Blown out spark plug? 78' IM

I took a day to read up on the internet about pulling a VW motor.    I have pulled motors out of a 914, a 912, and helped with a 911...   But never any sort of VW.

 

I have repaired a stripped spark plug hole before too...   it's fairly straight forward with a helicoil type repair kit.

 

I kinda debated super cleaning my engine;  new main seal...   The big Weber carb kit that I have yet to install?

 

Then I decided to take the whole day Sunday and pull the motor, repair the spark plug, and put the whole mess back together...     My goal was to take my girlfriend for a long drive and dinner Sunday night.    Car running perfect.

 

I also thought about what caused the spark plug to come out?    And I'm fairly certain that some past owner paid for a "tune up" that included new plugs and the mechanic damaged the threads in the process...   And then it took a few years for pressure and heat, and vibration to eventually shoot the plug out of the motor.      Also.   I could feel with my fingers that #4 spark plug was so loose I could rotate it with my fingers! 

I had this happen to me #3 plug blew completely out and was sitting on my tin , had it towed to Rascon motorsports at 11am and called me to pick it up at 4pm.

I didn't have to drop the engine 

 

Roland is my go to guy for all my VW fixes 

Anyway;

       It took me 3 hours to get the motor pulled, by my self.   Maybe an hour to repair the damaged threads and re-install the plug.    And check, regap, and tighten all the others.

       Maybe an hour and a half to reassemble the car.

 

$60 repair;  new oil and a thread insert kit.

 

You might want to check your plugs? 

 

 

So you think this could have happened on it's own?   just from vibration?

Damned impressive--congrats on a great fix.

 

I just had a similar deal---I was having some work done on my VS and gave the mechanic a new set of plugs to put in while he had the car-as they are so damned hard to reach to get them out.  The threads for #3 were stripped and he used a Time Cert to make the repair.  Although he was good enough to repair the threads without removing the engine, it wasn't cheap.  I have no idea how the threads were stripped---maybe he did it himself removing the old plug---who knows?  He was sure to use anti sieze too with the new plugs.  

 

I sure wish I had your talent!

 

 

I also am impressed!

My guess is that plug was loose and when I jump on it the pressure blew it right out the head, Roland double check the other plugs and it's been running great for the last 2 months.

Glad to see your Tub back on the road 

I like to coat steel plug threads with anti-seize compound when installing into aluminum block.  Dissimilar metals tend to corrode.

It happens, and as you noted, it's usually from improper install of a plug in the first place, or removing a badly corroded plug which takes the threads with it so the new plug doesn't have much holding it in, which then eventually works its way out enough that it blows out, taking a few threads with it.

 

Easily repaired with a Heli-coil and I have never had a properly installed hell-coil blow out - they tend to stay put.

 

Like Wolfgang, I often put a little copper-based anti-seize compound on the plug threads to prevent them from galling the head threads going in or coming out - especially on an aluminum head.  Don't honestly know for sure if it works, (there is a debate going on somewhere as to whether it helps or not) but I've never had any problems.

Starleaf...

 

"no clearance for even my hand let alone a tool!"  Same here, especially #1 & 3

 

Using a 4" hole saw I opened a hole opposite 1&3 and glued in the tough plastic neck and screw on lid from MilK Bone dog treat containers...It's a charm!

 

Plugs are in plain sight three inched away. Plenty of room to get my hand and ratchet in there to position the correct angle on the socket (They're NOT at 90 degrees to the block, and easy not to take that into account and wind up stripping the threads!) The only drawback is that the wheel has to be removed...no big deal.

 

A picture is worth a thousand words...and when I get around to learning how to post visuals you'll see what a neat and easy modification it is!

 

 

I have something similar to Carl.  In my case it's rectangular plates that can be removed to get at the plugs. 

 

 

"It happens, and as you noted, it's usually from improper install of a plug in the first place, or removing a badly corroded plug which takes the threads with it so the new plug doesn't have much holding it in..."

 

Correct.  The installation of those plugs can be very difficult, and can lead to problems later on.

Ron, do you not clamp your breather hose at the valve cover?

I do remember changing plugs with the VW aircooled engine and even with my medium size hands, things were tight. Sometimes a small rubber hose...maybe three inches long attached to the plug lead end of the plug helps "wobble" the plug into the hose nicely enough to get threading started. I always use antiseize. Carl's suggestion is an excellent one...as usual.

Yep, using the hose is an oldie but a goodie!

You Hoser!

 

Thanks for the ideas.     One of the things that I read on the Internet is that a decent German mechanic can remove an air - cooled bug motor in around 30 minutes...  easy.
       As I mentioned...   it took me a solid 3 hours!       I bet I could do it in an hour now.  Maybe

The more you practice the easier it gets.

The porthole thing work for me as well. My manifolds are tapped and connected to each other right near the spark plug. It would be very difficult, even for a gifted mechanic (not me) ,to get those buggers in the hole without them. You can find a variety of shapes and sizes at any good marine store and installation is simple.

Bill, no clamps and they have never come off.  The brass ends have barbs and the pressure isn't great.

 

The biggest hassle, when I pulled my engine, was taking off the throttle bodies and disconnecting all the fuel lines (coming from and going to the tank) and wires from the ECU.