Hi all,
I haven't posted in quite a while but have been keeping up to date via digest format due to a lack of time. Yesterday I picked up a 1990 740 gl that runs beautiful and drives like a new car for $100.00. Just a few receipts for oil changes were in it along with a whopper of a bill for a rebuilt tranny about a year ago for $2300.00 from aamco, but I digress. The coolant revervoir is milky after I drove it home(was a little milky when I first saw it) but the engine oil looks uncontaminated as does the tranny fluid. My first thought was a head gasket but now i am leaning towards a tranny cooler leak in the radiator(automatic trans). I don't care either way since I will be repairing whatever the problem is. I can't think of any way to diagnose the tranny cooler leak except for replacing the radiator but I'd rather be sure. Any ideas? Almost forgot, in the trunk there is a bottle of tranny fluid that may or may not mean anything.
Car has 211,000 miles and a very good body and great interior except for the headliner and needs some odds and ends. This is for my 16 year old daughter with a liscence soon. She loves it.


Thanks in advance

Dan



2) 82 242 GLT, 87 745T, now 1990 740 gl, 1986 Big Blazer tow vehicle

Had a tranny cooler failure within the radiator on a 91 740. First symptom was milky ATF and then milky coolant. This is generally terminal for the tranny (not necessarly immediate) as the water/antifreeze turns to steam within the tranny destroying the clutches. Our tranny failed about 2 months after the initial radiator failure. I'm wondering if Aamco fixed the tranny but not the rad and you have the same problem all over again. The opinion of most guys on the board is to look for a used JY tranny as opposed to rebuilding one.

bl

thanks for the reply. The receipt i found also shows a new radiator at the same time as the tranny. I was able to track down the previous owner late yesterday and she is almost certain that in the 4 years she had it the car was never overheated and does seem to remember the milky coolant happening around the time the tranny job was done. she is going to talk to her son and we are going to speak again next weekend...she is very helpful and says it was a great car for her family. I am suspecting even more that the radiator may have been defective on installation. In looking thru the aamco literature, I found a 12 month warrantee that goes with the car if sold...I'm going to try to get a new radiator out of them. The warrantee still has 2 months left.


Dan

The problem with a trans. cooler leak is that the water can go the other way and get in the trans, and this is definitely not good, ruin a trans. I know from experience. you can disconnect those lines and hook up a bypass hose for a short period of time, it won't hurt the trans. Then when the radioator gets hot and up to pressure us can see if water(cooland is the proper term) comes out of the connections where the trans fluid lines were hooked up.

Great suggestion...I may try this over next weekend.



Dan

You could pressure test the cooler in the radiator with a piece of hose and a gauge T arangment.Low pressure like #15 or so and watch for a pressure drop. GASSIT M.J.

Thanks for the reply.



Dan