So I posted a couple weeks ago that I wiped some lobes on the old comp cams XE274H. I replaced the cam and lifters with an Isky 280 magnum (232/232 lift at .05") and hydraulic lifters. Engine is running pretty well but after about 50 miles on the new cam I notice that the oil pressure is lower than it normally is. I haven't verified the gauge, but it now says that at a 1000rpm idle there is only 5-6 psi and about 20psi at 2200rpms. I have reason to believe that the gauge reads low, because with the old and new engine it has never been much above 30 psi. That said, I have significantly less oil pressure than before, it used to be 20 psi at idle and higher.

I didn't do anything stupid, like not change the oil/filter, its the same grade of oil, the cam was properly installed and broken in with sufficient oil pressure bla bla bla.

I'm thinking that with all the metal the lifters/cam munched up, I may need a new oil pump. I certainly hope its not a bearing(s) or two going out. I need suggestions as to what oil pump I should get. I don't need high volume or anything like that. The old one was a sealed power federal mogul. Any other suggestions on what I should do after a nasty cam failure like that? How much oil pressure do you guys get with what pump? I'd like to get a little more pressure out of the next pump, assuming thats the problem.

on a side note I don't even think I'll get a free cam and lifter set. Thanks comp :rant: Thanks for any replies, I'll get this worked out. Although this ordeal is delaying my new black paint job and bodywork.

 

Before I switched to my new engine I would get MAYBE 10 PSI while cruising and it would sit on 0 at idle :eek:

I don't think I can offer any useful advice but I will say that a friend (with a Supra) was having oil pressure problems and we switched himt to Mobile1 15050 and he gained a lot more pressure.

 

change the gauge,
oil filter (again)
i assume the bypass is plugged

 

Didja have any problems getting the new cam in? Didja have to push/twist too much? If so you may have chewed your cam bearings a little with the cam gear and lobes when installing. This will reduce oil pressure. If the cam went in easily then I would also say oil pump or filter screen is plugged. :(

 

How did you remove the metal that was worn off the cam lobes and lifters ?

Geo

 

I changed oil/filter twice, flushed the system with oil and installed a magnetic drain plug.
I was careful replacing the cam, some of the lobes did hit as I was doing it but I don't think I could have gouged the cam bearings hard enough to ruin them. I pulled the latest filter after 40 miles and it did have a fair amount of small metal flakes, but oil still flowed freely through the element. There were some sand sized chunks O' metal which the pump had munched. Too bad I didn't cut apart the filter that took the brunt of the mess :crazy:

Bought a new clevetite oil pump from napa today, 19.95 is darn cheap. :D

I'll be praying this is the last of the issue.

 

on the other hand, if you didn't plug the oil filter bypass, shavings could of plugged up the oil line, causing a low reading. They could also plug up you know what.
So you might want to unhook the line and run it into a bucket and see if it clears up or is ok.

 

If you didn't remove the crank, and rod journals and clean them as well as your oil galleys you have likely taken out your crank bearing and possibly you crank, get the pan off and inspect the crank and bearings before you do any more damage to your crank, thoses little sand sized metals pieces will make their way to your bearings, metal fragments smaller than you can detect will ruin your crank bearings and cause a drastic drop in oil pressure, your entire oil system needs to be cleaned after a cam shaft melt down. Also inspect your oil pump for scored rotors. If they are scored replace it.

Hope this helps



[Modified by mxzx turbine, 2:22 AM 4/9/2003]

 

:iagree:
I agree with the above advice. Man, if you had that much going through your oil, then that same crap probably went through all your bearings and did their damage. You should check the bearings. A couple of mains and/or rod bearings would probably tell you. Anyway, I think other bearings were probably compromised. I do not think your oil filter is clogged unless it got a big chunk to wedge itself in there. The gears are pretty stout. If you don't see any serious crap in the bearings and everything looked fine, retorque to specs, and replace with a Melling high pressure pump, maybe use a thicker oil. Run just for a few minutes and then change the oil, to try and flush anything left out. Maybe you got lucky...but it doesn't sound like it. :nonod:

 

Your cam bearings are where you build or lose the most oil pressure . I bet you have a rear cam bearing starting to wipe. A stock oilpump will work all you need is flow at idle and 10psi per 1000rpm there after in a stock to slightly mod. motor. Good Luck on the filter and pump change.

 

now you see why people plug the bypass(thanks to the previous 2 posters)
with it plugged all the oil goes thru the filter.
i had 12 lobes wipe with near a pound of shavings, no engine damage. just a full filter :nopity

 

I am taking my oil pan off this weekend to check on what is causing my low oil pressure as well. It fine until I did my first change a few weeks ago. Had been running 40 wt, changed to 30 wt now have very low pressure. I am going to plug the bypass as Matt suggested to try to figure out why it is now so low. I used to start it and the guage would jump to 70 then settle around 30 - 35 all last year while cruising. Something must have clogged up over the winter, although I used to start it every 3 weeks and let it run for at least 20 minutes, has always worked for me over the years.

 

I had the XE-274 go flat in the 406 after only 2000 miles as well. The bottom of two of the lifters were ground concaved,and the corresponding lobes flat.There was a significant grit in the oil,and I felt the block needed hot tanked to clean all the grit out. Good thing I did.When the crank came out,the main journals were slightly scored.The machinist told me I was lucky,and a few more miles would have trashed it for sure.
Take the engine to a shop,you can thank me later.

 

Thanks for the replies. Since I didn't plug the bypass, I fear that the engine probably is going to need to be pulled and partly rebuilt at least. Hey! That would give me a great excuse to postpone the bodywork and black paint for afr 195s.