1g cooling fan

[93AWDDSM]

hey, so I have noticed most of the time my cooling fan (passenger side) turns on and then while its idling doesn't turn off or even after a cold drive in 50 degree weather the fan turns on and then stays on.

Could is be my ecu seeing potentially the car starting to overheat even though my dash temp gauge says it's ok?

 

[1990TSIAWDTALON]

I don't have a '93 so I will just ask, Does your radiator have a electric connector that hooks up to a sensor in the bottom of it? If it does, like mine ('90), then that switch is being tripped by the temperature of the coolant and makes a connection to ground to make the fan come on. In 2g's the ECU controls some fan functions but I didn't think a 1g did. Mine uses that switch in the bottom of the radiator just under the passenger lower hose, look for it and you may just need to replace it.

 

[luv2rallye]

^agree. Unplug it and if it goes off you'll know that's it. Otherwise you probably have a stuck relay.

 

[93AWDDSM]

I don't have a '93 so I will just ask, Does your radiator have a electric connector that hooks up to a sensor in the bottom of it? If it does, like mine ('90), then that switch is being tripped by the temperature of the coolant and makes a connection to ground to make the fan come on. In 2g's the ECU controls some fan functions but I didn't think a 1g did. Mine uses that switch in the bottom of the radiator just under the passenger lower hose, look for it and you may just need to replace it.

the car is actually my 92 talon tsi fwd, my 93awd crank walked. but i will try and unplug the connector. if it goes off then i should be able to swap them correct?

 

[luv2rallye]

If by it you mean the sensor then yes. That sensor controls the fan relay.

 

[93AWDDSM]

sorry, I didn't clarify the last post and I confused myself as well. so, unplugging the connector "should" shut the fan off?

could a bad relay, or sensor start to wear out for this type of thing or just go bad? I've noticed that sometimes it will kick on and then off, and sometimes it's constant on and doesn't matter if it's cold out with no boost/with boost. should I worry about overheating while the fan is constant on because the ecu is seeing a higher temperature - the idle gets kind of iffy when it turns on and stays on. The car starts to idle around 650-900 with a vacuum between -15 to -19 which is strange

 

[luv2rallye]

Yes either the sensor or fan relay could go intermittent or bad.
Unplugging the sensor should shut fan off unless the relay is stuck on.

 

[93AWDDSM]

Just got home from a 15 minute drive, water level is fine. No bubbling from overflow. The fan stayed on for about 3/4 of the drive. When I got home, let it idle for a minute. -18 HG and idling around 700 with the cooling fan running. Left the car running for just another minute or so to see if the fan turned off. It did not.

When I turned the car off, obviously the fan turns off but I turned the key to "on" the fan came on, ran and then turned off shortly after. I guess once the temperature got back to normal? Would the sensor/relay stuff still be worth checking? Or am I looking at overheating issue?

Any input is good input as long as it's not "boost leak test it" .


Edit: it's around 80-90 degrees summer currently and I have a fmic which I know doesn't help with cooling for radiator, just some background information.

 

[luv2rallye]

When I turned the car off, obviously the fan turns off but I turned the key to "on" the fan came on, ran and then turned off shortly after. I guess once the temperature got back to normal? Would the sensor/relay stuff still be worth checking? Or am I looking at overheating issue?

Sounds like the fan sensor and relay are working ok. Do you have shrouds around the fans against the radiator?

 

[93AWDDSM]

Should be the stock cooling fan. Haven't adjusted it or cut it. The Ac fan was removed for the fmic piping.

I'm starting to get stumped. It's not loosing coolant, it's not burning it. Not burning oil, or mixing oil/water. The compression on hot motor was still 155-160 across all four cylinders. It does have 2 boost leaks I know of at the throttle body shaft seals. That can't make it idle fine and then go crazy can it? The fan thing on, maybe the car is actually getting hotter and the fan just can't cool it but even at night 50 degrees it should be way cool enough to have fan turn on/off @ a certain temperature.


Edit: if all else fails, I'm pulling the head and redoing the HG with arp studs. Timing was cake, electrical isn't my thing haha. Also, please see attached cylinder picture. I was informed potentially I could throw a new HG and good I think the chip cylinder might be my problem all along, leaking compression into the cooling system

 

[enriquez2000]

Fans turning on and off is pretty elementary stuff... on a 1g the radiator sensor turns the fan on at a certain temp(no one agrees at what temp but my brand new sensor comes on at 200* and off at 190). This trips a relay that opens current to the fan(so does the ac button). If it stays on the only culprits are

Sensor
Relay
Ac on signal

If it is turning off at a certain point but not at the right temp(you really need to know what temp) my bet would be the sensor going bad. When mine went bad it came on at 206 and off at 203... my temps ended up at 216 most days. With the new sensor its never seen over 206 and thats only when im going crazy on turbo pulls. Cruzing around ill be 183 to 190 now on a 90* day.

Many people here were pushing me to assume a bigger issue but it was a 12 dollar sensor and im golden.

 

[93AWDDSM]

I will try that, but we had a 97 degree day yesterday and on a no boost, cruise drive of about 25 minutes the car temp gauge was starting to heat up towards the end of the drive. Got to my destination and popped my hood after shutting it off and had bubbles in the overflow and the whole drive just felt like power loss. also, I was more on the 0 mark of the boost gauge while driving when usually it's at -10 in hG.

my fan isn't turning off period. Once it comes on, it stays on for my entire drive like it can't get it to cool it down enough to shut it self off. I will check tonight when I drive after work in 60 degree weather @ 11PM. That should been cool enough for my fan to turn on, cool it enough and turn off at the correct temp.

 

[pauleyman]

This whole thread nothing is said about coolant temp. Is the car getting hot or cold? Kinda sounds like you're chasing a problem that doesn't exist.

 

[enriquez2000]

This whole thread nothing is said about coolant temp. Is the car getting hot or cold? Kinda sounds like you're chasing a problem that doesn't exist.

My reply mentioned coolant temps as a result of my thermo switch being faulty. It caused me to start overheating.

If your hot for another reason then you can look at HG and waterpump issues. My advice is get a good coolant reading. IF FANS STAY ON AT 190... you have a sensor/relay issue.. if your temps are just too high, chase down the overheating issue.

 

[93AWDDSM]

I'm not sure of the "exact" temp. as I don't have a logger or dsmlink. The car will start leaning towards the hot side of the dash cluster even with the cooling fan running. I did a HG in February and for some reason I feel as the HG is going bad or about to. I checked the length of the 6 bolt head bolts, they weren't stretched and they were fine so I reused them (probably a big no no and why I'm dealing with all this now).

When I boost at 9psi, that's when the engine is starting to get hot. I can do 4-5 pulls of only 9 lbs to 5-6k and then it starts to heat up and at idle the boost gauge reads way lower vacuum and I start to get a rough 575-650 idle that sounds like its going to die with vacuum bouncing from -15 to -18 and the cooling fan is on non stop when this is happening. I posted a picture above asking if the chip on the firing ring of the cylinder could possibly be leaking compression into my cooling system?

I also let it idle from cold with heater on, with rad. cap off and it was foaming quite a bit and then would flow slightly and then foam over again. Am I still chasing nothing like the ghost busters?

 

[pauleyman]

Have you changed thermostat? It sounds like fan is doing its job and the root cause is car is hot. You need objective info and find the root cause. You started the thread thinking you had a fan problem. I'd say no.

 

[93AWDDSM]

T stat has been changed, new radiator cap. New coolant temp sensor, new temp. Gauge sensor all within the last week. I'm going to pick up a tester to see if I'm leaking exhaust into my cooling system. I think that's my real issue, can you comment on the pictures provided about compression leakage?

Thanks

Pics attached below.


Edit: wouldn't those chips on the block leak compression or no? When I compression tested it, it was about 155-160 across all 4 cylinders

 

[pauleyman]

Compression it what it is. You have a problem alright. Youre on the right track. Id also rule out the radiator itself and the air path through it. Would those chips cause a prob. Yeah I dont like it but youre getting ready to test for sure.

 

[Scott Cooper]

Could a boost leak cause this issue of it's combined with a sensor that's going out?

 

[93AWDDSM]

I do have a fmic, with no proper ducting for air towards my radiator?

 

[pauleyman]

But did this problem just now crop up or since fmic or what?

 

[93AWDDSM]

No, I have had the fmic before the car overheated in December and I replaced the HG and the head got rebuilt and put it back together in January. I reused the stock 6 bolt head bolts, I checked them for stretch and they were ok. I'm wondering if that could be my problem leaking compression into my cooling system because of reusing the head bolts? If so that is a complete fail on my side and I'll re do it with a HG.

I did the cold idle, rad. Cap off and it was foaming over and bubbling. Upper hose seems very pressurized. I will get a coolant tester for exhaust gases. If it shows I can assume just go to replace the head gasket correct?


Edit: I have a oem HG and arp studs in my shopping cart now, in case!

 

[pauleyman]

And just ignore those chunks? How did those get there?

 

[93AWDDSM]

Not sure, the head overheated and I pulled the head and noticed those chips. I asked if that would have anything to do with compression leaking. Few answers I found were I could use a oem composite HG and arps and I should be fine because I'm not going past 15lbs of boost. This is my daily driver 198k

Thanks for helpful advice

 

[enriquez2000]

If you overheated did you check for a warped head?