Overheating

Check the parts xref post you might find it there. I have seen posts on Fchat. Good luck. You can, I think take it to NAPA and they can match it up. You need to find the temp that closes the switch and find one close.

 

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

 

I had the exact same problem, and it turned out that my sensor was fine.

It's also possible that you have air building up at the thermostat housing, which will prevent the T-stat from opening up fully...and results in the coolant at the radiator never getting hot enough to trigger the sensors. (Ask me how I know!)

So take a moment to bleed both the t-stat housing (be careful if you don't have Verrell's easy-bleed screw), as well as the knurled knob on the top right of the radiator (which is an easy-bleeder from the factory.)

 

You could also pull the switch from the bottom of the radiator and put it in a pan of water with a thrometer and a DVM and see when/if it closes. But the switch is only $15. For that much trouble I probably would put a new one in no matter how it tested.

Perhaps this is an excellent excuse to buy one of those non contact IR thermometers and see what the radiator temp is.

 

That VW switch might not be the same, and over heating could potentially ruin your engine! Why use non-original parts when you can spend $900.00 for the original part in a super nice yellow box with a horsey on it and have peace of mind? Isn't your ferrari worth it??

No. It's the same darn part and you're an idiot if you let ferrari rape you on a part that ferrari sourced from a non-ferrari parts bin in the first place...

Of course, if you enjoy throwing your money away foolishly then by all means walk into any ferrari dealership and get a free latte with your raping....

 

If its been getting warm in traffic then OK, it might just be the fan switch. If its staying too warm on the open road then you need to look elsewhere because the fans (or lack of) won't cause that.

In that case, bleed the system at the thermostat & the radiator & then check the coolant level. If its low then that would cause overheating & the most likely cause would be a bad expansion tank cap. But also pressure test the system to look for leaks elsewhere.

If you don't have any coolant loss & its still getting too warm then check the waterpump belt's not slipping, change the thermostat & after that you'd be looking at the radiator being blocked.

 

Iain, what is your definition of "getting warm in traffic"? I take it you're referring to the coolant temp, not the oil temp?

My 328 never goes beyond the midway point on the coolant, but I am paranoid, I guess. So that's why I am interested in other drivers' observations on what's "normal"

Thanks!

 

The thermostat is designed to open at a specific temp (usually 185-195) which means that your car should run on the open road around 195. If you get stuck in traffic and the temp starts to rise, the temp switch should kick the fans on. (Also above 195).

 

Your fine. Mine will creep a tad over mid-line in traffic then the fans kick on and bring it back down. I had an issue with the gauge reading high. I fixed that by cleaning the connections on the back of the gauge.

 

I know, I know - I am just paranoid ;-)

My fans run pretty strong, and as soon as I reach the mid-point, they kick in, especially in slow traffic, or standing at a stop light, and bring the coolant temp back down again.

 

Definition of "getting warm" is going above 195 whether the fans kick in or not (and they should at that level).

Mine runs at the second mark on the gauge unless sitting stationary when it will go to the middle (i.e. 195) & then the fans kick in, bring it back down to the second mark & then cut off - and repeat ad infinitum whatever the weather.

The Thermostat does not run the car at 190/195 - its more like 175 during normal operation.

 

Yep - sounds like perfectly normal 328 operation.

 

Do the fans have more than one speed. My gauge goes to the 3/4 mark sitting in traffic, the fans come on but don't seem to make a significant difference in the temp.

 

AFAIK the fans will be on or off.

What temperature is that on the gauge?

Cooling on 308s can be a bit marginal - might be you need to investigate this further.

 

My gauge is in in Celsius. On a highway is reads about 90c, once traffic starts it goes to 110c, the gauge tops out at 120c. Of course the outside temperature this weekend in NJ is over 100 degrees...not helping matters.

 

I'd be getting an infra red thermometer onto that to see if what the gauge is telling you is accurate. If it is (IMO) its running too warm.

Do the fans cut in or not?

ETA - noted that you said above that they do. If so then what temperature (on the gauge) are they coming in at? They should bring the temperature down, not just stop it rising, so if they are not doing that then it suggests your radiator is a bit marginal.