warming up during change oil (engine and m/t)

[spyghost]

hi,

- its a normal procedure to warm up the engine prior to changing oil right?
- is this the procedure to be done for a manual transmission too prior to chaning gear oil?
- considering that the working environment is safe and you got all your safety gears on, is it alright to drain engine and m/t oil after a city drive (let's say 25km)?

 

[PandaBear]

Originally Posted By: spyghost
hi,

- its a normal procedure to warm up the engine prior to changing oil right?
- is this the procedure to be done for a manual transmission too prior to chaning gear oil?
- considering that the working environment is safe and you got all your safety gears on, is it alright to drain engine and m/t oil after a city drive (let's say 25km)?


Yes to all 3, but not necessary.

 

[oilboy123]

Should help get more contaminants out. I think even getting it somewhat warmed up should be OK.

25km would be pretty scalding hot where you live. No sense burning yourself. But if you don't mind scalding fluids it would probably be best.

 

[spyghost]

is this a truth or myth:
bolt removal from hot engine parts can strip the bolt - separate bolt head, while leaving the threaded body inside

 

[oilboy123]

Should help get more contaminants out. I think even getting it somewhat warmed up should be OK.

25km would be pretty scalding hot where you live. No sense burning yourself. But if you don't mind scalding fluids it would probably be best.

Manual trans and differentials will take a longer to warm up than the engine.

 

[oilboy123]

Sorry for the double post. Got some Ice cream and then whoops.

Bolt or drain plug? Should not be a problem as a rule. Bolt stuck is another problem. Just don't disassemble a major assembly like a timing cover "aluminum" or cylinder head etc while it is hot or warm. I could become warped.

It won't harm the bolts and threads. If a bolt head comes off it is usually that it is seized from rust or has a thread lock compound of some sort.

 

[spyghost]

i was referring to drain/filler plugs

sorry for the confusion. would penetrating oil help in this area? i am quite skeptical about removing a hot tranny drain/filler plug torqued at 24 ft lbs.

i know you all will kick my *ss here, but its the first time that the tranny drain bolt will be taken out since year 2000 (since the car was bought).

first gear oil change after 9 years of 75000 kms of use.

 

[Colt45ws]

I wouldn't worry about it. Some trans oil will have seeped into the threads.

 

[crinkles]

24 ft lbs are not alot for a bolt. my tranny pan specs 36. wheel nuts are 74.

 

[rg200amp]

I go out for a 30 min drive before oil change. Get everything real hot so most of the contamination comes out with the oil.

 

[cousincletus]

I always thought it just allowed the oil to drain faster. If the car sets overnight, wouldn't the contaminants be in the oil pan anyway?

 

[ARB1977]

I change my oil hot...the benefits over take the burn marks.

 

[Eddie]

I'm not sure it makes a difference with modern detergent oils. Todays detergent oils keep stuff in suspension. I do like to stir it up so I drain warm (old habits die hard).

 

[demarpaint]

The oil drains faster when its warm/hot, also if there is any condensation it would have boiled off if the oil is hot. What I do is take a nice drive, then let the car cool off for about 10 minutes while setting up, then drain it.

The only downside I see is the oil is also running down from the heads and other parts when hot, so less might come out. I generally leave the drain plug out while greasing the car, and removing the filter, then I check tire pressure, and do some cleaning up, or yard work to extend the drain time. Its usually about 45 minutes before I put the plug in. Seems to work well for me draining it that way.

 

[eljefino]

If you're worried about your drain bolts loosen them when it's cold then retighten to about half their rated torque. They won't leak.

 

[BuickGN]

I've had the opposite problem. Bots come out easy when the engine is hot but if you torque them while hot, they're hard to get out once it cools.

 

[Steve S]

Originally Posted By: spyghost
is this a truth or myth:
bolt removal from hot engine parts can strip the bolt - separate bolt head, while leaving the threaded body inside
Myth oil drain bolts do not get hot enough to make a difference Think about how hot aluminum and steel have to get to change their properties. Opinions on sparkplugs may differ.

 

[rationull]

Whenever I've taken samples for UOAs on three different cars I've always gotten them really hot, and haven't had a problem with the drain plugs yet.

 

[mechtech2]

On the other hand, if a sump is cool because it has not been running, more oil is already drained down from any overhead components, thus an advantage and improvement.
A cool oil change will not burn or scald you, and you can get into tight places to get at the oil filter easier.
You may have to let it drain a bit longer, but are they shooting at you and you have to get away?

 

[PandaBear]

Cold change for me for sure, have taken out an oil pan and saw how little oil sits at the bottom and how much would have been up in the overhead components if it is drained hot.

I'd say OCI every 5k doesn't make much of a difference enough to burn my hand.