SLK350 - Rushing Water?

[st13phil]

Started Angie's SLK on Friday afternoon after it had stood for a couple of days and immediately the engine fired I heard the sound of water rushing through what I assume is the heater matrix. On subsequent starts it made no noise, but we didn't use the car on Saturday and on first startup Sunday it did it again.

This sounds awfully like there's a partial airlock in the cooling system somewhere, but I've noticed no other symptoms such as poor heater performance. Any comments before I talk to the dealer? The car's under warranty so I'm not overly concerned, but it will mean leaving the car with them for a day or two so thought I'd canvas opinions first.

 

[radiovic]

I had a Rover 75--rushing water on them was a sign of headgasket failure.

May be something entirely different and simpler on your car --so dont be alarmed!

Check your radiator expansion bottle and make sure theres no oil floating on top---also check your oil and make sure theres no traces of what looks like mayonnaise (water in the oil)

 

[gkerr4]

is there enough coolant in the system? if not then the top-hose could be empty and the noise could be it being filled by the water pump at startup - did you check the coolant level?

 

[st13phil]

Thanks for the responses, guys. I'd already checked the oil (clean as a whistle, no visual signs of any water contamination) and the coolant expansion tank which shows no sign of oil contamination. The coolant level is OK, too.

Angie used the car yesterday and when I fired it up first thing this morning there was no discernable rushing water sound so it looks like the car has to be stood for at least a couple of days before it does it. I'll keep an eye on things and try to pin down how long it has to stand for to be able to reliably get the noise on first start up before talking with the dealer.