Cooling issues

[Vigri]

I have some cooling issues with my Maserati 222 SR. It starts overheating when I drive on track days. When I drive in city or on highway there are no problems, as I have never got water temperature over 90 °C but usually it’s around 80 °C. When I go to track, it quickly rises over 90 °C up to 120 °C. I replaced the radiator with a custom made, but it didn’t solve the problem.
I have heard that overheating has been a problem for Biturbo’s. Any ideas how to solve this problem?

[Thorsten Ruge]

Did you flush the radiators that there is no inside restriction at all? It is either the thermo switch for the fans on the radiator or its cable connections, or the thermostat inside the upper water hose connector at the inlet plenum. Is it still overheating if the fans are enabled(aircon on mode)? Are the fans coming on automatically?
If a.m. things are fine I would further guess the water pump bearing, i.e. your cam belt is already quite loose man?!

[Vigri]

I have tried 2 radiators and it makes no difference, so problem can’t be restriction in radiator. Both fans work fine and come on automatically when temperature rises. On track I drive aircon turned off.
I don’t believe that cam belt is loose, because it’s changed about 8000km (2 years) ago.
My mechanic thinks that the air flow under the bonnet is bad and replacing fans with ones with bigger flow rate might help. Any thoughts about it?

[rd2224v]

Hello,

you must check the thermostat inside the upper water hose connector.
You can also have a problem with the waterpump impeller.
I have seen waterpumps with loose impeller on the shaft.
And you must check the fuel pressure, if it is to low at full power (on the track) the engine heat up.

[ItalyTuning]

You can also have a problem with the waterpump impeller.
I have seen waterpumps with loose impeller on the shaft.

Yes,here a loose impeller/waterpump from a Alfa 166 V6,slow ride cold engine, fast ride hot engine.

[Thorsten Ruge]

Ok Vigri: May be the reason for the over heating is an air bubble only, unscrew the water heat temp. sensor at the front top of the engine and let it bleed during idling until the water runs out of the sensor's mounting hole bubble free for approx. 5 min,- don't forget to refill the lost cooling agent amount!
If this does not help you really need to check on all a.m. issues, which will find the problem.

[Vigri]

I don't believe it's a air bubble, because I have radiators and also bleed the system.
Thermostat is one thing I will check probably on this weekend.
Water pump would be logical but I don't want to believe this, because I changed it 2 years ago when I did the cam belt. The problem started 1 year ago, when I switched to road legal slick tires (Toyo R888) and gained a lot more grip on track. With ordinary street tires I didn't have this problem.
Is it possible that the cooling system is just badly designs and I just can't handle the heat from turbos when driving hard on track?

[veith2224v]

From my experience on 2,8 3v and my current 2,8 4v, these engines get hotter than normal 90 degrees if driven sharp. I.e during my last vacation I experienced 100 degrees partially while fans constantly on during "race" over San Gottardo Passo and such like. However, 120 degrees (if gauge shows correct) I had never experienced, under no regular ciscumstances except when my head gasket slightly started blowing 1,5 years ago. You wouldn't necessarily notice that under slow and regular conditions. My guess would be a slightly blown head gasket and / or micro-cracks of one of the heads.

veith

[Thorsten Ruge]

Well roared Veith, also Vigri, since your "believing" is accdg. to the Deutsche Duden defined as not knowing, check on those issues before you gonna loose your engine.

[fab]

Have you checked your Air to Fuel Ratio. If set too large, the engine get warmer,more fuel in, it should get cooler. There is a screw to tune on the Weber ecu.
En allemand maintenant (tentative) ;-)
Haben Sie messen Ihre AFR. Wenn zu groß eingestellt, der Motor wärmer, mehr Kraftstoff in, sollte es kühler bekommen. Es ist eine Schraube zu stimmen über die Weber ECU.