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Blow Over? (Newbie)
https://www.slantsix.org/forum/viewtopic.php?t=21064		 Page 1 of 2
Author:  hack4th [ Mon Dec 11, 2006 9:49 pm ]
Post subject:  Blow Over? (Newbie)
First I want to say that this seems like a really solid site. I've already found great information on here and am collecting the recommended books.
I'm starting to restore a 1962 Plymouth Valiant with a slant 6. It ran ok before but seemed like it was skipping a cylinder. I read a forum on stuck cylinders and I'm going to try the tapping-it-with-a-hammer technique.
A new thing the engine is now doing is that oil is coming out of the dipstick tube with some force. My mechanic brother-in-law says that it's probably related to the cylinder issue and that maybe a seal is bad and compression is 'blowing over' into other parts of the engine (sorry...not sure if I'm using the right terminology). He told me to take the valve cover off and look for 'milkiness' in the oil which would indicate water getting in and probably means a bad head gasket. I did and the oil looks fine, so I guess it's not that.
If this sounds familiar to any of you reading this, any advice would be greatly appreciated. Specifically- is this bad enough to warrant replacing the engine or can I just replace some stuff and fix it? I've worked on cars a little bit before and am enthusiastic about being able to wrench on the engine and learn and fix it myself.

Thanks!
Author:  moparfiend [ Mon Dec 11, 2006 10:04 pm ]
Post subject: 
do a compression check if all cylinders are within 15lbs of each other should be ok. you'll probably find 1 cyl has near zero compression which is causing your miss and the oil out the dip tube. it's called blow by. cylinder coming up on compression stroke. compression pressure blows by the rings into the crankcase forcing oil out wherever it can escape.
if you do have a low cylinder pull the plug on that cylinder pour a teaspoon of oil in the cylinder if pressure goes up bad valve. pressure stays the same bad rings.
let us know what happens .
good luck 8)
Author:  Doctor Dodge [ Tue Dec 12, 2006 12:07 am ]
Post subject: 
How many miles are on this engine?
Pull off the valve cover to see if all the push rods are still where they should be. A "kicked-off" push rod will cause the problems you discribe.

A head retorque, valve adjustment and compression check (in that order) would be good things to do while you have the cover off.
Let us know what you find.
DD
Author:  hack4th [ Thu Dec 14, 2006 8:03 pm ]
Post subject: 
Quote:
How many miles are on this engine?
Pull off the valve cover to see if all the push rods are still where they should be. A "kicked-off" push rod will cause the problems you discribe.

A head retorque, valve adjustment and compression check (in that order) would be good things to do while you have the cover off.
Let us know what you find.
DD

The odometer reads 88k... The first time I pulled off the valve cover nothing looked unusual that I could see. I'll try to post a picture here. Hopefully you can see it.

Image
Author:  moparfiend [ Thu Dec 14, 2006 11:52 pm ]
Post subject: 
what kind of oil pressure are you getting. rockers look kinda dry to me
Author:  Wizard [ Fri Dec 15, 2006 9:04 am ]
Post subject: 
Too dry!

Should be wet everywhere. My 2.2 rockers/cam etc is WET with oil.

Look at rocker bar rear bolt that has narrow neck for oil feed is clear. There get plugged up.

Once you get that feed fixed, then look at all rockers that all are leaking of oil, it is supposed to drool oil to keep everything wet with oil.

Cheers, Wizard
Author:  hack4th [ Fri Dec 15, 2006 11:09 am ]
Post subject: 
Not sure how to check oil pressure... I'll take a look at the back bolt to see if it's blocked up w/ anything. It sounds like maybe I should pour some oil over the rockers before I try to start it?
Author:  slantvaliant [ Fri Dec 15, 2006 11:29 am ]
Post subject: 
Quote:
Not sure how to check oil pressure...


Ideally with an oil pressure gauge. They aren't hard to install.
Here's some discussion.
http://www.slantsix.org/forum/viewtopic ... ht=#116737

You can check by watching the valves while the engine runs. Oil should come out throught the rockers, and splash around a bit due to the rocker motion. That should continue as long as the engine runs. Have some old towels or shop rags around.
Quote:
It sounds like maybe I should pour some oil over the rockers before I try to start it?
I would. And down to the lifters.
Author:  hack4th [ Mon Dec 25, 2006 12:14 am ]
Post subject:  Thanks for all the help
I really appreciate it, I've been tied up w/ replacing the fuel pump because the old one leaked. Now that I've got that done, I'm gonna start on the compression test thing. We'll see how that goes. Thanks again.
Author:  volaredon [ Mon Dec 25, 2006 5:52 pm ]
Post subject: 
Quote:
if pressure goes up bad valve. pressure stays the same bad rings.
let us know what happens .
You have this backwards. A burnt valve wont seal up with oil added.

S/6 Edit: Fixed Quote
Author:  moparfiend [ Tue Dec 26, 2006 2:06 am ]
Post subject: 
sorry was tired. my bad :oops:
Author:  hack4th [ Sun Jan 07, 2007 7:03 pm ]
Post subject: 
So compression check gave the following results:

1. 105 psi
2. 95 psi
3. 115 psi
4. 105 psi
5. 70 psi
6. 100 psi

Seems like #5 is the culprit... I did the oil test thing and the compression read 75 psi. This means it's the valves on #5 I'm assuming? So a valve adjustment is the next step?
Author:  sandy in BC [ Sun Jan 07, 2007 7:35 pm ]
Post subject: 
Valve adjustment is always a good plan.
Author:  Fratzog [ Sun Jan 07, 2007 7:59 pm ]
Post subject: 
An increase in the compression reading after doing the oil test would point to worn rings.... if the reading stayed the same then you would have a valve or head gasket leak.
Author:  mpgmike [ Sun Jan 07, 2007 8:55 pm ]
Post subject: 
Your '62 slant wouldn't have had hardened seats. If it has been running unleaded fuel for awhile, then you probably have a burnt valve/seat. I guess either way, "Off with the head!"

Mike
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