Strange Diesel Like Noise

[tym2clm]

I recently purchased a 1999 Xlt w/ 4.0L SOHC w/78,900m. It makes a strange diesel like noise at start up when it's cold. The noise seems to be coming from the top end of the engine. It does not sound like valve train noise. Possibly in the fuel delivery system some where. After it has warmed up the noise goes away. It also seems to idle a bit low upon start up, around 800 rpm. It does not spit or sputter any, runs very smooth. I have read some of the other threads here about how the MAS can do funny things when it gets dirty. Could these symptoms be a result of a dirty or bad mass air flow sensor? Also, after it sits overnight and starting in the morning the check gage light comes on because the oil pressure gage does not move for about a minute. Then it suddenly shoots up to normal pressure, the check gage light goes off, and is fine for the rest of the day. Bad oil pressure sending unit? Loose connection?
Any help you guys could give would be very appreciated. Thanks

 

[Jason_25]

Timing chain tensioners. Search for 00M12.

And yes the 2nd problem is probably the oil pressure sender unit.

 

[tym2clm]

Thanks for the lead? Sounds like its more of annoyance than a real serios engine problem. Does anyone know if Ford is still fixing this problem on an X such as mine, '99 4.0 SOHC w/78,900miles or how much they are charging for the fix?

 

[tenikiwon]

I think you just pasted the mileage mark

 

[TPLYNCH]

Contact Ford and see if ONP 00M12 and 01M01 have been performed. One extends warranty to 72K but the other is good to 100K, and I think 01M01 is the one that deals with the cam chain tensioners and casettes. Search for these on the site and read. There is a ton of info on these problems with the SOHC engine.