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Engine Problem

John Marinan

Contributor
Sr. Member
Joined
Aug 9, 2009
Messages
680
Loc.
Durango CO.
I have a chevy engine question. I have an 86 4x4 with a crate 350 that came with a mild crane cam. Two years ago the back cam lobe wore out at 90,000 I had a new cam installed by a good shop owned by a bronco nut. It's very quiet the 1st ten minutes, after that it starts to make clicking sounds like there are loose rockers arms. It will quiet down after it colls down.
The oil pressure reads 60 lbs highway, 30 lbs at idle. I have mobil one in it with ZZDP. The shop owner tells me that this noise is normal, I know that this noise is not normal.
I'm planning on starting with new cam saver lifters, pushrods, Kool nuts, etc. Does anyone have any ideas as to what causes this, I'm stumped.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,345
Does the oil pressure stay at that high value even when hot? If the oil thins out enough, you could get clicking and ticking. But this is only if the pressure is going down to a dangerous level. As you said, it's definitely not normal.
What caused the original cam problem? Did you find any culprits? That's not really normal either when you come right down to it.

Paul
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,345
Did the Crane cam have 90k miles on it too? Or just the truck? Did you brake in the cam originally yourself?
Do you think the noise is coming from just the rear area like before perhaps? Might try a stethoscope just to verify exactly where it's coming from

Good luck.

Paul
 

Muddn7

Jr. Member
Joined
Dec 11, 2008
Messages
143
Loc.
alamogordo, nm
Two cents!

I dont care who worked on it, or what they were into... That doesnt build credability, just good taste. I would go through my valve adjustment steps. I know that my 351 has three different degrees that you turn to, to adjust your valves. This is on a hydro lift motor. I actually saw a mechanic adjust all the lifters at tdc. (WRONG)!!!! I also know that my 351 has two different length lifters.... They go off of criteria with the three different measurement areas..... I'm not a bow tie guy, but its something to ponder!!!! Muddn7
 

d.c.parris

Full Member
Joined
Aug 26, 2005
Messages
168
Loc.
cumming ga.
I dont care who worked on it, or what they were into... That doesnt build credability, just good taste. I would go through my valve adjustment steps. I know that my 351 has three different degrees that you turn to, to adjust your valves. This is on a hydro lift motor. I actually saw a mechanic adjust all the lifters at tdc. (WRONG)!!!! I also know that my 351 has two different length lifters.... They go off of criteria with the three different measurement areas..... I'm not a bow tie guy, but its something to ponder!!!! Muddn7


''what" two different length lifters? three measurements?
 
OP
OP
J

John Marinan

Contributor
Sr. Member
Joined
Aug 9, 2009
Messages
680
Loc.
Durango CO.
This is a genuine Gm factory crate engine. It is a flat tappet cam. It runs fine, it just starts making valve train noises. I have no idea what caused the cam to wear out. The shop checked the spring pressure and it was good. I'll go ahead and put in some Crower cam savers, and some Kool nuts, it can't hurt. Thanks for the help!
 
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