Question:
Can I replace a broken valve spring (Cyl 4) while engine is mounted in car?
What tool?

Recommendations?

Thanks

No. Unless you want to try to remove the cylinder head while the motor is in the car.

I've done it.

you can build a tool that rocks on the rocker arm mounts... depresses the spring and allows everything to bolt back together
brant

Various vendors have them for sale...you can rent for $35...

https://vwparts.aircooled.net/Type-4-Heavy-...l-tool-rent.htm

I stand corrected.

you can always do the rope trick.. Fill the cylinder with sash cord, then use the hammer type Lisle tool to remove the keepers.

not a lot of room to swing a hammer, but it might work. Otherwise, do the other style...

I have replaced valve springs on lots of engines with the engine assembled and in the car.

1. Make a tool that hooks to the rocker shaft to depress the spring.

2. Remove the rockers on both intake and exhaust valves on the cylinder that needs the spring changed.

3. Put your tool on the engine, and pressurize the cylinder with about 100 psi of compressed air.

4. Push down the spring and remove the keepers.

5. Carefully remove the tool and replace the spring.

6. Push the new spring down with the tool and reinstall the valve keepers.

7. Disconnect the air, and reinstall the rest of the parts you removed.


100PSI will hold the valve in the head. I know it works, I have replaced lots of valve stem seals, and springs that way. In fact, the type IV horizontally opposed engine makes it easier. If you lose air pressure, the valve won't fall into the cylinder.

I replaced valve seals on my old V8 Dodge years ago by taking out the spark plugs and then inserting a few feet of clean clothes line rope into the cylinder to fill up the combustion chamber so that the valve wouldn't fall into the head. I brought the piston up most of the way to TDC then pushed in a long length of new rope. When it seemed mostly full I would then turn the crank a little more by hand to tighten the mass of rope up against the valves and hold them in place. Then use a spring compression tool to remove the spring. When done then back the piston off again and just pull the rope out.

Now that we've come up with some ways "how" to fix the broken spring, can you let us in on "why" you have to replace this spring?

Never had a 914 valve spring break. Have had valve seats let loose, burnt valves, etc.

What's your take on this? Was there a valve train geometry problem? Badly manufactured spring?

Just curious & good luck with the fix.

Hello,

First of all I want to thank you all for the responses and suggestions.
A little history on the car:

I purchased this 914 out of Virginia Beach VA, without seeing it in person. I live in North Port, FL so I had an old Navy buddy that lived close by have a look at it.
According to him all looked good, even the hell hole. Started quickly and drove ok.
So I purchased it. Got it home about 4-5 days later.
Things weren't exactly as my buddy described. The car did start and run ok. Gas pedal was broken, so I replaced it. Placed car on my lift and saw the RUST and some bad repair job. I was very frustrated with the bad repair job of hell hole with mostly Bondo and some fiberglass.
Later my buddy said he couldnt look under the car due to his bad back.

So I parked the car for another day. I drove it frequently around the block and eventually decided to sell it. During a test drive the car lost power...that didnt go well with the interested buyer. Still ran but had low power, misfiring and very rough idle.
Found no compression on cyl 4. Upon removing the valve cover found the cly 4 valve spring broken.
I dont know why it broke. Havent figured out how to place a pic here. Ive worked on Vanagon and other vw engines before so I was just gonna replace the spring and test the outcome.
I decided to drop the engine and repair it.
Now that the engine is off I can see the nightmare of bondo, fiberglass and some sheet metal. The rust repair needed goes from the battery tray mount to the jack point and rocker.
Ill be deciding what to do soon

Sometimes springs just break, but it's pretty rare on a stock engine.
One thing to check is that you don't have a loose seat. Sometimes the seat can bounce back into it's seat bore, but there should be tell tale signs or it might even fall out when you remove the valve. If not cycle it through an oven, it will fall out when hot.
Just don't heat a dirty head in the wife's kitchen range....
Run it through the dishwasher first!

Over the twenty plus years I worked with used T4 heads I saw a great many come in with a broken spring. The number one cause was rust. Engines that sit for an extended period of time have a problem with this.

Weak springs also are the number one cause of dropped valve seats on T4 heads.

The springs are over 40 years old now. If one broke, the others can too. And I would bet my corona stimulus check they're all weak, even if they aren't rusty.

I just had the same issue(rusted springs from sitting a long time) Just wondering if your valve was bent as a result. Mine broke at idle! Planning to put air pressure in it tomorrow and see. If it seals Im just going to replace all the springs with the in-car tool, I think!

You are 1000% correct on ALL of that...Now the question is .."Where do you get 4cyl/typ4 valvespring set...or even ONE!!!!!?????ANYONE????HELP???

[/quote]
You are 1000% correct on ALL of that...Now the question is .."Where do you get 4cyl/typ4 valvespring set...or even ONE!!!!!?????ANYONE????HELP???
[/quote]

HERE FOR ONE

Webcam has type 4 spring sets:

http://www.webcamshafts.com/pages_vehicles...rsche/1691.html

Aircooled.net has single springs:

http://vwparts.aircooled.net/Valve-Spring-...21-109-623k.htm

[quote name='pilothyer' date='Jun 4 2020, 04:10 PM' post='2822080']
[/quote]
You are 1000% correct on ALL of that...Now the question is .."Where do you get 4cyl/typ4 valvespring set...or even ONE!!!!!?????ANYONE????HELP???
[/quote]

HERE FOR ONE
[/quote]
Thanks, had finally found a site that lists them, very little info and NO phone number. Ill see if they are actually IN stock at these other places.

TY Yea I was aware of these places, full set non-performance was surprisingly more difficult to find

Was wondering if you have took it apart yet? Was it broken from heavy rust spot on the valve spring and was the valve bent/tweeked? Hope its going well.

[quote name='pilothyer' date='Jun 4 2020, 04:10 PM' post='2822080']
[/quote]
You are 1000% correct on ALL of that...Now the question is .."Where do you get 4cyl/typ4 valvespring set...or even ONE!!!!!?????ANYONE????HELP???
[/quote]

HERE FOR ONE
[/quote]

TY!