colder thermostat effect on oil

[EvanD]

I just dropped off my truck today for a colder thermostat from lingenfelter 160 vs 195 from chevy. I was wonderering what effects this will have on my oil???


I am tuned with bolt on mods and when I am towing my boat I am getting a little knock from the engine when its hot out 115 weather sitting in traffic a/c on it causes issues. I am hoping this will help a little if not a set of e-fans is coming in next.

 

[demarpaint]

Cooler thermostat might delay or even stop the engine from reaching full operating temps. Engines are designed and spec'd to use a certain temp thermostat to run properly. Even in the hottest of climates a car calling for a 195* thermostat should have no issues. Cooler operating temps can cause moisture to build up and not burn off causing sludge. It can also cause oil to never reach the desired operating viscosity, causing additional wear.

Long story short, use the thermostat the car calls for, if you are using a colder thermostat because the engine is running hot, find and fix the problem.

 

[Gary Allan]

I would have gone to 180F before dropping down to 160F. Find out when your PCM/ECM cuts out fuel enrichment. I think mine is 170F for closed loop but I can't verify it at the moment. Changing the stat shouldn't alter your system capacity. It will give you a bit more time to too hot when the load is put to it.

Sorry, the question. If you're not out of open loop, plan on a substantial amount of fuel dilution. I don't expect any effects of moisture or whatever since you will have more than enough time at temp.

 

[willix]

If the motor is tuned to run on the 195F t-stat it may effect efficiency. It would be more logical to add oil cooling. A oil temp guages for crank case & trans may benifit you.

 

[EvanD]

I have the software tuning is not an issue.

 

[Mustang Man]

The electric fans may not kick on either. Computers are set for certain temperatures as well.

 

[wolfc70]

You might get a CEL with the 160F thermostat. My 03 L300 (a GM car) will throw a CEL if the computer does not see 170F in 500 seconds (8 min or so) of driving. When my thermostat stuck open, I got the CEL in the summer. If you have emissions testing in your area, this will cause issues too. If the computer needs to see a certain temp to enter closed-loop mode, it might run too rich all the time. With all of the mods to your vehicle, make sure you are running a quality gasoline with the appropriate octane rating for the vehicle. Going up a grade may help with the slight spark knock.

I would have gone with the 180F thermostat if it was my vehicle. A lower thermostat will only delay the onset of heat soak, not eliminate it.

Do you have a scan gauge or some other form of OBDII reader? This may have the ability to pull actual coolant temps, not what is going through the dash gauge.

I do not see an issue with oil by changing thermostat temps. If you are seeing 115F ambient temps, oil warm up time is pretty short. Now in winter, that would be a different story...

EDIT: With your mods, you are also making more power, which produces more heat. You may need a larger radiator to deal with the increased heat output, and towing only increases the load.

 

[UNC017]

Guys, it sounds as if he's got a fully re-programmed PCM from Ligenfelter, which is designed around the 160-degree thermostat. None of the issues with closed loop, fan operation, yadda yadda are going to be a problem in that situation- he's asking what a colder-running engine may do to the OIL.

Answer- it will be slower to drive away moisture and fuel dilution, so some acidic accumulation may happen a little faster on short trips. Change the oil more frequently and it should be OK, especially since you obviously plan to push this engine pretty hard, which will raise oil temperatures quite a bit. A hard-worked engine with the coolant at 160F will probably have oil temperatures higher than a loafing engine with the coolant at 195. Oil temperature doesn't DIRECTLY track coolant temperature, since a lot of the heat in the oil comes from cooling the undersides of the pistons, which aren't well-cooled by the coolant anyway.

 

[The_Jeff]

Originally Posted By: 440Magnum
A hard-worked engine with the coolant at 160F will probably have oil temperatures higher than a loafing engine with the coolant at 195. Oil temperature doesn't DIRECTLY track coolant temperature, since a lot of the heat in the oil comes from cooling the undersides of the pistons, which aren't well-cooled by the coolant anyway.



+1 and I think oil temp tracking would be very useful for OP.

 

[Jim Allen]

I think you are barking up the wrong tree. The lower temp t-stat is just a band aid. If you are pinging under load, that's a tuning issue that should be dealt with. If your tune is for a go-fast situation (more timing and oft times a leaner mixture than stock), then it may be too aggressive for towing. Many times, fattening it up a little and/or backing on the timing a little is all it takes for a "tow" tune. Running the vehicle in open loop or in one of the cold enrichment maps is rather inefficient, depending on the numbers in those cells. I'd put my energy into getting that tune right and staying with a 195F t-stat... but you're the pilot.

 

[Zaedock]

Originally Posted By: evandostert
I just dropped off my truck today for a colder thermostat from lingenfelter 160 vs 195 from chevy. I was wonderering what effects this will have on my oil???


I am tuned with bolt on mods and when I am towing my boat I am getting a little knock from the engine when its hot out 115 weather sitting in traffic a/c on it causes issues. I am hoping this will help a little if not a set of e-fans is coming in next.


The 160* will keep the incoming charge cooler (which will help) but when it's that hot, you may need to adjust your tune. As far as the oil goes, the 160 stat won't allow all the contaminants to burn off, so I'd stick to 3K mile changes.

 

[EvanD]

Yes keep it on the oil. I can turn down the timing at any time. I am ok with tune and software and yes I can turn it down if nothing else works. It's so slight at only the most extreme situations.

 

[Zaedock]

Originally Posted By: evandostert
Yes keep it on the oil. I can turn down the timing at any time. I am ok with tune and software and yes I can turn it down if nothing else works. It's so slight at only the most extreme situations.


In that case dude, I think you'll be good to go with the stat.

 

[c3po]

Originally Posted By: evandostert


I am tuned with bolt on mods and when I am towing my boat I am getting a little knock from the engine when its hot out 115 weather sitting in traffic a/c on it causes issues


So this happens when you are TOWING a BOAT, I think we need to look at the TRANSMISSION.

1) Do you have an External Trans Cooler on the truck.
2) Can you put on an aftermarket trans pan that has more capacity.
3) What brand of transmission fluid are you using.

I have an Infrared Gun and when I have taken trans pan temps I noticed I had lower pan temps when I switched to Amsoil ATF.

 

[mechtech2]

Your new colder thermostat won't do jack squat for hot conditions, and subsequent problems.
Because if a thermostat is open, it is open.
If you have problems with a medium 195, then fix them. A thermostat is not the way to fix things - it is a band aid..

 

[edhackett]

Right. If your truck is running at over 195 towing the boat with a 195 thermostat, it's going to run over 195 with a 160 thermostat. All the thermostat does is control the minimum temperature. The cooling capacity of the system determines the upper level.

Ed

 

[Jim Allen]

Originally Posted By: evandostert
Yes keep it on the oil. I can turn down the timing at any time. I am ok with tune and software and yes I can turn it down if nothing else works. It's so slight at only the most extreme situations.


My point exactly. Unless the tune is designed for a 160 t-stat, keep the 195 t-stat and adjust the tune when towing. If it was tuned for the 195 and you go with the lower temp unit, you may be operating in non-optimal areas of the tune. PIng might stop but you might lose some power the rest of the time.
Among other things, tow tunes run fatter than solo performance tunes, and have less timing. I've been going through this with a pickup so it's all fresh in my mind. I have try to tow in one of the performance settings and it's ping city... more load = more ping.

As mentioned before, maximum oil temp will be about the same, (which is partly dependent on coolant temp and partly dependent on the engine situation) perhaps rising more slowly with the lower 'stat.

 

[EvanD]

I think you guys misunderstand engine tuning. I am really more concerned with oil effects

 

[Unleashedbeast]

Originally Posted By: evandostert
I have the software tuning is not an issue.


Why not just tune the PCM to turn the fans on sooner instead of the cooler stat?

The 160* stat in my LS1 caused a sludge problem from H E double hockey sticks!

 

[UNC017]

Originally Posted By: Unleashedbeast
Originally Posted By: evandostert
I have the software tuning is not an issue.


Why not just tune the PCM to turn the fans on sooner instead of the cooler stat?

The 160* stat in my LS1 caused a sludge problem from H E double hockey sticks!


Turning the fans on earlier won't do anything to lower the coolant and engine metal temperature, it'll just make the thermostat close partially. Sometimes you actually want to lower the metal temperature to reduce the chance of detonation, and lowering the coolant temp is a good way to do that. Yes, efficiency will be lower because as the metal gets cooler the quench area where fuel/air won't burn gets thicker. But if it allows you to operate at higher power without pinging/detonating, it can be worth it.