratec tested to see exactly what it is. As we figured, it a super concentrated moly additive. Here are the test results:
https://www.speediagnostix.com/new-o...lysis/cera-tec
As I've told many of you who have emailed me, I wouldn't use this product with any oil other than Liqui-Moly's oils, because of fear of additive clash.
The standard A40 additive package used by most manufacturers has 0 to 50ppm of moly.
For comparison, DT40 has 600ppm and DI40 has 300ppm of MoDTC (moly).
Based off multiple research papers I've read on hypereutectic bores, increased levels of ZDDP and Moly are the key to reduced wear.
#823
Three Wheelin'
I had a 2008 BMW 535 and , reliability wise, it was a disaster. Under warranty they replaced a turbo and waste gate, vanos solenoid, high pressure fuel pump, injectors, fuel pressure sensor. At 40K miles it was really falling apart. It also had a second rate factory paint job. Never drive a BMW unless it is covered by a warranty. Luckily, I had the standard suspension with all season tires so I did not have to deal with runflats, bent rims and destroyed tires. When the engine was running well it was great but the dealer had the car often and I was left driving 328 loaners with runflats. I guess they need to have a strong warranty while their cars are being leased.
I had an opposite experience. My 128i (N52 engine) was completely faultless. Excellent car, never had an issue. I think its more about being smart which model you buy. There is plenty of documentation online showing which engines are trouble, just have to read it before buying!
#824
Rennlist Member
I'm not really up on oil analysis. I have a 997.1 so I don't care about LSPI obviously. I was considering Ceratec. Can you explain how additive clash works with common A40 oils? For simplicity, I'd consider changing oil with 8L oil and 300ml Ceratec. Ceratec would be 3.6% total volume or about 1:28 dilution. The components of Ceratec are present in most or all A40 oils I assume. The moly component would add about 164ppm to oil used. Other components added at lesser concentrations. I'm currently using M1 so doesn't seem like anything added in Ceratec would be detrimental and only better with Ceratec. LiquiMoly has several A40 formulations. Shouldn't they reasonably know if Ceratec is adequate to use with any A40 oil? I suppose a boutique oil with especially high concentrations of some additives already may be an issue. Thanks
Lake and I have spend the better part of fifteen years trying to explain that more is not always better. It's about a balance of the additives. Too much moly and you get sludge, too much calcium to keep the engine clean and you get accelerated wear, too much ZDDP and you end up with increased wear, etc. It's always best to use a fully formulated oil without additives when possible.
I would have to trust on blind faith that the Ceratec additive would work in a synergistic manner with their own oils and keep the additives in balance.
#825
I had an opposite experience. My 128i (N52 engine) was completely faultless. Excellent car, never had an issue. I think its more about being smart which model you buy. There is plenty of documentation online showing which engines are trouble, just have to read it before buying!
You are right that I should have been smarter. I am smarter now that we have a flawless,absolutely trouble free 2016 Audi A6 with 45K miles. I am also smart because my 2008 C2S has had only one repair since new ( water pump).
There is good and bad luck and there are good and bad designs.