When the engine temperature reaches approximately 195 Degree I loose the overdrive gear. To get it back I have to get the engine temperature below 195, turn the ignition off then on again,(possibly to reset it). If I'm on the highway and I'm in overdrive I won't loose it since the engine temperature wont' go up to 195 degrees.

I presently have a drilled 180 (less than one year) stat and have changed the tranny oil and filter.

I've had the engine go up as high as 220 d. in standing traffic but then my gauge is most likely not accurate.

How can I tell if it has an aux cooler? Was the tranny cooler an option in the 95 SSEi?

I think what you're trying to tell me is:

1. The engine temperature can't go over 195 degrees or
2. I'm in need of a tranny cooler.


What I question though is why the engine is running so hot only at idle with a 180 drilled stat?

Not exactly the same tranny in my '95 SE, but I solved the same problem on all but the hottest days by installing a $40 tru-cool auxiliary trans cooler from http://www.bulkpart.com I'll bet if I had gone for the bigger $60 model, it would stay in OD on even the hottest days.

The real fix for this heat-related OD dropout is to change out the bore and piston in the tranny that wears and is aggravated by high temperatures. Sonnax makes a sure-cure kit to fix it, but the tranny has to come out to install it.

Meanwhile, a bigger tranny cooler will do wonders.

jr's3800



BTW how does your Fluid look? Reddish... Reddish Brown?


The tranny fluid was changed last year and when the weather got warm enough I started noticing the problem. At the moment the color is a nice clear red.

Mick has the car at school at the moment but I will check for the tranny cooler when he gets home.


bill buttermore


The real fix for this heat-related OD dropout is to change out the bore and piston in the tranny that wears and is aggravated by high temperatures

Thanks for the suggest but I really really don't want to drop the tranny. That sounds a bit to scary for me to attempt. As for the aux tranny cooler, I would think that if the car came with one then it should be doing it'* job. What I have to wonder now is why the car'* engine temperature rises as high as 40 degrees at idle and then goes back down when in transit? That would lead me to believe in these problems.

1. Low coolant.
2. Problem with Stat (New 180 Drilled)
3. Radiator
4. Air lock in cooling system.

What are your thoughts?

I think you are right about the cooling system. It must be working properly. And it is the first area to address. To eliminate air, follow this fill procedure: http://www.bonnevilleclub.com/forum/...=article&k=100

If the temperature still doesn't come down, you might try flushing the system: http://www.bonnevilleclub.com/forum/...ic.php?t=84203

If that doesn't keep the temperature down, install a new radiator.

I think you are wrong about the transmission cooler. There is a huge difference in the cooling capacity of the relatively small cooler provided by the factory, and the low pressure drop Tru-cool coolers sold at Bulk Part. When I installed my trans cooler, not only did my tranny temperature drop, but the engine temperature also dropped about 20 degrees. This is a case where size does matter. As stated above, if I had it to do again, I would have purchased a larger cooler than I did. (I bought model 4454; next time, I will buy model 4490.) BTW, these coolers come with all the necessary fittings and can be installed very easily.

95 SSEi will have a small factory cooler. And on the temperature..the high speed fans don't come on until you reach about 228F or slightly over 100C. It'* a silly temperature in my opinion.

Frank.. you installed the high speed fan over ride right? Any differences when using it?

bill buttermore

follow this fill procedure

When I get a chance I'll read it and give her a try.

I think you are wrong about the transmission cooler

Just a thought but why am I the only person on this forum that seems to be having this problem and it'* a stock car? Maybe I'm a bit nieve but what about the 95 Bonne'* that don't have a factory tranny cooler installed and they don't have the OD issues. Again just a thought.

BillBoost37


And on the temperature..the high speed fans don't come on until you reach about 228F or slightly over 100C

By the time it'* reached that point I would have lost the OD feature.


Frank.. you installed the high speed fan over ride right? Any differences when using it?

Absolutley Bill, if I have the over ride switch on, the engine temperature won't get past 190 degrees, even in standing traffic. I would assume your suggestion would be to keep the switch on in stop and go traffic. Only problem with that is my dear wife Cathy, she doesn't monitor gauges and won't know or care to turn on the switch when needed. She is sort of a turn key person.
Your other suggestion may be to leave it on during the whole summer, that'* a consideration but I don't want to overwork the fans, even if I do have a good friend that get'* me Bonne replacements parts at an amazing price .[/b]

You have a trans cooler on the car. Eh Franky....I know this fact.

You may want to do another trans service and add an aftermarket cooler on that has a thermostatic control (like WillWrens where it restricts fluid flow under 160F). It seems your radiator is driving up the trans temps too quickly.