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New 428 low oil pressure, running hot


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#1 68BIRD428

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Posted 03 June 2011 - 06:06 PM

Looks like I'll be pulling the 428 out. It's rebuilt, only have about 100 miles on it. Oil pressure is low. warmed up 2500rpm has about 35psi at idle 5psi. oil prseeure goes right up with rpm. tonight is the lowest I've ever seen it at idle. also notice it seems to be getting a little hot. 160 degree thermostat. reading 190. getting hard to start once warmed up. Prior to tonight pressure at idle would be about 15-20 psi. oil is mobil 10W40.

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#2 WHITE-68

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Posted 03 June 2011 - 06:21 PM

My engine is appx 6 yrs old has less than 10 k on it its a mildly built 455 oil pressure is 15-20 at idle but goes right up to 40-60 depending on rpm. Always been that way. I run synthetic 10-40 always have. I have the feeling somethings failing on yours of course I am sure you know that. No other indicators though? Noises? Anything?
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#3 Formula77

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Posted 03 June 2011 - 06:37 PM

First off, Change your oil filter. WIth a fresh build there is going to be deposits. The filter may be clogged.
If that does not improve things you may need to haul the engine out, and start looking for the problem. Any number of problems could cause this. Its a simple matter of trouble shooting the problem. Start from the easy stuff and work up from there.
Let us know how you work out. Progress and questions are always welcome.

#4 nflfreak43

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Posted 03 June 2011 - 06:56 PM

did you install the crank and etc? was the clearances withing spec?

also like before change filter.... that may help some..

what type of oil are you running?

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#5 68BIRD428

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Posted 03 June 2011 - 07:11 PM

My engine is appx 6 yrs old has less than 10 k on it its a mildly built 455 oil pressure is 15-20 at idle but goes right up to 40-60 depending on rpm. Always been that way. I run synthetic 10-40 always have. I have the feeling somethings failing on yours of course I am sure you know that. No other indicators though? Noises? Anything?



My oil pressure started out 20 lbs at idle and goes right up like yours. I also use 10W40 syn. I've had the engine a couple years. just got my convertible on the road this summer for the first time. oil and filters have been changed 2-3 times since being on engine run/test stand to car. oil and filters are fresh. I've only put maybe 100 miles on 428 so far this summer. Something is failing. engine was rebuilt when I got it, don't know who or machine shop that did the work. I did have some work done to RA#12 heads, hardened valve seats, valve job, etc. I can see that engine has new pistons, etc. Looks like I'll be pulling 428 soon. Have a rebuilt stock 350 to put in for rest of summer. I had flywheel resurfaced but not rebalanced. think I should get it balanced ? I'll have 428 ready for summer 2012. will be a Tremec 5 spd behind it then.

#6 gdf 73

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Posted 03 June 2011 - 07:17 PM

Make sure the guage is correct.Check the press in oil plugs behind the timing chain sprocket.I just had some problems with my engine and the second time we put it in I had one of these push out after about 50 miles of driving.My oil pressure went down to 20 pounds and 5 pounds at idle.I shut it down and had a rollback take me home.We tapped the holes and installed pipe plugs this time.Oil pressure came back up and everything seems good.Good luck man.I know your pain.
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#7 WHITE-68

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Posted 03 June 2011 - 07:19 PM

Well I think its best to pull it and go through it, I had figured you changed your filter a few times, double check clearances everywhere, at least you will have peace of mind and know everything about it. Good you have a back up, and you will love that 5 speed I sure enjoy mine!! Let us know what you find.
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#8 68BIRD428

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Posted 03 June 2011 - 07:27 PM

Make sure the guage is correct.Check the press in oil plugs behind the timing chain sprocket.I just had some problems with my engine and the second time we put it in I had one of these push out after about 50 miles of driving.My oil pressure went down to 20 pounds and 5 pounds at idle.I shut it down and had a rollback take me home.We tapped the holes and installed pipe plugs this time.Oil pressure came back up and everything seems good.Good luck man.I know your pain.


Didn't know there is oil plugs behing timing chain. will look into that. My engine is making a ticking noise, my brother pointed out a few days ago. never noticed it myself since my hearing is bad. Thanks for the help everyone. will keep you posted.




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