s52 possible cooling issues

[dmjensen]

So I've noticed that my engine seems to run fine, but when I stop for more the five minutes or so when I'm already at opperating tempature it seems that the needle likes to creep past half way almost up to 3/4 and my fan will kick in and catch up with it to bring it back to opperating. I'm not quite sure if that's normal or what's up but my previous 70 degree C thermostat seemed like it would let the engine get to opperating temp on cooler days. Only reason I am concerned is because I'm moving south and don't want to deal with it later..

Current set up is:
S52 with aprox 48k
New aftermarket m42 radiator
New BMW 82 degree C thermostat
New metal impeller water pump (can't recall the brand)
Original DME temp sensor
New BWD e30 singal pin temp sensor
New BMW heater core and pipes
New gates hoses
New BMW 3 pin 80 degree C temp sensor for fan (from 95 TI)
New hayden pushed fan (can't recall size)
And just reinstalled the A/V so that won't help either.

Any tips would be appreciated. I'm fairly certain all of the air is bled out as I've been using my Air Lift to refill the system.

[dmjensen]

If anyone thinks this is normal opperation please don't be afraid to inform me, But every e36 I've owned would warm up to normal opp and would stay there.

[agent]

Are you still using the stock E30 temperature gauge in the E30 cluster?

From what I've been told and been able to gather the M20 inherently runs cooler than an M5x or S5x, and the stock gauge is calibrated for that. Thus an elevated reading on the stock E30 gauge is to be expected, even though the engine isn't actually running hotter than it should be.

In the hot summer months with the car sitting in traffic, I've seen the temp needle on my swapped carl go up near ¾. Conversely when it's really cold out I have trouble keeping it over ¼ when it's moving.

[dmjensen]

Okay that's what I wanted to hear, I was about to get the infarred gun out and see what was going on.

[Luke_M]

I've had a similar problem.
- S50, MZ3 3 row behr radiator, 2 prong 82 degree switch. Wired per these directions: http://www.r3vlimited.com/board/showthread.php?t=210783

I've had it up to 230 degrees or 3/4 many times before the fan will turn on. Sometimes it doesn't even do that and I just shut it off in frustration. Sits right on 180 or 1/4 when driving. Never moves, just like when I had the m20 in. When the fan does come on it comes down fairly quickly.

I've bled it manually and I'm also using the late model expansion tank so I'm certain it's bled. Also euro S50 means no bleeder screw at the thermo housing. It was intended to be self bleeding as I understand it. Heat has always worked awesome and I've been driving with the heat on to assist the self bleed for a few months now.

Anywho, I've used an infrared gun and even when I'm at 230 as confirmed by INPA and the needle at 3/4, I'm only seeing 150/160 near the switch when I tested it. Very frustrating. I'm considering getting an adjustable switch to have some peace of mind. Scary to see it climb up with no fan coming on. Basically it's a probe that sits anywhere in the aluminum fins that you choose.

Not real sure that's the problem though being that it's the OEM location.

I can feel that the radiator hoses are both hot and so is the radiator except for the area with the switch. It's always colder then the rest and only gets hot if I'm in some serious stop and go. And even then it takes a while.

Example of an adjustable switch: http://www.summitracing.com/parts/flx-31147/overview/

Or maybe this: http://www.summitracing.com/parts/afc-80199/overview/

[treff-7]

I have the m20 radiator with my s52 swap. If properly bled the needle goes past the halfway mark just enough to see the mark on the left side of the needle and then the fan kicks in and goes back down. And that's in LA traffic. You most likely have a clogged radiator but the one for an M42 isn't sufficient anyways. Or there's still air trapped in the head.

[36brua]

I have the m20 radiator with my s52 swap. If properly bled the needle goes past the halfway mark just enough to see the mark on the left side of the needle and then the fan kicks in and goes back down. And that's in LA traffic. You most likely have a clogged radiator but the one for an M42 isn't sufficient anyways. Or there's still air trapped in the head.

what he said ^^ S52obd1, fresh M20 rad. elec Spal pusher stays @1/2 in traffic or stopped on hot day in Norcal

[jstam]

Bumping this back up - I have ~ same setup: s52, OBD1, M50 intake man, spal, stewart H20 pump, m44 rad, etc. If I sit in traffic temp goes to 3/4, or 230 on the secondary gauge. Fan will help control it but usually can't get back to 1/2 w/out the car moving. At the track it's fine b/c I'm moving.

so consensus is that something is not operating correctly? I should bleed again?

[Luke_M]

I fixed my problem by pulling the sensor. I found tons of air. I thought the system would self bleed with a late model setup. I was wrong. Or if I was right, it must take 6 months to bleed that much air.

After I pulled the sensor to let a majority of the air out and let it run for approx 30 minutes with the cap off the overflow it's been fine. Comes on just a tick before half and holds it there. Just in time for summer.

[jstam]

Luke_M - what sensor do you mean? Clearly I have to re-bleed the system...what I'm experiencing doesn't sound normal.

[Luke_M]

Sorry, the coolant temp sensor for the fan itself on the side of the radiator. I'm not familiar with how it works on the m44 radiator however. Moral is: bleed like crazy.