‘87 Carrera 3.2 engine running cold

[wanderboy99]

Hi!

Engine Temperature reaches just above 120 after warm up and it hovers there after hours of driving. It gets close to 180 after a few laps on the track. These are what I did so far:

1. Replaced thermostat (thinking it was stuck open) on engine that feeds oil to the oil cooler. Not much change.
2. Hot air ducting to cabin deleted since Im from the Philippines and we have warm weather here all year round.

Thanks in advance for your help!

Randy

[GH85Carrera]

On my 85, if the outside air temp is below freezing, it will never go above 120. Only on warm days can I get it to 180. On the track, in 90 degree heat, after running flat out for 25 minute sessions can I get it to 210.

I would have to guess that the sender or your gauge is just not working right. In the Philippines with warm weather the engine should be full temp in 10 or 15 minutes of driving.

Get an IR thermometer, and read the temp of the oil filter, the engine case and oil hoses. Do the front oil cooler lines get warm to the touch? After driving for 15 minutes, reach up over the tire, and tap the rubber oil line. Don't grab hold of it until you are sure it will not burn you. It should be 180 degrees or warmer and will burn your hand real fast. If it never gets hot feeling there is something magic going on.

I suspect the oil temp sender is not the right one, or the gauge is not working right.

[boyt911sc]

Originally Posted by wanderboy99

Hi!

Engine Temperature reaches just above 120 after warm up and it hovers there after hours of driving. It gets close to 180 after a few laps on the track. These are what I did so far:

1. Replaced thermostat (thinking it was stuck open) on engine that feeds oil to the oil cooler. Not much change.
2. Hot air ducting to cabin deleted since Im from the Philippines and we have warm weather here all year round.

Thanks in advance for your help!

Randy

Randy,

You need to test and check the auxiliary thermostat located in the right rear wheel fender well. Confirm that the slide valve is closing above @ 185°F and fully closed @ 200°F. If it passed the test, your oil temperature sender and gauge could be the culprits.

The temperature right now in Manila is around low 77°F/high 88°F. There is something wrong with your temperature instrumentation. As suggested earlier, monitor your engine temperature using an infrared thermometer. Keep us posted, Kabayan.

Tony

[wanderboy99]

Thank you guys for taking the time to help. I will validate the temp with other thermometers and also try to check if there’s oil running prematurely towards the front oil cooler when engines still cold. Will keep you posted.

[AG81]

I've check mine repeatedly. Only on a hot day in traffic can I get the gauge to seriously move.
It has run cool for over 3 years. I've had the gauge check by a reputable shop.

[cabmandone]

Question: Isn't an 87 supposed to have a different gauge? That looks like the older gauge to me. Mid to late 80's cars are supposed to have the gauge below. And if I recall correctly there's also a different temperature sending unit needed for the numeric gauge.

[FrankM_]

Originally Posted by cabmando

Question: Isn't an 87 supposed to have a different gauge? That looks like the older gauge to me. Mid to late 80's cars are supposed to have the gauge below. And if I recall correctly there's also a different temperature sending unit needed for the numeric gauge.

Agree, that is the gauge on my 1985 also. So the one without the numbers.


Sent from my iPad using Tapatalk

[cabmandone]

Here's a thread that covers my car running too hot. Any guesses what i found to be the issue?
Part numbers for gauges/sending units is covered here
I hate gauges that don't show temp. Is this too warm??

[wanderboy99]

Hmm…I may have to do research on my gauges and look at the sending units too! I do have a G50 and Im quite sure it’s an ‘87. I do remember Palo Alto telling me the clock I sent in for refurbishing was not correct for my year. Perhaps some of the origl gauges were swapped with older ones in the past. Bummer, but as long as the car’s working sweetly I’m fine with it. Thanks for your inputs Nick & Frank!

Boyt911sc, salamat Kabayan! ��

[Cairo94507]

My '87 3.2 engine was exhibiting the exact same temperature gauge issues after it was assembled following a complete rebuild. Turns out they had installed the wrong temp. gauge sender - easy fix and now it reads correctly.

[hcoles]

Originally Posted by Cairo94507

My '87 3.2 engine was exhibiting the exact same temperature gauge issues after it was assembled following a complete rebuild. Turns out they had installed the wrong temp. gauge sender - easy fix and now it reads correctly.

Yes, when I switched to the numerical gauge I had to put in a different sender.

[cabmandone]

Originally Posted by wanderboy99

Hmm…I may have to do research on my gauges and look at the sending units too! I do have a G50 and Im quite sure it’s an ‘87. I do remember Palo Alto telling me the clock I sent in for refurbishing was not correct for my year. Perhaps some of the origl gauges were swapped with older ones in the past. Bummer, but as long as the car’s working sweetly I’m fine with it. Thanks for your inputs Nick & Frank!

Boyt911sc, salamat Kabayan! ��

The good news is, with no A/C compressor and the heat ducting removed most of the "hard part" of changing the temp sending unit is done. It's on the right hand side of the engine. Look at your fan housing. Just to the right you'll see a wire going to a large metal cylinder (pressure sending unit) and just to the left of that will be the temp sending unit. Not a hard fix if that ends up being the issue. I'd bet someone thought the gauges were interchangeable and just installed the older style numeric gauge.

[wanderboy99]

Originally Posted by cabmando

The good news is, with no A/C compressor and the heat ducting removed most of the "hard part" of changing the temp sending unit is done. It's on the right hand side of the engine. Look at your fan housing. Just to the right you'll see a wire going to a large metal cylinder (pressure sending unit) and just to the left of that will be the temp sending unit. Not a hard fix if that ends up being the issue. I'd bet someone thought the gauges were interchangeable and just installed the older style numeric gauge.

Thanks for that info Nick. Will definitely compare it with a correct sender.

Randy

[famoroso]

Remove gauge. Remove sender. Put together a test rig to check 212° F with a pot of boiling water (or your significant other's Breville steamer). Apart from sending the gauge + sender to Palo Alto Speedometer, North Hollywood Speedometer, etc. and having them confirm the calibration, it's the only way to know for sure on YOUR gauge / sender combo.



Alan Caldwell had an Upfixin' Der Porsche write-up on the procedure for a 914. It's pretty easy to do, especially if you have a 12VDC bench power source.

Check post #8 in this thread. It details the procedure...

Center Console Temp Gauge

[cabmandone]

Originally Posted by wanderboy99

Thanks for that info Nick. Will definitely compare it with a correct sender.

Randy

FWIW, in my description of location the "large metal cylinder" is only about 2 1/2 inches tall and maybe 1 1/8 inch around. You'll see it when you look down at the right hand side of the fan housing. If you need help I can post a pic of the location but I have the A/C bracket in the way on my car.

[wazzz]

You can also start by simply measuring the sender with an ohmmeter. Unplug the wire and test resistance between the sender terminal and a ground. You should find around 3000 ohms when ambient temp is 22C or so and engine is cold. This is what I found with my 88 last time I checked it good. Don't know what 22C is but that should be around 75-80F.

And since it is a NTC, the higher the temp, the lower the resistance. Heat it with a gun or air drier and you should see the resistance drop. If not, the sender is bad.

[pampadori]

i also think the gauge might not be correct for year/sender on your motor. However, you are showing 4 bar of oil pressure at just 2,000 RPMs. If you have truly been driving the car long enough for the oil to heat up, that pressure should be much lower too.

I think your thermostat(s) is stuck open and your oil actually is that cold.

[cabmandone]

I don't know what I was thinking! You have a picture of the oil temp and the oil pressure sending units in your OP. The yellow arrow is your oil pressure sending unit. The blue arrow is your oil temp sending unit. You should be able to see some numbers stamped in the housing that will indicate which one it is.