Author Topic: Coolant boiling, bleeder hole leaking (Read 8720 times)

ten2doyle102 · « **Reply #15 on:** April 01, 2011, 06:53:32 AM »

Ok, well I am going to check that tonight as well.... but I think I got it figured out. The whole time I think it was just the stupid ground nut on the back of the cluster. Pulled it out last night and it was unscrewed about an 1/8".... LOL. Tightened it back up and its rock steady just under halfway tick. I put a 92* Wahler in there so that might be why its just a shade high than most I have seen.

Thanks for the help. I'll be taking a 2.5hour drive with it this weekend so wish me luck. This will be a good test.

Also, part of the problem was that the radiator cap is really finnicky and if you don't be care it will screw on crossthreaded-like causing it to not be able to hold pressure.

ten2doyle102 · « **Reply #16 on:** April 01, 2011, 11:55:23 AM »

I may have spoke a bit too early..... lol. Its not overheating... but it does seem to be leaking coolant from somewhere... though I can't tell where. I am going to spray it off and try to find this damn leak. Its gotta be going somewhere. Its weird actually.... it loses about the same amount everytime. I bled the system for about 45 min yesterday and from what I could see... no more bubbles were coming out at all. But this crap has to be going somewhere.

ten2doyle102 · « **Reply #17 on:** April 01, 2011, 12:22:15 PM »

Also, when I had the thermostat, the profile gasket felt good. it was nice and consistant all the way around.

DesktopDave · « **Reply #18 on:** April 02, 2011, 10:25:18 AM »

Odd. Keep us updated. At least you found the loose ground nut; temp is OK. Coolant leaks are frustrating.

Cristian G in Oz · « **Reply #19 on:** April 02, 2011, 02:23:39 PM »

I've had a read back through the thread but I couldn't find if you replaced the rad cap.
When I got my M42 it was loosing coolant (about 1/4 ltr per week).

I decided to change my thermostat, hoses, cap etc (basically service the cooling system) and this fixed it until I changed the plastic return pipe on the induction side of the block.
When I changed that I couldn't get it to seat properly and it continued to weep.
The water wouldn't hit the ground after driving as the water would pool on the block web behind the the oil filter housing and then evaporate, before it cooled when I could stick my hand in and feel around.

I was doing some other work there yesterday and it had definitely been weeping.

The pipe if the black plastic one the fits into the block above the oil filter housing and runs along the side of the block and connects to the heater return and the radiator bottom left side. The seal in the block on this pipe might be a little dodgy, or the typically the pipe cracks around the recess for the seal and leeks.

Hope this helps.

DesktopDave · « **Reply #20 on:** April 02, 2011, 03:05:38 PM »

I just got finished changing my thermostat & fanstat out for slightly hotter 92degC units. I also solved a personal puzzle...the thermostat needs no bleeder hole because the housing already has one. I had some trouble bleeding it this time too. I keep getting bubbles...I'll try again tomorrow after it's cooled off.

Also discovered that the PO's mech hadn't done a good job, he just re-used the old paper thermostat gasket and added some silicone to seal it up. After I cleaned out the goo it fit very nicely, now we'll see if I get some better mileage. Unfortunately, I'm suspecting that the old thermostat was working well...the temp gauge acts just like it used to, still takes about ten minutes to heat up nicely.

Also swapped my aux fan for a nicer one (mine had some chipped blades). Found I need a cam position sensor o-ring and maybe a new gasket set for the cylinder head cover.

ten2doyle102 · « **Reply #21 on:** April 04, 2011, 12:16:47 PM »

Alright, well after a long drive to Blackhawk farms and a hour or so of thrashing at the track and then a long drive back..... car seems ok. I have to check the coolant level, but it didn't seem to drop much, if any. Also, did well too because the car is not set up for highway since it was cruising at 3700 rpm at 75mph. Never overheated though!

DesktopDave · « **Reply #22 on:** April 04, 2011, 04:16:42 PM »

Great. Do keep in mind that the e30 thermostat is pretty heavily buffered. It's not proportional and tends to always "find the middle." Overheating must be stopped promptly, as BMW didn't make the motor capable of resisting any kind of severe overheating.

pdxmotorhead · « **Reply #23 on:** April 04, 2011, 08:47:04 PM »

Quote from: ten2doyle102;102820

Alright, well after a long drive to Blackhawk farms and a hour or so of thrashing at the track and then a long drive back..... car seems ok. I have to check the coolant level, but it didn't seem to drop much, if any. Also, did well too because the car is not set up for highway since it was cruising at 3700 rpm at 75mph. Never overheated though!

?? Interesting, my E36(318ti) Cruises between 3500 and 3700 all the time.
3400 is the peak of my mileage curve on the highway, around 34 MPG..

Sounds like you at leased knocked the gremlin unconscious...

Dave

ten2doyle102 · « **Reply #24 on:** April 05, 2011, 10:17:05 AM »

Yeah, I don't know... It just seems very high in the RPM's to be cruising at. My speedo is 5-10 mph off on the high side so yeah.... little wheels... LOL!