e12 to e28 radiator upgrade questions

socalfiver · Post by **socalfiver** » Sun Oct 03, 2010 8:32 pm

I pulled a radiator out of an '87 535ia. I am installing it in my 1980 528ia. The lower 535ia hose fits great, but I'm having trouble finding an upper hose that fits properly. Has anyone done this, and what hose did you use? I've checked the upper hoses from 528e, 533i, 535i... none seem to fit. The one specified for 535i (according to AutoZone) is too big around and about 6" short of where I need it to be.

wkohler · Post by **wkohler** » Mon Oct 04, 2010 12:19 am

You have to change the thermostat housing cover, but that only affects the lower hose, which you say fits great.

The hose that AutoZone is showing is probably wrong. The upper hose should look like this:

Part number is 11 53 1 276 647

Be very careful tightening your clamps. E28 radiators are known to break the necks off of the tanks, as well as the overflow nipple. Used radiators, especially.

I have to say I don't really understand this as an "upgrade." I had the radiator in my M535i rebuilt (simply because I have a poor track record of not replacing radiators when I do cooling systems) and that car stays cooler than my 533i does with a brand new Behr South-African made unit. Plus, you don't have to irreversibly hack up the core support.

socalfiver · Post by **socalfiver** » Mon Oct 04, 2010 12:32 am

That's not the hose that AutoZone has indicated. Other stores have nothing but a flex hose listed. I will order online, thanks for #!

The increased heat transfer properties of aluminum versus brass alloy is what qualifies it as an upgrade. (according to parts interchangability chart) The 528i has a brass alloy radiator, the later cars have aluminum. The aluminum radiators have larger cooling passages, with plastic helixes inside. Also, the trans cooler heat transfer line is longer, but I don't know if it cools the trans any more efficiently.

Buying the radiator at the salvage yard on half price day makes the upgrade cheaper than having my original radiator redone. The radiator I found is in good shape. My original radiator was in very poor shape. So it's a budget-inspired upgrade.

socalfiver · Post by **socalfiver** » Mon Oct 04, 2010 12:48 am

I had read the posts about the cooling upgrade beforehand, and luckily I got the t-stat cover and housing (mine was corroded and had 2 stripped t-stat cover threads) from another e28, probably a 533i.

socalfiver · Post by **socalfiver** » Mon Oct 04, 2010 4:50 pm

I got the new radiator in, got everything back together.... no start. i can't figure it out. I removed and replaced the AFM/air cleaner assembly, but everything else stayed plugged in.

I've got fuel pressure, so I'm leaning toward no spark. do you think that moving the wire harness to plug in the relocated radiator sensors has caused a short in the electronic ignition trigger wire?

socalfiver · Post by **socalfiver** » Tue Oct 05, 2010 3:32 pm

I charged the battery overnight, and the car started right up. I guess I shouldn't listen to satellite radio while I work!

The new radiator is definitely an upgrade over the old one! My car stays nice and cool all the time now. I just drove it for 3 hours, mixed freeway and in-town, and it never even got to the halfway point. It stayed between 1/4 and 1/2, whereas it used to hover around 3/4 with the old radiator. I am running h20 and Water Wetter, same as before.

BTW, while I was swapping out radiators, I went inside to wash my hands and someone swiped my old radiator! I hex them and hope it brings them terrible luck. It may have been the Recycladeros.

Mike W. · Post by **Mike W.** » Tue Oct 05, 2010 11:36 pm

socalfiver wrote:
BTW, while I was swapping out radiators, I went inside to wash my hands and someone swiped my old radiator! I hex them and hope it brings them terrible luck. It may have been the Recycladeros.

WTH!!! Well with the copper thefts I saw a couple of years ago I'm not surprised. Whereabouts in LA? I used to live in the Valley way back when. Some stuff disapeared, but not much.

socalfiver · Post by **socalfiver** » Wed Oct 06, 2010 7:08 pm

I live in Northeast LA, "Glassell Park" to be exact. Between Los Feliz and Eagle Rock/Pasadena. It's a pretty decent neighborhood, but lately all of LA has fallen victim to Recycladeros, the guys who troll around in pickup trucks stealing anything made of metal that's not nailed down. Then they sell it for scrap.

The biggest hit I've taken was my '82 BMW R100RS motorcycle. Picked up off of the street on my birthday last year. Cops said that it was most likely broken up for scrap. Valued at almost $4k as a complete bike, it's worth about $60 in scrap.

DMS · Post by **DMS** » Thu Oct 07, 2010 6:44 am

GripGreg · Post by **GripGreg** » Thu Oct 07, 2010 12:08 pm

You said you use H20 & Water Wetter. Since H20 will rust, is that a good idea? I also heard from Mike that Water Wetter is a waste of time.
Almost straight anti-freeze with a lil H20 has always been recemmonded to me.
I'm just sayin';;;;Good Luck

socalfiver · Post by **socalfiver** » Thu Oct 07, 2010 12:48 pm

I used Water Wetter per the recommendations on the Cooling System FAQ. It smells rank, like antifreeze, but 5 times stronger. It has anti-corrosion additives in it. I used distilled h20, again per the FAQ.

Since I just changed the radiator and have not run antifreze in it, only water wetter, I have no idea if it cools better than ethylene glycol or not. The explanations on the FAQ were convincing to me...