I think by the time we listed all of them from the entire Big 3, we'd hit the end of the internet (remember that ad?).

One comment that did make sense, though, from an engineer that worked for Toyota a decade ago. His contention about the reliability of the US makes had to do with their retirement policies. In the last spate of downsizing, all the senior people were launched with golden parachutes and early retirements. That left the younger people, who didn't have 30 years experience behind them to know what worked and what didn't. He went on to say that whenever Detroit downsized, it was always the senior people that got launched- be it marketing, engineering, production. Sooo...in spite of all the years experience, Detroit was always having to re-learn the industry.

 

Exactly ….. All auto manufactures lay down a stinker every once in a while.

 

BigF350,

The only source of metal fatigue in a cylinder head is thermal cycles. Ive seen cast iron heads full of cracks. Cast iron is brittle, the metallic equivalent of glass, 18ksi yield and ultimate. Aluminum has a little "give" to it. That is why you can have a cast aluminum wheel, but not a cast iron one.

The main reason almost all new engines use aluminum head castings is not just weight, it is heat transfer. Iron does not conduct heat to the coolant nearly as well as aluminum.

Jim

 

The Vega was an Iron head on an aluminum block and even then, the major peoblem was the cylinder wall surface. The last foreign car I recall that had an iron head was my 67 Opel Kadette L.

The problem is not the aluminum head on iron blocks but the implementation of it. Proper sealing materials, proper head bolt placement, proper torque and correct coolants have resolved most of the problems but a few still come up (like the early quad 4) and keep some people afraid of them.

 

Last couple posts were great- I learned something!

 

The main souce of metal fatigue in cylinder heads is due to thermal cracking, but remember they are also under immense pressure as well.

I also have seen cast iron eads full of cracks.
However, just because it is brittle, doesn't mean it isn't strong.
If an Aluminium yields, a head warps. Just as undesirable as cracking IMO.

The main reason you have a cast aluminium wheel and not a cast steel one is more due to weight (although, cast steel would never be used, for the reasons you mentioned.)

If you ask GM's (or Isuzu's for that matter) engineers, I would imagine few of them would mention Heat conductivity as their top reason for changing to aluminium heads.
Reason being, the cast iron cylinder heads can reasonably transfer the heat in a combustion process, yes aluminium is better, but cast iron isn't that bad that it can't be used.
The main reason would be the weight savings - the heavy nose it the big reason pickups handle so badly (lead tipped arrow anyone?) - what GM have been targeting recently is to make a pickup handle/ride more like a car.
To do this, partly what they have to do, is to remove weight over the front axle.
Hence your aluminium cylinder heads.

And I believe a BMW M3 has a cast iron cylinder head... Could be wrong though.

 

This is good for GM but when you check 2004 models silverados had 350 TSB's and F150 had only 59 and this being on a new redesigned truck. Check out at www.nhtsa.gov. So I guess GM's quality is one up on Ford.

 

The Duramax (Izuzu) has been in production for about 5 years now, with no problems regarding alumum heads. I often hear people say what a mistake it is, but it has worked perfecrty so far. I doubt there will be any issues at all, the largest Diesel manufacturer in the world doseant get to that spot without knowing what there doing.

Unlike Ford, Izuzu is not using customers as guniea pigs.

 

I forgot all about the Vega, my parents had one, what a STINKER. Blew headgaskets all the time. The block cracked at one point, so my dad welded, and it worked. That car was sold qucikly as we were afraid it was going to exlpode.

 

Being 1 - I can tell you there are more then just programming issues go on there. More then likely it wasn't Microsoft tools used for programming but rather some very basic, low-level assembly language that mitgated motor functions depending on supplied variables and parameters.

 

I can tell you there are more then just programming issues go on there

Please define

 

The injectors on the dmax are guinea pig injectors.

The hardware couldnt handle the software, that much was apparent. But the new emissions stuff has had a lot more problems that most would like to admit. I still read often or turbos failing. In my opinion the design is flawed. Too complicated.

 

It's not whether you have problems, but how you handle them that counts.

"General Motors has extended the Duramax 6600 fuel injector warranty coverage for owners of all 2001/02 model-year Chevrolet and GMC Duramax 6600 equipped pickup trucks. Special Policy #04039 was sent to all current registered owners in June of 2004 indicating that additional warranty protection is now available for a period of 7 years from the date the vehicle was placed into service or 200,000 miles - whichever occurs first."

 

I agree! "PISTON SLAP IS NORMAL" GM made the statement true by refusing to repair the problem. They just forgot to say it is normal only for their trucks (it happens in others but not to the extent it is in theirs). If it is normal, why did they fix it in the newer models?

 

As we beat this dead horse once again...

Ford TSB's 12798 and 12799 deal with piston slap on certain 4.6, 5.4, and 6.8 engines produced before 4/14/99. As with GM, there are many motors with this dreaded problem that have logged well over 100K miles.