bad thermostat mess with torque converter?

[eightyfour84]

At highway speed my torque converter will occasionally disengage and engage again quickly. Doesn't happen much, but enough to be annoying. After doing a search I've tested the resistance on the lockup solenoid and checked the kickdown cable and everything is looking good there. Then I seen a thread by GTP where he solved some torque converter engagement problem by changing his thermostat. But his symptoms were very different. Other than this issue the tranny shifts pretty smooth. Something about the problem seems electrical, like some sensor is dicking me.

I also didn't get much heat output from the vents in the winter, not as much as my last cb.

Guess I will give the thermostat a go if nobody else has any better ideas that has dealt with this issue.

[cloudasc]

Since you have an automatic you should read this thread: ENG: 90-93 TCU Fix / Preventative Maintence

Since you seem to believe its an electrical issue, you should definately take a look at your tcu, as it is the "brains" behind controlling the transmission.

[93redcb7]

At highway speed my torque converter will occasionally disengage and engage again quickly. Doesn't happen much, but enough to be annoying. After doing a search I've tested the resistance on the lockup solenoid and checked the kickdown cable and everything is looking good there. Then I seen a thread by GTP where he solved some torque converter engagement problem by changing his thermostat. But his symptoms were very different. Other than this issue the tranny shifts pretty smooth. Something about the problem seems electrical, like some sensor is dicking me.

I also didn't get much heat output from the vents in the winter, not as much as my last cb.

Guess I will give the thermostat a go if nobody else has any better ideas that has dealt with this issue.

you can take the t-stat out and test it in some boiling water, and also im not sure about it affecting it or what not, but does your car heat up to normal operating temp? does it only do it when it is not warmed up or when it is or both?

[eightyfour84]

The guage is approximately horizontal. And it does happen once at operating temp. Also I've heard its the 90/91 (mine is 1992) that have the tcu problems, and also my problem doesn't match the symptoms described in that thread. I'll look into it if all else fails I guess.

[alan lx]

Here is another test: drive the car to warm the engine and take the radiator cap off. Use a cooking thermometer and put in the radiator while running. It should read somewhere between 180 and 190bought degrees. If its cooler than that, the thermostat could be sticking open.
By the way, is the guage on normal while driving?

[eightyfour84]

Here is another test: drive the car to warm the engine and take the radiator cap off. Use a cooking thermometer and put in the radiator while running. It should read somewhere between 180 and 190bought degrees. If its cooler than that, the thermostat could be sticking open.
By the way, is the guage on normal while driving?

Yeah it's approx horizontal or slightly above a few degrees.

[cloudasc]

Also I've heard its the 90/91 (mine is 1992) that have the tcu problems, and also my problem doesn't match the symptoms described in that thread. I'll look into it if all else fails I guess.

I thought I would post up another example of a users (Tippey764) 92/93 tcu going bad:


In this case, the repair would be as simple as cleaning up the electrolytes from the leaking capacitors with a q-tip and some isopropyl alchohol, then replacing all the capacitors on this board; which should return the tcu to "like new" condition.

This issue isn't just related to 90/91 TCU's anymore, its all of them... old age is catching up, so anyone with an Automatic should have this procedure done.

If you think you can just get a replacement from the junkyard, just remember this, it will fail, its only a matter of time, so your best option is to REPLACE ALL CAPACITORS before putting a replacement into use... otherwise the cycle will continue.

Heres a cool video to help you understand capacitors:

You may not be fitting the symptoms, but a leaking capacitor can cause all sorts of problems, thats why I suggest taking the cover off and inspecting at the bare minimum. Should only take about 5 minutes.

In regards to the thermostat, if you don't know how old it is, it probably would be a good idea to replace it, a genuine honda replacement will set you back less then $20, and should offer some peace of mind.

[eightyfour84]

You may not be fitting the symptoms, but a leaking capacitor can cause all sorts of problems, thats why I suggest taking the cover off and inspecting at the bare minimum. Should only take about 5 minutes.

In regards to the thermostat, if you don't know how old it is, it probably would be a good idea to replace it, a genuine honda replacement will set you back less then $20, and should offer some peace of mind.

I checked the TCU since it's the most readily accessible and everything seems rather pristine in there.

[ChIoVnIdCa]

Here is another test: drive the car to warm the engine and take the radiator cap off.

lolz..

Have you ever done this? Good way to get burned by coolant bursting out under pressure.

[ChIoVnIdCa]

I checked the TCU since it's the most readily accessible and everything seems rather pristine in there.

The thermo wont cause issues with the torque converter. If you suspect it is failing then replace it. But the TC is unrelated.

[GeoffM]

lolz..

Have you ever done this? Good way to get burned by coolant bursting out under pressure.

You can do it, you just have to be careful.
When my mechanic was pressure testing my cooling system, I drove 10 miles to get there. He covered the cap with a rag and popped it off. Didn't wait for anything.

[alan lx]

Yes, I use a rag as Goeff said. Been doing it probably for more than twenty years now. And I do not stand right over it.