A couple of questions

[90Q45blue]

Well my car has a lot of miles so it's gonna have some problems right?

Here's what I've got:

1. When I'm backing out of my driveway and go to shift from reverse to drive the car vibrates pretty roughly. Then after I shift into drive the car stutteers. Once I punch the gas it's fine after that. I am going backwards down an incline on this driveway. Any ideas what this might be? My transmission is under warranty and I have a transmission flush planned in two weeks.

2. When I start my car, the RPM's immediately shoot up to about 2100 rpm and then slowly come down to around 1100 rpm. After I shift out of park they come down to around 750.

3. I'm getting an odd noise from the car. When I'm driving and I hit the gas, I hear a noise like a fan that's chopping something???

Thanks in advance,

Nick

[Q45tech]

When you crank any car the warmup system sets the idle speed according to the coolant temperature. Depending on the exact coolant temp the [in park idle] could start out at 750-1500 rpm as the coolant warms up to 176F the idle speed progressively declines.Since cold oil does not function correctly [provide max lubricity] till it warms to 150F minimum.........it is assummed that owners will let their oil warm up before doing any aggressive driving.....this takes 5-10 minutes depending on ambient.

There has always been a debate about crank and go vs crank, idle to warm, and go. Really a function of how long you want your engine to last and how close you want it to maintain new specs with mileage.

Each cold [winter] crank and go probably does as much wear damage as 200-500 miles of temperate highway driving...........this is why engines don't last 1,000,000 miles in city driving service............as they do in continuous track testing where they are only stopped to change the oil [which by the way is added hot to the test engines].Getting 300,000 miles in normal [6 cranks per day] driving is a challenge...........easier in South where Lunch late afteroon is warmer half the year.

Each cold crank [warm up cycle] consumes average of [1.44 lbs per hour or 0.25 lbs per 10 minutes or 0.05 gallons of gasoline].........on average waiting 5 minutes EXTRA x 42 times uses an extra gallon per week MAYBE [probably half that amount] costing you an extra $40-$80 per year.................never seen an exact study done so these numbers are rough............spending $400-$800 over 10 years to extend the engines life.Same as getting oil changed every 90 days vs twice per year. Same as using synthetic vs conventional oil.

Note the injector cycle [2.2 milliseconds per injector per cylinder] is the same at idle [as is the fuel pressure] as it is at 60 mph level, 4th gear, no AC, driving: so the rpm is a direct indicator of non acceleration fuel consumption in pounds per hour of running.

!!!The point of all this is you were unclear as to how long you let the engine warm up before all those problems you described occured!!!!

[maxnix]

I am wondering also, is the car on an incline when it is started and being warmed? I have heard anecdotal stories of lubrication deficiencies when cars (including early Q45s) are idled on a steep incline, even when warm.

If true, would this extend to the torque convertor being higher than the transmission? Seems from the symptoms described the torque convertor is starved of fluid initially.

[90Q45blue]

Dennis,

Sorry about not being clear. Unless I am in a hurry, my car sits and idles for 10 minutes before I back out of the driveway.

Brian,

The incline is not EXTREMELY steep. Just probably 2-2.5 degrees more than your typical driveway incline.

thanks,

nick

[90Q45blue]

Any ideas on what my problem(s) might be?

nick

[Q45tech]

How are your motor and transmission mounts? The engine shifts a good bit in direction transitions.......hoses, wires, etc........one of those things one needs to see/drive to figure out.

Sure its not just the ABS doing the start up cycle test in reverse when speed gets above 4-5 mph?

[Q451990]

Just for fun you might test Brian's theory and try parking somewhere more level overnight to see if you have the same problem.

Also, the ABS self test is far more evident backing down a slope...

Heath

[forecast]

my read from Brian is that the car is stopped when it's shaking.

seems like he's describing:

1. Warm up - coolant to operating temp2. Normal backup (litte or no throttle)3. Shift from reverse to drive (shudder) [do RPM's drop as stumble or misfire or transmission shakes?]4. throttle in drive and stumble5. near WOT, deeper stumble and recovery6. normal driving experience until car has fully cooled.

Brian, anything to add?

the choping noise makes me suspect somethings wrong with the exhuast, hairline cracked manifold maybe. Probably a seperate issuse from the shudder