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Discussion Starter #1
The off topic thread of "what was your first car" got me thinking. My first car was a 72 Chevy Vega. As you might know the Vega is famous for having a self destructing engine that was only good for about 70k miles. At the time of introduction it was billed as being very "hitech" for it's time due to it's racing inspired silcone alloy cylinder walls. Turns out they were crap. You don't see to many Vegas anymore.

My second bad experience with a new GM engine came years later when my wife bought a new 93 Saturn SW2 with the twin cam motor. We loved the car but after about 25k miles it began to use about a quart of oil every 1000 miles. After much arguing with the dealer about how much is "with in specs" they finally replaced it with a new engine and after about 20k on that engine it started to use about a half quart every 3k miles. We got gun shy and traded it for a Subaru that we have now had for 103k miles and uses no oil. I have also had very good service from other older GM engines but I am curious to know how much is really known about the long term reliability of the Ecotec engine.

Makes me wonder about this new wonder. Anybody know how good they really are?
 

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As far as I know the ecotec engine was primarly a drag race enigine for the caviler. i believe that somewhere in an old post the posted somthing about a 705HP 4 cylinder ecotec engine with a massive turbo. The ecotec engine in my opion is a hard engine that is capable of holding high pressure turbos, cause if u can turn over 700HP with a 4 cylinder damn thats some impressive technology. so yeah i would say it is reliable engine.:cheers
 

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Discussion Starter #3
Good to know about it's drag race history. Sounds strong, just wondering if any one knows of any personal experience with the engine in a street application?
 

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Have had any number of Avis Aleros recently with the EcoTec, is a comfortable package for commuting even at Interstate speeds.
 

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Hope they are better now...

I have been out of the loop for a few years, but in 96-99 I worked as a quasi-mechanic in college and saw quite a few problems with the ancestors to the current GM 4-cyls that were built in the late 80's and early to mid 90's; mostly problems with the heads.

So, I am not sure what has been improved and updated on the new versions of these engines, but I am trusting that GM got wise enough to stop p**sing away money on warranty repairs and improved the heads. I am banking on this heavily since I do intend to buy one!

Please correct me if these are completely different engines (like I said, I have been out of the loop for awhile), but I don't think so. Also, how about since that time - anybody work at a GM dealership or other shop?

Also someone mentioned the unreliability of the Saturn engine - I am pretty sure that until very recently, the Saturn engines were unique to Saturn and not used in other GM vehicles.
 

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My son has a Grand Am with a Quad-4 and around 110,000 mile it developed a head gasket leak. The Chinese puzzle involved in disassembling/reassemblg was incredible (had have had a number of DOHC engines apart before from FIATs to Jags). Thank heavens for digital cameras and zip-locs.

From the manuals and TSBs it does not seem like GM ever figured out the right way to assemble it, every six months they would come out with a new way. Was so much engine sealer in it that I had no choice but to do what everything said not to and chase the threads.

The car also has various components in unusual locations, I never had to remove a battery before to replace an air filter (suspect few get replaced) and about removing the radiator to get the alternator out...

Finally, about the integrated ignition assembly all in the valley cover, the less said the better other than it is almost impossible to troubleshoot. Just to see if you have a spark requires four spark plug jumper leads with a female connector on both ends. Recently we spent quite a few hours troubleshooting an ignition module that tested good on a factory tester but would not fire in the car. Like the alternator, on a 3800 it is trivial to swap but a jigsaw puzzle on the Quad-4, particularly getting the primary coil leads to stay in place while assembling the plastic cover.

That said son now has over 140,000 miles on it and is running well so the basic design is sound, just a royal PITA to work on. Hopefully the RWD configuration will be more maintainable.
 

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A good friend of mine worked on the Quad-4 head gasket problem. The basic Quad-4 problem with the heads is relatively straightforward.

Aluminum head, iron block, and the fire ring in the head gasket did not like the thermo cycling every time you started your engine from cold. The different coefficient of expansion of the block vs. head would fatigue the fire ring, which was a pressed piece of metal around the gasket material. Then combustion eroded the gasket, and the smallest distance was the coolant port at the #4 cylinder.

The engine performs beautifully under almost every dyno test, and I have owned more than a few vehicles and know several people who have them with well over 100,000 miles.

The head gasket problem was found everywhere, and applies to pre-"twin cam" engines (circa 1995 intro, offshoot from the Q-4, with smaller bore and longer stroke, 2.4 displacement).

I understand there was a significantly higher incidence in colder climates. Garage parked quad-4's fared better, mostly making it to 70,000+ before head gasket/fire ring finally cracked enough to dump coolant into the #4 cyl. Basically, about 600-1000 cycles from below 50 deg F to running temps was enough to fatigue the fire ring. Padgett, since your son got over 100,000 miles, you either have a heated garage or live somewhere below the mason-dixon line.

As a race engine, it is possible to tune them to run the 2.3 displacement with over 220 hp (n.a.).

I do have to admit, I had to replace both ignition coil and module on one and the spark boot assembly (the black thing under the cover with the boots that plug into the spark plugs) on another. And friends who had to troubleshoot same. real PITA.

[/techno geek commentary] :smile

[Thread Topic discussion]
The Ecotech has been in production in europe and here for a few years now, and haven't seen anything major yet, so my guess is pretty good reliability.

Disclaimer: my comments on ecotech only apply to the displacements tried in production so far, which I think is 2.2 liters max? No telling how they get to 2.4 liters, don't know the reliability of the VVT, and no telling how much weaker the block or head gets with the larger displacement.
 

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Suspect that Orlando is warm enough. Problem was an oil leak at #1 that appeared from a botched fix sometime in the past ( I am exceedingly slow but rarely need to do the same thing twice), purchased the car with nearly 100k on it already.

After revieing all of the literature (factory service manual, TSBs, web notes) it became clear that GM never really found a good way to torque the head so I "improvised" and used the same general pattern but did chase the threads first so that head bolts could spin in by had far enough for proper torque.

I *suspect* the leak started because there was so much sealer in the head bolt holes that some bolts could not be seated fully.

Also there is no way to retorque the head bolts once the chinese puzzle of an engine was assembled so I used a "torque once" head gasket.

The head assembles normally to the block, it is getting the timing cover, two cam carriers, two cam covers (all gasketed) assembled after that which is the pain. Perhaps it gets easier if you do it a lot.

Found some VVT info on the Vibe site: "VVT-i — variable valve timing intelligence — is a high-tech setup in which intake valve timing is continuously varied throughout the rev range by hydraulically rotating the camshaft relative to its drive gear."

Doubt that 2.0-2.2-2.4 will be a problem for Pontiac, they have had a lot of experience with stretching engines, after all the same basic 287 cid block of 1955 became a 455 in 1970.

More of an issue is that I do not know of a single modern four cyl engine of over 2.6 l that has been successful, is where you really want more cylinders with pump gas and are really happier under 2.5 l.

That said Pontiac (or is it "GM Powertrain" ?) is really pushing the limits on small engines - anyone notice the Vibe GT 1.8l with 173 hp at 7600 rpm without boost ? Or is it ? Web site also mentions "available supercharger" for the 130 hp engine that raises it to about the same point. OTOH the cr is quoted as 11.5:1, hardly one to use with boost even with premium fuel.
 

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padgett said:
More of an issue is that I do not know of a single modern four cyl engine of over 2.6 l that has been successful, is where you really want more cylinders with pump gas and are really happier under 2.5 l.

That said Pontiac (or is it "GM Powertrain" ?) is really pushing the limits on small engines - anyone notice the Vibe GT 1.8l with 173 hp at 7600 rpm without boost ? Or is it ? Web site also mentions "available supercharger" for the 130 hp engine that raises it to about the same point. OTOH the cr is quoted as 11.5:1, hardly one to use with boost even with premium fuel.
I definitely agree with that. I can only think of Porshe, Subaru and Jeep using 4cyls as large as 2.5L currently and only the Jeep is of the I4 variety. The problem is, to attain the NVH characteristics people expect now a days, they require balance shafts and that is a big problem if you want to spin the rpms required of a "sport" motor. The Vibe's 1.8L you mention is a Toyota sourced powerplant and there hasn't been much luck boosting the 11.5 HO version of the Matrix XRS or Celica GT-S though there are examples out there.
*EDIT* I really shouldn't say that as a number of kits have now been developed and are easily available. http://www.turbo-kits.com/celica_turbo_kits.html
 

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As someone else mentioned, GM will put things in strange places on some cars. I have a Monte Carlo with 3.4 liter DOHC engine. I have had the alternator replaced twice and it cost a lot. They have to take off the right front wheel and remove the half-shaft!! It is so low that I think water and dirt is getting in and ruining them. They both only lasted 25K miles or less.
 

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GM is putting some things in odd places. My first Fiero ('84) required removal of the rear wheel to get the alternator out though it may have been caused by the automatic. Easiest alternator I have ever seen is the 3800. Ten minutes to swap if slow. Son's Grand Am Quad-4 alternator required removal of the radiator.

Guess at the factory everything is assembled before inserting the powertrain module and are not supposed to be replaced for the life of the warrenty.
 

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2004 Acura TL said:
As someone else mentioned, GM will put things in strange places on some cars. I have a Monte Carlo with 3.4 liter DOHC engine. I have had the alternator replaced twice and it cost a lot. They have to take off the right front wheel and remove the half-shaft!! It is so low that I think water and dirt is getting in and ruining them. They both only lasted 25K miles or less.
Ditto that on my SO's Saturn. She's been through 3 alternators, IIRC. I think in the case of the Saturn the half shaft can stay, but it does require removal of the wheel and some inner fender liner / access panel. I normally do a lot of work on our cars, but I took one look at what was involved and decided it was a job for the dealer.
 

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When we lived in Texas my wife had a BMW 2000A with a/c. On that car the a/c compressor hung very low in front and if you pulled to close to a concrete curb the pully would make contact. I do not know how many times I had to remove the pully, bang it about straight and then turn on a lathe so that it would not eat another belt.

Fortunately we did not have that car for very long.
 
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