Thinking of cancelling my S38 swap

[Xat1cZ]

The M3's stock electric fan is sufficient for me.

[e30m3s54turbo]

I using factory e30 fan and two 10" puller fans. No problem driving in slow city traffic at 100 degree.

[fronton]

One other question for you guys with completed swap. Since I used 20mm spacers for the front subframe, the rack sits lower. Now the steering u-joint (not sure if proper name) will not slide all the way onto the splines of the rack. There is a locking/pinch bolt there but makes me kinda nervous its not completely on. What did you guys do? I am running a stock rack btw.

You need to add spacers in the Ujoint coupling by the booster. I think someone here sells custom spacers for this but three or four washers on each side will do the trick.

Car is still overheating around the city. Any ideas? I have power bled it a few times using an AirLift bleeder. Its fine on the highway. I added a 12" electric puller fan, should I need more than that? its creeps up in temperature until it hits the red. Really stumped again, want to enjoy the car for the few months we have left before snow!

12" is too small of a fan for idling in 80F+. You need a 16" puller that draws at least 2000CFM mounted ~1cm off the radiator. If you like spal, buy #2049. I am using the stock M3 dual temp switch and resistor so it runs low from 10-11:30 then high and holds just on the cool side of 12 oclock. Frankly my setup runs a little cooler than I like 75% of the time but that can be fixed by changing the resistor and/or temp switch.

I have also heard that the b35 water pump is much more efficient than b36 since it has larger fins. It is a direct swap in and might bring your temps down enough to stick with 12" fan but not necessarily any cheaper.

[Sharino]

You need to add spacers in the Ujoint coupling by the booster. I think someone here sells custom spacers for this but three or four washers on each side will do the trick.



12" is too small of a fan for idling in 80F+. You need a 16" puller that draws at least 2000CFM mounted ~1cm off the radiator. If you like spal, buy #2049. I am using the stock M3 dual temp switch and resistor so it runs low from 10-11:30 then high and holds just on the cool side of 12 oclock. Frankly my setup runs a little cooler than I like 75% of the time but that can be fixed by changing the resistor and/or temp switch.

I have also heard that the b35 water pump is much more efficient than b36 since it has larger fins. It is a direct swap in and might bring your temps down enough to stick with 12" fan but not necessarily any cheaper.

I will try to add the spacers, I never felt safe the way it is currently.

I will order that fan and try it, I figured mine is too small. Strange thing is, I am not getting much heat inside, I hope I have the cooling system routed properly. I do have the B35 waterpump BTW.

thanks again!

[fronton]

I will try to add the spacers, I never felt safe the way it is currently.

I will order that fan and try it, I figured mine is too small. Strange thing is, I am not getting much heat inside, I hope I have the cooling system routed properly. I do have the B35 waterpump BTW.

thanks again!

Before you buy another fan, make certain you have it fully bled. I have had to modify my coolant setup at least 4 times and bleeding it can still be an one hour affair due to there being no way to actually bleed out the air. If the heater is not blowing hot air, it is not bled. Here is my procedure assuming you already have your expansion tank full to the mid level seam:

1. Start with cool engine so splashing coolant doesn't burn you and you can leave the M20 tank cap off. The cap can remain off for the entire procedure.
2. Jack up the driver side (or whichever side your expansion tank is on). The higher the better.
3. quickly squeeze each hose then slowly release. The idea is to force air up to the tank then replace that air with water. repeat this several times making sure the expansion tank doesn't run low.
4. start the engine and turn the heater to hot and run on blower 4 for the rest of the procedure.
5. continue to squeeze/massage all hoses while it is warming up, slowly adding water as needed. When the tstap opens, you should have a stream of water recirculating into the tank from the tiny hole at the top of the cap area from the line that branches off the top of your tstat housing.
6. Keep checking for hot air out of the cabin vents. When it is hot, put the coolant cap on and go for a quick spin around the block then pull right back in and pop the hood. If there isn't coolant everywhere, you are ok to slowly unscrew the coolant cap and is shouldn't bubble over. If there is water everywhere, it came from the overflow hose and you still have air in the system, so start over.

Few tips to remember:
1. anytime you add water, do it very slowly and massage hoses as you go.
2. be careful not to add water past the mid level seam on the tank, particularly when the engine is running. If you do, and put the cap on, it will be over pressured and you'll have coolant everywhere when you get back from your drive.
3. just use distilled water. it makes that much less mess and actually runs at cooler temps than coolant mixture. Once you get a good bleed, be sure to swap in some coolant for the winter season to be safe but for three seasons, distilled is best in my opinion.
4. keep lots of towels on hand to protect electrical items, practically when the engine is running.
5. if you think your air pocket is on the passenger side, you can use a temp sender as a bleeder but be careful not to get the electric portion wet or burn yourself. you'd also need that side jacked up when attempting. I don't really recommend this but it is possible.

Lastly, without seeing a pic of your hose setup I can't tell you if it is correct but you need to have a double T junction like the s38b35 that connects the top of the tstat housing with the lower rad outlet and with the cylinder head nipple below the TBs

[Sharino]

Still having overheating issues.

Can somebody (Fronton?) check my cooling line layout. I believe this is as close to the OEM layout on a S38B35 as possible. The ugly red silicone line goes from the reservoir to the thermostat, T's off and goes into the block under the throttle body of cylinder 1. The rest is oem routing I think. I am using the summit racing rad that was recommended to use. Also using stainless steel bendable pipe to go into and out of the radiator with rubber couplers.

Anything look wrong?

[fronton]

The T spot you have needs to be a double T, not a single. You are missing the second T from that line to the radiator outlet hose (larger diameter on driver side). Without it, I don't think you can even fully bleed the system. The stock s38b36 coolant hose that goes there has a small nipple for a hard line. I reused that and took it into a double T. Pic of the same function on the s38b35 which you are essentially shooting for.

[Sharino]

Ok, I see the double T you mention in Realoem, so basically I just need to connect another T and route it to the radiator upper hose on the drivers side, I will try that. Just don't understand is that not the same spot it is tapping into at the thermostat anyways? Does it just need a loop to circle back with?

thanks again as always!

[e30m3s54turbo]

One hose comes from radiator to the double T . The second one other from thermostat to the double T. The third one from the head to the double T. The fourth one the reservoir to the double T.
Here is a pic of mine.

[Sharino]

ok, so I took my front end apart to get the rad out (its mounted in the front of the rad support) then got a third flange added on by a custom rad shop and connected it in with the other Ts.

Spent a couple hours trying to bleed it tonight, still overheats. I am still not getting any heat inside either! Pretty frustrated at this point. Think it could be the heater control valve not working and causing an air pocket yet I can hear it working when I switch the interior temp from cold to hot.

Any ideas appreciated! About to give up again until next year! lol

[The Dark Side of Will]

Hard to tell from the pics other people have posted, but is the UPPER radiator hose really on the right and the LOWER on the left?

Water should come out of the engine and go to the upper connection, then come out of the lower connection and go to the waterpump.

[LJ851]

Could you have your thermostat in backwards ?

[Sharino]

Yes, the rad is 'backwards' so to speak. But, this is the exact same rad Fronton is running and he has been using without a problem.

The thermostat is brand new oem and it won't even fit backwards.

[Sharino]

Ok, so after bleeding for quite a while I think I got it beat! I ripped around for about an hour and temp stayed fine. Still no heat inside though?!? Could I have the two hoses going to the heater core backwards? Would that cause this?

I need to wire in my electric fan, I just have it hooked to the battery correctly and disconnect it when I stop driving. Anybody know an elegant place to wire it to so it just stays on while driving? I will look into a temp switch later but for now I just need a power source when running.

[e30m3s54turbo]

I read on mye28.com the m88 thermostat housing was a self bleeding system. In the 17 years never had to bleed it. In the beginning I would over heat because I had the factory electric fan. It would work if it was 80 degrees and below. I had to add to two 10" puller fans for 80-110 degrees. That solved my heating problem.