- This topic has 41 replies, 7 voices, and was last updated 12 years, 4 months ago by
.
-
Topic
-
So, I just finished rebuilding the heads on my Comet. 289 V8. It has hydraulic lifters and I’m wondering if I crushed them after tightening the rockers too much or what… After installing the heads I had tightened down the rockers to a good starting point. Started the car and it actually ran very well and sounded great. Oil was flowing, no problem. Some of the rockers were clacking. I turned off the car and started to tighten them down per the service manual specifications (zero lash, plus 1/2 turn). Afterwards, I went to start it and it wouldn’t start. It squealed real bad like something was stuck. So, I loosed all the rockers just a tad…and tried again and it started fine, only no oil was flowing anymore. What the heck happened? Did I crush my lifters to a point that oil isn’t following through them and up the rods? I pulled a couple rods to see if they looked damaged and they were still straight and un-impeded. Anyone have any thoughts or had this happen to them?
-
Replies
-
How do you know you don’t have any oil flow? Are you running it with the valve covers off? What does your oil pressure gauge read? That would tell you if your pump shaft is broken or not. It does sound like a clearance issue though. Are your pushrods properly seated in the lifters? You won’t screw up your lifters by tightening the rockers too much. The plunger will just compress more and the engine will run like crap because the valves won’t close all the way. A clearance issue would cause the engine to not turn over. An oil pressure issue would not cause the engine to not turn over unless the bearings were seized as a result. Then when you loosen the rockers up, the engine still wouldn’t turn over.
Oil was flowing out the top of the push rods previously… that is not occurring anymore. So If there is any oil pressure it’s not enough to move the oil up to the top of the engine. The valve covers are off since I was adjusting valve lash.
I don’t have an oil pressure gage on this car, just a light. And the light is on… so it’s either low or no pressure.
The engine turns over. I’m sure it was a clearance issue before I loosened the rockers, because it wasn’t turning over. But now, it’s turning over, but no oil flowing out of the push rods, and while it is turning over, it’s struggling to turnover and that’s with the rockers loosened to the point where i can jiggle them a bit.
So, with the rockers loosened, something is still impeding the engines ability to turn over well. I thought I’d just run the battery down, but I’ve been charging it all day and it’s still turning over slowly.College Man, you were right. I pulled the distributor out and the end of the oil pump shaft was sitting there below it…snapped off.
Gah… oh well, I’d been needing to change the oil pan gasket anyway…guess I’ve got an excuse now.Thanks for the help guys.
yeah, definitely not a happy ending. i’m just hoping there isn’t any other damage as a result of running it without the oil pump operating. not that it was operating long like that, but jeeze…
draining the fluids now… blah… A:(
When you say you just finished ‘rebuilding the heads’ did this include milling them to gain higher compression? If so you would need to change your pushrods because now they may be too long. Also if you installed new valves they might sit higher than the old valves, in short it sounds like you have a clearance issue so check the parts you installed or altered.
No, everything was left stock and no milling was done. I just replaced all the valves and hardware on them and cleaned them up all nice. The car had leaking head gaskets so I used that as an excuse to clean everything up.
Everything seemed to be running great though until I tightened things apparently too much. So I’m wondering if I just did the valve lash adjustment incorrectly.
In the past I’ve done it with the engine running, but I did it with it off this time and just bumped the engine over since that’s what the manual said to do. Now I’m wishing I’d done it the way I usually do.I’m guessing I’m going to remove the intake to see what’s going on with the lifters, but I’m assuming something has happened to them since oil isn’t flowing anymore. It was initially circulating perfectly.
Can lifters be compressed to the point where it doesn’t work anymore? Or do you think I’ve damaged the cam or worse??
If I remember right. didn’t Ford drive the oil pump shaft off the distributor? You may have snapped the shaft.
You would need to drop the oil pan to see the op shaft. I’m getting old knowing stuff like that.C8-)
A service manual is your best friend here.Thanks for the input. Boy, I’m hope that’s not the case, I don’t really feel like lifting the engine today.
You think the oil pump shaft would snap before a push rod would bend or something?something wasn’t turning the oil pump drive. do you have a oil primer. you could pop the distributor
and and with the oil primer shaft stick it in where the distributor goes and with a drill spin it to see if
oil comes out the push rods.that will tell you if the pump works or not.C8-)Are you sure you was on the correct stroke when you started your adjustment?
I would pull the intake check the push rods to see if any are bent. if not then i would redo the valve lash with intake off just to be sure I could see what the lifters are doing during setup.
you can collapse a lifter but i don’t know if they would push oil or not
I ran into the same issue with a small block chevy last week. The tech working on the motor adjusted the valves to the point where the truck would not fire up (71 GMC 2500). After doing a compression check and seeing 0 psi, we knew at that point after going over his work what the issue was. He said he went ‘by the book’.
So after backing the rockers off, we adjusted them in the correct sequence to zero lash, ran the vehicle, and then readjusted them once more going by ‘feel of the push rod rotation’ more than that book.
Truck ran the best it ever had after that.
That is bad news but I’m glad you found the problem, keep us updated on your progress and please use this same thread when you do instead of starting a new one that way all the info on this stays in one place.
Yeah, that’s the last time I do zero lash without the car running.
I got the oil pan off today and pulled the oil pump… twisted off shaft seen in the attached pic. Also found a bolt in the oil pan. Oops… Might have had something to do with it. No idea how that got in there.
At least a new oil pump and shaft doesn’t cost much…and this gives me an excuse to get the oil pan cleaned up.
- You must be logged in to reply to this topic.