argh... chronic overheating... help....

I always wonder if the radiator gets clogged then are the water jackets in the engine block clogged too??

 

Not necessarily, recall the engine passages are much closer to the water pump so see greater agitation, runs at higher temps also....the radiator is the furthest away from the pump and also by nature is the point where heat exchange occurs, that's where the falling particulates and other chemicals in the water will be prone to 'fall out' of the flow stream as the mixture cools and starts it's long journey back to the engine.......

Signed,
Doctor Science

That's also why your hot water heater in the garage is full of scale.....I have Mercury 150 that ran so long in the Hill Country the water passages filled up with limestone! They told me to run it in salt water sometimes to let the sand scour all that stuff out!

 

I cannot imagine anyone's 308 QV (or any 308 for that matter) not benefiting from a trip to the radiator shop for a good rod job. There is a minimum of 22 years of deposits on the inside of those things now. I went around and around with these same issues on my 84. The biggest help was pulling the radiator out and letting a shop boil and rod it. Turned out mine really needed it and it was not very expensive either.

Replacing the hood foam (from Home Depot - NOT a dealer) is nice but it will not cure a overheating problem. I did it and it didn't.

Trip to the radiator shop, 1.1 cap, 180 fan switch, new thermostat (wait until you see the price for that little thing) and bleed, bleed, bleed. These are the BASIC first steps that you absolutely HAVE to do.

 

I am struggling a bit on this cap thing. As I remember the pressure cap allows for running higher water temp. in a closed system prior to the water boiling. I seem to recal that for each lb. on the cap you get 3* in water temp before the water boils. So the .9 bar (13 #) cap as OEM would give you 39* over 212* = 251* qnd the 1.1 bar cap (16#) would give you 260* boiling point. So now enters the air/steam issue which would/should cause dead spots in the cooling system which will become steam. So even with a .9 bar cap your water temp would be greater then 250*. Also back in the old days when you had a leak in the cooling system you would loosen the cap and still be able to drive. So I guess I would like some help/education on how the difference of the .9 vs the 1.1 cap makes that big a difference. I can also see if you have a weak cap that it would blow off at a lower pressure . I just replaced my .9bar cap with a new stant 13# cap. My old OEM cap lower gasket started to deterioate so I just replaced it. No cooling issues on the car but knew the old cap would go eventually. Enjoy the ride

 

I simply couldn't get a 0.9 cap to keep th coolant in all the time. This was the second problem I ever had with my car right after I bought it 10 years ago. Someone I spoke with when I was ordering a new cap in Atlanta told me to use the 1.1 despite what the parts book said. I did and I never had another problem. That cap finally wore out about 3 years ago and I replaced it with another 1.1. Still no problem three years later and I live in ALABAMA. We have hot summers.

 

The good Doctor is correct on this. Its easy to take the rad out, 4 bolts 2 clamps and its out. I would stake my neighbors life that you have a clogged Rad, and that is impeading the flow....

Now lets talk about what your doing now... STOP DRIVING THE CAR.... take the rad out, and get recored. I had my qv's rad re done and they had room for a couple extra rows of cooling piping...so it increased the volume a bit... WOW... it never overheated ... you could rev the hell out of it in traffic ... and it ran nice and cool around 195 all day in Atlanta traffic.

If you keep heating up the engine with out proper cooling... all kinds of fun stuff happens... In my case the guy I bought the car from must have overheated the car severly ... and retorqued the heads ... which had the effect of making the block warp... and get brittle... we are talking a lot of HEAT... so let me put it to you like this... recore of the rad, hoses, clamps, coolant, water wetter, bruised nuckles - $500 max.... overheated engine rebuild - $18,000 to $20K ....

All the other stuff folks are telling you to do is good advice, but if you aint got flow... its either no water pump or belt, or your rad is clogged...

the Ferrari 308 left the factory and did not overheat, there is no reason that is should today.... but it will cost you. a little now or a lot later!!!

 

+1 vote for the rad.

 

Hi James, after all the years of owning the car she never overheated on me, I also did not drive it as much as you are but I did drive it in the summer with the hot weather. I might have to agree with most of the post, the radiator may have gotten pluged over the years even though I flushed the system a few times it may need to be taken out and professionally cleaned. I think since you are driving the car a lot more than I did, it may be causing the radiator to show it's age... I would have it pulled and cleaned, then I bet Bella will be back to her usual self. Let me know.

Robert

 

Sorry, I forgot to mention that the car never leaked out of the tank unless it was filled more than 1/2 way. At 1/2 or under it was fine, ond she never ran over 210 to 215 measuring the temp of the tank with a laser thermometer??????

 

When i was a young niave lad, I had the unfortunate occassion to over heat, blow a head gasket and seized up an engine (not in a ferrari thank God). Get the radiator out and too a shop ASAP! If the records show its never been done just get the thing cleaned out or upgrade the whole system. A little of $ now will save alot $$$$ later. Stop trying to figure it out and hoping its a quick $5 fix. Its maybe a few hundred now. A new cap may give a little of help but it really sounds like the system needs to be cleaned out and those old hoses replaced. The more water you boil out the more lime and scale you add to the inside fins and further hamper the ability to cool the coolant.

When you get it done, I suggest a little Royal Purple Radiator additive. My Mondi T loves the stuff. Drove her from St. Louis to Indy for the USGP and she barely got warm. I think the floorboards inside got hotter than the coolant did.

Best of luck.

 

If she was running over 195 on the highway, she needs a radiator.....

 

Hi James,

Sorry to hear about your problems.

These really are great cars once you get them sorted out.

This sounds a lot like the same problem I was having when I first purchased my 308.

Can you say deferred maintenance.

The cooling system needs to be flushed every 12 months due to the all aluminum block.

My car had a partially plugged radiator, plus there was sludge in the heater cores and the block.

I remove the radiator (had it rodded), the heater cores and the engine.

The radiator shop flushed the heater cores.

I flushed the block with prestone multiple times.

Also, someone had installed the wrong thermostat in the car.

It looked identical to what should have been installed, but did not extend or retract (I forget) anywhere near the amount called for in the service manual at temperature and did not have the bleed hole.

I also removed the radiator pipes that run longitudinally and srubbed them out with a round brush stuck into the end of a broom handle.

Basically sludge was everywhere.

Finally I replaced every rubber hose in the car including AC lines, coolant lines, vacuum lines, fuel lines, and the overflow tank (it was corroded inside).

I now run Red Line water wetter and a 35% (versus the normal 50%) coolant mixture (I was living in CA at the time and now live in Florida so freezing is not an issue).

I would drain the coolant system and pull the radiator.

Bring it to a local radiator shop and have them check the flow.

If its clogged I would also pull the heater cores and let the radiator shop flush them out with their chemicals for removing sludge.

The entire coolant system needs to be flushed before you reinstall the radiator and heater cores.

Either pay some one or do it yourself.

If you decide to do it yourself, while your waiting for your radiator and heater cores drain the coolant left in the block (drain plug in the passenger side rear vee of the engine block) remove the thermostat, re-install the thermostat housing.

Check the thermostat operation per the workshop manual (let me know if you don't have one).

Use compressed air to force any remaining coolant out by pressurizing the upper radiator pipe and a bucket to capture what comes out of the lower pipe.

Then repeat the process with a garden hose.

Once the water coming out is clear stop and open the heater valves.

Place buckets under each heater hose and flush again with the garden hose until you get clear water from the heater lines.

Re-install the radiator, thermostat (with a new gasket and be sure the thermostat vent hole is at the 12 o'clock position) and heater cores.

Now proceed to flush the system with prestone super duty flush.

Finally fill with a bottle of water wetter and a 50/50 mix (3 gallons of coolant and 3 gallons of distilled water) assuming you are in an area of the country where it gets cold (Denver).

Bleed the system (you are probably an expert by now).

For extra insurance replace the factory radiator fans with two surface mount 12" SPAL pusher electric fans.

I hope this helps.

Please forgive me if I oversimplified anything or left anything out.

It's not hard to do it your self, just a pain and messy.

Also, be careful if you have any pets because anti freeze can kill them if they drink it (apparently it tastes sweet).

I prefer to do it myself so I know it's done properly without any shortcuts for convenience.

 

If your thermostat is 195 degrees and the gauge reads 195 that is perfect. The thermostat won't open until 195. Regardless of outside temp, it should try to get to 195 and stay there.(on bitter cold days it may not get that high- 60's isn't bitter cold)
If it goes above 195 degrees the fans will bring it down.
Looks like it's working properly to me. Just bleed the system often, I bleed mine after every drive.(a bit excessive I know but I do get some air out almost every time)
(the gauge and sender aren't perfect in these cars either)

 

Agreed, a properly working coolant system should stay between 190 and 200 regardless of outside temp. If the thermostat, fans and radiator are doing their job to regulate temperatures. You WILL see a wider variance in oil temps, as the 308/328 series do not have a thermostat on the oil cooler. So when colder out, the oil temps can be significantly cooler. But under normal conditions hover around 200/210.

 

Sorry, but I understood that the car was overheating.

If its not exceeding 195 with outside air at 67, you're fine.

 

This sounds like its good to me (in fact better than a lot of 308s).

On my 328 the thing runs at the first mark on the gauge - as long as the car is moving. In traffic the temp will climb towards 195 at which point the fans kick in & then the temp will fall back towards the first mark.

If that's what's happening & the car will sit at idle at under 195 & no coolant is being lost out the overflow then its fine & would seem your only issue was a bad cap.

If it overheats when you take it for a "spirited drive" then maybe you have a cooling capacity issue - i.e. you need to look at the radiator - but heating up towards 195 in traffic is normal & should be expected.

Last thing - air temperature really doesn't have that much effect on the thing if its working right. My car does the same whatever the weather.

rgds

Iain

 

Silly question: are you sure the hoses aren't reversed to the radiator?

Ken

 

I think the standard 308 thermostat is 170 and the fans kick on at 195. The thermostat needs at least 10 degrees colder than the fan switch or the fans will pretty much run all the time. If it's running over 195 on the highway, the fans will be running on the highway and doing more harm to the air flow than good.

It's probably worth changing the thermostat to be certain you have the right one in there......and drop the radiator off for a re-core. Do a search, I think it's a honda core that fits right in and give you 20% more cooling or something like that. You don't have as much air in Denver as the rest of us and to make it worse, the boiling point of your water is lower. you need all the help you can get.

Oh, and if it's dribbling coolant out the vent line at 195, the cap is bad.