So here is my situation. On my wives SL2, we have had a lot of coolant problems. This is the most recent, after replacing most of the system last year (including a new radiator).

My wife took a short 2 block drive to the store, went into the store, and came out. The engine would not turn over (lights and accessories came on) and so she got out of the car and noticed coolant all over the ground and called AAA. I rode out to her to check things. It seems the expansion take boiled over and spewed 50/50 all over. I got in and tried to turn it over, and it started right up. I still let AAA tow it since its free.

Next day, friend took a look at it. Could not find a leak, and let the wife run it on an errand. She got to her destination, went in, and came back out. More lime green 50/50 under the car, and it wont turn over. Again, go out, and by the time I got there, I could turn it over. I drove it back, but I noticed the cooling fan was not coming on after I stopped.

So, the cooling fan is not going. Will this cause a boil up after you turn it off? Also, would this keep the engine from turning over? I tried connecting 12V to the fan leads, but I cant get to them. The plus is extremely hard to get to. Any tips on that? Im trying to get to it from the fan motor itself.

Any help would be great. I was able to fix the bad shifting problem (Valve body) from this sight and that saved me a TON of money! The mechanic wanted to replace the tranny!!!

Kevin

 

Try replacing the Engine Coolant Temperature Sensor (ECTS). There's a good chance it will cure both your problems ...

 

Do these SL2's chew temp sensors? I have gone through 3 in the past 2 years.

Also, is there a diagram showing were it is? I would like to try it on my own this time around.

 

Well, as I usually mention when I suggest that this sensor is defective, is to obtain one with a brass tip. The other ones usually have a resin coated tip, and they will not last (so much for after-market parts). In this case, OEM is usually best.

The sensor is located on the driver's side of the engine, just below the cooling water outlet from the engine to the radiator. You will probably have to remove the air intake duct to get a clear view. It is a two-wire sensor (yellow and black wires). Just make sure you are working on a cold (cool) engine, to prevent scalding, and use Teflon tape on the threads to ensure a proper seal.

The sensor itself costs about $14usd. I also recommend replacing the connector at the same time. It is a bit more expensive (about $24usd) and some people bypass this suggestion, but the choice is yours ....

 

OK. On another forum, I read that you can test if its the ECTS or the fan by simply turning on the AC. If the AC does not kick the radiator fan on, its the fan, not the ACTS. Is this true? I tried it, and the fan does not come on.

 

Well, that's assuming that the ignition key is in the RUN position, the A/C is set for maximum cooling, and the fresh air selector is set to the RECIRC position. It also assumes that the fuse has been checked and is known to be good, the fan control relay has been checked, and is known to be good, and that there are no wiring breaks out to the cooling fan .....

 

Well I checked the fuse, and also the fan is free and clear of obstructions. Is there an easy way of removing the fan lead from the fan? The plug has some type of locking clip I cant seem to get free. Is there some trick to that, or is it possible to get to the fan wires some other way to give it 12V?

 

The expansion tank is not supposed to leak. I had this happen to me and I replased the expansion tank cap. It's a $4 item so just give it a try 1st. If you can press on the white area on the backside of the cap and it gives a little of makes a clicking sound its bad.

The engine needs 3 thinks to keep the car cool. Water flow (water pump, thermostat) higher boiling point (antifreeze) and pressure (good hoses, radiator cap)

By having 15 psi the water temp can get 30 degrees higher. The fan is not even supposed to turn on untill 226 degrees.