How long until a 85 300D bad bearing/rod fails or is it my Head gasket? - PeachParts Mercedes-Benz Forum

Carrameow · #1 10-20-2004, 07:36 AM

This summer I plugged my breather hose on my 85 300d and my engine ran down to 1 qt of oil. After that my engine was noisy and shook like it would jump out of the compartment, made all kinds of rata tat sounds and metal hammering sounds.
I kept the car on the road and even took it to Virgina high in the mountains, waiting for the engine to fail. It wouldnt!!!!
One day I got a brainstorm and changed the IP and suddenly the engine sounded like it was new...I found out the old Ip literally had two cylinders not running..and a badly leaking ALDA..the low oil had killed the IP..
That was 10K ago. The engine still runs.
Somedays its so quiet, it sounds new. Other days I swear I can hear a bad rod or bearing. Sometiems I think I have a hole in the Exhaust. Somedays I swear the car sounds perfect..
This morning I came in to work and it sounded Brand New! Tonight I know it will sound different. The noise is dependent on IP timing, the better I time it, the quieter it gets ( I think)

My question is , how long until a bad bearing or rod finally fails Big Time?

Could the failed IP introduce a "lean Condition" which could have trashed the Head Gasket?
I definitely hear a maetallic ring on some days after a cold start.

Could anything else be wrong?

I have really stressed this car , trying to get the engine to fail, i have taken it up mountains, had it to 100 mph...Maybe I should just get a loud Radio and ignore it...finally why do I think its an Exhaust leak somedays?

tomm9298 · #2 10-20-2004, 07:46 AM

At what RPM do you hear the rod/bearing noises? I have read, and cannot find the page, that rod/bearing noises get much louder after 2500 rpm. The faster the rpm the louder the noises. Maybe some of the techs can chime in.

tomm9298 · #3 10-20-2004, 07:58 AM

Have you ever removed the inspection/cover plate near the torgue converter? It is oval in shape. There is a flex plate in there held in by six bolts. If a bolt is loose or missing it can sound like bearing or rod going bad. With the low oil level maybe not, but I always look for the cheapest easiest way out. Good luck!

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