Desperately need some advice

edothekid:

Just coincidence, imho. The aux. cooler should not affect the operation of the rad even though the stock transmission cooler is built into the rad.

Have you changed out your coolant regularly? Have you done a chemical flush of the cooling system? Is the temperature sender OK (i.e.--is the car really running hotter or just indicating hotter)? Have you checked the rad fan fuse or checked to make sure the fan is operating properly? Is the ambient temperature significantly warmer than it has been or are you using the A/C more due to weather?

Please post with results of what you find.

Where is the trans cooler mounted??? It's not in front of the radiator, is it??

It sounds too coincidental to be coincidental, if you know what I mean. It's mere presence on the vehicle shouldn't affect engine temp...unless it's obstructing flow to the radiator, and/or adding heat to the air flowing through the radiator. If either of those is the case...I think that's your problem.

I think you just found your problem. The cooling system only has so much capacity. If you exceed that (by increasing the power output too much), or decrease it's efficiency too much (what you're effectively doing), and you're going to compromise it's ability to adequately cool the car.

You're improving the cooling of the transmission...but you're expecting the engine cooling system to take on the additional load. Two ways - 1) you're obstructing the flow through part of the radiator by expecting airflow to be drawn through both the cooler and the radiator. Which hurts both the efficiency of that portion of the radiator, as well as the efficiency of the trans cooler. You're also dumping hot air from the trans cooler through the radiator - either further reducing the efficiency of this section of the radiator, or, possibly, even adding heat to the engine coolant (if the air temp out of the cooler is higher than the coolant temp in that portion of the radiator.

It's clearly causing a problem. Your best solution would be to relocate the cooler somewhere where it's neither obstructing flow to the radiator, nor adding heat to it. If the trans cooler doesn't cool effectively enough then under all conditions, add a fan to it of its own.

Of course...if it's only causing slightly elevated temps, and not truely overheating, maybe you're o.k. the way you are. But I think the cooler setup is clearly your "problem".

No problem. I hope you get it cleared up and everything working to your satisfaction.