This is an easy answer for majority of you but i am still fairly new to this car and need to do a complete flush. Brown murky water in my reservoir and coolant system so flushing it out, however, i cannot find the damn block drain plug. I have been looking for over an hour. I have the service manual handy but the picture they provide isn't sufficient. Can someone please explain where exactly to find it so i can clean out the entire system. Do i need to jack up the car to find it? The car is fairly high so i can get underneath it but still can't locate it. Pics would be awesome because there are so many nuts lol
It is an 89 S13 KA24E
Thanks!

There may not be one on that engine. There is no absolute guarantee that an engine has them anyway. The freeze plugs are unusually low on that block and create the lowest spot to drain from but of course that means knocking out a freeze plug then putting it back in. Often very difficult to do engine in car.

Although helpful there is no real need for a drain plug anyway. Open the radiator drain and then refill slowly at the fill point and run engine at idle while letting the clean water circulate in and through the engine to drain back out, if you can figure out the normal coolant direction then flushing backwards of that is often better. Some people cut into a heater hose to do that.

Go to Rock Auto and call up the year and engine then long block, they show all sides of the block and I see nothing that jumps out at me as being a drain point low on the block.

Prestone sells a very convenient kit for block backflushing ! You install a hose thread and 2 plain hose barbs Tee into the heater hose. Open up your heater intake valve [yea, turn the heater on]. Remove the radiator cap. Snap a plastic outlet fitting [part of the kit] into the radiator where you have just removed the cap and slip any old radiator hose over the plastic outlet to prevent the engine coolant from messing up your paint or chrome and hook a garden hose to the threaded fitting on the tee. If you can't figure out what to do next, sell your car !

No need to remove the engine drain plug.

amc49 wrote: ↑

Thu Jun 21, 2018 6:18 pm

There may not be one on that engine. There is no absolute guarantee that an engine has them anyway. The freeze plugs are unusually low on that block and create the lowest spot to drain from but of course that means knocking out a freeze plug then putting it back in. Often very difficult to do engine in car.

Although helpful there is no real need for a drain plug anyway. Open the radiator drain and then refill slowly at the fill point and run engine at idle while letting the clean water circulate in and through the engine to drain back out, if you can figure out the normal coolant direction then flushing backwards of that is often better. Some people cut into a heater hose to do that.

Go to Rock Auto and call up the year and engine then long block, they show all sides of the block and I see nothing that jumps out at me as being a drain point low on the block.

I was told that every KA engine has a block drain plug somewhere...unless i was misinformed. I have been flushing my system through the radiator drain plug quite a few times now and it is still coming out brown. However this is only after running the car a few mins with water in the system. If i let water through while drain plug open, it is clear which leads me to believe the block could still have a lot of gunk. This is probably the 6th flush i have done where i fill up with water, run the car, drain and repeat. Any ideas? I should have probably bought that radiator cleaner...

A drain plug really won't help that much, you need the ability to get into the water jackets to loosen years of crap and it's impossible without head off of block.

I've spent as long as an hour flushing before to get out much of the trash but not all. Some people pull a stat on troublesome engines to let the flow increase to have a bit more removal force.

The cleaners being weak acid will remove more of it. If the grunge seems to be oily in partial nature then gasoline poured into rad (not a lot!) can remove that part of it but consider vapor when removing it, not real dangerous but give it some thought. Even better if your local fuel has some ethanol in it.

The engine block's drain plug is on the driver's side of the engine, just to the rear of the oil dip stick tube, and just a little bit lower than where you grab the oil dip stick tube. You can't see it from the top of the engine, only by viewing from underneath the car. You can search the Factory Service Manual (free online) for location and removal procedure.

My 1991 Nissan has had its coolant changed via radiator drain and fill every three years- the coolant that leaves still looks as good as the coolant that goes in. When I got the car in 2010, I decided to remove that engine block plug. Removing it is a combination of inserting everything from below the car, and working to wrench it from the top of the engine- because you are doing it "blind". Old timers here at NICO talked about the dangers of cross threading a 20 year old+ plug....so be VERY careful about re-install.

I deemed the procedure unnecessary since the radiator drain and fill every three years works fine. The old coolant is not bad stuff- it is like an oil change- you don't drop the oil pan and power wash everything, you just drain and fill. Regular maintenance beats radiator, heater core, and head gasket replacement every time.

As these cars age, I would be careful about removing a metal engine plug that has not been turned in 29 years....especially if there is no reason to do so. There are several old posts here about people cross-threading that plug and a simple procedure becomes yet another repair project.

You can recycle your old coolant for free at many county agencies, if not some auto shops.

I also wanted to add that if you do use the garden hose back flush procedure, make sure you flush THAT garden hose water out with distilled water. Here in Chicago, our lake water is pretty good- but even it has some minerals which will shorten the life of your entire cooling system. If you live in NV or AZ, the water there has a very high mineral content and you will destroy your car by leaving that stuff in your cooling system.

Never mix coolant brands, nor types.

You have to be aware of your local water hardness, I have not used distilled in anything at all here in North Texas including batteries for 40+ years and zero issues over it.

I mix coolants all the time as well but I NEVER use Dexcool, which is where most of the issue comes from, it can even do it by itself and pure. The parts stores typically sell coolant that guarantees to mix with all others and selling it for years I never saw any issues with it. Dexcool (orange) only was the problem.

I happen to disagree with the sentiment that it's not necessary to flush the block by removing the coolant block drain plug.
After plenty of flushes in the past I FINALLY found the block drain plug on my KA24E. What came out was surprising, I'm glad that third+ beer motivated me to find it. Lots of scale and sediment that never made it out until now.
Once you know where it is, it's really not the worst and can be done in a few minutes.

Tools needed:

1. 1-inch 14mm socket
2. 8-inch flex head ratchet, or regular ratchet which will require #3 on this list .
3. 6-inch extension
4. 2-inch ‘90 universal joint adapter

You wont need the extension when going at it from below.

Here is a short video I made showing where it is:


Here is a longer video showing how-ish: