Rep Power: 117

Hello everyone, I have recently installed a dual oil and trans temp gauge in my 05 Civic to watch the temps. I am pretty surprised to see how long the engine's oil takes to warm up, it can be more than 100 degrees behind the coolant temp while warming up. When the coolant reaches 180-190 (a normal coolant temp for my engine), the oil might still at 60 degrees. I am planning to get an oil to coolant heat exchanger setup to help warm the oil up quicker with the added benefit of keeping it cooler in the summer or under heavy loads.

So my question is what the minimum oil temp should be before I can safely floor it. I know that running the engine hard with cold oil is bad for it and can cause failure or premature wear, but I'm not sure how hot the oil needs to be before I can safely push the engine hard. I used to floor it every time I get on the highway (around 2 miles from my house), but now that I realize that the oil is not even getting up to 100 degrees by the time I get to the highway I stopped flooring it. Hopefully I didn't do much damage flooring it with less than 100 degree oil every time I get on the highway for the last year.

Thank you very much in advance, I really appreciate your help!

 
Rep Power: 242

Where are you measuring oil temp at? The drain plug?

 
Rep Power: 117

Yes, I bought an adapter to screw the sensor into the drain plug hole. Is that a problem? Thanks

 
Rep Power: 223

Something like 140F for oil temperature. As long as you're using the correct oil though you really shouldn't have a problem. Try Google searching your question for more results.

 
Rep Power: 511

Personally, I would have either got a t-fitting to measure at where the oil pressure sensor reads or got a sandwich plate with sensor fittings at the oil filter. Maybe not so much a sandwich plate on the D17 bc that filter is a pain in the *** to get to already. Nevertheless, I'd imagine a reading where oil is moving as opposed to a location where it's relatively stagnant (relatively being the operative term there, since oil) since oil at the bottom of the sump is at the mercy of the oil pickup, whereas the flowing oil is oil that's actually coursing through your engine. But that's just me.

 
Rep Power: 242

This was my thinking. Taking a temp reading at the bottom of the oil pan is going to take longer to heat up. The oil running through the engine is going to be plenty warm.

 
Rep Power: 117

Thanks for your help. Great point about the location of the sensor! I noticed that when I stop and shut the engine off after a couple minutes of driving the temp goes up. If the temp shows 100 degrees when I shut it off, it may read 110 degrees or more if I turn the key on after it sits for a minute. I think what's happening is the sensor isn't responding very quickly. I wasn't expecting this to be a problem since I was thinking the oil moves around the pan enough for the sensor to read accurately, but I guess I was wrong. It seemed a bit weird that the oil temp sometimes only heats up to around 150-160 degrees on a cool day, I was expecting it to run at around coolant temp or a bit warmer than the coolant. Unfortunately I guess I need to get a sandwich plate to put the sensor in.

 
Rep Power: 117

Thanks for your help. I am also wondering if pushing it with the trans cold is a bad thing? I don't mean extreme cold, I mean probably around 60 degrees at the lowest. I park in a garage but I have a large cooler for the trans, so it doesn't heat up that much. I don't think the trans has the same problems as the engine with low temps though, am I correct? Thanks

 
Rep Power: 366

you never lived above TN?
QC -38C

 
Rep Power: 117

Yes I have, I'm from Chicago.

 
Rep Power: 366

so why are you so afraid of cold? Too late. TN is warm. one would be afraid up north. Took 1 hour for the car to get to normal temp needle position when I was in QC. Driving in highway speeds.

 
Rep Power: 117

I'm not "afraid" of cold, it doesn't really get below 10 degrees here and I park in a garage that doesn't usually get below 50 degrees.
My concern is the damage or excessive wear I could cause by pushing it hard before it gets up to a normal operating temperature. I'm just not sure how warm the oil and trans needs to be before I can safely run it hard. Obviously running an ice cold engine hard is a great way to cause unnecessary wear, but I'm not sure how warm it needs to be.
Also, what about the transmission? I get the feeling that it's not bothered like the engine would be by operating at a lower than normal temperature (within reason). Is that correct? Thanks

 
Rep Power: 221

Heat is what kills automatic trannys. The engineers have designed all this stuff to operate properly and last a long time in all sorts of climates around the world

 
Rep Power: 117

That's pretty much what I thought, thanks. I figure if the engineers thought the transmission running too cold was a problem it probably would have a thermostat on it from the factory. Contrary to what most people think, the heat exchanger in the bottom of the OEM radiator doesn't really warm up the fluid in very cold weather.

 
Rep Power: 117

I have an update. I installed a 30 plate oil to coolant heat exchanger to help warm the oil up and keep it cool, this is the model I chose
I am running the oil through one side of it and I am running coolant through the other side. It seems to have added about 40-50 degrees to the oil warmup. Before I installed the heat exchanger, the oil typically warmed up to around 100 degrees at most once the coolant reached normal temp, often even lower. But with this heat exchanger, the oil is up to 140-150 degrees once the coolant is up to temp, which is a huge improvement! And once everything is warmed up, the oil temp is always within a few degrees of the coolant temp. I am quite pleased with this setup, it works very well! I'm sure it will work equally well to cool the oil off in the summer too.

 
Rep Power: 223

Glad to hear it's working for you

 
Rep Power: 242

 
Rep Power: 117

Another update. As I said, I have been having a problem with moisture in the oil creating a vanilla pudding type substance under my oil cap in the winter because when I drive shorter trips, the engine wasn't getting hot enough to evaporate moisture out of the oil because the oil took so long to warm up. A few days after I installed this heat exchanger setup, I rechecked the oil cap and it is now perfectly clean, no more vanilla pudding. My driving style hasn't changed, the only change was the addition of the heat exchanger.

One thing I forgot to mention is the effect this setup has had on my coolant temps. My coolant now takes a little bit longer to warm up as I expected since it is warming the oil up too, but the difference isn't too dramatic. I would say that the coolant's warmup has been delayed by about 1 minute, which is less of a difference than I was expecting. But even though the coolant's warmup has been delayed, in my opinion it is still much better to warm the engine up more evenly and heat the oil up with the coolant than to heat the coolant up quicker but leave the oil and other parts of the engine cold.