Ok......despite searching this forum and the Rave for the actual procedure to pressure check......and failing to find the procedure......

I put on the adapter and pumped her up to 15 psi........one hour later.....she is still 15 psi. No bleed down. The hoses feel pressured.

The Rave stated 20 psi.....is this what I should go too?

Right now I am thinking it could be the reservoir cap or something is expanding when the engine is hot....

Thanks,

RS

 

In consideration of the heater core issue suggested, is heater turned on?

 

I have used the heat a couple of time in last week or so. The carpets are dry and no smell inside the car. I get the whiff of the sweet smell after I get out of the Disco and walk towards the front end.

 

Well, it is certianly not summer in your town, and the only ones feeling any heat are incumbent politicians. But the RAVE spec for the cap pressure is :


The expansion tank is fitted with a sealed pressure cap. The cap contains a pressure relief valve which opens to allow excessive pressure and coolant to vent through the overflow pipe. The relief valve opens at a pressure of 1.4 bar (20 lbf.in2) and above.

 

There is no heater control valve on the D2 like on the D1. Coolant always circulating through it due to the design of the system.

 

Yep, I typed before checking the cooling schematic, so OP's comment about no smell inside is more important, because if it was leaking it would be noticed. Here are two ways to add that bypass option, from slaninsanjuan (just kidding):

 

pump the system up to whatever preasure the cap is set up for, I think it's 20 pound.
15 pound is not be enough, if it is a 20 pound system you are trying to dupucate operating preasure. if after 30 minute it has not lost any, any preasure at all; I would replace the cap.

 

If the cap is venting, many times it will leave a mist on top of the coolant jug.

 

I will take it up to 20 PSI tonight after she cools down.

I drove her to work and back today with the scantool/laptop hooked up. 203 to 207 degrees when driving. Will go to 216 degrees when idling at the stop light.

About 6 months ago she was running 198 to 204.

No signs of residue or mist on the coolant tank.

I am thinking I will change the thermostat, switch to good coolant, change out the plastic bleed screw for the BMW brass (already have this), change the plastic radiator plastic plug and then regroup.

Is there any place that will have the brass radiator plug and thermostat? Is a new expansion tank cap worth spending $24? Any other suggestions?

Thanks RS

 

Several options that everyone has mentioned except, check your back window and tailgate for fluid stains.. You may only be leaking while driving, which happened to me and it could be the weep hole on your water pump.. This will start to leak only while driving when the inner guts/bearings in the pump are starting to fail..
Only way to check it, is to turn engine on and let it sit and idle.. Then watch the passenger side of the water pump, and fluid might start spitting out..


Another, and worst case scenario is that you may have a failed head gasket.. Antifreeze could be slipping out of the engine through the exhaust and being burnt through the cat converter.. That would be why you see no stains or leaks.. this also happened to my '04