Never Ends: Motor Issue

[PeteA216]

Okay now... today I was driving on the express way for about 25 minutes, everything running beautifully. I hit about 90 MPH at one point but it was gradual and the RPMs never went further than 3600 RPM. When I got off the engine was smoking like all hell. I pulled over and oil was everywhere on the front passenger's side, the engine was shaking and had TONS of blow by through the breathers. When driving it again, during accelleration it sometimes had plenty of power and ran smooth, or it was weak and shook lightly, but always under accelleration there was tons of blue and brown smoke pouring from the car no matter how well or bad it ran. When at a stop you could see all the blowby smoke coming from under the hood (yes I know I still have to put the PCV System on, but even without it it's never been like this). For 10 miles of driving I went through 2 quarts of oil, then the leak almost subsided and I was able to make the 20 mile drive back home without loosing too much oil, but all other symptoms persisted. When at a stop and the car in park, if you start the engine and rev it or let it idle, the exhaust is normal, except when you rev it sometimes it will show a little white from the tailpipe. I never noticed it before, but I never looked either. Any ideas? The motor only has 1K on it and has had one oil change at 500 miles.

[silicon212]

I know this isn't what you want to hear, but ...

it doesn't look good. My guess is you have a broken or burned piston and the resulting crankcase pressure is blowing oil out of the engine.

You will have to inspect it. Pull the heads off and see what you can.

If you can get a borescope, you won't need to remove the heads, but do look for damage.

Years ago, a friend had a Datsun 280Z that we had done a 350 transplant into. He killed the first 350 by oil-starving it and then WOT'ing it when he thought 'it fouled a plug' (what happened was oil pressure failed and the lifters collapsed). We reused the heads on another short block he got, but about a month after putting the short block into it, the #6 exhaust valve seat came out of the head, resulting in piston failure. The #6 is the cylinder that grenaded on the original engine, and during the melee the piston slammed into the cylinder head, leading to the seat failure a month later. Pieces of the hard metal seat wound up in the intake, where they went into each cylinder that plane on the intake fed (#1, #4, #6 and #7).

The heads that were on the engine? 1.94/1.5 sized 64cc closed-chamber '461' heads, the original 'double hump' heads with no bolt holes (they were originally cast in 1964).

In short, we replaced the engine again from the damage.

[PeteA216]

If you can get a borescope, you won't need to remove the heads, but do look for damage.

What's a bore scope and where can I find one? It just figures with my luck that something like this would happen. What would cause the piston(s) to burn like that? I'm running cooler plugs, and when rebuilding the engine the pistons all looked great with no signs of overheating or burning. Could the "near header meltdown" from break in cause that or no? I wouldn't think so, but yah never know.

[silicon212]

A borescope is like a doctors' endoscope - you remove a spark plug, put the probe into the hole, and move it around while you look into it. There's a light at the end of the scope to illuminate the inside of the cylinder so you can see the condition.

They're fairly expensive though, so I wouldn't expect you to be able to just go out and get one.

Detonation can cause piston burning, so can running lean (which leads to detonation and heat). You could also have mechanical damage. This is the engine you bought from someone else, right? The original builder may not have checked for proper compression or deck height, and the head could have been nailed by the piston, resulting in piston damage (smashed ring lands, broken rings, that sort of thing).

[PeteA216]

I took it out for a drive today, still leaking some oil and a PCV valve and a hose from the other breather to the air filter chamber fixed the blowby and blue smoke from behind the car. It runs good again aside from the blowby and when warm had that shake at low RPMS and idle. I reminds me of a wounded animal limping. But it still has all the amazing power it still had before. For now I'll drive it and keep my sense keen in terms of engine sounds. I'll just drive very gently. Once I get the transmission on my truck fixed the Caprice will stop being my daily drive, but until then I have nothing else to drive unless somehow ATVs suddenly become road legal.

This is the engine you bought from someone else, right? The original builder may not have checked for proper compression or deck height, and the head could have been nailed by the piston, resulting in piston damage (smashed ring lands, broken rings, that sort of thing).

Why would it have waited 800 miles before colliding with the head? My neighbor build muscle cars as a hobby. He owns an all original (except motor's internal components) 1967 Plymouth Road Runner with the 442 (I think). It's got 3 Two-barrel Holley style carbs. Anyway, he said he thinks it's more likely somehow I fried rings on one or more of the pistons. I dunno. Whatever happened it's not gonne fix itself. Any advice to hold it off for now?

[GreyGoose006]

no matter what is wrong with it, i dont think driving it will help any
i wouldnt drive it any more than you absolutely have to
or else you risk having to replace the engine if you do serious damage to it

[PeteA216]

no matter what is wrong with it, i dont think driving it will help any
i wouldnt drive it any more than you absolutely have to
or else you risk having to replace the engine if you do serious damage to it

Agreed, but the only other vehicle I have to drive is my Sierra, but the tranny's shot. The only way to fix the tranny is with some $$$ and to get money I have to go to work and the only fully operational vehicle I have is the Caprice right now. Like I said I'll just baby it to minimize the chance of complete destruction.

[GreyGoose006]

i guess that is the best you can do

[ISmellRubber]

This condition definitely sounds as if there is blow-by getting past the piston rings.......it is very real that the rings might not have seated properly or were miss gapped......thsi would explain the oil blasting out......

Another inexpensive way to check is a cylinder blance/compression test, this will tell you which the cylinder the leak is coming from and how bad it is with out tearing down main parts........start there. Any true mechanic should be able to do this with a half hour.The ideas that silicon had to offer are sound as well look in his dirrection as well.


"If they catch up, THEN use your NOS!!!!!"

[bobss396]

I wouldn't say that the engine is that badly hurt just yet. You did have a LOT of oil up in the valve covers and it has to go somewhere, possibly down the valve guides no matter that they're new... or were new. They're not designed to have a pool of oil to deal with.

The shaking probably came from the oil-starved lifters. Residual smoking can be from a general result of oil being where it does not belong. Now that you have a PCV system on it, keep an eye on the oil pressure and go easy on it. I'm also not an advocate of taking a 1000 mile engine up to 90 mph.

Bob

[PeteA216]

Now that you have a PCV system on it, keep an eye on the oil pressure and go easy on it.

Yeah I'm going to definately baby the engine now so I'll make it through the summer or hoever long it takes to repair my truck. It's running okay now. It shakes more when cold, but it runs fine when past 110 degrees. I have the PCV valve on and have a tube going fron the other breather grommet to the underside of my air filter chamber. That eliminated all blowby and all of the smoke from behind the car when under load, but when accellerating when the sun hits it right you can see the passenger compartment filling up with smoke. It did that before when smoke was pouring out of the car, but I thougght the PCV system would fix that. How can I eliminate that? I want to be able to drive with the A/C on and not suffocate.

I'm also not an advocate of taking a 1000 mile engine up to 90 mph.

When cruising on the long, slightly downhill straightaway of an expressway near me on route 531, I accidently hit 105 about 2 weeks before. It truly was accidental, I was accellerating to get up to speed from the on-ramp, not to heavily either, and got distacted my a conversation and never let off the gas until I realized how fast I was going. It's strange because if I didn't look at the speedometer I wouldnt have know I was moving that fast. The passenger (my girlfreind said the same thing, she had no idea we were going that fast). The motor seemed completely unharmed by that, but for some reason hitting 90 this past time must have did it in.

[bobss396]

Look on a stock motor to see where the PCV valve should be routed. Make sure the valve is operational and not gummed up. They're not made to be filled up with oil.

Pull the spark plugs, you may have fouled a few of them. Also do a compression test which help you evaluate the condition of the internals. You still may have lucked out if correcting the PCV valve routing and the compression test comes up good.

Do you have oil dripping on the exhaust? When a motor can't breathe, it tends to come out from everywhere up top and may take a week or more to burn off. You can always Gunk it to generally clean up the motor and engine compartment.

Bob