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Cooling System Hell - Refresh + Upgrade Part 1 (July 2016)



While I was cleaning the engine compartment up in the previous entry, I kept noticing some coolant puddles on the block by the starter.  I pushed on one of the hoses and some coolant leaked out.


OK, just some hoses, no big deal right?


Not so much.  When I started taking the hoses off, found the water divider coming off the head was completely corroded.  It was also the wrong one for the car, this was the E21 style that doesn't have the hose coming off the back, which is why there was a big ugly red heater hose coming out the top.



I was planning to take the intake manifold off at some point to clean it up, rebuild the carb, and make sure it was ported correctly for the Weber 38, so now is the time I guess.


And then it gets worse:



Yes, that's a hole.


Also found this nipple was clogged up.  Not sure how important it is, but I pulled it off, cleaned it out, and put a fresh crush washer on it.



Pulled the starter and alternator too, figured I'd give it a good cleaning




As I was cleaning it up, noticed one of the freeze plugs was weeping.


Guess which one?  The one that looks like it wasn't replaced (middle)



Figured if the divider and intake manifold were corroded, I might as well replace the water pump and thermostat.


Old pump:



Time to order some parts:

Water divider

Silicone hose set from IE Motorsport (cheaper than buying a full set of OE-quality hoses)

Water Pump


Freeze Plug



New bolts/nuts/washers for water pump and intake manifold from Belmetric - there's a good post here that says what to order for WP bolts:

I also ordered a bunch of extra nuts and bolts for various other things that I'm sure will pop up while working on this car.


Aaaaaand, here's when scope creep comes into play.


I got everything apart, might as well upgrade the starter and alternator, and why not do the radiator too?


1979 320i 65amp alternator (Remy #13113)

1990 M3 Starter (Bosch #SR440X)

ebay Honda aluminum radiator and fan -


I removed the A/C system while I was pulling the water pump, lots of dead weight I won't need.


Studs were installed for some of the WP bolts (I think) when the A/C system was originally dealer installed.  For the life of me, I could not remove one of them, and since I wasn't interested in breaking it and then having to pull the front timing cover, I just left it in.


New WP installed, plus alternator and water divider mocked up



Thermostat + test fitting hoses, since I won't be using the stock fan, it was removed.  Also gave the pulley a fresh coat of paint

You'll also noticed the "speed holes" a previous owner put into the pulley for an unknown reason.  Maybe it had a WP at some point that didn't have the same bolt spacing as stock (stock is more like an X pattern rather than cross pattern)



The radiator looked odd to me, almost like it was factory, but didn't look like it fit right.

Turns out, it was a 320i radiator, larger than stock, but doesn't bolt in like stock.  It requires a bracket on the bottom and extensions on the top (check out pictures in my previous blog posts)  It also uses a 320i lower hose.


Here's the radiator comparison, the honda radiator is slightly shorter and narrower.





It also mounts completely differently, so I had to come up with a solution for that.


So here it is!


Vacuum cap and dipstick grommet on the bottom two posts







1" aluminum bar with 4 holes drilled in it, 2 for the radiator, 2 to bolt it down (I used one of those stepped drill bits with multiple sizes on it to drill the holes, as seen in pic)





In hindsight, I should have put that lower bar mounting bolt under the radiator instead of off to the side (which I did for the other side because of tight space)


Bar mounted to car, I used the sheet metal bolts the previous owner had used for the 320i lower brackets.

Lots of surface rust here too.



Test fit



Location is very important here.  I wanted to move it all the way to the right so I only had one hole to cover up in the front panel, but I couldn't use the stock-style hose if I did that, so it got mounted more in the middle.


Fan mounted to the front of the radiator (blades need to be reversed, just remove the nut, flip the blades, and put the nut back on)



Installing the radiator with the fan mounted is a TIGHT squeeze.  The bullet connectors were chopped off and replaced with a 2 pin Weatherpack connector.


I bought some aluminum sheet from Home Depot, but in hindsight (again) I would have got some thicker stuff elsewhere, this is pretty flimsy.  A bead rolled down the middle would have been nice (also hindsight)  Those extra bolts I bought are already paying off


Also hit the rusty areas with a wire brush and painted the front radiator support, lower bar, and battery tray with some Rustoleum "Rust Tough" enamel.
  Is it good?  I have no idea.

Also note the original plastic wire holders were all broken, so I bolted in some insulated ones I got at HD, plus wrapped the wires in new electrical tape, the old stuff had fallen off.



For the upper mount, I bought some Dorman replacement bushings for a Nissan? radiator, part #924-130

They require a 1.25" hole to mount into.  I bought some 2" wide aluminum, 1/8" thick, and used a 1 1/4" hole saw to put the bushing hole into it.


My original plan was to just bend the strip in 2 places and mount it to the nose panel, only to find out that 1/8" thick aluminum doesn't like to bend 90 degrees without breaking.


Plan B:  angle aluminum bolted in, then upper mount bolted to that





And finally, the lower radiator hose solution - a universal hose - Gates #25250 - 9" long



I ordered a 7" and 9" hose, thinking the 7" would be OK, but it wasn't even close.  A slightly longer one might be better yet.


So that's where I sit for now.  I thought I could repair the intake manifold, measured one of the nipples and figured I could drill and tap it for 3/4 NPT and put in a brass NPT hose fitting, but it turns out that even though the nipples are the same size, they have two different size holes in the manifold, and the NPT fitting would only work for one hole.


So I have to find another manifold, and since I've got this much torn apart, I also pulled the heater box, which revealed some other nasty surprises (in the next blog post)


Updated numbers:

Belts $10.00
Water Pump $28.00
Temp Sender $5.00
Water Divider $76.00
Freeze Plugs $10.00
Silicone Hose Set $120.00
Thermostat $15.00
Gaskets $10.00
Alternator $82.00
Starter $163.00
Radiator $60.00
Aluminum $25.00
Paint $12.00
Lower Hose $8.00
Radiator Bushing $5.00
Belmetric Bolts $60.00
Running Total $8,589.00




Recommended Comments

Also found this nipple was clogged up.  Not sure how important it is, but I pulled it off, cleaned it out, and put a fresh crush washer on it.


That nipple feeds the water choke for your carb, if you are running a manual or electric choke it needs to be capped off.


Looking good, everything on these cars is scope creep.



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Thanks, it previously had a hose running from the intake manifold to that engine port, but if it's not needed, I'll cap them off.


Realoem shows a plug for the block, should work on the manifold too - PN 11111254189

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