Many of us have worked in the automotive repair industry or at least are familar with a number of different vehicles, so my question to those that are in the know, is this:
In your experience and opinion, what are the worst of the worst automotive engines ever built, and why?

My contribution to this thread is this:
The Chevy 350 Diesel. Horridly underpowered, and cracks heads often... Amung other problems.

 

Take this with a grain of salt. For the worst engine FOR THE TIME IT WAS SOLD IN, i nominate the VW beetle's aircooled motor. I love me a good aircooled H-4 as much as the next guy. Keep in mind this motor was designed before the collapse of **** Germany. In it's prime, it could have been called the best automotive powerplant out there. But it had gone largely unchanged up until 1979, and it was apparent. I actually love this motor, but feel it deserves being mentioned. Compared to my dodge, which outside of fuel injection, consists almost entirely of 1960s technology, these things are like rolling time capsules. They feel completely lost in the modern era, yearning for the days of hand-crank starts, 6 volt electric systems, generators instead of alternators, and a car's total life expectancy was 10 years.

My rationale:

The bad:

mediocre gas mileage out of a 1.1-1.6 liter motor in a featherweight car. (literature claims high gas mileage, but realistically, its maybe 20-25)

An all time high of about 60 horsepower. (The Pinto's base motor put out 88hp in 1979)

No oil filter. Just a wee little screen. This means you change the oil every 1000 miles.

Valves need adjusted every few thousand miles.

Its air-cooled, so its very gas sensitive in terms of detonation, as heat builds up quickly. Expect to need 91 octane unless you cut the timing back to unbearably slow levels.

The valve covers are held on with bails, and sealed on cork gaskets. Pushrods run outside the block and heads in nylon tubes which are held in place by springs. Neither one of these designs is good at retaining oil.

Redline is lower than on a stock truck 318, being around 4500rpm. Though if you fed it enough air to go higher, but kept it sane, it might not care.

Stock carbs were horribly small.


This being said, I still love the little boxer, and here is why:

60 horsepower in a vw beetle is enough to feel sporty, and go make use of most of the 100 mph speedometer.

True dual exhaust sounds AWESOME

If it leaks oil, it just means its practically changing itself!

Its super easy to work on, and parts are cheap. Everything but the starter is easily reached with the car still on the ground. Valve adjustments are frequent but simple, a weekend is a generous amount of time for an engine swap, and a turnkey NEW performance motor will be only a couple grand.

Valve cover and pushrod gaskets are just a few bucks, and take just minutes to change.

The design of the air cooled motor works well in extremely cold and hot conditions without issues, so long as its not just idling in the sahara for a day or two.

*All in all, you can't really call the aircooled VW a bad motor. But in the 70s it was far outclassed, and falling far behind, even compared to the junkiest crap GM could manage to slap into a crapbox with wheels like the chevette or vega. If well maintained and well tuned though, they can be reliable until they get positively worn out (lost compression, burning more oil than gas, etc.). 20ish mpg really isn't that bad for something that can be a pretty cool car. It was a good . . . great motor when it was young, and can certainly be rewarding to own, but was positively archaic in its later years.

 

First generation ford 5.4 3v triton engine, I had a bad one in my 04 F-150, cam phaser issues and the dual timming chains kept lossing thier tension, half the time this truck was under the care of ford techs more than under my foot!

 

Was 04 one of the years that had all the issues with stripped spark plug holes in the 5.4?

 

wontacceptthis: The same could be said for Henry Fords model T engine. Great for its time but technology always wins out.

I believe the Ford 4.0 SOHC is right up there. It uses plastic parts in the timing chain cassettes that will fail eventually, normally within 125,000 miles. This failure if not repaired immediately when the noise is heard is catastrophic to the engine. Repair of this problem requires engine removal and special tools.

 

Was the model T ever good? This is a serious question, not sarcasm. I know they were cheap, simple, and plentiful, but I have no idea if they were ever "good" when new.

Ford must have had done some pretty crazy experimentation with plastic, because the drive gear for the oil pump, which runs off of the camshaft sync gear, in the 3.0 vulcan is plastic. This usually fails sometime around 100,000 miles. Mine started to fail at 180,000. If left alone, a whine quickly turns into no oil pressure.

 

How about the Ford 6.0 Powerstroke? Sure they had good power and torque but you couldn't go a year without blowing the heads.

 

My point was that it was considered the best there was at its inception. Anything can be the best in its own time or place without ever being good. This is kind of like saying this is the best hotel in town when there is only one hotel in town or a stone wheel was the best wheel in its time.

 

I agree, but I think what wontacceptthis was saying was that it should have been phased out much sooner than it was. It was a dinosaur and far outdated by the time VW pulled it from the line. Great idea at the time, but as technologies advanced, it moved to the back of the pack.

 

Same holds true for injectors... After a while, it turned into a joke when there wasnt a Powerstroke in the shop for injectors, like, "Hey, somethings missing!"