Torque Converter Won't Engage

[rh77]

Long story short, the Integra was parked at the airport all week, and I just got back, with the temps in the high 20s and 40s during the day. It started right up with a temp around 28.

I've noticed lately that the torque converter won't engage when it gets cold out. I'm on the highway doing 60 and usually the torque converter will shift and decrease the RPMs by about 400-500. The trip is a little over 50 miles, and it took 40 before it locked-up (I think it may screw up economy).

I know it's the converter because if I step on the gas, the RPMs immediately go up. When it "slides" into lock-up mode, it's firmly at the RPM unless more power is needed, then it unlocks, RPMs go up 400-500, or the car shifts from 4th to 3rd. Trying to think like the ECU, I looked at the temp guage -- 1/4 way up -- I think the thermostat is sticking open. I turned the heat to the coldest position and floored it. The temp guage went up to the normal operating position (slighty half-way up), then the converter locked up, 40 miles later. I turned the heat back on and when I merged onto another interstate, it wouldn't lock up and the temp guage was back into the 1/4 range (cold).

Is there a connection between coolant temp and the torque lockup converter? I plan on replacing the thermostat with a hotter one anyway. When it's warm outside, the TC locks-up on the highway every time. I really wish I had a 5-speed, but...anyways. Is there more to it than coolant temp?

RH77

[n0rt0npr0]

Yes there is a direct connection to that TCC locking up, and operating temperature: The TCC will not lock-up when the coolant temperature is under a certain amount(varies depending on Tranny fluid requirements(built into computer))

Reason is: The tranny fluid has its own set of operating temperatures from the way I've understood some repair manuals I've read. Theres TWO reasons the tranny fluid is routed into the radiator, to warm the fluid up as fast as possible and to maintain a delicate balance of the fluids high and low temp requirements.

Transmission fluid definately has set thermal boundaries. My GF cooked her tranny fluid in this past hot summer. Stop and go traffic in July. No wind. I wished her radiator would have done a better job of cooling cuz it was a ***** to get her tranny pan off. Factory used some liquid nail on it or something, lol.

Anyway, replace that thermostat and IF its convenient for you while you are under the hood, remove your temp sensor for an inspection(good measure). If theres any corosion, wire wheel it off, or them scotch brite pads work very well too. You insure accurate temperature readings being sent to the computer that way.

Then reinstall with some teflon tape, and top off the coolant system(but watch out! Some engines require a massive amount of work to get the air out of the system...lol, check into that before you do it...I've screwed that procedure up on a nice engine, and messed its driveability up before...lol never again will I take that step so lightly)
~Will

[diamondlarry]

I had a Durango and the torque converter would not lock up when the temp was below a certain level; I think near the zero mark give or take a few degrees. It didn't seem to matter how warm the engine was but how cold the outside air was.

[n0rt0npr0]

The Durango is a little different I think...Big heater core(s) in it in that weather trying to keep the interior warm(which takes away from the engine temp)...ALL had the OBD II system, which knows exact temp of tranny fluid and due to all the space under the hood and around the radiator it might have just took a helluva lot of WOT to warm up that fluid to specs. That thing might have had a towing hitch on the back also, which means it might have had a tranny cooler...(no valving on the line cooler and having 0 degree temps comepletely cooling the fluid. That'll do it!)
And Dodge HAS the worst reputation for transmissions in the first place, especially for new models (Durango's of 1998-2000) So programming or sensor outputs may have been rickety...
Umm ya I don't think too highly of Dodges...

[diamondlarry]

And Dodge HAS the worst reputation for transmissions in the first place, especially for new models (Durango's of 1998-2000) So programming or sensor outputs may have been rickety...
Umm ya I don't think too highly of Dodges...

I do know that Dodge 4-speed automatics until after 1998 were known for early failure. I lucked out though and had no problems even after 67,000 miles. I have heard many good things about the 318 engine though.

[rh77]

Originally Posted by n0rt0npr0

And Dodge HAS the worst reputation for transmissions in the first place, especially for new models (Durango's of 1998-2000) So programming or sensor outputs may have been rickety...
Umm ya I don't think too highly of Dodges...

I don't mean to bash GM also, but Blazer transmissions almost programmed to fail at 60-90K intervals. I think the newer models have improved, though. I've gone through my share of GM vehicles, and Honda/Acura has earned my respect.

At any rate, the TC seems to react very much to coolant temps. I went to the parts store(s) to find a 192-degree thermostat which is available for the Integra but had to special order it -- so I can't get that installed this weekend. In the daylight hours and temps in the 30s I can get the coolant temps up, but if I hit the highway, the air across the radiator is too much for the little 1.8 and the guage drops like a rock, and the TC is out to lunch. I'd hate to put cardboard or something in front of the radiator air flow, but if the new 'stat doesn't do the trick, I might resort to a plexiglas baffle on the air dam.

P.S. Sorry to all the GM workers and fans out there, but they've done me wrong too many times. They need to make their car lines more exciting and reliable (the Toyota principle) so they don't loose Billions of dollars a quarter. It kills me to see plants close and workers out of a job, and I'm sure we all have someone in our family that works or worked for them. But, they're always last to figure it out: the gas crunch of the 70's, reliability of the 80's and 90's, and most recently, the appeal of the product.

RH77

[Compaq888]

Now I understand what you are saying. You seem the converter won't lock up till the engine warms up. So if your engine is warming up it won't lock up.

I have this happen everyday. The rpms have to be 1900 when the converter is not locked up to get the same amount of accelaration it is when it is warmed up. When it is warmed up the car has the ability to accelarate( don't confuse this with keeping the same speed) at 1100-1250rpm. When the car does warpm up I can keep the same speed at 1500rpm 30-36mph. After that I can keep the same speed at 1250rpm at 37mph. Overdrive baby! My thermostat is 195. It takes me 4.5 miles of driving to go to locking up converter and ability to go into overdrive.

[n0rt0npr0]

The only reason any tranny fails is lack of maintenance! It's not really anything Blazers were prone to, or any other manufacturer(Dodge excluded). A good car owner would always be aware of what may be leaking or making noise from their vehicle, and service it accordingly. In this "Blazer" instance, I think its driver carelessness.
You know what makes a driver feel that they can be careless? A vehicle that "feels" ROCK SOLID. And that's the thing about most American vehicles...They are built with thicker/denser everything. Not to say that is a "good" thing...BUT, it does lead most American vehicles to be highly neglected compared to hondas/acuras/toyotas...
I work at a private auto auction, I've driven ALL of your cars before. They feel "solid" too...but not as solid as a blazer

P.S.~...this could be a never ending argument.

[diamondlarry]

[quote]

The Dodge 4-speed automatics 1998 and prior would fail even WITH proper maintainence. I know of one person personally who had his transmission regulary serviced at the dealer ended up having his transmission replaced TWICE. The first was under warranty, the second one was on him. My in-laws had a 1978 Blazer that was regulary maintained and it's tranny failed at around 50K give or take. I always heard from my uncle who is a mechanic that GM trannys failed more often because of the way they shifted. People complained about shift harshness so they designed them to shift smoother by letting them slip a little while shifting. Some GM's almost needed a tach to be able to tell when they shifted. Fords on the other hand shifted more firmly but tended to last longer.

[rh77]

Originally Posted by n0rt0npr0

P.S.~...this could be a never ending argument.

I was afraid this would happen. This is my story, and this is how I think and act. Long story short, statistics show premature failure of transmission of American brands -- just check consumer reports. I had a '95 Chevy Beretta, 4-sp. automatic, brand new, that developed a whine under 5000 miles. I wasn't hard on the car -- verdict from the dealer: "faulty factory assembly" -- new trans-axle.

NOT to say that Asian brands are free of tranny problems. Even my beloved Honda/Acura brand has a nasty blemish of 5-speed automatics that they put in 2000-2004 models, including the TL and MDX. My brand new 2003 Mitsubishi Lancer Evo-8 had a POS 5-speed manual, that was recalled. My point is: just look at the statistics -- let data be your guide.

My decisions have been based on my experiences and research.

Newer "American" models can probably compete better today with most "Foreign" brands for long-term reliability, but I'm going with Honda. They have earned the respect of both myself and my wife (she had her Integra before I met her). My money's on Honda.

So, what IS an American car? A Honda "Civic" made in Ohio is more "American" than a Chevy Aveo, built in Korea.

RH77