Bad Otterstat... ?

[refugeefromcalif]

I want to verify that I need to make an Otterstat purchase.
I recently started having issues with my radiator fans not running again without the A/C on. I've done the Otterstat Jumper wire test. The fans work in any other mode.
They also come on when I cycle the HVAC switch to A/C, (In any position for A/C).

I did do a search but, I couldn't find a thread/condition that mirrored my symptoms. (I might have also missed it).
I'm looking for verification that I need to order a new otterstat from DMCMW tomorrow.
ALL help is appreciated. Thanks in advance!

George

[Mike F]

You said you did the jumper test; did the fans come on then?

[DMC5180]

If you have By-passed (jumpered) the Otterstat and that makes the fans work, you have a faulty Otterstat. What are the Typical gauge temps you would normally see the Otterstat cycle ON and OFF?

[kings1527]

From what I understand, the fan circuit is one of the more simpler.

Are you saying that you jumped the otterstat and the fans DID come on and when you flip your mode switch they also DO come on? But the fans DON'T come on under normal circumstances when you're driving and the engine gets hot? Sounds like an otterstat problem to me.

If your engine temp was running high but the fans weren't coming on and you jumped the otterstat and the fans still DID NOT come on, that'd lead me to believe that it was a relay/fan fail problem or fuse problem.

[refugeefromcalif]

You said you did the jumper test; did the fans come on then?
Yep, the fans came on.


If you have By-passed (jumpered) the Otterstat and that makes the fans work, you have a faulty Otterstat. What are the Typical gauge temps you would normally see the Otterstat cycle ON and OFF?

The normal place where the fans come on is between the first and second white lines on the gauge.

Alex, yes the fans come on when I switch to any A/C mode and Don't come on when I'm just driving around.

Thanks all for the replies. I'll call DMCMW tomorrow and get a new Otterstat on the way. BTW, the Otterstat that I have now is facing Down, has 2 Zip ties running between the contacts for the wires. I don't know if it's original but I'm guessing it's not.

George

[kings1527]

BTW, the Otterstat that I have now is facing Down, has 2 Zip ties running between the contacts for the wires. I don't know if it's original but I'm guessing it's not.

George

If you're saying the otterstat contacts are located on the bottom of the coolant pipe and the wires connect underneath, then that's the best configuration of the two that the car had. Technically, you'd say the otterstat was facing upward in that case.

[Mike F]

Definitely sounds like the otterstat then. I was actually going to ask about the orientation of your otterstat pipe. Although unlikely, if it were facing up you could have possibly had an air bubble trapped in there. My car had the pipe turned that way when I got it and I believe I had that problem at one point before I turned it around. No, the zip ties aren't original but it's pretty common to have something there to keep the retainer clip from being the sole point of failure for holding the otterstat in. I've got a zip tie on mine as well.

[kings1527]

In the better configuration and 'facing up', I was referring to the actual orientation of the sensor inside the pipe. Just to clarify.

[Mike F]

In the better configuration and 'facing up', I was referring to the actual orientation of the sensor inside the pipe. Just to clarify.

Yep, we're on the same page. Sensor up, contacts down. Guess I'm just used to referring to the contacts when I talk about the otterstat orientation. That could definitely be a point of confusion depending on how the person you're talking to thinks about it!

[refugeefromcalif]

I think I didn't write this right. :confused:
The wires that I jumped were plugged in at the underside of the the pipe. (Contacts Facing downward).

I ment to take a picture but,,,

George

[Mike F]

I think I didn't write this right. :confused:
The wires that I jumped were plugged in at the underside of the the pipe. (Contacts Facing downward).

I ment to take a picture but,,,

George

No, you wrote it right! We were just discussing the difference between the contacts facing downward (which means the otterstat itself is facing upward) vs. the other way. What you are describing on your car is the proper way for it to be oriented. All good!

[Rich]

The wires that I jumped were plugged in at the underside of the the pipe. (Contacts Facing downward).

Did I miss part of the problem description? Earlier posts asked for engine temp condition when the fans are "not coming on".

Coolant temp at otterstat must be >97degC (207degF) before the o'stat will close the fan relay circuit.

You imply that you expect the fans to be coming on without the A/C compressor and, yes, at some point they should engage but only after the coolant flowing from the engine to the radiator is hot enough.

[AugustneverEnds]

Did I miss part of the problem description? Earlier posts asked for engine temp condition when the fans are "not coming on".

Coolant temp at otterstat must be >97degC (207degF) before the o'stat will close the fan relay circuit.

You imply that you expect the fans to be coming on without the A/C compressor and, yes, at some point they should engage but only after the coolant flowing from the engine to the radiator is hot enough.

The stock set-up otterstat must be 207F before the relay closes. Some aftermarket otterstats work at different temps.

http://www.specialtauto.com/delorean-parts/cooling-system.html

[Jonathan]

Hey George,

Just a quick clarification on the orientation of the otterstat in the coolant pipe. One way to help describe it would be to mention which way the pipe T is pointed. Is the T pointing down or up? Then the sensors or wiring can only go in one way after that is established.

Here's a photo of the otterstat in the left hand corner showing it with the T pointed down, which is the preferred orientation. The idea being if there is air in the line, it is at the top of the pipe and not nestled in the T with the sensor (which it can't really do when these are now on the bottomside of the pipe).

25948

As others mentioned, if it isn't air in the line somewhere, from not enough coolant or not purging the system well or the T not facing the right way, then it could also be that the coolant didn't get hot enough to turn the fans on. On my car at least, the fans turn on before the halfway mark on the temperature gauge and long before the red area. On the second photo here, the needle is shown almost where they kick on, say halfway between that unnumbered marking and the next one at 220 degrees. If it starts getting past the 220 degree mark and the fans still haven't come on, you should shut your car off and continue figuring it out with the engine off (or turn your A/C on and force the fans on as you said it can do).

25947

[DMC5180]

George,

Just to confirm, Your fans not working while driving was in traffic (stop n go) is that correct? the reason I ask is because I can go for a drive in the country and the fans may never come as long as I have adequate airflow moving through the radiator especially this time of year if the temps are mild.

[refugeefromcalif]

Hey George,
Here's a photo of the otterstat in the left hand corner showing it with the T pointed down, which is the preferred orientation. The idea being if there is air in the line, it is at the top of the pipe and not nestled in the T with the sensor (which it can't really do when these are now on the bottomside of the pipe).

25948

As others mentioned, if it isn't air in the line somewhere, from not enough coolant or not purging the system well or the T not facing the right way, then it could also be that the coolant didn't get hot enough to turn the fans on. On my car at least, the fans turn on before the halfway mark on the temperature gauge and long before the red area. On the second photo here, the needle is shown almost where they kick on, say halfway between that unnumbered marking and the next one at 220 degrees. If it starts getting past the 220 degree mark and the fans still haven't come on, you should shut your car off and continue figuring it out with the engine off (or turn your A/C on and force the fans on as you said it can do).

25947

Jonathan, Yes my otterstat is in the same position as in your picture

Per your second picture, My fans used to come on *just* below, Or at, that second line that your needle is just above.


George,

Just to confirm, Your fans not working while driving was in traffic (stop n go) is that correct? the reason I ask is because I can go for a drive in the country and the fans may never come as long as I have adequate airflow moving through the radiator especially this time of year if the temps are mild.

Dennis Yep, stop and go traffic. The temps have risen higher then they ever did before with No fans coming on.
When I hit 65 on the 4 lane road for the trip home, Temps drop back to what, for my car has been, right between the 100 deg. line and the next up.

I think I've been a bit Paranoid about letting my temps get closer to the 200 mark just too see if the fans come on. (They never used too)?
A member here PM'd me a crossover part from Auto Zone. I stopped by after work and ordered one. I'll test a bit more and let it get a bit hotter but, having a new one in hand, makes me a little better. :)

Thanks All for the replies!

George

[DMC5180]

George,

It sounds like there is quite a bit of variation in the temp gauges. Your Temperature gauge fan operating positions are quite a bit lower than most. For example my normal (driving) operating temp is the same as Jonathans in the photo, or just above the middle mark, My fans cycle ON @ 220 and Off about half way between the middle and 220 marks.

[mluder]

George,

It sounds like there is quite a bit of variation in the temp gauges. For example my normal (driving) operating temp is the same as Jonathans in the photo, or just above the middle mark, My fans cycle ON @ 220 and Off about half way between the middle and 220 marks.

Mine is about the same... It's possible a bad electrical connection of ground could cause the temp gauge at the dash to read incorrectly. You could take the car's temperature at the coolant pipe the otterstat is installed in. It's not entirely scientific but a good digital instant read or non contact infrared thermometer on the underside of the pipe will give you a bit of info on what the coolant temp inside is. For giggles you can also measure the temp at the metal return pipe on the other side. It should read lower.

Cheers
Steven

[Jonathan]

Another thought on gauge inaccuracy... as long as you know what your own individual car does, it's not that crucial to have the gauge say exactly 200 degrees or 220 or something. If you know about where on the gauge your fans normally kick on, then if a day comes and they do something else, then you know there is a possible problem. More like a case for monitoring trends as opposed to the absolute value. Same kind of idea with fuel mileage or RPMs, etc. Yes, it would be amazing to have gauges that are all 100% consistent across the board, but knowing what yours does inparticular is equally as valuable.

[refugeefromcalif]

Another thought on gauge inaccuracy... as long as you know what your own individual car does, it's not that crucial to have the gauge say exactly 200 degrees or 220 or something. If you know about where on the gauge your fans normally kick on, then if a day comes and they do something else, then you know there is a possible problem.

Very True. This is why I started getting worried. I did a test this afternoon and found some pics I'd posted a while back.

This is where the gauge was at today about 5 seconds after the fans kicked on.
I realize that the gauge is still in the white but it never used to get this high when the fans turned on.

http://dmctalk.org/attachment.php?attachmentid=25959&d=1394576545

This is a pic I posted July of last year. It was posted for alternator reasons but, it shows the temp gauge with the fans on and no A/C.

http://dmctalk.org/attachment.php?attachmentid=20785&d=1374963486

Today the fans only ran around 30-45 seconds before shutting off with the needle dropping only a needles width. They turned on again 4 minutes later. (Based on the time stamp between pics I took).
In the past the fans would run a few minutes before shutting off and end up between 100 and the next line.

Like I mentioned in a previous post, I'm probably being a little paranoid about this and it's Normal on other cars but, the Last thing I want is my car to overheat because I didn't take the time to fully understand the problem and Fix it.

George

[DMC5180]

Hmm,

Is this with the original Otterstat or replacement?

If anything I'd say your gauge is indicating correctly for a 207℉ ON - 196℉ OFF otterstat. Electrical connections can miraculously fix them selves (temporarily)

[DeLorean03]

Very True. This is why I started getting worried. I did a test this afternoon and found some pics I'd posted a while back.

This is where the gauge was at today about 5 seconds after the fans kicked on.
I realize that the gauge is still in the white but it never used to get this high when the fans turned on.

http://dmctalk.org/attachment.php?attachmentid=25959&d=1394576545

This is a pic I posted July of last year. It was posted for alternator reasons but, it shows the temp gauge with the fans on and no A/C.

http://dmctalk.org/attachment.php?attachmentid=20785&d=1374963486

Today the fans only ran around 30-45 seconds before shutting off with the needle dropping only a needles width. They turned on again 4 minutes later. (Based on the time stamp between pics I took).
In the past the fans would run a few minutes before shutting off and end up between 100 and the next line.

Like I mentioned in a previous post, I'm probably being a little paranoid about this and it's Normal on other cars but, the Last thing I want is my car to overheat because I didn't take the time to fully understand the problem and Fix it.

George

If it makes you feel any better, my gauge's needle would cut the numbers 220 in half before the fans came on. At one point, the needle started passing the 220 mark before the fans came on, and that made me nervous.

We got a thermal gun and hit the coolant with it; 207 degrees - WAY lower than 220+. Gauge was faulty and on its way out. We replaced it with a new one, and it was 100% accurate after that.

[Jonathan]

Good point on the gauge possibly being on the way out. And giving it a sanity check measurement with a heat gun too.


If anything I'd say your gauge is indicating correctly for a 207℉ ON - 196℉ OFF otterstat.

Out of curiosity, are there different degree ranges (on/off) for our otterstats? Was it consistent throughout the VINs, or another chronology variance? Can you pick one or another if you order a replacement?

[Chris 16409]

In my opinion, the otterstat sucks and should be replaced with a more modern equivalent like Toby's adjustable fan switch. It's much more reliable and you can set when the fans turn on. I even went a step further and got rid of the original otterstat coolant pipe. I had a new pipe made without that silly hole. Now I don't have to worry about the otterstat ever popping out.

[David T]

In my opinion, the otterstat sucks and should be replaced with a more modern equivalent like Toby's adjustable fan switch. It's much more reliable and you can set when the fans turn on. I even went a step further and got rid of the original otterstat coolant pipe. I had a new pipe made without that silly hole. Now I don't have to worry about the otterstat ever popping out.

An adjustable switch is OK but just keep in mind it has to work in synchronization with the thermostat. If you set the O switch too low the fans will always be running. Ideally they should come on after the thermostat opens but below 240 degrees. The fans do not need to run if the radiator can do it's job without them when the car is moving through the air fast enough. The fans have to turn off before the thermostat closes, you need to have the motor running at or above 180 degrees.