[Very] Cold Starts - Oil Consumption

UnhandledException

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After 64,000 miles, my GT350 started consuming a bit more oil. It has been fairly consistent up until this point requiring 1 qt every 1250 miles. It seems like now that has gone down to 750 miles. The only thing that changed is now the car is kept outside and cold starts when ambient is around 40F does take about 10 minutes for the car to reach to 150F coolant (so I have to idle it as I dont want to drive it right away due to very heavy oil). Is this normal? Is it simply the tolerances built around the pistons for track use do not play nice with very cold temps where the metal needs to expand a bit more to close that gap? Or is it the open loop in cold start that is dumping too much gas to get the catalysts up to temp which is eating away the oil as it leaks inside?





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Sletcher

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This is my understanding as well. Warm the engine by driving, not letting sit and idle. Very low revs until warm.
 

Alain

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I also agree that the best way to get the engine and fluids up to temperature is to drive the car. Start it, let that fast idle come down to normal and take off.
 

matthewr87

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I don't have any cold weather experience with the GT350. However my previous Mustangs regularly experienced cold start temps of -25C and below in the winter. I waited for the cold start revs to come down (sometimes 5 minutes or longer depending on the temperature) and then drove while keeping the revs down (but not too low, you don't want to lug a cold engine either).

In those conditions both oil and fuel consumption increased for me. But again, this was in a 2012 5.0.
 

CJJon

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^^This

Wait until the revs come down and then drive. When its hot outside it takes seconds, when cold could be much longer.
 

stanglife

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You're correct about the fact that these need to get some heat in them to grow the pistons, though. I always make sure I'm putting light-medium load (not no load) on it when I first start driving. Seems like getting some heat in the pistons reduces the sound quickly...even if the coolant hasn't warmed up completely.

That said, these are likely 4032 alloy which is said to reduce piston slap (which is more common with short pistons, like many performance pistons)...and @.003 piston to wall clearance is pretty typical for 4032..which IS tight. I wonder what Ford sets these up at? I've always suspected that they set them up purposely loose to help the engine live in extreme conditions (lots of heat and prolonged high RPM).
 

stanglife

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I know this isn't technically a piston slap thread but..... My 16, you could hear it when cold and almost 100% went away when warmed up....but at the time, I didn't notice it until after my first oil change. Now that I have my 2nd R (2020) - it really doesn't do it at all even when cold - it's till on the factory oil. I am curious to see if I'm going to start hearing this after my first oil change, as some have indicated. Either way, it doesn't concern me much.
 
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UnhandledException

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My car has had the piston slap and the typewriter tick since day 1/mile 2.

Also, I may have exaggerated a bit when I said I wait 10 minutes but in reality I only wait until the revs drop (i.e. the catalyst warm up cycle ends) and then I drive off. But in this car with very cold temps, that does take several minutes. It could be because my cats are now too old and maybe they are soaking with oil/gasoline now and take time to warm up or just how this car is inherently. My GT3RS and the ZR1 both have their warm up cycle literally take 15 seconds and no more. GT350 is at least 2-3 minutes and perhaps more.
 

JR369

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My car has had the piston slap and the typewriter tick since day 1/mile 2.

Also, I may have exaggerated a bit when I said I wait 10 minutes but in reality I only wait until the revs drop (i.e. the catalyst warm up cycle ends) and then I drive off. But in this car with very cold temps, that does take several minutes. It could be because my cats are now too old and maybe they are soaking with oil/gasoline now and take time to warm up or just how this car is inherently. My GT3RS and the ZR1 both have their warm up cycle literally take 15 seconds and no more. GT350 is at least 2-3 minutes and perhaps more.
My neighbors 19 Bullitt has the tick. My R never had it. MC 5-50 all it's life. No noticeable oil usage. Our C7 taps a little on cold start up for no more than 2 minutes. No oil usage.
 

cmxPPL219

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After 64,000 miles, my GT350 started consuming a bit more oil. It has been fairly consistent up until this point requiring 1 qt every 1250 miles. It seems like now that has gone down to 750 miles. The only thing that changed is now the car is kept outside and cold starts when ambient is around 40F does take about 10 minutes for the car to reach to 150F coolant (so I have to idle it as I dont want to drive it right away due to very heavy oil). Is this normal? Is it simply the tolerances built around the pistons for track use do not play nice with very cold temps where the metal needs to expand a bit more to close that gap? Or is it the open loop in cold start that is dumping too much gas to get the catalysts up to temp which is eating away the oil as it leaks inside?
Jeff knows what he's talking about re: forged pistons and the expansion that takes place as heat builds up.

A cold engine start in warm ambient temps, vs a cold engine start in cold ambient temps can make a difference with respect to oil consumption, where you will have a little more consumption in the cold temps, if you just let it idle "to warm up," because through every full combustion event in every cylinder that takes place, where the engine isn't up to temp yet, that is all oil that will be blowing by the rings and being consumed, as the forged pistons are never able to fully expand, due to no load from just sitting there idling.

Excessive idling is just not good for any engine.

As others have said, do not let it sit and idle. Start it up, give it about a minute, then start to drive slowly and gradually increase your load, watching pressure and temps the whole time. The key is to be gradual when driving away from the cold start, go easy on throttle, let the block and pistons gradually come to operating temp.
 

EFI

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It has been fairly consistent up until this point requiring 1 qt every 1250 miles. It seems like now that has gone down to 750 miles. The only thing that changed is now the car is kept outside and cold starts when ambient is around 40F does take about 10 minutes for the car to reach to 150F coolant (so I have to idle it as I dont want to drive it right away due to very heavy oil). Is this normal?
It's normal by what you're doing, which you can easily change by not doing what you're doing

As other said, it's not the best practice to let your car idle to warm up and you're causing more of this issue on your own.
 

key01

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I must add that I'm loving the fact that you drive this thing. 64,000 miles- simply awesome!
 

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