Last post on Jun 02, 2013 at 7:08 PM
You are in the Chevrolet Impala
What is this discussion about?
Chevrolet Impala, Sedan
#12045 of 13620 Cop Cars/bearmer
Jul 15, 2003 (6:54 am)
I have a minor correction. There indeed have been many successful unibody cop cars. Every Chrysler Corporation car (except the 1960-1967 Imperial) was unibody since 1960, and they had well over 60% of the police market for many years, and were a strong contender for police sales until the Diplomat/Gran Fury were discontinued in 1989.
Also, Chevy's Nova was unibody, and it was a successful (in performance, at least, maybe not by sales volume) police car.
I think you mean front drive cars, given your later points (which are correct). You can and did have unibody RWD cars. The FWD cars are also unibody, but have other problems (as stated)--the whole drivetrain is out front and can be damaged more easily. Ford had a lot of problems with this very issue in the police Taurus--ask the city of Baltimore. They dropped the police package with the redesign for 1996. Chevy's had more luck with the Lumina and Impala, though there are still some problems.
Suitability often depends on use. One department may find Impalas or Intrepids to be the perfect car, while others need and want the Crown Victoria.
One note on the Impala--apparently the transmissions are not holding up on the cop versions. The Greater Boston Police Council (which coordinates buys of equipment) went with some 2000 and 2001 Impalas. They were well-received, and one department gave a glowing report to the Impalas, and another department bought 5 based on that. In the time it took to deliver the cars, the first department's Impalas hit 60,000 miles and beyond, and the bottom fell out. When the second department asked again, the first said they were sorry that the second had ordered the cars--the first department had so many problems that put cars out of service that they'd had to put unmarked detective cars on patrol, and they'd since ordered all new Crown Vics. These are now in service and they have no Impalas any more.
The second department is now having the same troubles now that their 5 Impalas have over 60,000 miles. The main trouble is transmissions, not front ends though. The department mechanic says they are constantly having problems that take them out of service. He said they are much more troublesome than the department's older Crown Vics, with close to double the mileage on the Impalas. He even commented that one unmarked (former patrol) '89 Crown Vic seemed less troublesome, and it had over 120,000 miles.
I'd post a link to the newspaper article where I got this info, but it's no longer there and they don't archive. It was in the Medford Transcript, at www.townonline.com/medford
Just food for thought, since the civilian transmissions are generally considered quite good.
#12046 of 13620 Impala Transmission
Jul 15, 2003 (4:10 pm)
Hi. New to the board, and I would like to ask about the Impala transmission. Is the difference between the success between civilian and police transmissions that the actual transmission is different, or just that the police ride them a lot harder and differently than a regular driver?
#12047 of 13620 Impala transmission
Jul 16, 2003 (4:27 am)
Wish I knew. I couldn't get any sense of that from the article (and the PDs involved had bought the cars for patrol--I don't think they got any new Impalas for unmarked units. They just hand down the old patrol units when they get new ones).
The first town mentioned is suburban to rural and the second is much more urban (more traffic lights, more traffic, more stop and go, more idling, more calls to respond to), which makes it even tougher to say what's going on, since they aren't quite using the cars the same way.
The writer did contact NYPD, since they have a huge fleet of Impalas, but he was unable to get in touch with anyone who could comment in time for the article's deadline. I'd have been interested to hear what their experiences have been.
I would hope that GM used a beefier version of the transaxle for the cop package Impalas, but I can't say that for sure.
#12048 of 13620 ehenness re cop cars
Jul 16, 2003 (5:53 am)
Thanks for commenting. If the new unibodies aren't having a lot of chassis alignment problems in police service, it unravels my thesis that they're too weak. You're right about Chrysler's early unibodies but those cars had heavy side rails and crossmembers that looked like a real frame. The body was welded to them instead of on rubber cushions. I think they had a separate stub frame in front like the new ones. I had a 64 Chrysler that was as rigid as anything I've owned but it had too much road noise. I believe that Lincolns in the late 50s were unibodies too.
I think what I'm grumbling about is replacing the frame with U-channels pressed into the floorboard in the name of fuel economy. That's an oversimplification, I know. I read that major body work has become less common because it's more difficult. Collisions that in the past just needed Bondo and paint now require a chassis bending jig to move the wheels back to where they belong. Too often the result is a car that's unsafe to drive. Insurance companies prefer to call it unrepairable and not take the risk. They're becoming disposable.
#12049 of 13620 Bearmer/Cop cars
Jul 17, 2003 (5:11 am)
True. I agree 100%. I was being a bit picky I guess--they are all unibody, but they're structurally different today in terms of how the car is put together (frame rails, area forward of the cowl).
I think the drivetrain/suspension problems were all rolled together (at least for Baltimore and the Tauruses). Jump a couple of curbs, and you can foul up a lot of stuff up front on a FWD car.
I think you are right, and the cops tended to feel that way too. The Impala was supposed to have fixed that weakness, with an HD cradle and suspension for the 9C1 (police) cars. Maybe it has and now there are other problems showing up. The complaints for the Impala around here concerned mainly the transmissions, and lots of other little bugs (electrical, I believe, that didn't take cars off the road).
#12050 of 13620 Just swapped out the car Battery yesterday...
Jul 17, 2003 (7:58 am)
I am not really a car fixer upper kinda guy, but figured out how to get the damned battery out of that tight spot they get it into. 2 questions for the group...
The battery is smaller in size than the original one, but once tightened into place does not move. What does concern me is it is labeled 630 Crank Amps. Is that enough? or is that a direct replacement for the old Battery?
Next question is about the spark plugs. I bought a set of plugs, and know that I have to gap em. What is the proper gap on plugs for the 3.4l Base Impala? and any opinion on replaceing the wires at the same time? I wanted to keep up with preventative maint. on this car and not sure what else needs to be done (aside from regular oil changes, tranny flush at 75k miles, new tires , brakes and rotors at 50k miles).
#12051 of 13620 dgonzalez13 re battery etc.
Jul 17, 2003 (11:48 am)
The battery will work fine. Physical size isn't meaningful anymore. Cold cranking Amps is a sham IMO.
The reason I'm answering you is about the plugs. What you're going to do isn't trivial. The heads are aluminum and there are rules that must be followed. You should try to get servicing literature about replacing the plugs before you start.
1. You're probably supposed to do the job while the engine is hot (if that's what the instructions say).
2. Apply anti-seize compound to the threads before screwing them in. Buy a tube of it at a parts store.
3. You must use a torque wrench to tighten them. This may be difficult to do in the rear bank because you don't have much room to work. If you don't have a wrench or the room to use it or don't know the correct torque don't do it yourself. To get to the rear ones, I've always removed the upper mount (also called the torque strut or dog bone) and pulled the engine forward with a rope to get space back there.
If the wires are undamaged they're probably okay. A replacement set of that quality could cost $100 from a dealer. They're usually replaced singly as needed these days, not in sets. They're weak so don't pull on the wire, only the boot.
Plugs are pre-gapped these days. The gap is probably at the end of the part number. The emission label under the hood should give it to you.
Forgive me if you knew all this but I felt like I had to say it.
Jul 17, 2003 (12:14 pm)
Thank you much for the info. I didnt realize so much was involved, you saved me from screwing up big time. I think I will bring it to the auto repair place and have them do it. It's not worth buying the torque wrench just to do this one job on my car. I really dont do too much to it anyway (aside from light controllers and XM radio). Thanks a lot for the info. Any idea on how much they would charge for the install (and plugs?).
Jul 17, 2003 (2:41 pm)
I just received a recall notice in the mail for my 2k impala ls. I called the dealer and he mentioned something about a coolant leak and some tabs in the rediator. Does anyone know what this might be about?
Jul 17, 2003 (6:08 pm)
Well, just about everything I said the last time is wrong. I looked up the car in a set of GM Service CDs I have here. The plug threads are supposed to be dry and the engine is supposed to be cold. It would take a mechanic an hour or less to do it but I can't guess what he'd charge.
Here are a couple of observations on your first post.
1. The plug replacement interval is 97,500 mi. Why do you want to do it now, anyway?
2. The transaxle fluid change interval is 50K mi. under severe conditions, otherwise not at all. Fluid change means remove the pan, change the filter replace the pan and add fluid. It isn't a flush. When a shop advertises a flush they mean stick a hose into the filler pipe, suck out as much as they can and replace it. That shouldn't be done because it doesn't service the filter and it can stir up sediment and send it to places you don't want it to go. It's also less work for them. If you're going to change it, do what GM says.
3. There's no regular maintenance for the brakes. Wait for them to wear out.
Here's something you didn't mention but I will.
The replacement interval for the air cleaner element is 30K. mi. Don't do it more frequently. Filters become more effective as they clog up and your engine will stay cleaner. Trust GM about how often to do it. Trust their recommendation for everything else, too, including oil change.
I saved the maintenance schedule in a zipped file. Send me an email if you want it. My mailbox is in my profile. It may be in your glove compartment because it's provided as a pamphlet with the car. Hope you enjoy your Impala.