Cold start, loud then normal- off and on

[hlavery1]

My 250 PU, 7.3 1999 powerstroke has real tough ntime on cold mornings. On cold mornings as it warms up seems to have some sort of exhaust valve switching off and on. Very loud when in one position and then it switches and sounds normal. As it sits and warms up it switches back and fourth.. When you drive and still little cold valve keeps changing. When in 1 position no power then it switches and great power.
Thanks for any Help!!

 

[idiabuse]

cold thick oil is not lubricating, hpop not functioning as it would be warm. do you ues your block heater for cold start?
Javier

 

[hlavery1]

Heater is used

Yes I use the block heater and it does same thing. After it warms for 20 Min. or so it runs fine.

THANKS

 

[69oiler]

there is an Exhaust Back Presure Valve that shuts to assist in warmup. mine was sticking shut so i disconnected it and have not had any problems since.

 

[hlavery1]

Thanks, just read about the exaust valve. I will disconnect tomorrow and see what ti does.

Thankls

 

[69oiler]

when you unhook it, just pull the plug, don't unhook the linkage. i unhooked mine and it was a royal pain to get hooked back up. it can leak oil with the linkage unhooked.

 

[Double-S-Diesel]

what rob said, the plug is in the front of the turo pedastal

 

[hlavery1]

DONE

Done!! pulled the plug and it is fixed. Works great. THANKS