190E squealing

[gp87210]

My 190E has a nasty squeal whenever the car is running. I originally thought it was the belt tensioner pulley as it had bad bearings but surprisingly it did not fix the noise. I am almost certain the noise is concentrated right above the water pump. The water pump was replaced on it almost a year ago, however the MB brand coolant was not used to refill the system. Could not having used the proper coolant caused the water pump to make noise? Other than the noise, the engine runs at normal operating temperature.

[engatwork]

Could not having used the proper coolant caused the water pump to make noise?

no

If I remember correctly you have an idler pulley up there somewhere. Check it to see if it has gone bad.

[gp87210]

I already replaced that

[dkveuro]

Originally Posted by gp87210

I already replaced that

Does the noise go away when you remove the oil filler cap ?

[gp87210]

What is the purpose of that?

But ill still try it and see

[dkveuro]

Originally Posted by gp87210

What is the purpose of that?

But ill still try it and see

Some times, the engine builds up vacumm and causes air to be drawn in past the crank seals which can make a loud noise like screeching metal.

Mostly happens to BMW's and Asian engines with PCV's.