Engines with questionable designs

[2004tdigls]

Originally Posted by Trav
Originally Posted by 2004tdigls
the audi/VW V8 engine, garbage

https://jalopnik.com/here-s-why-the-v8-audi-s4-is-an-awful-used-car-1676466510

the engine has to be removed to complete repairs, nice

http://auditimingchainproblem.com/audi_4.2.html


Big engines in small bodies usually spells maintenance nightmares but these are especially evil. You better really know what you are doing before tangling with one of these.
It doesn't get much easier the second, third or tenth time you only know where the bolts and parts goes better.

On the other hand, if you are competent have a garage to work in and find an otherwise nice example they can be had for dirt cheap with the $8-12K (dealer price and not many indies can/will even attempt it) defect not done.


my mechanic is trained by VW and ASE Master, he won't touch them, the only repair is re/re THE ENTIRE ENGINE. They let someone else do the chains.

that in itself speaks volumes how bad these cars are

 

[Number_35]

Originally Posted by quint
The optisparks were an expensive abomination against humanity, almost impossible to get to without several hours of surgery, and putting it underneath the typical 1990's GM quality water pump was a big bowl of stupid with stupid sprinkles wrapped up in a big ball of stupid topped with stupid sauce.
This was my best laugh of the day. I love the cascading stupids!

 

[StevieC]

The Cadillac with the cylinder deactivation system in the 1980's. What a nightmare those were.

 

[Trav]

Originally Posted by 2004tdigls
Originally Posted by Trav
Originally Posted by 2004tdigls
the audi/VW V8 engine, garbage

https://jalopnik.com/here-s-why-the-v8-audi-s4-is-an-awful-used-car-1676466510

the engine has to be removed to complete repairs, nice

http://auditimingchainproblem.com/audi_4.2.html


Big engines in small bodies usually spells maintenance nightmares but these are especially evil. You better really know what you are doing before tangling with one of these.
It doesn't get much easier the second, third or tenth time you only know where the bolts and parts goes better.

On the other hand, if you are competent have a garage to work in and find an otherwise nice example they can be had for dirt cheap with the $8-12K (dealer price and not many indies can/will even attempt it) defect not done.


my mechanic is trained by VW and ASE Master, he won't touch them, the only repair is re/re THE ENTIRE ENGINE. They let someone else do the chains.

that in itself speaks volumes how bad these cars are


No it speaks volumes about how low the standard is today for a master mechanic, if he cant do that job he needs to go back to school. It is a job for a skilled mechanic and not an apprentice but isnt that what being a pro is all about?

These are good engines but are little more high tech than their price point dictates making them expensive and time consuming to repair, most exotics need their engine pulling for maintenance at fairly low miles and I don't hear anyone ragging the R8 for high maintenance with its Lambo power.

 

[Trav]

Originally Posted by StevieC
The Cadillac with the cylinder deactivation system in the 1980's. What a nightmare those were.


The engine was fine, a little under powered but it had full iron construction and was solid, the control system was not. 10 min and it was deactivated and no more issues with that system. The Vega you mentioned earlier was one of the biggest dogs ever made.

Mixed metal engine with iron OHC head and liner less cylinders that got eaten up very early, the engine was years ahead of its time and an experiment that unfortunately had the consumers paying for.

 

[StevieC]

Quote
Today, GM's Active Fuel Management system works great— you can get 29 mpg from a car that runs 0-60 in under four seconds, and you never even notice when the system turns your V8 into a four-banger.

However, GM's first attempt to sell an engine with cylinder deactivation— the 368-cubic-inch V8-6-4 engine, available starting in 1981 Cadillac models— turned into a horrible disaster for The General (things got even worse for Cadillac soon after that).

The V8-6-4 system theoretically worked via solenoid deactivation of the rocker arms on two or four of the engine's cylinders, but it never worked so well in the real world. Coupled with the Oldsmobile Diesel 350 fiasco of the same period, the V8-6-4 gave GM a black eye that took a long time fading away.



Read more: https://autoweek.com/article/classi...dillacs-v8-6-4-engine-1981#ixzz5W861LxC7


Not my words...

 

[HangFire]

Originally Posted by Trav
Originally Posted by StevieC
The Cadillac with the cylinder deactivation system in the 1980's. What a nightmare those were.


The engine was fine, a little under powered but it had full iron construction and was solid, the control system was not. 10 min and it was deactivated and no more issues with that system. The Vega you mentioned earlier was one of the biggest dogs ever made.

Mixed metal engine with iron OHC head and liner less cylinders that got eaten up very early, the engine was years ahead of its time and an experiment that unfortunately had the consumers paying for.

Apparently there was 2 different v8-6-4 families of engines. According to an excellent article I can't find right now, the larger all iron engine was fine. The smaller aluminum block, iron head engine was the troublemaker. It was a real loser just like the iron head, aluminum block Vega engine.

 

[clinebarger]

Originally Posted by quint
I nominate the GM LT1 of the 1990's. I only had my Vette a few years and never really had any problems out of mine, but man lots of other people sure did. The optisparks were an expensive abomination against humanity, almost impossible to get to without several hours of surgery, and putting it underneath the typical 1990's GM quality water pump was a big bowl of stupid with stupid sprinkles wrapped up in a big ball of stupid topped with stupid sauce.


Dramatic much??

The Corvette was the toughest one to do, And still not all that bad....Dealer techs got paid a little over 2 hours warranty on a Y-body & I beat that consistently.
F-Bodies were a little easier....But you needed a lift as the fastest way was to do it from the bottom.
B & D Bodies with Standard/9C1 cooling......GRAVY with money sprinkled on top! If it took longer than 30 minutes before I was refilling the coolant, I was having an off day.

The HD cooling system B/D cars were another story.....I would put money on not many people on this site ever working on one?

The water pumps on these were actually very reliable & robustly built, They also had NO load placed on them from accessory belt tension. Never use the bleeder screw on the thermostat housing......Fill the block with the housing removed-right to the bottom of the thermostat, Button it up & fill the degas/radiator.

The venting hoses & check-valves are critical to the distributor living & often neglected. People & mechanics alike treating these engines like a standard SBC caused most of the Opti horror stories you hear. I could go on & on about the things I've seen with the Gen II engines that happened out of pure ignorance. I guess it's just easier to rant about how somethings a bad design?

 

[Trav]

Originally Posted by StevieC
Quote
Today, GM's Active Fuel Management system works great— you can get 29 mpg from a car that runs 0-60 in under four seconds, and you never even notice when the system turns your V8 into a four-banger.

However, GM's first attempt to sell an engine with cylinder deactivation— the 368-cubic-inch V8-6-4 engine, available starting in 1981 Cadillac models— turned into a horrible disaster for The General (things got even worse for Cadillac soon after that).

The V8-6-4 system theoretically worked via solenoid deactivation of the rocker arms on two or four of the engine's cylinders, but it never worked so well in the real world. Coupled with the Oldsmobile Diesel 350 fiasco of the same period, the V8-6-4 gave GM a black eye that took a long time fading away.




Read more: https://autoweek.com/article/classi...dillacs-v8-6-4-engine-1981#ixzz5W861LxC7


Not my words...


This thread is about bad engine design but I guess you don't know the difference between the engine and poorly functioning and implemented sub systems or you wouldn't post such things, that belongs in the "what can we do to a basically good engine to make it unreliable" category.
With the cylinder deactivation disabled the all iron 368 engine (not an olds engine but a smaller bore and shorter stoke Cadillac 472/500) was fine,

 

[StevieC]

It is a part of the original engine design therefor it's a bad design. It came from the factory like this. IT DOESN'T MATTER what you can do to fix the problem by modifying the original design. Any engine can be modified to not be the horrible mess from it's creator.

 

[Trav]

The 368 is the same engine block as the other big block Caddy engines which were a very reliable engine like the 425, 429, 472 and 500 engines. This is the base for the engine, a good strong design.
Was the SBC a bad design because they tried crossfire injection on it?

Even iron sleeving the Vega engine could not cure some of the issues with it, therefor any engine cannot be modified to make it not a horrible mess.
Your lack of knowledge is showing.

 

[StevieC]

Whatever you say.

 

[emmett442]

I'm with Trav on this one.

While the 4-6-8 certainly hurt Cadillac's stellar reputation, it wasn't a "nightmare". The basic 368 engine was tough as nails. Failure of the cylinder deactivation issues simply created some drive-ability issues, but created no engine damage as the modern AFM systems do.

Common repair was to just disable the system, which was as simple as snipping a wire.

No big deal.



The later aluminum block iron head engine had nothing to do with cylinder deactivation as stated by Hangfire. It was a clean sheet design. 4.1 liters, full skirted aluminum block, iron cylinder liners, iron heads, aluminum intake, fuel injection. Getting down to it, this engine was actually a pretty good design, but was plagued by problems created by poor (rushed) production. The later variants of this engine (4.5 and 4.9 liter) are actually considered to be among Cadillac's finest engines they've used.

I've owned a lot of the 4,.1/4.5/4.9 cars over the years. Still some of the best vehicles I've owned.

 

[Trav]

When the HT4100 overheated usually due to intake leaks they twisted the crank bearing saddles and the crank was tighter in the bearings than a bulls touch hole in a cat 5 hurricane. The block needed more webbing to stiffen it up.
There were twisted cam bearing saddle issues also. Line boring was not an option, it was too much, new block time.

 

[Silk]

We never got the Vega in New Zealand, but I did an engine rebuild on one in 1981, the owner brought the parts over from Canada for me. Similar to another GM design, the Vauxhall ohc 4 cyl, available in 1.6, 1.8, 2.0 and 2.3. It had an iron block, half a V8 on 45 deg, the dist drive where the cam drive would be for a V8...so not at all like a Vega...but the cyl head was. I was very familiar with the Vauxhall engine, and disapointed in the Vega head - the Vauxhall head was split, with the cam in a seperate alloy casting...you removed the cam housing to get at the bucket followers and valves. The Vega was a one piece casting, needing some tooling we didn't have, and had to make to extract the cam to get at the valves. Left me wondering how the same design team came up with that.

 

[BMWTurboDzl]

BMW B-series engines: Timing chain is at the rear.

 

[jeepman3071]

Originally Posted by BMWTurboDzl
BMW B-series engines: Timing chain is at the rear.


Yup, stupid.

 

[nthach]

Originally Posted by 14Accent

Original intake gasket design on 3xxx/3800 SII and above. Terrible design flaw, along with the EGR stovepipe flaw on the 3800.

The Toyota 1UZ starter vs. the Northstar starter: N*? Intake off in 15 minutes. 1UZ? Plan on a day's job, easy. Also, the starter on the 1UZ bolts from the BELL HOUSING side! Who thought that was a good idea?



I think GM can make a good engine - but the accountants man.

I've owned a Lexus LS400 and my parents now have an LS430 = both are UZ engines, the 430 has the lighter and not as stout 3UZ-FE. The good news is that starters on these tend to live a long, happy life but I dread the day the starter comes out. The knock sensor harnesses and maybe the water crossover bridge gaskets are NLA on the older 1UZs.

Another flaw with the pre-VVT-i UZs is the EGR pipes cracking. It's a PITA to replace those, especially on the 1995-1997 LS400s since there's two of them, the 1990-1994 cars simply had one from the back of the intake to the RH cat.

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/872259-95-ls400-egr-pipe-leak.html

 

[DoubleWasp]

Originally Posted by clinebarger
Originally Posted by quint
I nominate the GM LT1 of the 1990's. I only had my Vette a few years and never really had any problems out of mine, but man lots of other people sure did. The optisparks were an expensive abomination against humanity, almost impossible to get to without several hours of surgery, and putting it underneath the typical 1990's GM quality water pump was a big bowl of stupid with stupid sprinkles wrapped up in a big ball of stupid topped with stupid sauce.


Dramatic much??

.

The HD cooling system B/D cars were another story.....I would put money on not many people on this site ever working on one?


*raises hand*

Working on that setup always made me want to groan.

 

[quint]

Originally Posted by clinebarger
Originally Posted by quint
I nominate the GM LT1 of the 1990's. I only had my Vette a few years and never really had any problems out of mine, but man lots of other people sure did. The optisparks were an expensive abomination against humanity, almost impossible to get to without several hours of surgery, and putting it underneath the typical 1990's GM quality water pump was a big bowl of stupid with stupid sprinkles wrapped up in a big ball of stupid topped with stupid sauce.


Dramatic much??

The Corvette was the toughest one to do, And still not all that bad....Dealer techs got paid a little over 2 hours warranty on a Y-body & I beat that consistently.
F-Bodies were a little easier....But you needed a lift as the fastest way was to do it from the bottom.
B & D Bodies with Standard/9C1 cooling......GRAVY with money sprinkled on top! If it took longer than 30 minutes before I was refilling the coolant, I was having an off day.

The venting hoses & check-valves are critical to the distributor living & often neglected. People & mechanics alike treating these engines like a standard SBC caused most of the Opti horror stories you hear. I could go on & on about the things I've seen with the Gen II engines that happened out of pure ignorance. I guess it's just easier to rant about how somethings a bad design?




What? The only person ranting here is you. Geez, why so defensive? I usually like reading your posts but this one has me trembling under my desk here at work and the cleaning lady is trying to hand me a sucker and telling me everything is going to be ok.

No drama from me. The drama was (and still is) from the forums littered with thread after thread after thread of people having trouble with them. Mine never gave me a problem at all, nor the water pump. But I maintain my stuff, and many people dont.

The early unsealed non-vented optisparks were often reliability turds that could turn an otherwise decent engine into a misfiring or non-running pile of parts in a hurry. The later vented ones were fairly decent, relatively speaking, and luckily thats what I had. But still sometimes a good opti was taken out by a leaky water pump. They put the distributor under the water pump? Intentionally? If the LT1 design team built houses, they'd probably put the breaker panel in the master bathroom shower stall. Then they would route the HVAC vent work through the breaker panel, to vent it in case any of the mist from the shower caused condensation. And they'd think this was a great idea.

If seasoned mechanics are allotted 2 hours book time using a lift and all the tools and knowledge of their profession at their disposal replacing them, for the average DIYer that translates into a 3-4 hour profanity laced afternoon on laying their back after a $100 tow home and stopping at the local dealer spending $350+ for a new opti, wires, and plugs, and then 2 hours on youtube to figure out what they are supposed to be doing.

If you got so good that you were replacing them in a half hour or so, thats awesome, I'm all for good mechanics learning shortcuts, working smart and beating book time to make money, but a professional mechanic learning how to replace a problematic part quickly does not take that part out of the turd category.

Just my opinion.