Adjust oil pressure 472 -Update

[Jeff Rosansky CLC #28373]

I finally put a good oil pressure gauge in and the pressure when warm is lower than I thought. It is a recent rebuild so it should not be a worn out engine issue.
I will take more detailed readings at next drive but this is what I got after about 4 miles on a warm nite.
Low 50 when started when cold. I had checked it when warm (not hot) and it was upper 30's-- but that was in higher idle.
This is my first check when hot. Got down to low 20's when at idle in drive.
Oil pump was new. 10w-40.
I was not able to find anything in the book about adjusting the regulator. How do I adjust it up?
Thanks,
Jeff

["Cadillac Kid" Greg Surfas 15364]

Sounds like your presure is just about normal. If you check you will find the oil wrning light comes on at something like 6 or 7 psi, so 30 at idle is good.  since you start out cold at 50, I would think the reduction of pressure is due to engine clearances, not oil pump issues.  These numbers (oil and temperature) though normal for the 472/500 series motors are not what the average Chevrolet or ford owner would expect, and this is the reason Cadillac chose to eliminate the gages and replace them with warning lights that illuminate when non standard conditions arise.
Greg Surfas

[Bobby B]

Jeff.
Hi. Greg's post is right on. There's nothing to get excited about. That's pretty good pressure for 10W-40 when warm. I'd be concerned if it started to drop into the single digits.
                                                   Bobby

[The Tassie Devil(le)]

One has to remember that the upper limit on oil pressure is regulated by the pressure relief spaing within the oil pump.

I have yet to see anyone rebuilding an engine, and using the original oil pump, and installing a new spring.   They seem to forget that the spring will lose a bit of tension as it gets old.

When buying a new pump, there should be a new spring within it.

Every time I rebuild an engine, I manually check the oil pump for pressure before fiting it up for the first time, and in doing so, I am also priming the complete oil passages prior to distributor installation, and firing.

Bruce.

[Jeff Rosansky CLC #28373]

I probably should have put more detail as to why I am doing this im my original post, but it was late.
The reason I put the gauge in is that I have valve noise and a lifter tick when warm.
It seems to move around so I have not been able to localize it. Because it is NOT localized around say #4, makes me think that it is pressure related vs 1 bad lifter. I am getting oil to the top. Lifters all seem to have preload and there is nothing obvious showing when I pull the valve covers.
I was wondering if the noise went away if the pressure increased. That would eliminate pressure as the problem.... I dont have the noise when it is 'cold' and the pressure is higher so if it is higher when warm will I still get the noise?

I have posted about this before. Just trying to nail it down. I dont want to hurt anything of course but I dont want to replace the lifters if that isnt the problem.
It IS a job I can do, but pretty involved for me.
Jeff

[Scot Minesinger]

Jeff,

Of course you know that I have a 1970 Cadillac with a real good Autometer oil pressure gauge and I get about the same numbers you juts wrote about.  I do not think your tic noise is due to a lack of oil pressure based on these readings.  Understood that the garage that performed the rebuild is not going to help you, but the engine is under warranty.  Sometimes when business do not honor their commitment you have to really work at persuading them into doing what is right. 

If necessary, you should get another shop to look at the engine if you cannot figure it out.  You should not let this go much longer.  The tic sound if due to your lifter is likely the cam slapping it, and that is no good.  Cut open you oil filter at next change and make sure there are no steel shavings in it.  They are easy to see as they are bright and shiny.  My 2007 Avalanche has a tic sound only at start up and I'm cutting open the filter Monday, if shavings are in it will post pics so you can see what I mean.

[The Tassie Devil(le)]

So, with the recent rebuild, did you replace the lifters?

The way these engines were designed and engineered was for the oil pressure, and grade of oil that the factory recommends.

Too high a pressure will tend to over-pressurise the bearings themselves, and over-pressured bearing shells can in itself, cause problems.   Plus, too much pressure also puts extra pressure on the distributor drive, timing chain/gears, etc.

Don't forget that the engineers spent millions of dollars creating the ideal "living" conditions for many thousands of miles of driving, under all conditions, so changing things without a good enough reason is a waste of money.

Bruce.

[Scot Minesinger]

Generally lifters and cams are replaced as a set, so if lifters were re-used that would not be best, especially considering the sludge you saw in engine before re-build.  Presuming lifters were replaced, if not I would replace them.  It is not difficult-just remove intake manifold and valve covers.

Agree with Bruce, Cadillac spent millions in the 1960's to get this 472 engine right and they hit a home run.  I would be hesitant to change anything engineered by Cadillac unless it has a super proven track record.  My godfather replaced a chip in his MB 500 (engine equipped) that allegedly made it from 315 to 388hp back in the mid to late 1990's.  After about the 50k miles the engine was gone and it had to be replaced.

["Cadillac Kid" Greg Surfas 15364]

Jeff,
The oil pressure does not indicate ANYTHING is wrong with your motor. To answer your question, yes you can increase the pump regulator's outlet pressure by shimming the relief spring with a washer.  We do it for "race" motors, but I believe it would be counter productive in yours.
These "numbers" things is why I took all the gages off my 76.
Greg Surfas

[Jon S]

I've said it before and will say it again - add some ZDDP to your oil and watch the noise disappear.

[TJ Hopland]

A long shot here but did you replace the flexplate?  Loose bolts or cracks in that area can make all sorts of ticking and knock like noises and do tend to be hard to pin down to a specific area.

[Jeff Rosansky CLC #28373]

Oh, so I take it that you think the preasure is ok???
Just my sarcastic humor here, no disrespect.
Cam and lifters replaced at rebuild.
Scot, this shop had a Very good reputation. However this was one of the last engines he did. Found out the reason it took a while to get it done was that he was going for treatments every couple of days. He died a couple of months after this was finished. No real recourse here (at least I got it back before he died because that would have been a mess). The money I would spend trying to fight it would not be worth it. Plus, I dont want to lose control over it again-just cutting my losses.
Only have a hundred miles or so on the oil. Will cut the filter open at next change.
Thanks guys,
Jeff

[Jon S]

Jeff -

Why not add some Red Line engine Break In Oil before you next oil change?  It is rich in ZDDP.

If I'm correct, your tapping will stop within 15 seconds.

[Scot Minesinger]

I use ZDDP now, but only for the last 5 years.  The first five years (say 15-20k miles of driving) did not.  Noticed no difference at all.  I just do it now because you are supposed to.  Like I had written before had a tic sound due to # 7 intake valve wearing through the rocker arm, and that was with ZDDP.  The problem was likely the result of a recent valve job error.

Anyway, I like my gauges.  They do not give me alarming readings.  Yesterday enjoyed a top down drive at 2pm when it was 98'F (cold for summer in TX and AZ) with high humidity (heat index 104'F), and gauge never went past 208'F even at stop light idling for 3 minutes.  Did not run a/c though.  I think in extreme heat with a/c on in a closed car with dark colors in and out though, it might be best not to know what temp gauge reads.  Have temp., oil press., volts, and vacuum.  Going 60 mph coasting downhill vacuum goes to 25 - highest I have seen it.

Back to your oil pressure, again numbers seem right, I would look elsewhere for a problem besides oil pressure.

[Bobby B]

Jeff,
Hope the Cam/Lifters were broken in correctly. Seen a lobe wiped out many times due to incorrect break-in procedures with hydraulic cams. Maybe remove the valve covers and do a quick lifter height check with a dial indicator to make sure all the valves are opening to about the same number. There's a lot of aftermarket junk out there today. Quality of metal is not the same as it used to be. Do you know what brand parts were used? Do you have any specs on the cam itself?
                                            Bobby

[Jon S]

I use ZDDP now, but only for the last 5 years.  The first five years (say 15-20k miles of driving) did not.  Noticed no difference at all.  I just do it now because you are supposed to.

Scot -

My mom's 20,000 Mercury Grand Marquis 5.0 started tapping immediately after changing the oil/filter.  I added ZDDP and the tapping stopped within 30 seconds and has not re-appeared.  My 1958 also developed a slight tap with SM suffix oil and again, the addition of ZDDP stopped the tap in this case within 15 seconds.

I add Red Line's break in oil even to my 250,000 mile Jeep Grand Cherokee with flat tappets.

I believe the addition of the ZDDP does indeed make a difference as witnessed on both the Grand Marquis and Cadillac.  For that matter, all of my cars have flat tappet engines and all receive ZDDP with the exception of the overhead cam Mustang.

[Scot Minesinger]

I like Bobby's idea of measuring how high the cam moves the lifters but might be difficult because lifters pump up with oil pressure.  When I replaced my lifters the break in was stressed how important it was and I followed it to the letter.  Don't give up Jeff, keep working until you find the problem.  Are you 100% sure it is not exhaust leak, they sound similar - check torque on exhaust manifolds - I see that wrong all the time - maybe we already discussed this, as I know this has come up several times before.

Jon,

Because of guys like you I just blindly follow your experience due to a proven track record - thanks, it certainly does not hurt anything.

[RobW]

you guys normally run 10w-40? I've always used 20W-50 in my 73 coupe here in the hot, humid NYC stop and go traffic. In my el camino I use 10W-40 and 10W-30 in my tahoe

[Jeff Rosansky CLC #28373]

I actually have plans to check the exhaust. Bolts are tight but need to check the manifold for cracks. I suppose there could be a crack that expands when the manifold gets hot.

Will try the zddp. What is the best? I found additives with it in there but not sure which is correct. Would like to just go buy instead of on-line. I do use hi zinc oil.

It was broken in well..... At least by me. The builder had it towed to a shop for the first repair. They told me they did not run it but I was not with it all the time. In hindsite, I should have disabled the engine.
Jeff

[TJ Hopland]

20w-50 is pretty thick stuff.   If you are going to run that you have to make sure you only run it when its hot.   Cool temps that stuff is going to not flow well and be really hard on things.    Mid summer it may not be bad but you get some of those spring and fall days you got to be careful even down south.    If you want to get freaked out you should feel the drag on an oil pump running 5w-30 at 70*F,  that takes a fair amount of power.  Going 4x thicker can be a good thing.