3 Quick Questions

[Godofwarmike]

1994 Grand Prix SE 3100
4T60E 4 Speed

1.) At idle my cars temp gauge will rise to 210 plus (enough to get the fan to kick on) But at driving speeds (30 plus) it will fall to the 140 or lower range even with it being in the 90s out here. Thermostat? and could this be keeping my car in lower gears to raise the opperating temp?

2.) The oil is sure black enough when i got it. What oil should i use. i know it says 5w-30 on the oil cap but is there any brand that works well for my engine? and what would be a good brand filter to use? Also it has a nasty knock from the top of the engine for about a minute on a cold startup should i use lucas or some other additive to help this?

3.) My A/C doesn't work but for being 14 years old it doesn't surprize me. If i was to go get one of those cheap recharge kits from autozone which port do i use since they are 2 inches away from each other?

[tblake]

1. Yes, I'd replace the t-stat and do a coolant flush. A t-stat is cheap, and sounds like its your problem. If you have dex-cool, stick with it. If its green, use the green stuff.

2. The sound your hearing is probably lifter tick. Just a change of oil will clear that up, I've always used valvoline oil with a delco pf47. Wally world has the best prices. If you want to read a good article on oil filters, go here This guy did a great job, and some extensive research.

3. No, 1994 will have r12 and r134a isnt compatible. You can no longer buy r12 (or you can but its spendy) due to its harsh effects on the ozone layer. Your best bet is to bring it to a shop, have them find the leak, and convert the whole system to r134a. Then you'll be set.

[HotZ28]

Originally Posted by tblake

3. No, 1994 will have r12 and r134a isnt compatible. You can no longer buy r12 (or you can but its spendy) due to its harsh effects on the ozone layer. Your best bet is to bring it to a shop, have them find the leak, and convert the whole system to r134a. Then you'll be set.

Are you sure that the 1994 has R12? I thought they had 134a!

[Godofwarmike]

yeah after thinking about it while driving it made sense that would be why it wasn't shifting.

ok just making sure cause my last car i just changed it with cheapest oil and filter cause it was a beater with a heater.

In the engine compartment on the strut tower there is a sticker that says to only use R-134a or it will ruin the system.

[tblake]

hmmm, ok, so 1994 was the changeover year then. For some reason I thought it was 1996. Sorry guys! my bad....

Mike, do a search for troy1 and send him a Private Message. Troy's our 4t60e/4t65e (and proably more) tranny expert. For some reason, I remember a certain tranny (could have swore it was the 4t60e) will not stay in OD if the tranny senses torque converter slippage. Sorry to be the bearer of bad news, but better for you to find out before you go and stick a ton of money into it.

I'll see if I can find torque converter stall speeds for your car.... (in the meantime, see what Troy thinks.)

[tblake]

Mike, attempt to pull any trouble codes. Find the ALDL (usually by the drivers knees/feet), jumper with a paperclip the two upper right terminals on the top row. Turn the key to on, but not start. Count the SES light flashes like this.

Flash Flash Flash (pause) Flash Flash - Code 32

It will display each code three times, then move on to the next stored code. Once it displays all the codes, it will start over with the first code. You can now turn your key off and remove the paperclip.

Post any codes you have and we'll go from there.

BTW, you were carefull not to pinch any shift solonoid wires inside the tranny while you did the pan drop, right?

[troy1]

Stall should be about 1800-2000 RPM get your PRNDL checked out. any codes pointing to the PRNDL with diable 4th. The burned smell does not sound good.

[Godofwarmike]

Ok i tried to pull codes but there is only one terminal on the top row.

it looks like this:

_ _ _ _ _ X
_ _ X _ _ X <--- the X's are where there is a wire the _ is where there is nothing.

so i should try a converter stall test to see what it stalls at correct?

[Godofwarmike]

ok so i ran a torque converter stall test and the RPMs were around 2500 (the car moved a bit so it might be lower a tad) would that mean the tranny is slipping then? (bad bands or something?)

[doctorhrdware]

There is a obd1 code reader, and it is around $20.

[Godofwarmike]

I checked to see if the transmission cooler was plugged so i unhooked the input line from cooler to transmission and placed it in a 1 quart bottle to see how long it took to fill it. Well i started it left it in park at idle and it filled the bottle in like 5 seconds. I think that there is a pressure issue and that the fluid is going through the cooler too fast for it too cool so its burning up in the transmission.

[HotZ28]

Originally Posted by Godofwarmike

I think that there is a pressure issue and that the fluid is going through the cooler too fast for it too cool so its burning up in the transmission.

I think 1-qt in 5-sec is about the right amount. What makes you think your transmission is "burning up"?

[tblake]

Originally Posted by Godofwarmike

ok so i ran a torque converter stall test and the RPMs were around 2500 (the car moved a bit so it might be lower a tad) would that mean the tranny is slipping then? (bad bands or something?)

I would do this again. Start it, put it in drive, engage the parking break, and hold the brakes firmly. Make sure the car doesnt move this time. Then hit the gas and measure how high you can get the rpm's. Only run it like this for a minute or so.

2500 rpms sounds a little high.

[Godofwarmike]

you sure it doesn't seem a bit much for the tranny cooler? i would think maybe more around a quart every 15-20 seconds so it has a chance to cool. I tried it again (this time on the road instead of gravel driveway) and it was still around 2500 rpms (car didn't move this time). Plus when i dropped the pan to change the filter i had to add about 7 quarts to fill the tranny (isn't that about the same as a complete rebuild) And already (190 miles on the fluid change) the color of the fluid is starting to change and it has a little bit of a burnt smell (might just be the remaining old fluid left in the tranny).

Still doesn't change gears into 4th (should be around 45 right?) and still no lockup. when i can get it to change into those gears by manually doing it i can only do it once each time i turn the car on even if i let it sit idling in park for a few then try it again.

Maybe converter is slipping so the TCM is keeping it in a limp mode?

one other thing i noticed today when i place it in 1 it makes a weird noise from the tranny. like a grindy scratching noise but it goes away in all the other gears and when its in park (maybe other gears too) it sounds like its sucking air kind of like a suction sound. (needle bearings in converter gone?)

[tblake]

I'm stumped, If I had to take a guess (sorry to say this) but my first guess would be slipping torque converter.

And I think 1 quart per 5 seconds is pretty much the norm.

Just out of curiousity, you have pulled the vacuum line off the modulator and check for fluid contamination, correct?