Engine noise at startup
 

97 C280, 35k miles.

Until the car is warmed up, the engine makes a regular noise like TSCH...TSCH...TSCH...TSCH... localized in the front engine area. For a while, I thought (hoped?) it might be the belts, but I am not so sure.

Could it be the valve lifter noise I often read about?

TIA

You might spray a little water on the belts and see if that changes anything. That will rule the belts in or out.

Do Canadian cars use an Air injection system- emission system, access to the system is best attained through under the car.

Do a search cause I think I have read about this before.

I was thinking about getting some silicone spray for that purpose, but I like the water idea better. Thanks! I'll try that tomorrow morning.

Don't spray Silicone
 

Any silicone based spray which is put under the hood CAN wind up fouling your oxygen sensors, setting on your Check Engine Lights and costing you large money.

You might get away with spraying if you let it dry for a really long time before starting engine..... I didn't really understand how the silicone was going to help you anyway???
DanielW

It was the belts! Thanks Tangofox, great tip!

Daniel: the silicone was supposed to quiet down the belts. Same purpose as the water but longer lasting, sometimes "permanent". But thanks for the warning. Good to know.

My 92 300CE has an air pump that is audible when the the engine is started. Once it warms up, it goes away.

Cheers,
Steve Urban