Wow. I sure do like this car!

The seats are very ergonomic for me. Very little driving fatigue after a couple of hours of driving. That suprised me. :smile:

The low miles is what steered me into the car. The car smells like new and interior is flawless. Road noise from the trunk area was dissappointing..Even new Toyo tires didn't calm it down much...

I have yet to see higher than 24mpg though. (almost all freeway) :confused: The car came with some Precision Control System thingy...Does it hurt my mileage? Is there something I could do to raise the economy?

What do I need to do to this car that has sooo little mileage to keep her running like new?

Tom

I think you are doing well milage wise, keep in mine this is a 4,000 lb car. Drive it and enjoy it.

Thats not the mileage you should be seeing, especially if its all highway. I can pull 28-29 on the highway, and Ive got a tired old gal with 160,000 miles on it. Your mileage is about what I usually see with a city/highway mix and a heavy foot.


I would say you might want to replace the Oxygen Sensor, that has a big effect on mileage. But, you might just want to try a full tune-up first. Which on the 3.5 consists mostly of some new spark plugs, PCV valve, air filter, fuel filter, I cant think of anything else.

You could also check your tire inflation. See what the tires themselves can handle, not what GM says you should use. GM will say 31psi, which is fine, but some tires can handle 40-45psi with no problems. It may make your ride somewhat firmer, but I doubt youll notice it tremendously.

Also, when I see low mileage, it makes me think the car has been doing a lot of sitting, or a lot of short trips. Either way, I would want new fluids. Transmission, brake, power steering, etc.

I run 40 psi with a little less in the rear. Bfg Control 80k --> good touring tires are the best Intrigue mod and the OE Tires were fairly bad (loud, slippy in the wet)

Change the tranny fluid and filter.

Run Mobile1 or Amsoil or maybe the Walmart generic synthetic 5w30 or less.

1. Is it too soon for the tranny /filter flush?--sure looks like brite fluid though..:smile:

2. Whats the "wooosh" sound I hear a few seconds after the engine starts?

3. Will the mileage be worse due to the faster-accelerating 3.29:1 axle ratio (instead of 3.05)? How bad?

a good set of touring tires will gear you higher. At 70mph I am right at 2000 rpm before I believe it was ~65 at 2000. The stock tires are rather low profile.

The 4t65e tranny can have issues if not kept clean. = no flushes, take the tranny pan off and clean it.--> best thing you can do.

a good set of touring tires will gear you higher. At 70mph I am right at 2000 rpm before I believe it was ~65 at 2000. The stock tires are rather low profile.

The 4t65e tranny can have issues if not kept clean. = no flushes, take the tranny pan off and clean it.--> best thing you can do.

Although a tire's rolling resistance can affect fuel economy, as long as the tires are the same size, the speed relative to RPM shouldn't change any noticable amount. ALL Intrigues came with size 225/60/16 tires (except for 2002 Final 500 models which came with 17" wheels). The Autobahn (1998-99) and Precision Sport Package (2000-2002) Intrigues came with tires that had an H (130 MPH) speed rating whereas all the others came with S (112 MPH) speed rated tires.

The lower 3.29:1 gear ratio that comes with the Precision Sport package will lower fuel economy and what you are getting does seem in the ball park. How fast you drive on the freeway and running the A/C will affect fuel economy as well. Keep in mind anytime you turn on the HVAC blower fan the A/C automatically engages unless it is under 40*F outside. You can shut it off by pushing the A/C button unless you are using the defrost mode.

FWIW I make it a habit to change the tranny fluid/filter every 50K miles. The 4T65E tranny will last much longer if you do this. Do NOT get it flushed at a lube shop. If you can afford it run Mobil 1, but personally I don't think it's worth the extra $$$ for their tranny fluid.

I'm unsure what the "woosh" sound is, but I'm guessing that it is a normal sound coming from the A.I.R system at start-up.

Man, you guys rock!

I checked the sticker, I have the H rated sticker. So I guess 30mpg is outta the question for me. I can certainly live with near 28 or so. We'll see what the future holds. :biggrin:

I will heed the "flush" warning! I can feel the tranny slip when taking off--actually happened today! I was going at a crawl, not alot of momentum from the tranny. I applied more accellerator pressure and felt a little converter kick-in. Not good. Last week I had the same thing happen when I had it in reverse and -----again, more accellerator, then it kicked in. At first I wasn't sure I had the lever in reverse...it was.

So, today went in some Marvels Mystery Oil in the fluid--(I had a buddy at Oil Can Henry's pull a quart out via the dip stick) and I'll have the pan dropped and fluid replaced asap!

Would it be best to add one or two bottles of Lube guard AFTER the pan drop/fluid replacement or BEFORE?

What is likely the issue with my 48,860 mile tranny.

If you want to be sure of what ratio you have, you need to check the sticker again for the RPO code.

code FR9- Ratio, Transaxle Final Drive, 3.29

code F83- Ratio, Transaxle Final Drive, 3.05

As for the transmission, almost sounds like a weak pump? Or it might even be low on fluid.

You just bought it right? Isnt there some sort of warranty? Or did you buy it private party.

adding Marvel Mystery oil to your tranny is a new concept and could maybe be bad for seals etc. -seems risky but MM is similiar to tranny fluid.

Your tranny shouldn't be slipping -a possible reason for poor MPG.

New fluid (keep a pint out for the lubeguard) should clear up any problems since your mileage is so low. Taking the pan off (gasket is reuseable) and cleaning out the muck is the smartest thing you can do.

Read the manual to get the tranny fluid level correct.

I checked the trunk lid--code FR9- Ratio, Transaxle Final Drive, 3.29.

Fluid level right on......perfect.

So that's that.

The MMO (Marvels mystery Oil) was just to add a cleaner till Monday. Monday 10am the pans being dropped, filter changed, THEN-the system will be flushed with new fluid AND Lube guard added.

Thanks for the insight guys. I appreciate them.

Again, it does slip a little. (only noticed when idling though)
1. What basic parts are likely issues for that slippage?
2. Or, Will the fluid/filter/Lube Guard likely fix the issue?

I highly doubt a tranny with mileage as low as yours would be experiencing clutch plate slippage and the clutches in these trannys typically last 200,000 miles.

1. Tranny fluid breakdown could cause some slippage.
2. Most likely it's a solenoid issue and a minor one at that.

Will Synthetic tranny fluid help keep tranny solenoids from gumming up. I don't use it and tranny fluid is fairly light 5W straight etc. Couldn't hurt though -less burn off with the synthetic should cause less gumming/tarnish.

I checked the trunk lid--code FR9- Ratio, Transaxle Final Drive, 3.29.

Fluid level right on......perfect.

So that's that.

The MMO (Marvels mystery Oil) was just to add a cleaner till Monday. Monday 10am the pans being dropped, filter changed, THEN-the system will be flushed with new fluid AND Lube guard added.

Thanks for the insight guys. I appreciate them.

Again, it does slip a little. (only noticed when idling though)
1. What basic parts are likely issues for that slippage?
2. Or, Will the fluid/filter/Lube Guard likely fix the issue?

I've never heard of using MMO in the transmission. It doesn't sound like that bad of an idea though assuming you stick to your plan. I would add the Lube Guard additive after the fluid change. I am a firm believer in using that myself.

As far as the slipping goes, I doubt it's anything serious with only 48K miles. I wouldn't be surprised if it's just the torque converter not fully engaging right away b/c the car is used to the previous owner's "pamperish" driving habits. You might try pulling the ECM fuse and trans. fuse for a couple minutes and make the car relearn your driving habits. But if you don't want to do that then it will eventually adapt to how you drive within a few hundred miles.

FWIW I've found that when the A/C is on and I gun the throttle from a start on my wife's Intrigue that it feels like the transmission is slipping, but it's really just the A/C dragging the engine down. Since the 3.5L doesn't have alot of low end torque from a dead stop its pretty noticable, but it does reach the powerband soon enough to get out of it's own way and thensome.

a good set of touring tires will gear you higher. At 70mph I am right at 2000 rpm before I believe it was ~65 at 2000. The stock tires are rather low profile.

The 4t65e tranny can have issues if not kept clean. = no flushes, take the tranny pan off and clean it.--> best thing you can do.

I with you on pull the pan, clean and install a new filter. My 99 has a 143K on it and shifts just fine. At around 50K I had the tranny flushed at a 100K I pulled the pan. What I found was the filter pushed down into the bottom of the pan with the suction right in the goo that collects on the bottm. I have been happy with the car. The only repairs have been an intermediate steering shaft and a blower resistor. Not bad for a 10 year car with 143K.