Cooling System and Oil Pressure Questions

BRNIN8R

Registered User
Hello all,

I bought my 93 Super Coupe about a month ago and I'm a bit curious about how it's acting. The car is very slow to come up to warm up. Often it will take 20-30 km to come up to temperature. Once it reaches normal I think it is running very warm. The needle seems to settle around 3/4 on the range. If stopped for more than 30 seconds the temperature rises noticeably. The radiator fan will kick in, and bring it down somewhat. It is doing this in temperatures barely above freezing. It hasn't overheated since I've owned it and the coolant is brand new. I am having to top up the coolant in the resivoir about every 100km, about a cupful. The car has 89,000 km and new upper and lower rad hoses.

Secondly the oil pressure gauge rests at about 3/4 all the time, still in the normal range, but higher than I'm used to on any other car. The oil is brand new Mobil 1 5W30. Aside from one very minor rear main seal leak, the engine is tight. I am not losing any oil.

Lastly there is a slight roughness to the idle when the car is up to temperature. It won't stall, but it is noticeable. I' not sure if this is related to the above.

Based on many of the threads on the forum, I know these cars have HG issues, but they don't seem to show these kinds of symptoms. Please let me know if you have any ideas.
 
Honestly, the stock gauges aren't going to supply you with much information. The oil pressure "gauge" is a glorified idiot light, as it uses a on/off pressure switch instead of a sending unit. If the switch sees at least 8 psi, the needle shows "normal". The coolant temp gauge is a "real" gauge, however it doesn't inform you as to the actual temperature of the coolant (what temp is the "R" in "NORMAL" for instance?). Without real data, it's hard to say exactly what is going on with any certainty.
 
The needle on both will tend to point between the "M" and "A" or slightly past that if the car isn't moving.
 
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The cooling fan kicks on at 220 deg. Where exactly that ends up being on the gauge varies from car to car. It does sound like you may have a clogged radiator that is restricting flow. You can have that checked or you can just buy a new radiator. At nearly 20 years old, it's about time to replace it anyway.

If you plan to keep the car long term I recommend the radiator and a chip to turn on the fan sooner. If the car is primarily a warm weather car I usually install 180 deg thermostat and regulate engine temperature at 195 deg. If you want it stock, then the thermostat is 195 deg and then we regulate temperature at 205 instead of 220 but to do so requires a properly functioning radiator and a chip.

Oil pressure is as Rod said, it's either "up somewhere" or its not. As long as you have oil pressure it will read wherever it feels like.
 
Thanks for the help. I'm going to get the cooling system checked for leaks and probably install a new rad and thermostat.
 
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