Hello,

Firstly, I would like to mention that I am posting here on the FTE forum as it was suggested by a user here who saw my original post in the LincolnForumNet.com website. I'm guessing alot of Ford truckers have the 400CID block and may have come across a similar issue. Here is our problem:

My dad and I have recently taken out his '79 Lincoln Continental Mark V out of the garage. It hasn't seen the road since 1994 (it has been stored since then) with the last time starting the engine back in 2011. Despite it's very low mileage: 9,900 original miles. We are close to accepting the fact that an engine rebuild may be necessary!

Since 'awakening' the car, we have removed and cleaned out the fuel tank, replaced it with a new fuel sender, drained the oil, cleaned out the carb, and dropped in premium fuel. Despite all this, there is still the persistent BLUE SMOKE which comes out of the exhaust after engine warms up + rough idling. Yesterday, we added SeaFoam – half a can went into the crankcase and the other half in the fuel tank. Drove the car a few blocks for 10 minutes (we a trail of blue smoke and angry onlookers) and then let it idle for another 5 minutes. This morning, we started her up and now the engine is knocking, and oil pressure light is on. We therefore drained the oil, replaced with new oil filter, and placed in synthetic oil, hoping that it would finally solve the problem of the knocking and blue smoke. To our dismay, there has been no improvement.

My question is, how could SeaFoam have caused the engine to suddenly start knocking and make the oil pressure light to come on? Also, would a car with only 9,900 miles on it need a rebuild?

Any suggestions and comments would be greatly appreciated - thanks in advance!!

PS. I called and got a quote for the engine rebuild on a '79 Lincoln Continental 400CID... $3500+tax=$4000 (installed) *yikes*

 

Sounds like the engine rusted together internally and the pieces are being loosened up.

 

It's possible that the seafoam loosened up a LOT of junk and it's now clogged the oil pump pickup therefore causing the low oil pressure and the knock is a result of lack of oil (and oil light being on).


I would not run this motor any more until you investigate more.


The blue smoke could be bad rings or could just be dead valve guide seals. With that low of miles on an old motor its very possible that lots of gaskets are dried up. There is the chance that you have a intake pan/gasket leak and that could be sucking oil into the heads too (this is far fetched but is possible)


My sugestion would be to pull the valve covers and drop the oil pan to do an inspection on the lower end, oil pump, pump pick up and the upper valve train.


After that you can make a much better estimate if you need a rebuild or not.

 

I agree - drop the pan and pull the valve covers, but don't run it more for the interim. I think I'd start with the valve covers as they are easiest. Check to see if the drain-back holes in the heads are plugged, which would keep all the oil up topside and that'll starve the oil pump. If so, clean the drain back holes and start it again.

If you have a repeat of knocking and low oil pressure then it is time to pull the pan. Not sue how hard that is on a car, but it is a pain on a truck. However, the pans and crossmembers are different so it may be easier on a car. Still, you may have to raise the engine some to get the pan out, so it might be something you want to have a mechanic do.

Good luck, and let us know how it goes.

 

Thank you to everyone who posted suggestions, very much appreciated! We will try to inspect by opening first the valve covers, and secondly the oil pan if required – before residing to an engine rebuild. I will post an update as soon as we find out! Cheers!

 

So my dad and I lifted the valve cover on the side of the engine where the knocking sound was coming from, and discovered a bent pushrod (see attached photo)

How is it by adding the Seafood to clean out all the gunk cause a pushrod to come off the socket?

We will inspect the other side of the engine by removing the valve cover and check for further abnormalities. Once new pushrod is installed, will check if oil pressure light turns off. If still on, then oil pan will be removed to inspect filter and pump.

Thanks again for your help on this! Cheers!

 

Yipes! It looks like it broke out a chunk of the head. If so, won't the pieces have gone into the sump?

As for how Seafoam did it, I doubt it did. My guess is that the low oil pressure did. The lifters are the last things to get oiled, and the lifters provide oil to the rockers. That looks to be the driver's side, and you can see from the drawing here that the driver's side is the absolute last to get oil: Oiling System Mod's - ???Gary's Garagemahal.

 

Engines are carnivores and like red meat.

 

Where's the LIKE button????

 

With a push rod bent that much is it possible that the lifter got thrown out of it's lifter bore? If a lifter fell out that could be the cause of the low oil pressure.


The valve train look nice and clean at least.

 

A stuck/frozen valve would have caused that pushrod to bend, not the SeaFoam. Looks to be #7 intake...I would pull that lifter out with a magnet and take a peek at it's foot before you do much else. That will tell you what shape your cam's in.

Also looks like the rocker tower is cracked...or is it just my imagination? I would pull the pan and check for any chewed up and spit out red meat before you started her up again....also pull/check the oil pump. You don't want any bits of metal floating around anymore gumming up the works.

When you last changed the oil did you notice any silvery colored stuff in the oil?

And invest in a new oil sending unit if you can.

 

Hard to tell properly but the lifter looks like it may be out of its bore-probably right as there is nothing to hold it down on the cam. I hate to say it but I there is a good chance you have run bearings due to the oil pressure thing especially from the knocking. Hate that. I would block off the push rod port to the block and try to gently knock off that cracked portion of the rocker tower but that maybe a good job to do if the engine has to be pulled down?
Always liked the suicide door Lincoln's and a 460 or even a good stroked 400 would be a good engine for them, didn't know they ever come out with 400's but I am definitely no expert on Lincolns.

 

I can't tell exactly from the photo because it is blurry, but it kind of looks like the retaining clip might be missing from the top of the lifter plunger. I have seen those pop off and get stuck in the oil pump. In that case though, it locked up the oil pump and sheared the drive pin holding the distributor gear and the engine wouldn't run. We found that one because the engine would backfire and pop but not start. We found that we could turn the rotor by hand and that the OP drive shaft had also sheared. Good times.
I agree with Filthy Beast and pull that lifter out.

 

Serving suggestion: Pull that motor down to the tiny bits and replace anything that is worn. With that big chunk of metal busted out of the head, plus the oiling issues to begin with, my guess is you need the crank turned, a new oil pump and a host of other items.

You can patch it back together, but that blue cloud is only going to get worse, along with a short nasty life for the rest of the motor.

 

Ummmm... what's the big chunk missing? That is one of the casting ports with a bit of flashing isn't it? Forgive me if I am having a blonde moment please lol.