My 308 seems really hot but is it overheating?

'83 GTS owner's manual says 240F is "maximum permitted".

Way too high for regular running, IMO.

 

having read your other thread about the guage jumping around: how reliable are your readings, or what is your observation of overheating based on?

 

Hope it's not the Nick Forza water pump giving you the problem.



BTW Can you post a picture of that water pump in your 308? Want to see how it looks. Thanks

 

I had false readings on my gauge,after a service and thermostat,waterpump,and fluids changed to waterwetter,my gauge was reading 225*-250*,knowing that wasn't right and tapping on the gauge the needle dropped everyone one here said it was the contacts and they were wrong it was the gauge it self,$75 a new gauge,presto,the temp it at 165*,I also bought a thermo gun and keep that in the car at all times to get the true reading if your not sure

 

well thats good,you don't want to warp those heads,thats big bucks there,enjoy your car this weekend my friend

 

My experience is that while the guage or the temp guage circuit are sometimes the culprit, more often the unfortunate truth is that the car is just running too hot.

This has been discussed often because it's an issue. The cooling systems in these things are barely adequate--they are "just enough" to get the job done when they are in good working order, but unlike a modern car, they don't have much extra capacity in "reserve." So a partially clogged radiator, marginal thermostat, improperly bled system or leaking expansion tank cap, etc. can cause the car to overheat.

The most common things that seem to go wrong are:

1. Fans not coming on

Cause: usually the damn fuseblocks. Sometimes the thermostatic switch in the radiator. Easy to check. Just pull the two leads off the thermostatic switch at the bottom corner of the back side of the radiator. Use a connector or a wire with alligator clips to connect these two leads together. Turn on the ignition switch (car can be stone cold). BOTH fans should come on. If they don't, the issue is probably the fuseblock. Could also be a fuse, or a relay. Each fan has its own fuse and relay. The left fan is also activated by the A/C so it has a second relay. If they come on when you connect the leads, but not when the car is hot, the switch in the radiator is bad. This can be replaced with a part from VW for $15 or you can get the correct one from Ferrari which is pretty much the same exact thing. Check the cross reference thread for the VW part number.

2. System not bled right

Bleeding the air out of a 308 is a little bit of a pain. Not hard, just takes a while to do it right and it really is necesary to get it right. If there is too much air in the system, it expands too much when the car gets hot and forces too much coolant into the expansion tank. It overflows. Then when it cools, the car has less coolant and more air. Then the next time it is warmed up, the situation is a little worse. It just gets worse and worse. Instructions to bleed are on my website here. I actually bleed the air out of my radiator now and then as a matter of course. When the car is hot, even if shut off, the system is pressurized. So, pull it in the garage, shut it off, pop the front lid, grab a paper towel, open the front bleeder screw and let the air out, catching the coolant drips with the towel. Now close it up. Takes about 30 seconds and you will be shocked that you can get air out of the system virtually anytime you do it. If you put a neoprene washer or rubber o-ring on the bleed screw, it can be finger tight and won't leak or break, as those fragile brass screws are known to.

3. Bad expansion tank cap (i.e. "radiator cap")

This one is very common. A very cheap part and you wouldn't believe how often these fail. Mostly just because the gasket gets old and "smushed" so that the cap starts to leak before the system gets to pressure. If this happens, the water can boil at a lower temp. Car overheats. Get a new one cheap....and it's even the right one for your car...from Ricambi here.

4. Clogged radiator

It happened to me last year in the Mondial when deteriorating rubber hoses clogged the radiator with small rubber particles. I had mine re-cored for about $350 and now I have essentially a brand-new radiator. More often in older cars is a radiator which is clogged due to corrosion in the system and sometimes a radiator can be repaired by a rad shop by "rodding" it. (They take the top off the radiator by unsoldering it, then run a thin metal rod down each cooling tube to scrape out the gunk.) However, some shops will not rod an old radiator like this because they are afraid the metal is too thin and fragile. Especially when it says Ferrari on the top. I chose to re-core mine as a result. Drain the cooling system, pull the hose off the top of the radiator and look in there with a flashlight. You can see the top of the tubes and get a good idea what is going on.

5. Bad Thermostat

I'm listing this one last because it seems very rare that a 308 overheats from a bad thermostat. More often, they seem to not fully close so the car takes forever to warm up in cool weather. But in theory, a bad thermostat that doesn't open will not allow coolant to reach the radiator...and that is bad. If your radiator gets hot....the thermostat is probably fine. One thing to be careful about is that your car actually has a thermostat. An old trick with some cars that are overheating is to remove the thermostat entirely to increase flow to the radiator. It won't work on a 308/Mondial because it uses a special kind of "dual throw" thermostat which directs coolant in one direction when closed and another direction when open. Hence, without any thermostat at all, the coolant is not directed properly to the radiator. (Some will get there, but not enough).

For any car that is running hot, I would simply work my way down this list. Start with a new expansion tank cap (cheap insurance and takes 2 seconds to install), then add some coolant, bleed it correctly, check the fan operation and take it from there.

Birdman

 

Birdman your post on overheating deserves lots of gold stars. Very informative. I had a problem with the car chucking fluid out of the expansion tank when I went on a run and the engine got hot. Had to keep stopping on the motorway because people were flashing me.Tried bleeding at the rad end and loads of air came out. But the problem wouldn't solve until I put the heater valve to hot, ran the car and then bleed the system. This cured the problem. So please note everyone, you need the heater on as Birdman says or it won't work! Coming back to the first post, the temp gauge gave a higher reading when the system had air in it as the water was not reaching the rad and cooling properly.

 

Note that the air issue and gauge issues can be related. When I had air in the system, the gauge would jump up for a half minute or so, and then drop back down after the air pocket had passed the sensor.

And almost everybody forgets to open the heater valves full when bleeding, to get the air out of the heater cores, too. Otherwise that air just gets into the rest of the system.

On the 328, I've had good results with cold bleeding, using a hand operated pressure pump. I put a few PSI on the overflow tank (at the cap, below the overflow) then bleed the thermostat screw and radiator, and that usually gets the air out in one operation. No repeats needed, usually.


But to answer the original question: yes, the entire engine bay runs hot: 180-190F. Much hotter than, say, my EVO, which gets extreme hot spots (like the turbo) but doesn't get uniformly hot like the 328.

That does have an impact on city driving. Having that hot engine bay behind your back isn't a problem while you're moving. But when you're sitting at a traffic light for ten minutes, that heat tends to waft forward into the cabin when you have the top off.

 

Just out of curiosity...how hot is the oil temp when the water is running hot? My water will run a tad over 195-215 when driven hard and the oil moves to dead center. Otherwise they both run about the same. If you are just a tad over the 195 mark and not much more it's not a big concern. If it starts hitting the 3rd mark I would keep a keen eye on it. Bleeding the system is important, and I do mine cold first with the back of the car raised a bit. Then do a hot bleed if nessesary.

BTW...I also have a weird water temp gauge...It will show a slight temp. as soon as I turn the key. I have cleaned it but still strange so I suspect a bad gauge [unless it's normal to blip a little when I turn the key].

 

The oil temp on dry sump cars always tends to run cooler than wet sump cars. On my glass (euro) GTB even on a hot day it just goes over the 140 mark which is not even a 1/4 on the gauge . This is with water remp at just under 195. On a wet sump car (a GTS or GT4 in england/europe ) its easy to see 1/2 way on the oil temp guage on a hot run . GT4's need a front oil cooler for racing otherwise you see 3/4 on the oil temp which is bad. Since fitting a front oil cooler on mine even racing the oil temp stays at 1/4. I've never noticed the water temp go much beyond 195 (middle) though even with hot oil. If its running much beyond this you have one of the problems descibed in Birdmans excellent post.

 

Regarding the car spitting out overflow:
After an initial topping, my car tends to spit out what it doesn't want early on then it's happy.
However:
My driveway is very steep to the point where I must go up it at an angle.
*every* time I go up it & park briefly the car spits out a few ounces of fluid (turned off).
I also suspect it ingests some air as I hear gurgling in the engine compartment.
So watch for steep driveways.

 

Just a couple of random thoughts on overheating --

Don't bother rodding out an old radiator. It's a waste of time and money. Modern cores are much more efficient than the old ones, and you can get a good quality high efficiency core installed in your radiator for not much more than rodding it out.

Be sure to add a bottle of Water Wetter to your 50/50 mix of coolant and water. Red Line Water Wetter will help your coolant do a better job. And if you have hard water in your area, use either distilled or de-ionized water to mix for your radiator. And don't cheap out on coolant. Get Prestone or one of the good name brand green coolants (don't go to Dexcool, the orange stuff). They will have the right additives to fight corrosion and protect important engine parts.

 

I had hot running issues for decades , I tried everything I thought. I finally bought some new fans, & at the same time discovered how to bleed on birdmans site. I testest the car in blazing hotlanta traffic for almost 60 minutes stop & go, I was thrilled when it didnt go over 180, When I got home to inspect the fans & my new relay, they were not running, I forgot the inline fuse! The proper bleeding w verils nut was enough to keep it in check.! Now Ill drive it anytime .

 

That is not normal. Something is either wrong with the guage or the sensor. Can't trust anything that guage says!

 

Hi does anyone know what size neoprene washer I need to buy for my car. The one currently there has totally perished, and I'm hoping I can just buy a replacement at a local hardware store.

 

rubber o-rings are available at any auto parts store.
I bought a box of metrics from PepBoys and will be happy until 2020.

 

Just take the bleeder screw down to the hardware store and rummage around in their rubber o-ring/washer bins. That's what I did.

Birdman

 

If there is coolant in the car and you can't take the bleeder out for any length of time, just buy a selection of o-rings/washers and pick the best one when you get home. They are cheap as dirt.

Or, this is a great time to change the coolant anyway!