Oveheating/oil fluctuation

[93reddroptop]

Hi guys,

I just got my 93 and I've taken it on about a 50 mile trip and I noticed a few things that I don't really know if they are a problem or not.

1. Oil pressure fluxuation- When I am at a stop light or idling its about 20PSI but under cruise it goes up to 40PSI. Is this normal?

2. Temperature- I noticed also at a stop light or crusing through the park its about 215 but when I go on the highway it cools down to about 195-200. Is this normal?

3. My low-high beam switch has stuck on high. Is there any fix or does it need a new switch.

Thanks in advance for your help.

 

[Ken]

1. Oil pressure fluxuation- When I am at a stop light or idling its about 20PSI but under cruise it goes up to 40PSI. Is this normal?

Normal.

2. Temperature- I noticed also at a stop light or crusing through the park its about 215 but when I go on the highway it cools down to about 195-200. Is this normal?

Normal.

3. My low-high beam switch has stuck on high. Is there any fix or does it need a new switch.

Someone else will have to help you with this one.

 

[WhalePirot]

1) Yup, if slightly low. Depends on oil choice/viscosity.
2) Yup.
3) Yup. Does the switch 'click'? The electrical diagram to shows the headlights powered through a headlamp control unit((just aft of the AIR pump), from yellow (dimmer) and white (dash) wires from the switches. DRLs add a small amount of complexity by adding a DRL module(behind the DIC, or driver information center).

 

[93reddroptop]

1) Yup, if slightly low. Depends on oil choice/viscosity.
2) Yup.
3) Yup. Does the switch 'click'? The electrical diagram to shows the headlights powered through a headlamp control unit((just aft of the AIR pump), from yellow (dimmer) and white (dash) wires from the switches. DRLs add a small amount of complexity by adding a DRL module(behind the DIC, or driver information center).

It did the first few times. I pulled hard on the stick to dim them but it won't click. I'm afraid if I pull harder it will break.

 

[c4cruiser]

The oil pressure should be OK and fluctuations can be expected especially when the oil temp is up to normal temperatures. You didn't say how many miles are on the car, but usually high mileage cars will show lower pressures due to engine wear. You might try going to 10w-30 at the next oil change. And use Mobil-1 synthetic and a good quality filter like K&N or Mobil-1. The premium Purolator filter is also good.

The factory thermostat is a 195 degree stat so your water temps appear quite normal. In really warm weather, you may see even higher temps. The secondary fan will come on at around 228 degrees and quickly drop the temps. Also turning on the A/C will force the fans toturn on. One of the biggest problems with cooling in the C4 is getting debris stuck in the radiator. Leaves, dirt, paper, small animals, Hondas or other stuff can cut the airflow through the radiator. Use a garden hose to push a stream of water through the radiator from the fan side. An air hose works too. The front of the A/C condensor should be cleaned too. Look up under the license plate to see how much junk is up there.

As far as the high beam switch, it sounds like it may need replacing. The switch on my 92 makes a very audible click when I change from low to high beam and back and I can feel the detent on the switch. I would recommend having it replaced by a shop as it can be dangerous to work around airbags without experience with them. They can deploy as much as 10 minutes after disconnecting the battery. Then you wil need the tools to remove the steering wheel.

 

[WhalePirot]

Then, it sounds like a mechanical malfunction of the dimmer switch.

As for oil, there has been a lot of debate on the forum about choice of synthetic. The thinner oils may deliver better fuel economy but also indicate lower oil pressure. You might wish to follow the guidance in your owner's manual when choosing viscosity, based upon your local climate/season.

FWIW: I used to run nothing but Mobil 1, but have switched to thicker Valvoline for reasons I don't care to debate.

 

[93reddroptop]

The oil pressure should be OK and fluctuations can be expected especially when the oil temp is up to normal temperatures. You didn't say how many miles are on the car, but usually high mileage cars will show lower pressures due to engine wear. You might try going to 10w-30 at the next oil change. And use Mobil-1 synthetic and a good quality filter like K&N or Mobil-1. The premium Purolator filter is also good.

The factory thermostat is a 195 degree stat so your water temps appear quite normal. In really warm weather, you may see even higher temps. The secondary fan will come on at around 228 degrees and quickly drop the temps. Also turning on the A/C will force the fans toturn on. One of the biggest problems with cooling in the C4 is getting debris stuck in the radiator. Leaves, dirt, paper, small animals, Hondas or other stuff can cut the airflow through the radiator. Use a garden hose to push a stream of water through the radiator from the fan side. An air hose works too. The front of the A/C condensor should be cleaned too. Look up under the license plate to see how much junk is up there.

As far as the high beam switch, it sounds like it may need replacing. The switch on my 92 makes a very audible click when I change from low to high beam and back and I can feel the detent on the switch. I would recommend having it replaced by a shop as it can be dangerous to work around airbags without experience with them. They can deploy as much as 10 minutes after disconnecting the battery. Then you wil need the tools to remove the steering wheel.

Well the car has just 53,600 so I wouldn't consider it high mileage I guess. Its either 0W-30 or 5W-30 Mobil 1. I can't remember at the moment. I'll probably have the dealer take a look at the switch. I think I'm starting to **** people off with my high beams. LOL I will also check under the plate for all that junk that might be there.

Thanks so much for well thought out answers to my questions. I must say I'm quite pleased with this board so far.

 

[Vettefan87]

I am running regular conventional oil till i break my motor in, and at idle it will go down to about 24 then go back up to 27 or so and stay there. Now my brother runs Castrol 10w40 synthetic and I have never seen his oil pressure go under 45 at oil temps about 200. Is this due to the synthetic? Or does he have something done to his car he isnt telling me?


Justin

 

[c4cruiser]

0w-30 is a bit thin if that's what you might have in the car. The owner's manual for my 92 specifies either 5w30 or 10w30 based on seasonal temps or type of use. 0w30 is a viscosity designed for really cold climates where temps can hit -30 or lower. The factory fill was Mobil-1 in 5w30.

You can inspect the front of the radiator by looking thru holes in the radiator shroud on the right side of the radiator where the two A/C hard lines go past the radiator and into the condensor. Use a flashlight to light up the front of the radiator. Looking under the car at the air intake under the front plate will let you see the front of the A/C condensor and only the very bottom row or two of the radiator cooling tubes.