Do i check the transmission fluid on my 2003 Chevy s10 zr2 4x4 when the engine is cold or hot? 4

didnt specify if manual or automatic transmission the following link is the owners manual for an 03 s-10 pages 5-13 and 5-21 to 26 cover how to check either transmission
2003 Chevrolet S10 Pickup Owner Manual

Engine must be running to check the fluid level. Transmission should be hot, not cold. Then remove plug. Add transmission fluid until it comes out of plug hole. If the engine is not running and you remove the plug, you will lose a lot of transmission fluid.

in the absence of car manual, fill initially with one liter/qrt of transmission fluid. check for leaks and start engine. with transmission in park, slowly add transmission fluid with engine at idle. constantly monitor transmission fluid level with vehicle on level position until fluid level in "cold", then drive vehicle approximately for one mile until fluid is warmed up or hot. recheck fluid level with engine idling and on park. Add if necessary until fluid level in Hot position in dip stick. then your done. write down how much fluid you added for future reference.

It varies by make. Remember most transmission fluid is locked into the torque converter and didn't come out even when you changed the filter. So knowing the capacity isn't helpful. Filling from a filter change usually doesn't take much fluid. Maybe 3-5 quarts. Just add fluid one quart at a time with the engine off. Start the engine with the transmission in neutral and check fluid level. Repeat this process until it reaches the cold full mark. Then start the engine and let it warm to operating temperature. Check the fluid level again, it should now be on the hot mark. If it's not add some more until it is. Remember all checks should be done with the engine running and transmission in neutral but you should only add fluid with the engine off for safety reasons.

It could be ECM computer problems, you could to take to transmission shop to check up. its free for check up only.

Locate the transmission dipstick tube....on a rear wheel drive vehicle it should be near the firewall, on the passenger side of the car. On a front wheel drive vehicle it will probably be near the firewall on the drivers side of the car. You'll need a funnel with a rather small end to fit inside the dipstick tube.

Your Blazer is a rear wheel drive vehicle.

Fluid level is best and most accurately checked when vehicle has been driven and is up to normal operating temperature and parked on level ground.

With the transmission in Park, and the engine idling, pull the dipstick out of the tube, wipe it with a clean rag all the way to the bottom and re-insert into the tube (making sure it it fully seated).

Then withdraw the dipstick, taking note of the fluid level on the bottom end of the stick.

Be sure to purchase fluid properly formulated for your vehicle.

Add fluid as required, only to "Full when hot" level. Add only enough fluid to bring up to the correct level (be careful to not overfill).

You have to check under the Vehicle and locate the Fluid Check/Fill hole and plug on the Side of the transmission. Check your owners manual for the proper Fluid Type to use.

Automatic transmission fluid is added at the dipstick tube. Remove dipstick from tube, wipe and reinsert while engine hot and running at idle, park or nutral ok. Add 1/4 quart at a time in same tube untill fluid level is at full mark. Do not mistake engine oil dip stick for transmission stick.

Its best to add while all is hot..
Leave it runing in park while adding fluid..
Put a little at a time and keep checking being careful not to over fill..
The dipstick mesures in pints - not quarts..

Rate well ;o)

first of all the engine must be running when you check your automatic transmission. when the engine and trans is cold (you just started it for the first time of the day) the fluid should be up to the cold line when the the engine is hot(you have been driveing for awile) it should be up to the hot line.