First drive, overheating, bleeding issues?

[bmwm42]

the problem with using an m42 radiator is not know how to properly fill it thus causing an air lock and overheating. what you wanna do is first fill radiator to fill line then fill engine connect hoses and thats its you shouldnt have any problems

[etxxz]

how soon after start-up does the temp problem happens?

could be that there is no flow to the radiator ie - thermostat not working right or backwards. idk just shooting ideas out there. The T-stat is made to circular coolant inside the engine/head and when its hot enough, bypass flow to the radiator.

[florida_dirt]

So if the molten lava coolant is coming out.. Don't shut the car off? Keep bleeding? Maybe this is where I am going wrong because I turn the car off immediately in worry the car is going to overheat. Then I turn it back on and try the process over again


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[Nick_S]

Haven't had a single issue with mine, and as usual, more people constantly bitching about how hard they are to bleed, I've done mine 3 times without issue.

Yep this. I find them incredibly easy to bleed actually and they are more than enough for a normal 24v swap.

[florida_dirt]

1.Raise front of car 1 foot

2.Turn on car

3.open bleed screw and coolant cap

4.heat on blast

5.go inside your house and grab beer

6.come back outside in 20minutes

7.check temperature

8. Good? If yes repeat step 5, then go to step 12. if not go to next step

9. let engine cool down

10. With your right hand on the throttle body and your left on the rad hose, rev the engine up to about 2000rpm and start squeezing the upper rad hose with the bleed screw open. prepare for molten coolant lava to spew all over your arm from it erupting from the bleed screw. Then let it idle and squeeze the lower rad hose a billion or so times.

11. close bleed screw and coolant cap and rev your engine to 3500rpm for about 10 seconds, if you don't feel heat by now then you have an error somewhere in your cooling system, probably the thermostat.

12. Now that you have heat you can now properly let your car bleed at idle without worry. Open the bleed screw and coolant cap and let it idle for about 20 minutes. Squeeze rad hoses.



M42 isn't THIS hard to bleed, but this is as difficult as it should get. Normally you can just let your car idle from cold with the heat on blast and the bleed screw and coolant cap open and it will bleed itself. They are not problematic radiators like people think they are.

Followed these steps and worked perfectly. Thanks!


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