Hot Running 308QV

Thanks for the post JRV.

I

Thanks for the post JRV.

I will buy a new thermostat and radiator cap ASAP. It cannot hurt to have new ones, or at least a spare.

One question I have is "if" my radiator is clogged and needs to be re-corded, would that cause the oil to run hot too?

As to bleeding my radiator, I usually have to wait about 5-10 seconds after each drive for all of the air to escape. In fact, even if the car sits for a month or two unused I still have to let some air out of the system. Is this normal?

Thanks.
Ken

Hi Ken,

Alhough the solutio

Hi Ken,

Alhough the solution to your problem may take a bit to get to the answers, it's a great question that I believe many cars suffer from, to some degree. Although my currert...and long-time favorite ride is my BB, I have owned both a 308QV and 328, so I'm familiar with the collings systems in great detail.

To answer your question about the rising oil temperature...Yes, it happens if there's a weakness in the cooling system, or in the oil "cooling system function..." So, to see a rise in both oil and water temperatures is not uncommon.

You may be aware that I spent a long time tracking down why my BB ran hot whenever it got into even mild traffic, or the ambient temperature was over 70F.

In my opinion, the cooling systems, even when working properly are borderline effective. So, any deterioration, or components out of specs...can have noticeable effects on those engine temperatures.

Starting at the bottom...and working up.

1-Drain and fill the transaxle.
2-Dain and fill the engine oil
3-Remove and re-core/replace the radiator
4-Replace/verify therostat for correct oppening temperature.
5-Remove waterpump and verify the waterpump impeller to housing clearance. This can have a hugh effect on the pumps cooling/pumping efficiency. This is not your causual rebuild issue...
6-Verify that the thermo-fan switch turns on at 79C, or lower. Replace with low-temp VW/Porsche 924 switch.
7-Update if you wish to the later 328 5-blade fans...and verify the proper blade rotation.
8-Inspect cooling system hoses for "cold-seep"...evidence of green/white crud around hose connections. This could be your "source" of air seepage.
9-Verify spark plugs for proper heat range.
10-Verify ignition advance is not stuck/fixed.
11-Verify mixture strength (leaness could cause higher engine temps, if the car is driven hard)

Granted, this is a very comprehensive list but....these are all the steps I took, and ended up with a very cool (running) BB. Take no shortcuts, and I'm sure you'll be pleased with the outcome.

Best of luck!

Regards,
David

Morning Ken,

While I agree

Morning Ken,

While I agree that the transaxle is more, or less a sealed unit (there is a vent to the atmosphere), my reasoning for changing it was two-fold.

1-It may be low on oil...which in turn will cause higher than normal gearbox temperatures. In that the engine sits on top of the gearbox...this situation can also drive up engine temperatures.

2-Gearbox oils, no matter the type do break down over time, as well as miles. Airation can and does occur, again resulting in higher than normal gearbox oil temperatures....

These above reasons are why I stated "I like to start at the bottom...and work up..."

Oil preferences are about as subjective as what's makes a woman good looking...There's no substitute for quality products. Although I don't use Agip products in my BB, I feel that they clearly fit into the "quality" category. Personally, I use Mobil 1 in the engine...and Royal Purple in the gearbox.

The corrosion you refer to is evidence of "cold seepage" and should be addressed. Corrosion, in itself, on the sending unit, can act as an isulator or soft, and cause the fan to turn on at a higher than specified temperature. Simple, cheap fix, for sure.

This "air seepage" mystery that Ferrari seem to have, more oftem than not, is somewhat annoying...though I personally don't feel is of great concern. The overflow cap are truly junk, and have a useful life of maybe a year or so, before they leak at the seal...

I wish I could tell you that it was one specific thing that fixed my cooling issues with the BB...None of the problems I had were major....but all the little issues did add up to elevated engine temperatures.

Regards,
David

Ken,
My mechanic pulled the r

Ken,
My mechanic pulled the radiator on my 328 during a major and had it "rodded out" which apparently entails cutting the bottom off, and running a long round brush through the tubes in the core. They cleaned out a lot of crud. My car was not reading all that high, but was done as a precautionary measure. I think this is commonly needed on all these 308/328/Mondials as they are now "old" cars, and need the radiators cleaned out. Shoot, even the newest 328 is a 15 yo car now! I doubt a recore is warranted, just have the stock one cleaned out. This is a cheap repair, probably $400 or $500. Take Dave's advice and spend $15 on the VW thermo switch. They are available in two settings, stock and 10 degree lower value than the stock one. I'm still using the stock Ferrari one, but if I ever need a replacement, that would be the one to get.

Here's a link to the source....Automotive Performance Systems (although any VW shop should have them) http://snurl.com/3ayq

Dave,

thanks for making the

Dave,

thanks for making the OLD car point again. Even though most of these cars have low mileage and in many cases look almost new (on the outside), truly 15-20+ yrs is considered getting old in car terms. What speaks mightily of the product itself in terms of their ability to hold up, also tends to make us forget that on a lot of the parts the clock never stopped ticking from day one.

On the air issue:

The first problem with the cooling system is caused by what's known as cavitation by the water pump blades, as it spins air bubbles are churned out of suspension and into bubbles, the same thing that occurs on a boat propeller for example. These 'bubbles' are then carried forward and trapped at the top of the radiator. Every time the WP spins it creates bubbles. Another source of air (bubbles) in the cooling systems sometimes can come from the loss of complete seal between the head gaskits and block/head sealing surfaces that occurs because of corrosion/electrolysis at the points where the water jackets are closest to the head studs. I hate bringing up that point because it tends to scare people which I try to avoid in most of my writings.

Here in Texas where the summer heat is brutal, I'm a firm believer in the Low Temp Fan Switches Dave H. mentions. Along with Watter Wetter. And as David F. mentioned these cooling systems are on the edge of cooling ability even from new. Which means that all the parts of the system play heavily into the overall ability to keep the engine cool.

All the above suggestions play a big part in bringing cooling temps back in line. Generally it is not one thing, but a combination of many things as mentioned that prevents simple answers and simple solutions for what are often complicated problems.

Regards, JRV

Hi Ken,

the 1,1 bar cap wil

Hi Ken,

the 1,1 bar cap will help not hurt. 1 Bar is 14.7lbs.

The engine t-stat opens @ 78 centigrade (approx. 180F), the fan switch on the radiator turns on @ 87C (approx. 192F).

Regards, JRV