lets talk water temps/gauges etc...s50

[JRKOUPE]

95 s50 swap...90 325i


There are hours and hours of threads on e36m3 cooling issues, head gasket issues...warped heads etc etc...but yet I dont read that much here.

it seems as tho oe e36 water temp gauges are VERY buffered...and once they move to 3/4 hot, the car is really really hot.

I just instlld stewart pump and 80 deg t stat after getting some cooling issues after hard track sessions. She would puke up some coolant and run a bit warm. I had hoped it was /is a pump and or tstat..

Now w/ the new parts, she runs cooler( a bit to lt of half) but yet sometimes shows a creep to 3/4 hot.

And Im clearly seeing my needle move around...like under halfway at cruise....a bit of creep in stop and go etc etc..I run an elec fan w/ a temp switch in pass side mishi rad tank. W/ the m20 the needle almost never moved, and I ran a clutch oe fan.


Im wondering w/ our swapped cars do we still maintain the stock behavior(m20) w/ our oe temp gauges?.....or?..

Im not well versed on electrics......Im just trying to figure out what is going on.....and perhaps in denial over a potential head gasket/head job.

[frankie591]

if you are using an m20 temp sensor to run the gauge, then the temperature it displays will be the same regardless of what motor it is sampling the water temperature from.

[JRKOUPE]

I had a shop do the swap....and altho I did alot of research prior, and supplied many of the parts, Im still learning about all the little parts they used.

[dougsic]

Although I didn't know it, my s50 had an aftermarket sheet metal water pump impeller when I bought the motor. I've driven the car a few years (not my DD though) and the temp gauge always read a needles width below halfway.

Last fall the temp gauge would sometimes sneak past halfway so over the winter, I did the same as you - Stewart pump and thermostat.

Now I can't get the gauge to go past 1/4 even when I drive the car hard (on the street). In the winter, the car has heat but not nearly as much as before.

I'm running a stock late model radiator and stock clutch fan.

[Rugbyfan]

Although I didn't know it, my s50 had an aftermarket sheet metal water pump impeller when I bought the motor. I've driven the car a few years (not my DD though) and the temp gauge always read a needles width below halfway.

Last fall the temp gauge would sometimes sneak past halfway so over the winter, I did the same as you - Stewart pump and thermostat.

Now I can't get the gauge to go past 1/4 even when I drive the car hard (on the street). In the winter, the car has heat but not nearly as much as before.

I'm running a stock late model radiator and stock clutch fan.

What temp Thermo are you running?

[hwy84]

95 s50 swap...90 325i

.

I just instlld stewart pump and 80 deg t stat after getting some cooling issues after hard track sessions. She would puke up some coolant and run a bit warm. I had hoped it was /is a pump and or tstat..

Early build S50 are known to exhibit the "coolant puke" after sustained high RPM driving. I had a 9/94 build date M3 that did this - sustained high RPM would actually force combustion gasses across the headgasket and into the water jackets.

This would push coolant bubbles, forcing coolant out of the reservior cap, but the needle never showed an overheat because 1) the guages are super buffered in the e36, and 2) the coolant around the sensor was actually not too hot, but there were hot spots in the motor where the bubbles were, which would boil and worsen the puking.

I threw a head gasket at the problem - no dice. Ended up using the car on the street only, and other than using a little coolant here and there, never had another issue. At the track... It puked coolant after a single session, every time. Multiple water pumps, multiple coolant bleeds, 2 different head gaskets.

I don't want to be doom and gloom, but you could be in for a head/ block decking and a new HG to chase this down.

[JRKOUPE]

thanks for the replys.....

good to see some "faces" I know.

I have a later build....10/95..thats why I bought it.....better retainers i figgered
I know you have to pay to play, and tracking a car always has some expenses involved that are unexpected.....

but considering the costs of used Sx engines, and considering the cost of a used head and labor...sheesh...its a hard one to swallow.


The more I research the more it is clear that a bad hg can be so minor that it may only show up at times, and often many of the diagnostic tests ( block test, leakdown, etc etc are negative)..you end up just having to pull the head.

The more I think about it the more I think it may have been a sticky tstat that when stuck shut did not allow my pass side rad tank (that holds the temp sensor) to get hot enuf to get my elec fan to turn on...................grrrrr.

Im on the fence about doing a leakdown......shop cost is 100 and up...and even if its negative i still have symptoms......grrr again.

[e30pq]

I have an S50 in my 89 325ic. I installed it about 6 years ago.

I used the low temp thermostat, the low temp rad fan sensor with no engine fan (it couldn't fit). I kept the ac fan and I added a small SPAL fan puller.

http://www.r3vlimited.com/board/showthread.php?t=107147

The photos in the link don't show the SPAL fan because they were before I added that fan. It is located on the drivers side of the rad under the alternator snorkel.

I have both fans setup to go on when the temp gets high (it seems the trigger a little past 1/2 way on the stock gauge) but I also have the fans on a switch on the dash.

I typically switch the fans on as the temp gauge get close to the mid point. It does a great job of keeping the temps down and cooling the engine.

We just installed an S52 in our 89 club race car. It's fairly stock (no upgrades inside the engine). The engine had about 120k on it when we dropped it in. We raced it for the first time a couple of weeks ago. It was really a test of the chassis and the engine combo since we were running an M42 turbo which was lighter and made more HP. Up to this point we only had a one day test out at El Toro (the Top Gear test track).

http://www.youtube.com/watch?v=7PUPGNIiG6Y&feature=plcp

After the day at El Toro and a practice, qualify, race on Sat we had a practice and qualify on Sunday and we blew the head gasket. It's not bad but once that gasket gives the car will get hot relatively fast. The oil looks good (no milk shake) the water looks good (color wise). If it were a street car I could see how someone might think that the car overheated but it should be okay and drive it to work the next day. The car might be able to take some street driving but not full throttle track driving.

Anyway, my point is that if these engines overheat it could lead to a head gasket issue or be due to a head gasket leak.

We will pull the head. Probably do some upgrading of the head but end up using a BMW head gasket when we seal it up again. Stay away from the less expensive third party BMW part head gaskets. They probably work okay for driving a car to work but if you drive the car hard go with the BMW head gasket.

BTW -- Our M42 turbo engine had a safety fuse that would blow if we built too much boost... it was our head gasket. That's okay because on that engine we would rather blow a hg than do more expensive damage to the engine. We learned first hand that the BMW hg's were the best way to go.

[325issguy]

I hate to say it... BUt that sounds alot like a slightly blown HG. My car with the m42 radiator and stock 318 ac fan never gets above the halfway mark on my gauge.

To answer your question my cars gauge acts the same as a stock e30 or any other car for that matter.

[JRKOUPE]

ok...

so let me rephrase a bit....

it seems as tho once the temp needle gets to 3/4 on an e36 m3 it is already very hot and in danger of doing damage...this is due to large BUFFER in gauge

Im wondering if this is also true when viewing the temp needle in the e30 running an s/x swap.

I just confirmed the shop used an m20 temp sensor.....

I drove her today....and still she is running to lt of halfway almost always . I dorve her up to 50 minutes or so..on hwy and in stop/go.....but then she begins her creep to 3/4 or so, elec fan goes on and she steadys herself and slowly goes back down to halfway.

sorry to beat a dead horse....Ive read hrs on this, and actually learned alot in process.......I just dont want to pull head till Im FOR SURE, or as sure as I can be.

[giantkeeper]

At what point is your fan coming on, above 1/2 or at 1/2?

You still running the AC condensor up front?

[JRKOUPE]

At what point is your fan coming on, above 1/2 or at 1/2?

You still running the AC condensor up front?

my spal kicks in at a tick( barely) over half way on needle ..(and now w/ the new working tstat it kicks in consistently.)

I run an 88 degree temp switch in pass side rad tank to activate the fan...(88 c is what like 190 degrees F?)..

I run an 80 degree tstat..

hoses are hot and tanks are hot at NOT.

no a/c parts on car....


some1 suggested it could be a flaky temp reading in my cluster...I will pull cluster and check grounds...but I kinda doubt it....maybe, who knows. If it was flaky i assume it would read badly when fan kicks on and when thermo opens, but it seems to be ok at those times..

I just want to exhAUST EVERYTHING before I throw my hands up and throw my money to HG repair....

[giantkeeper]

I essentially run the same setup you do

Mishi
16" Spal pusher wired to aux switch
Aux temp switch
88c Stock thermostat
Stewart Water pump
No AC parts

My fan kicks on at 1/4 on the temp gauge.......

If the car is moving or the fan kicks on I never run over 1/4. Even beating on it in the Phoenix summer.

It's like polar opposites

[e30pq]

I have the stock AC pusher and and a SPAL puller on the inside.

I have the temp switch hooked up but I also added a switch which allows me to make a preemptive strike on a hot day or when I am autocrossing.

[JRKOUPE]

I essentially run the same setup you do

Mishi
16" Spal pusher wired to aux switch
Aux temp switch
88c Stock thermostat
Stewart Water pump
No AC parts

My fan kicks on at 1/4 on the temp gauge.......

If the car is moving or the fan kicks on I never run over 1/4. Even beating on it in the Phoenix summer.

It's like polar opposites

just thinking out loud here..


doesnt it seem like fan is kicking on early?..

I mean, when does your tstat open?....