308 cooling/thermo switch problems

Use think thread for complete info on Tommy's advice, there are Two TEMP choices for the VW switch one will give you 180 on / 172 off which is what Tommy is using.

http://ferrarichat.com/forum/showthread.php?t=59163&highlight=radiator+fan+switch

 

OK, I looked closely at my new radiator temp switch. It's a 92 degrees Celsius rated one. (etched on the side-very small print!) That converts to 197.6 degrees F.

Is that too high? I already installed it, test-drove it, and it indeed did kick on both fans at 196 F indicated on the water temp dash gauge.

Do I need to yank it and get a lower rated one?

Greg
77 308

 

That temp switch is stock so it should be fine if everything else is working properly a lower one helps in FL heat but is only an option.

Paul

 

Paul,
It's not a stock one, it's a Wells SW 533, cross-referenced to a VW.

195 is OK?


Greg
77 308

 

It is fine, just meant it was stock temp setting for Ferrari (195 +/- 4 degree's).

 

The later 308's (80-85) had tougher emissions to deal with then 76 -79's and since emission testing was done at idle back then the way to burn off the emissions at idle was to superheat the exhaust at idle. To acomplish this the later 308's had an ignition advance at idle that made the car run far hotter at idle (750-1100 rpm's) then at 2000 rpms. There is nothing you can do to reprogram the Magneti boxes (located in trunk) but an old trick is to use the gas peddle when stopped and kick idle up a 600 rpm's or so and them your ignition curve drops out of the superheat mode .

To really solve it get a set of euro Magneti computers which don't have the emission program issue, otherwise get better fans and the 180 degree VW fan switch....put Birdmans fuse blocks in as well!

Another solution is put in an aftermarket ignition system which does not use the stock magneti boxes.

Paul

 

Ken -- I'm not sure that they do as a population (can anyone else post their typical water & oil temp data for a '84~'85 US 308 QV at warm idle in 85 deg F conditions?), but it does seem that on the later 308s there are more problem children who seem to benefit from radiator "cleaning" or replacement (like they changed something in the radiator tube design/fabrication/materials/etc. that somehow affects how, or if, crude builds up internally -- but that's just wild speculation on my part). I accept Paul's explanation that less idle advance timing raises exhaust temps, but I didn't notice any difference in the coolant temp behavior when running my ex-'78 at 3 deg ATDC or 7 deg BTDC idle (and your report that it takes a long time to "recover", or that it even does "recover", when moving is not a good sign IMO). Perhaps the 4V heads transfer heat more readily from the exhaust ports into the coolant than the 2V heads, but that's just more wild speculation on my part.

If yours is not "normal" (i.e., there are other 308QV out there that don't run 210 deg F at warm street idle in 85 deg F conditions), things to check might be:

Is the thermostat not working so well? (i.e., allowing to much coolant recirculation within the engine when warm). Not sure what you could do here other than remove it to confirm the total physical motion when heated and the condition of the sealing disk/disk surface,

or

If the coolant temp exiting the radiator is not a lot lower than the coolant temp entering the radiator -- then perhaps the radiator needs more help than just flushing can provided.

Just some rambling -- I'll be interested to learn if yours is that abnormal or not.

 

Steve:

I installed a new thermostat and gasket last year and have yet to notice any difference in my temperatures. The only remaining item to check is the condition of my radiator. I will have to use a heat gun on the radiator next time I have the car out and check the temps. Perhaps the radiator needs a re-core.

Ken

 

Agree with 91tr, most cooling problems can be related back to a partially plugged radiator; experienced it myself on a 328GTS. My mechanic regularly pulls radiators on older Ferraris and has them cut open and rodded out. Says they clean lots of crud out of the tubes. Kinda like getting an angioplasty!

 

UPDATE:

OK, I installed an AUTOZONE cooling fan switch, but I'm afraid it's turning on the fans at 197 degrees F. (WELLS SW 533-- 92 degrees C is stamped on it) 1977 308 GTB owners manual says OEM switch should activate at 183 degrees F. Volkswagen parts desk can't locate the VW #s on the stickie.
I've searched for the parts listed on the 308/328 cross-reference stickie--can't find them ANYWHERE! Can anybody give me current info on how to locate a 180 degree 308 radiator fan switch. I'm parking the car until I install the correctly-rated switch in there.

BTW, Ferrari of Houston wants $75 for the OEM switch!


Thanks,
Greg

 

Sometimes it is just better to buy the Ferrari part. You may call GT Car Parts they are usually cheaper than the dealers 623.780.2200.

Ferrari UK (www.owners.ferrari.com) - #168008 RAD THERMO SENSOR £31.80
Italian Car Parts (www.italiancarparts.com) Radiator Thermo Fan Switch, 3° cooler than stock, all models: # FR168008A $54.95 ea
Ricambi America (www.ricambiamerica.com) Radiator Fan Switch 168008 $75

 

Automotive Performance Systems, 805.388.7171 Part #8.124.22 VW thermo switch 180 degree F

Perfect fit works like a charm....Tommy Cosgrove runs one as well.

About $10

 

You need to contact a VW parts house, they will know EXACTLY what you want. There are many independant VW parts houses on line or in your phone book...they will carry the two temp ranges you are looking for. Just make sure you specify the early two pole (two terminal) design, and not the later three pole version.

 

My thanks to everybody who helped me on this pursuit. I finally found a suitable radiator fan switch at BAP-GEON auto parts here in Houston. It's for a VW, turns fans on at 180? F.

It says "OEM" on the box, and says "made in Italy" also. Weird....


Thanks again to all...


Greg
1977 308 GTB

 

hi Greg, i just saw this, sorry i could not help. i wish you had pm'd me ! i have used the SW switch in my old / sold GTS and my current GTB both cars were fine. my GTB and my GTS stayed at 195 on the gauge in the Georgia summer heat. the cooling fans and the foam should keep things stready. my GT4 runs cooler because either the guage is not correct, or it has the 160 degree switch in it, which i think it does. the vw part numbers from the cross ref thread are as follows:

RADIATOR COOLING FAN SWITCH 2 POLE
VW PN# 82395948182 180F
VW PN# 82395948172 160F

again i have the switches from Autozone and i have had no issues with 3 cars in 14 months . i killed my cooling fans today by stupidity on my gtb
( i will be messing with the fans on both cars now !), so if you need any help, PM or post now that i am aware of this thread. i have had all of my cars apart at one time or another, perhaps i can help you in some way. Michael

 

Michael,
Thanks--I found a cooler switch and put that in last week--all is good.
Here in Houston we have some HOT weather and I just wanted to have maximum cooling available. My fans now turn on at 180?.

You might have seen my other thread addressing my low voltage-"G" light issue. I'm getting low readings on my VDO voltmeter, under load, even though I had my alternator rebuilt. I even replaced my fans with new Hayden
3680s, hoping to pull less amps.

Well, I still have low voltage readings--around 11 volts on my car, even at 3-4000 rpms. I need to wire the voltmeter directly off the battery--the way it is now, I have it in the clock location, using all those leads and grounds, post-fusebox (Birdman's, btw!). So, I'm going to run it off the heavy red wire going to the power distribution block next to the fuse blocks, to hopefully get a more accurate reading.

What has been your "voltage" experience with your 1977 GTB? I have the same car....

Greg

 

pm reply sent. i will take some reading for you today off of my Dino. my cooling fans were broken saturday on the GTB when one of my Fiamm airhorns came loose. i have a thread about it and have called the usual places. anybody have some stock or QV fans for sale let me know!!!

 

Great infromation. I can get my right fan to turn on by jumping the right relay, but when i jump the left relay the fan doesnt come on. I pulled the panel, and there is no wire behind 87 on the left fan relay....is there supposed to be?
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You'll note that there are two 87 terminals in a ...113 relay socket (and on the ...113 relay the two corresponding male 87 tabs are always connected together). If there is no female terminal with a wire in the bottommost 87 position, but there is a female terminal with a wire in the middle 87 position, use the jumper to connect terminal 30 to that middle terminal 87 instead.

If you have no female terminal with a wire in either of the 87 positions in the relay socket -- something's definitely not right/stock

 

No there isn't. The left fan relay socket has two #87 pins yet only one is needed. I have noted that Ferrari assemblers have stuffed the contact into either one or the other at times.

Finding one fan works but not the other fan...
Check fan fuse
Check fan relay
Check fan (they do go bad)

Shorting things is risky practice. Use of an inexpensive 12v test probe, looking to find voltage is far safer practice recommended for everyone. Expect to find voltage at:
Fan fuse
Fan relays #30
Fan
The probe can be used to probe the thermostatic radiator switch, expecting the relays to become energized.

Incidentally, there are 3 radiator fan relays (2 right & 1 left)...top row #2,3 &4 and are all wired slightly different...therefore shorting relay connectors can be a crap shoot.

 

Not in this case -- the circuit is still fully protected by the upstream fuse.

Just measuring with your 12V probe/test light at the fuse holder can give a false "OK" result if there is no current load on the circuit. So you either need to use the jumper, or use a known, good, energized ...113 relay -- which, when energized, is a 30-to-87 jumper!

 

I’m posting these sketches in the (slim) hope that it can help Paul_308 understand how measuring the voltage at the top of the fuses only gives a meaningful result if terminal 30 is connected to terminal 87 and a non-zero current is flowing in the circuit. He took the time to send me a personal nasty-gram email to tell me that he knows “electricity is your weakaness [sic] because of the strange ideas you often pen” and that it would be scientifically laughable to get “a ‘false OK’ result if there is no current load on the circuit” and “that itself reinforces your lack of knowledge”. I hope that these sketches help you, Paul_308, address your lack of knowledge, by showing exactly how how a false result can occur when only measuring voltages but no current is flowing.
He goes on to say “I've had to clean up too many messes when guys with your fast and loose attitude have 'relied on upstream fuses' and the like” – really? Please cite some specific examples Paul_308 where you’ve so graciously done that for me.
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I also have a 1980 injected 308 U.S version. My problem is my engine is not idling back down after warm up. Vacuum problem or cold start Valve issue. Can it be the smog air pump not sending air? Confusing. Just when I go need to go get it smoked it lets me down.. Any info will help.

 

Are you saying that the yellow "cold running" light in the dash does go out (which confirms the water thermoswitch is working correctly), but the idle stays very high?