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Here’s an example of complications when designers did not do their job well.

Troubleshooting a no-start, I determined spark plugs were fouled from repeated unsuccessful starts. So needed to remove plugs and burn fouling off or install new ones.
Except Chrysler designers stuffed the engine in so tight that it is extremely difficult to remove all rear plugs from inside engine compartment – in the past I and others raised the vehicle, and did the re-re slowly and carefully as operating blind. (See http://www.keithsketchley.com/caraplug.htm.)

Fortunately I took a new look at access and found that by removing and relocating things I could work from the front – I’ve added that to my plugs web page.

Some Allpar members suggested unbolting forward engine mount to rotate engine forward to try to get more clearance, but I think the radiator would need to be removed, and other mounts fiddled.

The engine is a stuff job as the 3.3L Chrysler is bigger in at least some dimensions than the 3.0L Mitsubishi, I don’t know about the 4-cylinder engines. A big part of the access problem is that the 3.3’s manifold projects well aft, whereas it should have been more centralized and higher as there is space below the hood.

Nevertheless, the engine compartment is full of examples of poor access that could have been avoided by proper installation design, notably:
  • several cases of hoses and sensors and vacuum taps in places that impede reaching down the back of the engine, could have been avoided. Examples include the hose to the PCV valve, the projecting boss the valve is connected to (why a 2+ inch projection instead of a simple threaded hole a tee could be screwed into?), the MAP sensor screwed into the back of the manifold, and a bracket that makes it very difficult to grip the RH spark plug wire to take it off.
  • A/C tube routing impedes removal of RF spark plug, could have been routed differently.
  • Coolant temperature sensors hidden under coil pack.
  • Coil pack awkward to remove because tubes and wiring harness are poorly routed.
  • Relays and modules hidden behind various areas of the dash, requiring removal of screws to get at (in contrast to those in the power centre and the ECM and TCM under the hood).

That’s on top of things that are somewhat more understandable, such special tools needed to rotate idler to re-re serpentine belt (due length of engine/transverse location only a slim bar with short socket fits), access to coolant temp sensor (requires removal of coil pack – couldn’t it be mounted higher?), access to camshaft position sensor, and access to crankshaft position sensor (though some locations of interfering pieces are questionable).
 

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I've seen a video on Youtube where somone with a 94 AWD Caravan removed the upper part of the intake manifold to get at the rear plugs easier.
 

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KOG
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Yep, removal of upper plenum isn't difficult and makes easy access for plugs or alternator removal. You will need a new gasket each time you remove plenum, they're cheap. And use a torque wrench when reinstalling plenum. I haven't done that since I put a lift in my shop, but changed plugs that way for 10 years before lift. If you have the exact right wrenches you can change the rear pugs from the top without removing anything, but it is tight.

If you think this is bad design you don't get out much. There are numerous other brands which are much, much worse.
 

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If you think this is bad design you don't get out much. There are numerous other brands which are much, much worse.
That's for sure!
 

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Here’s an example of complications when designers did not do their job well.
Really? :huh:

If you are using is "how easy is it for the backyard/shadetree/driveway mechanic to change belts and plugs" as the criteria, I could see where you might come to that conclusion.

But something tells me that there was other criteria for drivetrain and systems packaging and vehicle assembly that was probably met pretty darn well.

Changed plugs on a '95 3.3 once, and serpentine belt/tensioner twice. Easy? I suppose that depends on one's skill set and knowing what to expect before you get elbows deep into it. Knuckles were busted, curses were spoken, and the job was done. Did the same task on a '99 3.8 - wasn't any easier.

But I can tell you changing a serpentine belt on a '96 Buick Skylark was even worse. Changing the blower motor and recharging the AC on a late '90's Chevy Lumina is no picnic either.

Garage lifts are great - when you have access to one. When you don't, you go somewhere that does or you figure it out without one. (But I can tell you that a lift wouldn't have made a bit of different on that Lumina.)
 

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Here’s an example of complications when designers did not do their job well.

Troubleshooting a no-start, I determined spark plugs were fouled from repeated unsuccessful starts. So needed to remove plugs and burn fouling off or install new ones.
Except Chrysler designers stuffed the engine in so tight that it is extremely difficult to remove all rear plugs from inside engine compartment – in the past I and others raised the vehicle, and did the re-re slowly and carefully as operating blind. (See http://www.keithsket...om/caraplug.htm.)

Fortunately I took a new look at access and found that by removing and relocating things I could work from the front – I’ve added that to my plugs web page.

Some Allpar members suggested unbolting forward engine mount to rotate engine forward to try to get more clearance, but I think the radiator would need to be removed, and other mounts fiddled.

The engine is a stuff job as the 3.3L Chrysler is bigger in at least some dimensions than the 3.0L Mitsubishi, I don’t know about the 4-cylinder engines. A big part of the access problem is that the 3.3’s manifold projects well aft, whereas it should have been more centralized and higher as there is space below the hood.

Nevertheless, the engine compartment is full of examples of poor access that could have been avoided by proper installation design, notably:
  • several cases of hoses and sensors and vacuum taps in places that impede reaching down the back of the engine, could have been avoided. Examples include the hose to the PCV valve, the projecting boss the valve is connected to (why a 2+ inch projection instead of a simple threaded hole a tee could be screwed into?), the MAP sensor screwed into the back of the manifold, and a bracket that makes it very difficult to grip the RH spark plug wire to take it off.
  • A/C tube routing impedes removal of RF spark plug, could have been routed differently.
  • Coolant temperature sensors hidden under coil pack.
  • Coil pack awkward to remove because tubes and wiring harness are poorly routed.
  • Relays and modules hidden behind various areas of the dash, requiring removal of screws to get at (in contrast to those in the power centre and the ECM and TCM under the hood).
That’s on top of things that are somewhat more understandable, such special tools needed to rotate idler to re-re serpentine belt (due length of engine/transverse location only a slim bar with short socket fits), access to coolant temp sensor (requires removal of coil pack – couldn’t it be mounted higher?), access to camshaft position sensor, and access to crankshaft position sensor (though some locations of interfering pieces are questionable).
I had to chuckle slightly at your post since I had to replace the alternator on my 1994 Caravan 3.3L. I got it done but I was cussin'.
 

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When automotive designs moved to transverse mounted engines combined with a transmission, crowded engine compartments became standard. However some designs were better than others. I would agree that GM engine compartment design (that description is too kind) is very haphazard at best. GM engine compartments were a disaster from the 1980s and later. Chrysler was not too bad in the 1980s but when the stylists originated cab forward in the 1990s, Chrysler engine compartments became a disaster.

The 1995 and later Cloud cars with V6 engines are very inaccessible for components. The 3rd generation minivans, 1996 - 2000, are bad. When exterior body styling takes top priority (GM has always done this), fitting the engine and other components is always a compromise.

Problem with this approach is that this creates headaches for repair personnel. So repair procedures get compromised, botched repair work happens, the car brand and repair shop get a bad reputation and the consumer looks somewhere else for the next purchase. Everybody loses.
 

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Virginia Gentleman
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The 3rd generation minivans, 1996 - 2000, are bad. When exterior body styling takes top priority (GM has always done this), fitting the engine and other components is always a compromise.
Yes, they were. Bad enough that I deferred to my local shop when it came time to service the plugs/wires/EGR/serpentine belt on our '00 T&C Ltd we had at the time. Was well worth not going through the aggravation. By comparison, it was easier (though tedious) to R&R the 16 spark plugs on my Ram's Hemi myself.

I had no problems servicing any of the 2.5L engines I had - the easiest to work on by far.

I dread working on the 3.5L in my Journey - that engine bay is tight when to comes to serpentine belt servicing and servicing the spark plugs. About the easiest thing is replacing the air filter.
 

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Discussion Starter #9
Some of you are putting yourself in the position of defending the undefendable - sloppy work of Chrysler designers in locating accessories around the engine I clearly see that they could have routed tubes and wires differently, for example, perhaps even mounted the ignition coil on top of the manifold so it doesn’t hide sensors and is easier to remove. I a confident I can judge the design work.​

Look at http://www.keithsketchley.com/chrymess.jpg and http://www.keithsketchley.com/chrymes2.jpg for illustration of the rats nest of many of the hoses, pipes, and wires.​

That work would not be accepted in the marketplace for vehicles that are viewed as productive assets, such as heavy trucks, commercial helicopters, airliners, and commercial ships. They need to be repaired quickly to minimize downtime thus maximize productive use of the asset.​

What we buyers need is a “power-by-the-hour” deal, so the manufacturer gets to pay for their sloppy work.​
(To significant degree they already do, in warranty costs. The electronic 4-speed has been chronicled here in Allpar in the internal design context as hitting Chrysler hard financially, to their credit their bureaucracy was able to expedited fixe – the CEO was involved to ensure work progressed quickly and well. (Look through the SBs and you’ll see that most internal failures came at locations of high stress concentration that could have been avoided or found during extensive testing.)​
Chrysler lucked out in that competitors “just didn’t get it” for many years regarding the Caravan’s concept, so Caravan sales remained high. (Recall GM’s Dustbuster van and higher van (albeit good for rougher roads – used S10 pickup drivetrain) and Toyota’s engine-between-front-seats products, for example.)​

That sloppy design of accessory installation is generally different from the tight fit of the engine, which largely comes from putting the transmission in line with the engine to minimize vehicle height and length, and perhaps needing some length for the left axle shaft. In contrast the original Detroit front-drive package – the Oldsmobile Toronado’s – offset the engine with a chain drive.​

Though I’d have taken a hard look at the alternator mounts to see if that could be done better. Chrysler’s design of the right engine mount and the alternator mount have the appearance of an inadequate design patched with added braces.
 

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I looked at your pictures and can't see how you would relocate the alternator, what is your proposal? If you integrate the bracket with the upper manifold that's just one more fastener to remove to change plugs plus cast aluminum isn't as strong as stamped steel and you could induce a vacuum leak. Plus you should keep it high so it's out of deep puddles.

Also, if you put the coil on top of the engine would it fit under the hood of a sedan or should there be separate engines for minivans and sedans?

Don't forget the build process when you're re routing hoses and wires.

I disagree that chryslers dominance in minivans is just luck, it's an example of packaging genius, mechanical and ergonomic.
 

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Try changing the timing set on an early model Pontiac Sunfire. You'll find the Dodge not so bad then.
 

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What sanity?
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My sister has a 9 year old Kia Sedona. Chrysler's engine bays are works of art compared to that van. I know several mechanics in town that will no longer work on it, myself included. Last time I worked on it, it took me two hours to replace one single power steering hose clamp. Had to reach all the way down past the engine, practically kissing the intake plenum - that's how far down I had to reach - to access it with one hand, because there was no getting at it from below and only one arm would fit down there.

And I'm a guy who can now change the spark plugs on a 3.3/3.8 third gen Chrysler minivan in 20 minutes or less by just pulling the alternator and reaching through there to get at all three rear plugs.
 
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Some of you are putting yourself in the position of defending the undefendable - sloppy work of Chrysler designers in locating accessories around the engine I clearly see that they could have routed tubes and wires differently, for example, perhaps even mounted the ignition coil on top of the manifold so it doesn’t hide sensors and is easier to remove. I a confident I can judge the design work.
Really? Maybe you should consider how difficult it is to design an engine and then put it in a number of widely different vehicles - sedans, trucks and vans, some of which are designed years after the engine itself. I think it's completely unfair to blame the designers, when the decision to combine an engine and vehicle is largely out of their hands, and in the hands of marketing or other management. If you are an engineer yourself, you would understand how powerless we often are, in implementing a common-sense design.
 

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Have fun changing a water pump on a 2.7 for example of other tight areas. In 1957, Lincoln sent out a bulletin telling you to measure from a couple of dimples in the fenderwell and then drill a hole to access the rear spark plug. Tight areas are nothing new.
 

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The 1975 Chevy Monza V-8 requires unbolting the engine mounts and jacking up the engine a few inches to get at the rear two spark plugs. Most mechanics changed the 6 that they could reach and charged the customer for 8, never telling them that they still had 2 original plugs in there.
 

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From my POV (after 9 years of designing construction equipment... the last 4 spent with engine systems of midsize & large articulated wheel loaders...)

The 'mess' pictures look OK from a standpoint of ensuring safe wire & hose routings (no hard rubs on other components / appropriate sheathing where there may be rubs / adequate allowance for engine/transmission motion relative to the body), and for access to the regular service items (oil fills, coolant tank, etc.)

For the unscheduled & high-mileage items (replacing alternator, replacing the sensor under the coil pack, replacing the serpentine belt, etc) some component removal is acceptable if it allows the other goals of the vehicle design to be achieved.
 

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With platinum spark plugs requiring a 100K mile change interval, the placement of the rear plugs is forgiven.
The intake manifold needed long runners while staying flat, so that it why it covers the rear bank.
The first time R&R may be a learning curve, but after that the operation takes a shorter time. you know what tools work and it can be less frustrating to do.
 

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I have helped a friend change a water pump, belt, heater control valve front heater hoses on his 94 Town & Country with the 3.8. I didn't see anything complicated about doing that work and was pretty easy. I know he can do plugs and wires in about 30 mins going from underneath the van with no problems. I know there are alot of other cars that are designed alot worse. Try doing a timing belt on a 89 Ford Escort, spark plug wires on a 97 Ranger 4.0 or a fuel filler neck on the same Ranger, 4 frigging hours just on the filler neck. It all depends on the person doing the work and the car. My friend did the same maintance work on his 94 Town and Country that he helped his dad do on his 98 Town and Country, and it pretty much double the time on the newer van
 

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The worst vehicle I had when it came to servicing was the 93 Aerostar we had at one point. R&R the sparkplugs required jacking the front end up onto jack stands, removing the front tires, and working through the fender wells. It wasn't horrible but not great either. I could replace the driver's side fairly easily, and 2 of the 3 on the passenger side. The rear most plug on the passenger side was reached by crawling underneath and reaching up blindly to replace it. Replacing the plug wires also required removing an interior panel so you could access the distributor cap that was located on the rear of the engine.

The only item relatively easy to replace was the heater core. Two quick disconnects to remove the heater hoses (special tool needed), remove the glove box and then 4 or 8 bolts to remove the panel and there was the heater core right in front of you. No need to tear apart the entire dash.
 

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DO NOT FEED THE TROLLS!
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Heh. The other day I looked into changing an O[sub]2[/sub] sensor on an '86 Trans Am that I have, and the problems with accessibility and difficulty performing fairly regular tasks are certainly not limited to Mopar, and are certainly not limited to FWD. I decided to not do it and instead clean up one of the garages, it was going to be that annoying.
 
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