Should I use coolant system sealer?

[juliea]

Hi--hoping to get some advice.

I have a bit of a coolant leak. Took the car to the mechanic, and he said it was the "freeze plug" on the back of the engine block. To fix this for real, it requires removing the engine. He suggested that we think about using a coolant system sealer...

Has anyone ever used one of these before? Would anyone recommend or not recommend it? I'm a bit concerned about putting it my engine/cooling system in case there are any lasting negative effects.

Thanks for the help!
-Julie

[tjts1]

I've never heard of the freeze plugs leaking on this engine. It could be one of the dozen or so coolant hoses near the back of the block or the plastic . Have somebody with bmw experience look at it to get a second opinion.

[quinn11m20]

Yeah I don't think putting one of the "System Sealers" in your coolant is a good idea. It could lead to clogging of the radiator and all sorts of other things. Those additives are good for a temporary fix. Thats about it. I will agree with TJTS1 on this one to get a professional opinion from a BMW mechanic. Good Luck.

[1991 E30 M42]

Hi--hoping to get some advice.

To fix this for real, it requires removing the engine. He suggested that we think about using a coolant system sealer...

Your mechanic is full of shit, it is doubtful that it is a freeze plug issue, but if it is, the intake manifold is the only major thing that would need to be removed. I have heard of and seen freeze plugs leak but only on a lot older cars where the freeze plug has corroded. As stated by tjts1, there are many hosed there, both of the heater hoses connect in that area as well as a plastic pipe that has 1 outlet for the heater hose, one for the throttle heater plate, and one that goes to the radiator. In the attached image numbers 5 and up are under or attached in some way the intake manifold/throttle body