Hello. Just bought a D150 last week with a /6 in it, my first experience with these things. Truck spent some time with the valve cover off, and had water in the oil. Long story short, I've cleaned it up as best I can, and it seems to run great, except that there is no oil getting to the lifters.

I drained the milkshake out, FL1A filter and a mix of synthetic/diesel oil until I get some sludge out. Compression is about 120psi each cylinder. Oil pressure was 40psi at idle, stuck a nut behind the relief valve spring to bump it up to 60psi. I took the rear bolt off of the lifters and cleaned it out, wasn't much in there. Also ended up pulling the head bolt and verified that I could get solvent to flow from the lifter bolt to the head bolt passage.

That's where I'm stuck. I really don't want to pull apart an otherwise good motor just to fix one blocked passage. I saw a post somewhere in the depths of the internet where a guy drilled from the outside of the head into the rear head bolt passage, tapped a fitting into it, and ran a separate line straight to the valve train. I have plenty of room in the bay to get a drill in there, would it be a horrible idea to try that?

The only other idea I have is to bump the oil pressure up as far as I can get it in hopes it'll blow through whatever's clogging it up, but I don't want to blow any seals or force any gunk anywhere it shouldn't be. You guys have any advice? Pull the head bolt and blow through it with an air compressor?

Thanks

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1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

My concern over drilling and taping into an assembled engine is leaving shavings and metal splinters in the new passage,,,
Back on your issue, do you know there is no oil getting to the rocker shaft? Or perhaps is a plugged rocker shaft, or a rocker shaft assembled in the wrong direction the issue?

If you are not getting oil up to the rocker shaft and you want to try a different oil feed, I would run a small diameter line from the end of the oil pump, through the valve cover and connect to one end of the rocker shaft,

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Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

That's a good point. I was going to try shoving something down in there and then vacuuming it out with a shop vac afterward, but I like the idea of going through the valve cover and straight into the rocker arm a lot better. That sounds a lot less terrifying than going through the head itself.

To answer your question, I pulled the rear bolt out of the rocker and started it up. Not a drip out of the hole. Also cranked it, plugs out, with the head bolt out - enough to see 10psi on the gauge. Still nothing out of the passage.

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1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

No oil out of the rocker arm post, means the rear cam bearing may have spun, so no oil to the rear cam journal,,,
Can you get a thin - stiff piece of wire, like from a coat hanger, maybe sharpen one end like a chisel, see if you can probe the oil feed hole down some depth, maybe flood the oil hole with a solvent like WD 40, to see if there is blockage and loosen it,,,

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Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

+1 on Dadtruck's bearing is spun.

I, and several racers assisted Doc with the oil system bypass some years ago at MATS. That was a save your butt move to get the car home . It was not a long-term solution.

There was a lot to that tale.

I know you don't want to do it. Pull the engine and fix it.Slants are drying up. They can still be found, but the "Free, get it off my shop floor" slants don't happen like they used to.

CJ

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Part of Tyrde-Browne Racing

[consolidated this into next reply, sorry]

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

I've probed it and filled it with WD-40 and SeaFoam, nothing yet. I could've been better about probing it, maybe I'll take the head bolt out and try again.

Wait a second - anyone know if the cam bearing being out would drop the oil pressure? I find it strange that I'm still seeing 60+psi.



That's what I'm afraid of - is there any way to find out if it's spun, short of taking it apart? This was supposed to be a "buy a cheap truck to drive to the dump" kind of project, I've already got too many engines spread all over my shop as it is. Shouldn't have believed the guy when he said he'd been driving it...

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1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

Usually a spun cam bearing will increase the oil pressure (measured at/near pump, fewer "leaks" out of the rocker assembly, so pressure higher).

Lou

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Home of Slant6-powered fun machines

Ah, that makes sense.
Well... awesome. I'll see if I can jam a coat hanger through it, and if not, guess I'll be pulling yet another engine

I do have a cheap 318 available, maybe I'll throw that in instead. As interesting as the /6 is, the extra torque might be nice.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

Quick update - got a nicer, thinner coat hanger and sharpened it. This time I've noticed that I can't seem to get it into the hole in the head bolt - if I have the bolt in, I definitely get stuck at the bolt. If I have the bolt out, it just goes down into the bolt's bore, not into the other passage. I can't for the life of me get it to go down the lower passage. Might be blocked, but more likely I just don't have the right angle.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

WOOOOOOOO!!!

I got mad and coat-hangered the living hell out of it. Felt like something was catching at the head gasket area, so I just pounded it through. Now when I crank it, oil is definitely coming out of the hole.

Thank you guys. I'm going to go clean out the rocker arm so I don't ruin anything else with whatever crud got in here.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

One last question for you guys - would you recommend leaving the nut behind the pressure relief valve? I feel a little safer with the extra flow, but I don't want to ruin the pump, I've heard the gears are a weak spot.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

If you had 40 psi at road RPM without the nut behind the bypass spring I'd take it out. 40 psi is a nice number for a slant that works in the stock RPM range.

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Joshua

Congrats on the unplugging. You might pull the rocker assy and get it hot tanked? Or, maybe just spray carb cleaner through the shaft and each rocker oil holes... Depends on how crudded up they are.

Lou

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Home of Slant6-powered fun machines

It was 40psi at idle, but I'll check again now that I've got the crud out of it. Thank you.


Thanks!
I took the whole thing apart and soaked it in solvent, brushed it, and I think that got most of it out. I might try getting it cleaned though, I'm just too dang excited.

Speaking of which, I'm sitting here trying to figure out which direction the rod goes - I'm scared I got it turned around. Small hole toward the bottom on the rear? Oil ports pointing toward the valves? Does that sound right?

I need to be more careful with this thing before I really cause myself some trouble.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.