First Oil Filler Cap In Space!!!

[paulbone]

First of all, thanks guys for the help with the radiator foaming/bad starting issue on my D24.

It was indeed a warped head, got that milled and problem solved.

However, a new problem - the oil filler cap after 5 minutes or so of the engine runnig, blew skywards with an allmighty bang and cloud of smoke and embedded itself in the garage ceiling!!!!

I then took of the breather pipe, cleaned that, no blockage though? cleaned out as much sludge from the breather hole that I could, took the sump off cleaned that out, took of the valve covers and cleaned inside and then flushed the engine three times. I thought that should clean out any sludge and muck in the engine that my be causing a pressure build up.

Yesterday I took the car for it first drive around the block - the first time she has moved under her own power since 1963.

Wow what a great fun car the drive, I was very pleased.

Trouble was though it looked like a steam train - white/gray smoke was bellowing out of the breather tube, which alamred my neighbours somewhat! As I sat at idle after my test drive, BANG the oil cap blew off again, with another huge cloud of black smoke!

Any one have any ideas, oil pressure starts at about 40 then drops off to 20 ish after warm up, so that seems OK. Number six piston does need to be replaced as it showed quite bad wear, with a little smoke from the exhaust.

But what is causing all the gray/white smoke from the breather and the exploding oil cap????

Thanks for any help guys, I'm just so close the getting on the road now.

[Norm's Coupe]

I don't think I've ever heard of a oil breather cap being shot off like that. The only thing I can think of, is the cap stopped up? Try a different cap. Also check the blow by tube for any blockage.

[Brad Lustig]

Are you talking about the mesh breather cap? Any pressure should be able to go through it instead of forcing it off...

[TodFitch]

"gray/white smoke from the breather and the exploding oil cap"

A lot of something is getting into your crankcase.

I associate white smoke with coolant. Are there any bubbles in the radiator? Any gunk on the dip stick? Any particular smell associated with the smoke?

[randroid]

There is a second "breather" pipe toward the rear of the engine that could be plugged. My P-15 is inaccessible at the moment and I can't find a picture in the book to tell you exactly where it is, but it's located on the driver's side aiming down. The end is tapered, with the taper facing to the rear. If it is closed-off (plugged, bent, etc.) it could conceivably cause your problem.

Have you run the engine with the breather cap off and your hand covering the pipe? Doing so probably won't tell you anything you don't already know but it should make your hand dirty, thereby allowing you to become more as one with your vehicle. Good Zen therapy.

Seriously, look for that second pipe. I'll bet that if it isn't the culprit it's closely related to it.

-Randy

[Norm's Coupe]

There is a second "breather" pipe toward the rear of the engine that could be plugged. My P-15 is inaccessible at the moment and I can't find a picture in the book to tell you exactly where it is, but it's located on the driver's side aiming down. The end is tapered, with the taper facing to the rear. If it is closed-off (plugged, bent, etc.) it could conceivably cause your problem.

Have you run the engine with the breather cap off and your hand covering the pipe? Doing so probably won't tell you anything you don't already know but it should make your hand dirty, thereby allowing you to become more as one with your vehicle. Good Zen therapy.

Seriously, look for that second pipe. I'll bet that if it isn't the culprit it's closely related to it.

-Randy

Randy,

This is the blowby tube I was telling him to check. It is located on the right side (passenger side) just below the exhaust manifold toward the rear of the engine. If that is stopped up, it could cause a back force and maybe cause his oil filler cap to blow off. Don't really know, I've never seen one blow like that myself. As Tod mentioned, he could be getting something in the oil to create excess smoke or steam. If the oil is full of gas, it would also create a lot of smoke coming out the filler tube. That could possibly be what is causing the explosion too when the engine gets warm enough.

[1just4don]

Yes, first thing to check is bypass and screen open on filler cap. Those check okay ONLY thing left is the oil is getting gas in it and the combustion is setting off the gas in the oil for a flash boom bang.

Any whitish smoke is "usually" water or coolant. If antifreeze you might get a sweet smell. Are you plum sure the head,,,gasket, block surface is perfect and sealed?? IF head was warped how about the block??Pin hole leaks thru the block,cylinder walls,,,electrolisis(sp)???

IF you have to change piston 6 anyway,take pan off before head. Put one of those pressure tester on radiator neck and keep pressure on for quite awhile and see if it 'drips' water/coolant thru the bottom. Might take a 'few' days to get there IF its a slow leak or heat opens the crack or makes leak bigger.

Just some thoughts,random as they may be. White freezer paper makes a good show and tell under the engine, holds smaller spots of 'stuff' than concrete or cardboard!! Its waxy and doesnt absorb,,or use similiar stuff. Even tin foil works better than nothing. may only get a few drips that way!!

[Lou Earle]

I would like to know a couple of things before I make any observations

`1- If oil breather cap blew off and was imbedded in cieling Did it shoot thru the hood? Even with hood up it woud still hit the hood.

2 have u run it with the cap off? If it blows with capp on you should feel a steady stream of air with it off.

I would like tosee a pic of where it hit the cieling

[Don Coatney]

I believe 1just4don nailed it. I believe you have a lot of gasoline in your oil and it flash ignited and blew the oil fill cap off. When did you last change the oil prior to this explosion?

[Lee Exline]

I believe 1just4don nailed it. I believe you have a lot of gasoline in your oil and it flash ignited and blew the oil fill cap off. When did you last change the oil prior to this explosion?

I agree

Check the fuel pump!

The diaphram is probably bad putting lots of gas into the cranckcase where it will eventually explode, Even with the draft tube the explosion will exceed the ability of it to pass the gas.

Check your oil level! it it higher than you filled it? thin and runny?

[Dennis Hemingway]

When you check your oil, smell it I bet it will smell like gas. As I have stated before I had a Chevy that had gas get into the oil and when I hit the starter it blew the oil pan off.

Dennis:eek:

[Normspeed]

If it's gas in the crankcase, you really notice the smell.

Interesting approach to the oil cap launch. I usually use my bench mounted wire wheel to launch parts.

Might be someone on this forum in your area, that would give it a look-see. We're a helpful bunch.

[PatS....]

"I usually use my bench mounted wire wheel to launch parts."

Norm, I thought I was the only one

[Normspeed]

Excellent little launcher, the bench mounted wire wheel.

[randroid]

Norm,

I read your post just after getting out of bed this morning and wasn't awake-enough to realize that's what you meant. Sorry, wasn't trying to jump on your post.

Normspeed, you ever race hand-held belt sanders off an 8' workbench? It can be fun with somebody else's equipment, but be sure to already have another job before you do it.

-Randy

[paulbone]

Thanks for all the advice so far.

I cleaned out the tube on the passenger side of the engine, but may need to look at the oil cap again - it actualy came off a late 40's Dodge truck if that makes a difference.

The oil was fresh, 10 minutes old.

I also put a new fuel pump on as well. I didn't notice the smell of gas in the oil, but will run her again and check to see.

With the oil filer cap off and engine running, there is a steady puff puff from the filler tube, with a little puff of dark gray/blackish smoke.

I cant find any coolant in the sump, or gunk on the dipstick. just checked with my buddy and he said the smoke was white which does sound like coolant, so I will check again and see if it condensates.

If the smoke is caused by coolant, what would cause the cap the blow??

For entertainment value I will send a couple of pics of the offending item, when i've figured out how to do it

Thanks guys.

[Reg Evans]

Sounds to me like at least one of your pistons has a bad leak and you are getting a build up of unburned gas in the crankcase. Have you done a compression check now with the new head gasket installed?