gunk under intake manifold

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70dart318

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So I’ve been working on my 318 and first I saw the thermostat housing had a lot of what looks like old rust caked in it. So I under advice to check out what’s going on under the intake manifold I just removed the intake. Im new to this all, I know the engines 40+years old and sat for who knows how long but this seems pretty bad to me. Opinions? Options on cleaning the gunk? Anything lol
 
That's nasty,I would say oil changes weren't often..make's you wonder what the rest of the engine looks like..
 
Fairly normal as-found from gomer owners, but not in future w regular oil changes. I removed the oil pan and washed it all down w gasoline and brushes, but diesel or kerosine might work better. Then wipe off resdues. Good time to check/change rod & main bearings and rear seal. Flush coolant system w 1 lb citric acid & water.
 
Ya I figured that too lol, unfortunately the history of the car is a mystery for the most part. All I know is it hasn’t been registered since 1999 but has ran every few years, and I was told it’s a 74 318. Other then that I have no idea about anything else
 
The gunk you see is the lack of oil changes by the previous owner, and a lot of stop and go driving where the engine never got warm and stayed warm for a while. What to do now.........?? Choices range from nothing to complete rebuild, how much money do you wish to spend?

I'm gonna catch flack over most of this......so be it

Nothing would be new intake gaskets, bolt down the intake, put the engine into the car and start an aggressive routine of oil and filter changes and a quart of Risoline at each change, hot oil can remove alot of that.

OR, get 5 gallons of kerosene, scrape what you can out, with the pan still on wash down the valley with kero, you'll find the block eventually.

OR, very carefully take the engine appart, leave the rings on the pistons, mark them (the pistons) for what cylinder they came out of, keep the cam and lifters in order, keep the bearings in order, take the block to the car wash, blast the living day lights out of it, wash down all the parts in solvent, put the engine back together.

OR, do a complete rebuild to what level you desire.
 
I had to deal with a 67 monaco/poly.
Was fugly. Shop vac for the chunky stuff then a good washing. Who lets something go for that long?
A truck from long ago, couldnt pour oil into it. Off with the valve covers and took a look. Grey sludge,enough room for the rockers to move. Scooped it out with my fingers and poked out the drain holes. Changed oil and added a quart of gunk engine flush. Ran it for 5 times the reccomended run time, on high idle. Like 30 minutes.
Dumped oil and replaced oil filter with a heavy truck filter with no bypass. Ran it for a month and changed it again.

I ran that engine a long time,pulled it and dropped it into a 77 jimmy. Then proceeded to beat the snot out of it. It ran until my kid brother wrote it off.
 
The gunk you see is the lack of oil changes by the previous owner, and a lot of stop and go driving where the engine never got warm and stayed warm for a while. What to do now.........?? Choices range from nothing to complete rebuild, how much money do you wish to spend?

I'm gonna catch flack over most of this......so be it

Nothing would be new intake gaskets, bolt down the intake, put the engine into the car and start an aggressive routine of oil and filter changes and a quart of Risoline at each change, hot oil can remove alot of that.

OR, get 5 gallons of kerosene, scrape what you can out, with the pan still on wash down the valley with kero, you'll find the block eventually.

OR, very carefully take the engine appart, leave the rings on the pistons, mark them (the pistons) for what cylinder they came out of, keep the cam and lifters in order, keep the bearings in order, take the block to the car wash, blast the living day lights out of it, wash down all the parts in solvent, put the engine back together.

OR, do a complete rebuild to what level you desire.
I have been there with a '78 400-4. I tried to clean the rocker area. pulled the intake, and breastplate. I pulled a pizza out of the valley. Tried changing oil, and such, but it was a supreme hassle. If I had to do it over again, I'd do what was suggested: pull intake, rocker covers, timing cover, cam and lifters, oil pan, and pickup. Remove the hood, tow the car to the quarter car wash late at night, and blast the crap out of that engine. Then clean all you can with gasoline. Then reassemble putting everything back where it came from.
 
Try putting a quart of trans fluid in the oil and run it for a day or two... Trans fluid is high detergent oil and will help clean out most of the gunk...

then inspect and scrape off what is left if any...


then change oil...
 
Try putting a quart of trans fluid in the oil and run it for a day or two... Trans fluid is high detergent oil and will help clean out most of the gunk...

then inspect and scrape off what is left if any...


then change oil...
if any small chunks get sucked up, they will accumulate in oil pump rotors, bind them up, and shear oil pump drive. If you want to tow it home when that happens, because it aint going to happen in your driveway, have at it. Been there, done that.
 
if any small chunks get sucked up, they will accumulate in oil pump rotors, bind them up, and shear oil pump drive. If you want to tow it home when that happens, because it aint going to happen in your driveway, have at it. Been there, done that.

The pick up screen is supposed to keep out anything that will damage the pump...
 
I've always scraped that stuff off manually with a paint scraper/screwdriver and sucked any residual out with a shop vac...

Then change the oil...

the trans fluid trick will help clean out the oil passages and the oil won't be brown any more after changing it...
 
Thanks for the tips and ideas, I want to spend as little as possible right now cause I just want to get it back on the road. I’m gonna carefully clean up what I can and see how it looks then.
The rust inside the intake manifold where the thermostat housing is...would it be best just to replace it with another 318 2bbl intake or is there a way to clean inside there and get it off?
 
After you get it running again, flush the cooling system thoroughly. That rust is not only inside the thermostat passages in the intake!
 
I haven't tried this yet but I've heard it works great at cleaning the rust out of the inside of the engine.

Fill the cooling system with EvapoRust. It will attack the rust but leave the base metal alone. Run the engine up to operating temperature and shut it off. Let the engine cool over night. Then drain the system and refill with 50/50 mix.
 
Thanks for the tips and ideas, I want to spend as little as possible right now cause I just want to get it back on the road. I’m gonna carefully clean up what I can and see how it looks then.
The rust inside the intake manifold where the thermostat housing is...would it be best just to replace it with another 318 2bbl intake or is there a way to clean inside there and get it off?

Radiator flush (a couple of times backflushed)
Shop vac while you break that crap up, and then flush the engine out with kerosene, diesel or solvent then trans fluid with fresh oil and filter.
Then change it after about 100 miles of running.
This is your best chance and an inexpensive way to save it.
Even if you don't get crap all over the cam and lifters, it still ends up all over the rotating assy. Not good so the shop vac will minimize that.
IMO anyway.:D
 
Thanks for the tips and ideas, I want to spend as little as possible right now cause I just want to get it back on the road. I’m gonna carefully clean up what I can and see how it looks then.
The rust inside the intake manifold where the thermostat housing is...would it be best just to replace it with another 318 2bbl intake or is there a way to clean inside there and get it off?

Flush the cooling system real good when you get it running...
 
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I carefully went and scrapped and picked what I could get out, I was careful not to get much on the cam, what little I did I shop vac’d up. It’s a start for now. I dunno if you can tell in the pic but I got a nasty amount of gunk and sludge out
 
View attachment 1715098446 I carefully went and scrapped and picked what I could get out, I was careful not to get much on the cam, what little I did I shop vac’d up. It’s a start for now. I dunno if you can tell in the pic but I got a nasty amount of gunk and sludge out
it looks like the cam and lifters are worn out, so don't expect too much.
 
Unless you are removing the engine, here is what I would do.

Jack the engine up and remove the oil pan. Remove the valve covers, as the sludge will be in the heads, too. Loosen it up with a gasket scraper. Then get a wet or dry vac and vacuum as much out as possible.

Next, get some purple power and a squirt bottle. Squirt the intake valley and heads down with 100% purple power and let it sit about 30 minutes. Fire up your pressure washer and pressure wash the inside of the intake valley and heads. It's nasty, but it works very well. I have done many like this. Works real good.

Of course all this is unnecessary if you decide to remove the engine.
 
View attachment 1715098446 I carefully went and scrapped and picked what I could get out, I was careful not to get much on the cam, what little I did I shop vac’d up. It’s a start for now. I dunno if you can tell in the pic but I got a nasty amount of gunk and sludge out

That's a start.
 
Looks better than the first v8 swap I did as a kid, I scraped, shop vac, the heavy stuff out.
Stuck the motor in the car, every time before changing the oil I dumped 1 qt of kerosene in the motor and ran it for about 5 miles than changed the oil.
The oil eventually stayed clean.
It was a junkyard motor, so I was only out $50 if it blew up, but it ran for years, until I totaled the car.
Stuck the motor in another car and ran it some more, it did eventually spin a rod bearing, but I got about 4 rough, adding teenage years out of a wore out motor.
I think I blew more centers out of clutches and spider gears in rear ends, than any kid should be allowed.
 
Back in the old days, every engine I saw open, that ran Pennzoil looked like that. MOSTLY HI MILEAGE CHEVYS.

I didn't mention that because I didn't want to open yet another oil debate, but I have seen that as well on a lot of Pennzoil motors.
My Dad swore by it, but after seeing what I have three's just no way.
I even bought a Honda dresser motorcycle because I felt sorry for it when I saw a Pennzoil bottle sitting next to it when the guy said he just changed the oil.
I swapped it out for Castrol GTX before I even left with it.:D
 
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