polo1134

I noticed today my antifreeze is low in the plastic tank, and have been smelling antifreeze coolant after long drives. I have smoke coming from the back side of the engine (passenger side mostly) when I turn the car off after a drive. I was assuming that the smoke might be the oil pressure sensor leaking oil but now I think it's coolant dripping onto the exhaust/manifolds. No puddles of coolant under car and I can't see any leaks in or around the plastic tank.

I did have the A/C compressor changed about 6 months ago, and had to go in for them to fix a leak behind the A/C compressor about a month ago. That is when I noticed the coolant smell. Could they have messed something up.... water pump gasket?

I'm taking the car back to the mechanic on Monday but I would like to try and trouble shoot the problem before I do. Has anyone had a similar problem... any ideas what it could be?

Car is a 2000 M6. Thanks for your help.

vettenuts

A few things near the rear passenger side to check quickly with a mirror and flashlight. There is a plug between spark plug #6 and #8. Second, there is a freeze plug behind the head that might also be the source. Next, there is either a steam vent plug or a cross-over tube connection to the inside of each head (similar to the front except the front has a cross-over tube) that might be leaking as well. If it just started, the steam vent plug would be my first guess if the leak is truly isolated to the rear of the motor.

jbondfl

Determine whether what you see is smoke or steam. That is important.
My first thought was a loose/leaking heater hose.

dmarkshark

You also might take a look at your coolant tank after its pressured up. Mine had a small pin hole leak that was shooting to the back engine. Thus, no puddles.

dmarkshark

That being true. Actually, my leak was on the tank itself. Its in the corner area because of the way the tanks are made , the corners are the weak spots.

polo1134

I will check those areas closely this afternoon. I really don't think its the tank as I replaced it a year ago.

Thanks for your suggestions.

Got uid0

do you smell coolant near the tank?

Evan Sanza

vettenuts

What year is your car? Have you checked the plastic tanks connections, etc.? How about the water pump? It will weep coolant when it starts to go. Any puddles?