Thermoswitch for Oil Cooler Fan

[rzepko6194]

I just ordered a 99 degree thermoswitch for the oil cooler in my 87' Carrera. This replacement has two prongs instead of one on the original.

Is it ok to ground the extra prong to one of the nearby breather cover nuts or should I run it to the point where all the brown ground wires attach to the intake manifold or maybe to the alternator ground lug? I want to get this right while the injection system is off and I can actually see the switch.

Thanks!

[fintstone]

Any good ground will work. I would route it into the front trunk somewhere to ground it to keep the connection clean.

[fintstone]

This is the factory harness for an '89 and it already had two leads, one for ground (brown) and one for the center lead (blue). I have circled both ends of the brown lead. Take a close look and see if you already have the brown lead. If yours is like this one, you will also have to clip the connector off the blue wire and put on a compatible female connector.

[kqw]

Curious!!!!Why a 99 degree thermo switch? Once your secondary oil thermostat opens up that fan will be running all the time.....

[fintstone]

He is talkin 99C which is about 210F. The oil at the engine is darn hot ..probably 230 or more before it reaches 210 at the the external cooler.

[rzepko6194]

KQW, The new thermoswitch is set for 99 degress centigrade (210 F). I thought that the secondary oil thermostat opens at only 180 F, maybe I'm wrong. Can anyone confirm this?

[rzepko6194]

Originally posted by fintstone
This is the factory harness for an '89 and it already had two leads, one for ground (brown) and one for the center lead (blue). I have circled both ends of the brown lead. Take a close look and see if you already have the brown lead. If yours is like this one, you will also have to clip the connector off the blue wire and put on a compatible female connector.

Flintstone, thanks for the great advice and photo!

[fintstone]

JP
Anytime..Yes, you are correct..the external thermostat opens at @180F. Yes the 210F thermoswitch seems to be the recommended setup (the one I used). I even added a rocker switch so I could turn my fan on sooner if I anticipated high temps/hard usage or to test my fan.
Stoney

[fintstone]

JP
Another picture. This is the thermoswitch that you ordered installed--the top front of the oil cooler which is located in the right front wheel well.

[rzepko6194]

Stoney,

How difficult is it to remove the oil cooler just to replace the switch? Do I have to disconnect the oil lines?

[kqw]

Thanks for that clarification on C vs, F. However, 210F. is still pretty hot. I have my switch activating at approx. 175F. and my temp gauge never goes beyond the half way mark.

[fintstone]

You could probably support it with something and unbolt it and the hose clamps in the wheel-well and lower it enough to get the thermostat without disconnecting the oil lines. It is pretty tight under there and the horns are in the way...being able to put it on a lift would really help. If the bolts are not too rusty, it would not be terribly difficult, but I would expect at least 2 or 3 hours..You know..if anything can go wrong, it will. If I was not having temp problems, I would probably wait til I was "in there" doing something else.

[rzepko6194]

I've already got it up on jackstands, the wheels are off, engine is sitting on the floor and it just snowed about 5 inches yesterday! I guess this is probably as good a time as any to change out the switch. ;-)

[fintstone]

Good luck! I would try to leave it assembled (like the picture)..that is how I installed mine....and try to just unbolt the top bracket and bottom one, unclamp the lines and swing it back toward s the wheel well a bit. Be careful to support it so you dont put too much stress on the lines. It might help to take off the accordian-like bumper extension and the horns for a better view/access.

[vash]

i dont think you can get to it, without dropping the cooler first. the headlight bucket is just to big.

i was reading the first post. you suggested grounding to the breather? or alt ground lug? the cooler fintstone pictured is in the front of the car. right? are there not sufficient grounds near the front of the car? like the battery ground? is everyone on the same page? motor is out of the car. that doesnt help with the external cooler, except there is not motor oil in the car. maybe i am lost, just waking up from graveyard shift

[rzepko6194]

Originally posted by unfixed
i
i was reading the first post. you suggested grounding to the breather? or alt ground lug? the cooler fintstone pictured is in the front of the car. right? are there not sufficient grounds near the front of the car? like the battery ground? is everyone on the same page? motor is out of the car. that doesnt help with the external cooler, except there is not motor oil in the car. maybe i am lost, just waking up from graveyard shift

I was confusing the thermoswitch on top of the engine breather with the thermoswitch on the front oil cooler. I was hoping nobody would notice, but you did! Yes, I'm a dumb Newbie.. ;-)

[fintstone]

Unfixed
Yes you are right. Everything is straight now. Although I have never replaced the thermostat without disconnecting the lines, I have replaced the upper bracket that way (as described above). Disconnected the lower bracket at the firewall and swung the bottom back enough to reach the top bracket. Stands to reason that you could get to the thermostat similarly since it is right next to the upper bracket. I'm sure he will let us know if successful.
JP
Yes tried not to be obvious too..sorry dude By the way..got the engine out....you are no newbie any more.

[rzepko6194]

I've got shocks to replace (Bilsteins), brake bleeding and the engine to put back in. If the weather remains lousy, I'll try to tackle the thermoswitch replacement. If it gets nice soon, this will become part of next years winter projects!

It doesn't get much above 90 degrees around here, so this replacement may not really be necessary.

Thanks for the advice!

[vash]

yes,newbies dont have motors sitting on the ground
hell, i remember when i didnt even know where to put the damn jackstands. JP, just wanted to make sure you were getting the right info. good luck!

[rzepko6194]

Originally posted by unfixed
hell, i remember when i didnt even know where to put the damn jackstands.

That was me about 2 months ago, but I'm learning! ;-)