Acura MDX SUV Forums banner
61 - 77 of 77 Posts

·
Registered
Joined
·
15 Posts
Because of the difficulty in reaching and opening the engine block drain plug, I am curious as to how much coolant would come out of the engine block drain plug compared to what comes out from the main radiator drain plug. Is it about 5-10%, or closer to 50%?. Also, what is the down side of not draining the old coolant from the engine block, and just draining and refilling the main radiator. Wouldn't it just get mixed up with the new coolant in no time without much detrimental effect on the cooling system.
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #62 ·
Because of the difficulty in reaching and opening the engine block drain plug, I am curious as to how much coolant would come out of the engine block drain plug compared to what comes out from the main radiator drain plug. Is it about 5-10%, or closer to 50%?. Also, what is the down side of not draining the old coolant from the engine block, and just draining and refilling the main radiator. Wouldn't it just get mixed up with the new coolant in no time without much detrimental effect on the cooling system.
All of what you said makes sense and that same logic can be applied to any fluid change where you need to weigh effort/feasibility against the % of the fluid that you can actually change out (transmission, power steering, etc.). End of day, it would be completely okay to just do the radiator drain and fill, you're just going to have less fresh fluid and therefore your coolant will not be as effective as it would if you drained the block. If you've never changed the fluid before or just bought a used MDX (that probably never had it changed) then I would suggest doing the drain block as well. If you change it every 2-4 years, then maybe fine to just do the radiator.

Said via another analogy, you don't HAVE to floss your teeth after you brush. Just brushing will accomplish a lot. However, you're more likely to get a cavity much sooner if you don't floss. :)

If you go to page 4 on the thread you'll see a few comments on how much fluid folks have gotten from the engine block drain plug so you can do the math.
 

·
Registered
Joined
·
2,203 Posts
Or you can buy 5 gallon coolant and do it 3 times from radiator? The result could be better, just spend more money.
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #64 ·
Or you can buy 5 gallon coolant and do it 3 times from radiator? The result could be better, just spend more money.
Hmm, seems excessive to do a 2nd drain and fill at all. Someone did the math on new fluid/old fluid for the transmission that shows diminishing returns after a 2nd drain and fill. Based on the total coolant capacity of the MDX, I would think the returns after the 1st drain and fill would be very low (someone can probably do the math).
 

·
Registered
Joined
·
2,203 Posts
I did that ATF calculation! But for coolant, I shall just replace the whole thing. It will be nice if we have a drain plug in the torque converter. A lot less calculation.
 

·
Registered
Joined
·
15 Posts
Thanks for your sensible reply. I am doing mine for the first time on an MDX which hasn't had a coolant change in about 5 years. So, I will do the engine block as well; just waiting for the weather to cool a bit, it's going to be around 95 degrees here today. Just one question, I need to get clear vinyl hose for draining the engine block and am wondering what size hose will fit on the engine block drain outlet - 1/2", 5/8", or another size? Thanks again for your very helpful post.
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #67 ·
Thanks for your sensible reply. I am doing mine for the first time on an MDX which hasn't had a coolant change in about 5 years. So, I will do the engine block as well; just waiting for the weather to cool a bit, it's going to be around 95 degrees here today. Just one question, I need to get clear vinyl hose for draining the engine block and am wondering what size hose will fit on the engine block drain outlet - 1/2", 5/8", or another size? Thanks again for your very helpful post.
See post #34 on Page 3. Definitely give this whole thread a read through before you start. I added some tips along the way when I did this job for the second and third times.

Tip 2: Step 4 – I forgot how tough this step is. I recommend a 5/8 clear vinyl tube (for flexibility) cut at roughly 5 feet length from Home Depot or Lowes. Wide enough to get around the drain plug, but it is very tricky to loosen that plug and position the hose without making a mess. Try and loosen enough to get it to drain, but be satisfied if it is just a slow drain (if you risk opening up too much you may get a coolant shower). If you’re really wanting to make sure it doesn’t get everywhere, you can take the wheel off for a lot more room.
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #68 ·
I did that ATF calculation! But for coolant, I shall just replace the whole thing. It will be nice if we have a drain plug in the torque converter. A lot less calculation.
Haha! For some reason I thought that was you that did the ATF calculation. Time for a coolant calculation! :)
 

·
Registered
Joined
·
15 Posts
Is there an alternate brand of antifreeze/coolant, with similar specs as Honda Type 2 coolant and would work for an MDX. A dealer here wants over $50 for two gallons of pre-diluted Type 2 which is rather expensive. Thanks for any suggestions.
 

·
Registered
Joined
·
1,952 Posts
$20/gallon is the normal price. I’d ask if they’ll price match.

The cheap “house brand” stuff at an auto parts store is still $15/gallon so there isn’t much room to save money.

I’d just buy the Honda Type II.
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #73 ·
My 2008 MDX AC is not blowing cold air after changing the coolant. Any suggestions?
I suspect your changing the coolant and AC not blowing cold air are unrelated. I would take it in and check your AC refrigerant and system pressure levels. If they are low, you likely have a leak somewhere. You can charge it up, but the AC runs in a closed system so if you don't fix the leak, you'll continually need to recharge it.
 

·
Registered
Joined
·
8 Posts
thanks OP!!, your post was very helpful in changing coolant for 2014 Acura MDX SH-AWD.

Just for benefit of others you'll have to remove splash guardd for sure to reach the petcock in 2014 model as it is on the side of Radiator on passenger side, straight in front of serpentine belt.

I started with opening the valve at the back of block, look towards left of oil filter...It drained about 5qts and then opened petcock to drain the remaining one...last one in reservoir. you'll need 2 gallons of coolant from Acura dealer

Before you start, better buy the coolant bleeder kit from Amazon...must have for collant change for DIY.s
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #75 ·
thanks OP!!, your post was very helpful in changing coolant for 2014 Acura MDX SH-AWD.

Just for benefit of others you'll have to remove splash guardd for sure to reach the petcock in 2014 model as it is on the side of Radiator on passenger side, straight in front of serpentine belt.

I started with opening the valve at the back of block, look towards left of oil filter...It drained about 5qts and then opened petcock to drain the remaining one...last one in reservoir. you'll need 2 gallons of coolant from Acura dealer

Before you start, better buy the coolant bleeder kit from Amazon...must have for collant change for DIY.s
Good work! I agree you need to coolant bleeder kit. I'm able to reach the radiator petcock and rain the coolant without removing the splash guard but 1) it takes some serious torque at that angle with little room to break it free so understand if impossible for some folks and 2) it will make a mess and drain all over the place!
 

·
Registered
Joined
·
8 Posts
Good work! I agree you need to coolant bleeder kit. I'm able to reach the radiator petcock and rain the coolant without removing the splash guard but 1) it takes some serious torque at that angle with little room to break it free so understand if impossible for some folks and 2) it will make a mess and drain all over the place!
thanks! did u also change the thermostat as a precautionary measure? mine is at 124 K and realized it after the fact that I could have changed the thermostat also.

I went through this complete post before I started and saw your splash guard picture also multiple time to make sure where I am missing as I kind of try to avoid unnecessary taking things apart but then I realized 2014 models has different(it doesn't have that cut out in middle that you have in picture) splash guard and petcock is not in the middle(pointing to you) as you have shown in picture. In 2014 model they have petcock on thinner side of radiator at bottom and there is small nipple where you can attach hose (3/8" ID if I recall it correctly, same size on the engine block nipple also)..so I was able to drain all the coolant in empty antifreeze gallons.

Again thanks for writing such a detail DIY guide!
 

·
Registered
Joined
·
1 Posts
Thanks for the great detail, just completed radiator fluid change using your method today. One thing I noticed that has not been mentioned is the radiator drain plug, or petcock, was in my case stuck and no amount of prying or needle nose plier turning would make it budge. I looked at the removal sockets that are sold online but needed something quicker since I already had the splash guard off. Tried gently tapping the plastic petcock with my 3/8" ratchet on all accessible sides which worked - it turned easily just by hand and the radiator began to drain. I sprayed some Liquid Wrench on the block drain and was able to get to it with the 3/8" ratchet directly connected (no adapters to 1/4" or extensions) by way of the 12mm 3/8" socket. Used the 5/16" vinyl tubing and added a small radiator hose clamp around the tubing which I had tightened so that it was snug on the tubing but would still slide. After getting the block drain loose and putting the tubing on then slide the hose clamp over the tubing so that it covers the tubing and the nut which made the connection tighter and also importantly allowed me to turn the tubing to open the engine block drain easily to increase the speed of the coolant draining without making a bigger mess. Had to remove the front passenger side mud guard which had about 5 phillips screws to get access to the block drain. There was quite a lot of coolant that drained from the block, used almost all of 2 gallons of Honda long-life coolant type 2 filling the radiator and the plastic overflow tank to the low mark. Dealer wanted $32 per gallon(!) but paid the MSRP price of $19 x 2 after some discussion.
 
61 - 77 of 77 Posts
Top