4.6 oil pump question

[Secrets]

hey guys, any idea how much work it is to change an oil pump on a 4.6. and at 110k miles, do I need to change my oil pump? I heard a grinding sound two different times I started the car. A warning message "check oil pressure" came. I switched off the engine and started it right back and everything was ok. So hence the reason i was thinking its the oil pump, OR i'm not sure if it's the timing chain. Any previous experience or ideas would be greatly appreciated, Thanks...

[epdarks]

It's a big job but the only result from low oil pressure is a blown motor so do it ASAP. If you heard grinding then it's possible there are now metal chunks floating around in your oil, if the low pressure doesn't grenade your motor then those will.

There are probably plenty of "while your in there" items to do at the same time. Good luck.

[IanP]

Its a pig of a job, did mine with the engine in bits on the bench.

[Secrets]

Like I said, it only did that sound twice (two different times). But once I shut the engine and start it again, it idles normal. Reason why, I'm about to change the head gaskets so I was thinking if it's the oil pump that's going bad, I may as well change it . But here again, i'm thinking its the chain.

[steelheader]

Do You mean valve cover gaskets,cause if Your gona do head gaskets do the oil pump then . Check Your oil filter asap for metal flakes and let us know .What You have my friend is timing chain slap at start up stop driving it or the chain will wear through the cover and be junk>Take my word for it .

[Secrets]

Yes, I said head gaskets. Reason I'm gonna change it is because I have changed everything including radiator, water pump, thermostat, expansion tank and cover, hoses, aux water pump and I'm still having the same problem. Everytime I speed at or about 80mph, the temp guage would go up to red and I'd get the warning message, "check temperature" and the coolant would spill all over from the expansion tank. I know it can't be air in the system, cause I have bled it over and over again. And also twice when I started the engine, I noticed the driver side exhaust is steaming. Sooo, I know I'm in some kind of expense, that is why I wanted to know what was causing this noise. If I'm gonna go in there, I wanted to do a good job one time.
Thanks for all the info so far guys. Like I said if anyone of you have any previous experience relating to this problem, please feel free to share it, thanks

[IanP]

If you are going that far why not take the engine out and do a full strip? Did mine and once its out it is quite easy to work on

[Secrets]

Are there problems removing the transmission, and are there any issues with the wiring harness?

[SlickGT1]

Did you check the heater connections. The Hoses and all that goeas to the firewall. Do you get antifreeze inside car?

Have you tried to diagnose this? Compression check, leakdown tests?

I too have a feeling you have begining of chain slap. But check the oil ASAP just in case.

[IanP]

I took the transmission of before removing the engine, but fitted it before putting the engine back. Think it would be quicker taking it out complete. The only problems I had with the wiring was due to the LPG system that is fitted, if you label all teh connectors you should have no problems