K&N

[BodybyFisher]

I found this thread last week, and while I was primarily following the blown engine story, one sentence got my attention.

I have an aftermarket More Performance CAI with FFV-type intake. MAF was dirty from K&N filter, but no way did any significant debris enter the TB. This kind of confirms our discussions regarding K&N.

However besides the K&N issue, the ethics or specifically the lack of ethics is what bothers me. All of you who know how I feel about GM will not be surprised that some of the unethical posts ripped at my stomach lining.

Who thinks that if I reprogram my PCM and eliminate the rev limiter and torque management that if the engine destroys itself that it is GM's responsibility? I certainly don't. I really feel badly for this guy and his new 05 CTS-V, but once you modify the engine management system you are flying without a parachute. By the way, the owner appears to be an very honest guy.

It's about ETHICS guys, having ETHICS not playing Robin Hood Please don't post any negative statements we don't want a battle. Its about ETHICS these days.

http://www.cadillacforums.com/forums/showthread.php?t=57978

[Regis]

I read that thread the other day. I love the way that one particular member justifies how and why it's OK to sham GM. He has the makings of a politician. I guess he wouldn't mind sending me 25cents a day for the rest of my life. I mean, he'll never miss it....right? And I figure he "owes" it to me just for being a misguided ars that'll most likely pass on that warped value onto the next generation. And I'll directly or indirectly have to pay for the consquences of his value system. Heck, the way he figures things, he should send ALL of you 25 cents a day for the rest of your lives too. Because 25 cents is such a small amount......he'll never miss it....right? LOL too funny.

[tjtjwdad]

I just finished reading this. What I didn't hear was how has the owner of this CTS-V actually drive the car between the time of these MODS and his engine failure. It seems to me that a MOD that removes the rev-limiter is not for cruising the BLVD @ 35 MPH.

Jim

[Ranger]

I will be amazed if he gets a dime under warranty.

[KHE]

I read that thread during my lunch hour today... My take is that he is not telling the full story or he injested water with his cold air intake and screwed up the engine. Either way, I can't believe that guy or any of the responders think that over-revving the engine couldn't lead to engine damage and believes GM should pay for it....DUH...GM should not pay for his stupidity...and to think he is a physician....he may have more money than brains but I wouldn't let him take my blood pressure...

[BodybyFisher]

I just finished reading this.  What I didn't hear was how has the owner of this CTS-V actually drive the car between the time of these MODS and his engine failure.  It seems to me that a MOD that removes the rev-limiter is not for cruising the BLVD @ 35 MPH.

Jim

I know I thought the same thing. From my brief talk with Mark99STS he was saying that if the air/mix leans out for too long of a period severe detonation can occur. I wonder if severe detonation could cause a block to crack.

See this link:

http://www.asashop.org/autoinc/aug2003/techtotech.cfm

Detonation (also called "spark knock") is an erratic form of combustion that can cause head gasket failure as well as other engine damage. Detonation occurs when excessive heat and pressure in the combustion chamber cause the air/fuel mixture to auto-ignite. This produces multiple flame fronts within the combustion chamber instead of a single flame kernel. When these multiple flames collide, they do so with explosive force that produces a sudden rise in cylinder pressure accompanied by a sharp metallic pinging or knocking noise. The hammer-like shock waves created by detonation subject the head gasket, piston, rings, spark plug and rod bearings to severe overloading.

If the RPM has been limited by the software, couldn't the engineers have limited because beyond the limit the A/F mixture leans out and potential damaging detonation occurs beyond that point? To me, this change should have been tested on a dyno to see what happens to the air/fuel mixture beyond that point. If the mixture leans out the change becomes risky unless the lean mixture can be can be corrected in some manner. (higher flow injector?) Am I making sense? Is this an LS1? Why isn't there a better engine management software tweak than what he had? Of course this is assuming that the changes damaged the engine and it wasn't something else..... Kevin you mention over revving can it damage an engine like I am describing and not necessarily valves and pistons hitting?

I found this article on Detonation and Pre-ignition, its a good read. I just found it and saved it to my Engine Technical Articles folder, its a keeper

http://www.contactmagazine.com/Issue54/EngineBasics.html

[tjtjwdad]

I don't know enough about the internal going-on's in engines to say the least but it certainly sounds possible. One thing I've learned since getting into the semi-conductor industry (and it applies to all engineering I'm sure) is the ole' "Domino" theory and I bet that is what happened here.

Basically in that scenairo WRT CTS-V; " something stinks" or I think there are somethings that aren't be made public. I can understand frustrations with car dealers because while what they do it times maybe legal ... it might not be right!

Jim

[KHE]

It seems like over-revivving can cause valve flutter and interference with the pistons and subsequently catastrophic engine damage. Too bad we don't have the guru's analysis here as I am not qualified to offer anything other than an opinion though...

[KevinW]

If the RPM has been limited by the software, couldn't the engineers have limited because beyond the limit the A/F mixture leans out and potential damaging detonation occurs beyond that point?

I would say that's extremely unlikely. From what I've seen, there's built-in protection for exceeding look-up table ranges, and I believe the car in question is MAF-based, suggesting that heavy-throttle fueling is based primarily on the actual airflow consumed by the engine.

Many PCM 'tuners' are not aware of the full implications of the changes they make. I doubt that the RPM limiter threshold would be the only value that was altered. Also, RPM limiters are of limited value in the case of a manual transmission, since it is possible to select an inappropriate gear (on a downshift) and spin the engine above this speed in the absence of injector activity.

Another factor is that oil contamination of a MAF, from a 'factory' oiled K&N, will decrease the PCM's perceived airflow in many cases. This has the effect of enleaning the WOT fuel mixture, which would be 'double trouble' in the event a PCM 'tuner' had also changed the fuel calibration to be leaner under these conditions.

[BodybyFisher]

KevinW, so what you are saying is that besides the possibility that the 'tuner' could have leaned up the a/f mixture by accident or on purpose the fouled MAF could also have contributed to a lean a/f mixture? Can this condition at very high RPM cause severe engine damage?

[MAC]

I'm going to play devil's advocate a bit by saying that there has yet to be a definitive diagnosis as to why the engine failed. That said, it would appear the dealer/GM is assuming that the mods, including PCM reprogramming, caused engine failure? My guess is that once a PCM is reprogrammed outside factory parameters all bets are off?

[BodybyFisher]

I'm going to play devil's advocate a bit by saying that there has yet to be a definitive diagnosis as to why the engine failed. That said, it would appear the dealer/GM is assuming that the mods, including PCM reprogramming, caused engine failure? My guess is that once a PCM is reprogrammed outside factory parameters all bets are off?

Mac, I said this above, to be fair also, "Of course this is assuming that the changes damaged the engine and it wasn't something else"....

I have not looked but I am sure that someplace in the warranty it states that modifications could void warranty. Removing the rev limiter and a affecting the torque management system kind of falls under this heading.

What Jim said above "What I didn't hear was how has the owner of this CTS-V actually drive the car between the time of these MODS and his engine failure" also applies to GM, they have no idea of how the engine was driven, all they know is that a safety feature, (read that rev limiter) was eliminated.. Someone said that the stock LS6 valvetrain limit is 6,800..

Years ago a friend of mine worked at a Ferrari dealer, they allowed a potential buyer to take one for a test drive and he blew the engine by reving too high, I think he missed a shift.

See this link:

http://pages.sbcglobal.net/gorf/bmwtips/maintoverrev.html

Here is a teaser from that article:

Three times this year alone, I have had M3s fall into my hands. One came in running on five cylinders, the other two had been overreved so bad, engine replacement was required

[tjtjwdad]

all they know is that a safety feature, (read that rev limiter) was eliminated

Maybe that is why GM is taking a hard line. When you interfere with the safety mechanisms that are built in it would seem to me you’re getting outside the box.

Something I've been thinking about that was mentioned in the referring link, was the law (don't remember the title) that allegedly says the dealer/manufacturer has to prove an aftermarket device caused the failure. Now as I read it, that's a broad statement. We’re talking from the mundane items (filters being the simplest) to the exotic (PCM, MAF). Maybe it’s just me, but if you tinker with the safety devices designed to protect the engine (in this case) then you’re on your on.

Another thing, these folks that owned these high horsepower cars, CTS-V, GTO, Z06, STS-V, and so on … should be luck that they even have a warranty. I remember when a neighbor of ours bought a 426 HEMI in 1968 Plymouth had a direct approach: “NO WARRANTY”!

I remember a while back there was someone here on the topic of discussion was “speed”. I remember ole bbob chiming in and quoting (I hope I got it right) …. Speed cost money. How fast do you want to go?... Not to make light of this persons bad fortune but I think he just found, at least with this particular car.

Jim

[KevinW]

KevinW, so what you are saying is that besides the possibility that the 'tuner' could have leaned up the a/f mixture by accident or on purpose the fouled MAF could also have contributed to a lean a/f mixture? Can this condition at very high RPM cause severe engine damage?

I would expect that if damage were to occur from a lean mixture (not lean enough to misfire consistently), it would likely occur under high load conditions of a significant duration; heat is a factor. Heat generation would be the highest at WOT and the engine RPM corresponding to peak power generation.

A 'hot wire' MAF sensor works on the principle that the rate of cooling of a heated (at a fixed rate) sensing element is proportional to the airflow rate at that location. Surface contamination of the sensing element acts as an insulator, decreasing the cooling ability of the passing air. Also, since this sensing occurs at one location inside the MAF, much of the calibration work is performed in situ; changing the air intake pathway leading up to the MAF sensor may affect readings under some conditions.

[keith_99_sts]

Any engine can fall apart, even a Corvette block. But if a car comes in with a widget installed to change the upper RPM limit that will be the quickest warranty denial in history.

I had to laugh at the guy who thinks it's okay to undo the mods, go to another dealer and pass it off as an unmodified engine breakdown, and say that GM is rich and can afford it. NEVER do business with that thief!

[Bill K]

If a guy screws up his MAF by cleaning/oiling the K&N I've got to wonder about his abilities. I have had K&Ns on three vehs. for 4 or more years and have had no MAF problems. The "secret" is to read & follow the directions. It aint rocket surgery......

[Regis]

pssst Bill........ it's "science"......rocket "science".

[BodybyFisher]

Well, I am not sure what he meant by his MAF was dirty. I don't think he implied that he cleaned his K&N. I just think that he said his MAF was dirty. That was what caught my eye. In addition, I am not trying to debate the virtues of K&N here, only pointing out that a K&N user made a statement regarding his K&N easily accepting that the K&N somehow allowed his MAF to get dirty..

From what KevinW has noted, the dirty MAF contributed to the computer receiving erroneous information.

[tjtjwdad]

I've oftened wondered about a K&N in my 01 STS. I have one on my 92 Bronco and I really like it but it is an oil thing. Same goes for the air box mod as well but the last thing I need is a water entering the system so I've left her as is, besides, the car is still under a warranty.

What would really be nice to here is bith sides of the story.

Jim

[tjtjwdad]

kger2 Posted on Nov 27 2005, 07:53 AM

pssst Bill........ it's "science"......rocket "science". 

Nice ....... real nice.

Jim

[Bill K]

Psst...kger2 Ever watched the movie "Mystery Alaska"? Rocket surgery. Phrase coined by the hocky announcer.

BF The cleaning was an assumption by me as that is the only knock I have read on an open element filter as far as dirtying a MAF. If just useing them caused dirty MAFs than I should not have any cars running.

[BodybyFisher]

I've oftened wondered about a K&N in my 01 STS.  I have one on my 92 Bronco and I really like it but it is an oil thing.  Same goes for the air box mod as well but the last thing I need is a water entering the system so I've left her as is, besides, the car is still under a warranty.

What would really be nice to here is bith sides of the story.

Jim

Jim, as you know we have debated the K&N filter subject many times. A few members like them, but the overall impression is that they don't filter adequately for the benefits received. The oil issue is just another chink in the K&N armour if you ask me. If you do a search on K&N there is plenty of information on it.

Here are a couple of threads that are interesting

http://caddyinfo.ipbhost.com/index.php?showtopic=5147&st=15

http://www.bobistheoilguy.com/airfilter/airtest1.htm

Exerpts from the above mentioned link at bobistheoilguy:

"For the record, the K&N was the best flowing filter. Of the 3 types of media tested, the cotton gauze type filters flow best. There are other brands besides K&N for sale, of which most are probably made by K&N for resellers. Foam air filters flowed marginally better than paper".

"That said, both the cotton gauze type (K&N) and foam filters (Amsoil & Jackson Racing) showed the same levels of filtration. Both performed poorly compared to the fiberous or paper filters (Napa, Baldwin, and Mazda)".

[tjtjwdad]

I just went back and caught my self up on this thread. As someone on that site posted:

11-27-05, 12:33 AM 

heavymetals,  Cadillac Enthusiast,  Join Date: Nov 2004,  Posts: 995 

Ownership: 2003 Z06 (Maggied) & 2005 CTS-V (Maggied,LPE,UUC,B&B headers, CORSA exhaust, Stealth tune, Ultimate pedals )

Re: Blown Engine?!

--------------------------------------------------------------------------------

It sucks that your car is broken.

It sucks that you can't get your dealer to fix it under warranty.

However (no flame please), you modified it (CAI) and the PCM (rev limit).

You said you do some WOT stuff.

Ok, so probably doing that stuff is what stressed it/cracked it.

It just happened to fail when you were doing normal driving.

The owner of the vehicle should know what type of MODs void a warranty. It would seem to me that removing the rev limiter is one of these but that's just me.

1. It needs to be determined if the MODs performed void the warranty...period. IMO it's either yes or no! Just because a dealer REP says "no" doesn't always make it so.

a. If the MODs void the warranty then; he has the burden of proof to show that these MODs "did not" have any correlation to the cause of the engine failure if he wants GM to pay for it. I don’t think he’s going to prevail but maybe it’s worth a shot.

b. If the the MODs "do-not" void the warranty then General Motors would have to prove the MODs "did" have a correlation to the engine failure. Otherwise, they have to pay.

2. The owner of the vehicle "knows" what type of driving this car has been through since these MODs were installed. In the event the engine hasn't been abused since these MODs, including driving in wet conditions that could cause hydro-lock and "if" he feels GM should foot the bill for this, then this person should gather his facts and get with an arbitrator and give it a go.

3. Either way he could replace the engine in the thing and get his warranty back. Does anyone know what these motors cost? After all, it’s still a nice car.

4. I don’t know where anyone would get this idea;

11-24-05, 06:33 PM  10secvette  Cadillac Fan  Join Date: Oct 2004

Age: 39  Posts: 55 

Re: Blown Engine?!

.... If you take it to another dealer, I would r/r the pushrods, maybe there was a over rev situation and some pushrods got bent along the way ....

certainly GM is smarter than that. I can take my car to any GM dealer and they can tell ne where it was sold, warranty start & stop date, mainternance history and so on ...

Jim

[KevinW]

From what KevinW has noted, the dirty MAF contributed to the computer receiving erroneous information.

I do not believe there is sufficient information to draw any conclusions, though the scenario I presented is not atypical for K&N filter use and PCM modifications involving fuel calibration changes.

[KevinW]

If just useing them caused dirty MAFs than I should not have any cars running.

The PCM is able to compensate for skewed MAF sensor data under most conditions, within a certain range, however, several assumptions are made in the process. Most of the time, the driver is unaware that the MAF sensor response is not ideal, as there's a fairly wide operating limit before a DTC is triggered. Do you realise your cars will still 'run' if you unplug the MAF sensor altogether?

It might help to support your assertion by providing some data (scan tool and accurate wide-band air-fuel measurements) from a variety of operating conditions.