Hey All!

Got my new-to-me '89 740 N/A A/T brick back from the garage (in tank pump, front pipe, cat, timing belt, tensioner, belts, hoses, etc.). Runs great! Except...

1. Occasionally it will hesitate going into drive out of park. When it engages, it does so a bit hard. Once you are driving, it shifts firm but otherwise behaves perfectly. Transmission fluid looks new.

2. Idle fluctuates when warm. Sometimes it goes low enough to stall. Starts right up again (fortunately).

Have not cleaned idle control valve yet. Will be going over hoses to look for vacuum line issues.

Any thoughts? Thanks in advance, couldn't do this without you guys.

 

Your tranny is going out... If the fluid is new, no other explanation.
Idle, Control Valve probably.

 

Wow, you really think the transmission is going to break? That seems unusual, it's only got 140k miles on it.

 

Well, these are signs of a failing transmission... It can still go a very long time.
How long a wait to engage?
How hard does it slam into gear? The "kick" may be due to a worn U joint...
140K is low for the tranny to fail but not unheard of. But if the fluid was not changed then failures are more common.

BTW, are you sure the car has in fact 140K? You have records, other documentation etc. to support it? These days I see a lot of older cars on the market with low, low miles when the wear and tear simply do not support the shown miles. Often it is ridiculously obvious that the miles were tampered with...

 

Thanks Lev,

When it does hesitate, it takes ~1 second, and it may have been engaging hard because I was anticipating it actually being in gear when it wasn't (used to my other brick engaging immediately). I'm actually going to test this a bit more to be sure (by making sure to keep my foot off the gas until it's been engaged for a full second!).

What's strange is it doesn't do it all the time, and it doesn't seem to matter whether it's hot or cold.

I'm wondering if it was way overdue for a transmission fluid change and that's gummed up a valve somewhere, and now it's sticking.

The car looks like it's got 140k miles on it as far as the body, windshield (not very sand pitted), underside, interior, pedals, etc. go. Basing this from looking at my '92 with 200k+ miles on it. Plus I bought it from a Volvo enthusiast (he has a 144 model and a couple modern ones), he said he was the second owner and I'm inclined to believe him.

Maybe some Gunk transmedic will help. Always had good luck with that (all Gunk products, actually).

 

You said the fluid was fresh...
What, no records at all? I'd run a Carfax or Autocheck. Look for a deal on the internet, may be $5, and just for the hell of it see what comes up. 140k for an '89 is unusually low and especially a NA car should be pristine with these miles...

 

OK, an update:

Let the car warm up, engaged in reverse immediately. Put it in drive, it took about two seconds to engage, did so normally (not hard, I made sure to keep my foot off the gas).

Going to go look for that bottle of Transmedic I have stashed somewhere...

 

Update:

Went and got some Transmedic (using it because it's worked in the past).

Checked the fluid levels with the dipstick just warm to the touch (WAY under 105F). Transmission was overfilled by over a quart! The previous owner appears to have filled the transmission fluid to the hot line when it was cold (the previous owner had loaned it to his brother, which while a nice guy, didn't seem to be the sharpest tool in the shed). Somehow I missed this before. Rrr...

So I sucked out ~1.5 quarts of fluid to make the level right with the 10oz of additive, and got a good look at it in the process. It's not actually new, but isn't totally spanked. So that's better news.

Anyway, so far so good. Going to drive it some more. Hopefully this works and can help some others here.

 

Well, that may work... Too much fluid, wrong fluid, worn fluid, all these can cause symptoms.

 

Update:

Just may have gotten lucky here. Seems to be shifting fine now.

Can anybody else comment about too much transmission fluid causing problems like this?

 

Anyway...

Got a new idle control valve, problem solved. Changed the flame trap while I was there (probably not needed, but it was cheap), plugs/cap/rotor/wires, reseated all the ground wires I could get to easily. Motor is running really well now, I am a happy brick owner.

However, it's still shifting kinda funky very occasionally, e.g. hard downshift to first gear in about one in twenty, *may* have slipped under hard acceleration once...

Going to just drive it like an old lady whenever possible and change the fluid when it warms up.

Thanks for your help, Lev!

 

So anyway...

I've been DERP DE DERPing a lot on my bricks lately.

Anyway, I noticed the transmission hesitating from park to drive again. Took it out and drove it hard, and it slipped on a downshift (engine revved, brick didn't speed up like it should).

So, I'm looking around at used transmissions, checking FAQ's about how to swap one out, wondering if I'll have to do it during the Winter, humming 'poor poor pitiful me', etc, ad nauseum, etc.

Then I came across Transmission-Auto1

Went out, got some Lucas Stop Slip, sucked out a quart of xmission fluid, put the LSSTF in, drove it, ...Viola!

Now it drives great.

Anyway, assuming there's not a pile of metal bits in the drain plug (I put a sooper-dooper NiDb magnet on the drain plug, in the event it had a weak/no magnet), this Spring I'm going to get some Transmedic transmission flush/cleaner, flush it, and replace the fluid/filter.

DERP DE DERP DERP DERRRRRRP...