scottharvey 60 Report post Posted August 19, 2014 I just recently got another e30 with an m20b20. First thing on cold starts it turns over as if it has no gas I have put injector cleaner in it a d it still has same issue once you have started it its fine to keep starting up. It takes up to 5 minutes. Next thing temp gauge is running at just above half and then will rise to 3/4 and then drop down again eventually it already has no thermostat could that be a cause Quote Share this post Link to post Share on other sites
Kepes 231 Report post Posted August 19, 2014 If it has no thermostat, then that is unlikey to be causing it to run hot. A thermostat stuck open would cause the engine to run cold. Having no thermostat is essentially the same thing as a stuck open one. I had one which was stuck open, so I can speak from experience. Not sure what else it could be (I'm pretty new to E30's too!) but I would be concerned if it was getting that hot with no thermostat.... Quote Share this post Link to post Share on other sites
scottharvey 60 Report post Posted August 19, 2014 Yes no signs at all of blown head gasket or blocked radiator or leaks etc. No cambelt history tho (waterpump). Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2122 Report post Posted August 19, 2014 M20s are worth changing the timing belt on them anyways, and a fairly simple job with basic tools, nothing special required. Waterpumps are dirt cheap and need to be done at the same time on this engine, so looks like you are going to do that anyways. Could be a lot of things though Blocked radiator Blocked other hoses 100% water and no coolant Air in the system i strongly suggest you do not drive the car, if you absolutely have to, make sure you have the interior heater on full hot and fan full tit to at least shed some of the heat..... Quote Share this post Link to post Share on other sites
Kepes 231 Report post Posted August 19, 2014 Perhaps bleed the cooling system. There is a bleed screw on the thermostat housing. Lots of write ups on google. Air in the system could be stopping the coolant from circulating causing it to overheat. Otherwise very likely to be the waterpump Quote Share this post Link to post Share on other sites
scottharvey 60 Report post Posted August 19, 2014 OK it has never shot up over 3/4 temp as of yet and I have checked for airlocks through the bleed point and it just flows out no bubbles and its running just coolant there is one hose that has a slight kink in it looks like its been chopped in two and has a metal pipe in between is it suppose to be like that or just straight hose would get a pic but at work currently Quote Share this post Link to post Share on other sites
scottharvey 60 Report post Posted August 19, 2014 this is the hose Quote Share this post Link to post Share on other sites
E30 325i Rag-Top 2918 Report post Posted August 19, 2014 M20s are a complete pain in the arse to bleed, with many points in the system that can be airlocked. Whilst there may be coolant coming out of the bleed screw, there may well be air still trapped in the system. Have you filled the system with the coolant or was it done before you bought the car? Like Andy says, it could well be one of many problems so not easy to diagnose and fix. Quote Share this post Link to post Share on other sites
scottharvey 60 Report post Posted August 19, 2014 it already had coolant in when i got it but ill sort out that hose first repco doesnt have one listed tho so where else could i go?? BNT maybe? Quote Share this post Link to post Share on other sites
scottharvey 60 Report post Posted August 20, 2014 OK I fixed that hose up but is it suppose to close up like it's sucking when I rev is that air lock or something else I'm stuck Quote Share this post Link to post Share on other sites
turbolizard 38 Report post Posted August 20, 2014 You should put a thermostat back in, or at least a restrictor the size of an open thermostat. I don't know the specifics of the M20 cooling flow path but the pump will be meant to work with a thermostat. It is possible that the pump may not be totally effective without one and too little restriction in the flow circuit can lead to pump cavitation. This will cause a lack of circulation and ultimately pump damage. The hose sucking in may be a symptom of this situation, or could be caused by a blocked radiator (which might also cause pump cavitation). Quote Share this post Link to post Share on other sites
antil33t 90 Report post Posted August 21, 2014 (edited) this is the hose the one below it? connects to the t-stat housing and then to the lower radiator? meant to have a metal part, wouldn't fit behind the fan otherwise. and yes, needs a thermostat to work properly. Edited August 21, 2014 by antil33t Quote Share this post Link to post Share on other sites
