oil coolers and engine temp

LOL. Why would any one wast money/time doing this to a Caravan?!?! LOL

And as Nate said, "...Keep in mind that too cool is as bad as too hot..."

I just installed an external Derale oil cooler (with electric fan) in my '96 Dodge Caravan (4- cylinder) and I am very impressed with the sudden drop in operating temperature. I can drive in slow-n-go traffic during hottest times in a Florida afternoon, unscrew my radiator cap, and I don't get a scalding steam bath blowing up in my face. Radiator water is hot/warm but not boiling.

I installed the oil filter sandwich adpater to add external hoses in/out to cooler. Also increase oil capacity to about 1.5 qrts.

Perhaps he is not wealthy enough to buy a new van and has to keep the old one running? Or he could be a Derale spammer.

It sounds like your engine is running TOO cool. It should boil if the cap is removed, or be close to boiling, with modern systems.

The higher the coolant temperature, the higher the engine efficiency, as long as the temp does not get so high that it damages the engine. If they had higher temp lubricants, they would run water temps higher than they do today. One of the reasons for the improved engine efficiency today is that the engines are run hotter with pressurized coolant systems, compared to sixties and earlier.

Nathan M. Gant wrote: > I just installed an external Derale oil cooler (with electric fan) = in my '96 > Dodge Caravan (4- cylinder) and I am very impressed with the sudden = drop in > operating temperature. I can drive in slow-n-go traffic during = hottest > times in a Florida afternoon, unscrew my radiator cap, and I don't = get a > scalding steam bath blowing up in my face. Radiator water is = hot/warm but > not boiling. >=20 > I installed the oil filter sandwich adpater to add external hoses = in/out to > cooler. Also increase oil capacity to about 1.5 qrts. >=20

I'm assuming that this is an oil/air cooler. Keep in mind that too = cool=20 is as bad as too hot - oil should be over 212F to boil off any=20 condensation that makes its way into the oil while the car is sitting. =

Are you using a thermostatic adapter?

This is one reason why I like oil/water heat exchangers like Porsche = (at=20 least in the 944) and VW use. No need for additional thermostats as = the=20 oil can only be cooled to the temperature of the water in the cooling=20 system, which should be around 195F. In practice, the oil always runs = a=20 little hotter as heat transfer slows as delta T decreases.

nate

I'm not convinced it's possible to run an engine too cool in subtropical enviroments of Florida. Heat is the main enemy of an internal combustion machine.

Keeping oil cool in not necessary in northern areas, for sure. But I'd say it'd be okay to install one in that case, and not run the electric fan so you only have partial cooling. Every 20 deg. drop in oil temp, doubles oil life. So I've read.

I'm not using a thermostatic adapter, I'm afraid it would be a redundant part to go wrong and block the oil flow in system. FWIW I've heard that removing the thermostat in the radiator will also drop temperature down a few more degrees, so that's been recommended for cars in tropical or subtropical environments.

I'd say at the moment the radiator will get close to boiling, but no way will it blast steam in my face when I unscrew the cap. Maybe it might do this in July, I fear we'll have a brutal summer this year, but so far it runs okay for me.

Not a derale spammer, I'm not promoting any brand of oil cooler, just that it is definitely more efficient to use an electric fan mated to the oil cooler.

I happen to like Caravans myself.

I've had lots of previous experience running external oil coolers in air-cooled vee-dubs, so I am well aware of its benefits to these air-cooled

4-bangers.

I have 160k miles on this 4-cylinder van, and I want to see it go for another 100k.

Aren't oil coolers de riguer > > I just installed an external Derale oil cooler (with electric fan) in my '96

Doesn't matter whether you're convinced or not; oil should run at

that, of course, but it needs to get hot to drive out moisture.

nate

Granted, rate of water evaporation slows as temperature drops, but evaporation is a surface effect that will happen even during icy conditions.

Oil loses viscosity with increasing temperature, so 212F may not necessarily optimize lubrication. I would guess that the amount of moisture in engine oil isn't such a big factor to warrant a mandatory 212F temp. Any moisture (water) in an engine will evaporate at any temperature, hot or cold. Moisture does not have be (boiling) at 212F to evaporate. You can hang clothes on a laundry line, the temperature is far below boiling point, and you have rapid evaporation (dry clothes).

0W-5 and 0W10 have much more stable viscosities thru the range of oil temps (say from 180F to 280F), so why not, when using an oil cooler w/electric fan, switch to a lower-viscosity grade of oil?

------------------------------------------------------------ Properly maintained 911 engines can last over 300,000 miles when oil temperature is kept in the optimal 180-210F range." from

"The ideal operating range for engine oil is 180F through 200F."

Doesn't matter whether you're convinced or not; oil should run at

that, of course, but it needs to get hot to drive out moisture.

nate

| I am very impressed with the sudden drop in | operating temperature.

I think if a intercooler is added to PCV hose, air intake will be much cooler til (i) EGR ( consumes electricity - scarce when alternator is hot esp when heated by aircon radiator's hot air fanned out ) will be unnecesary (ii) lower octane petrol can be used (iii) air intake is denser ( more oxygen ) & combustion faster so more torque & lower exhaust noise. Less messy & weight than an oil cooler + oil.