engine problem

[ppetion]

I would like to remove the head on my 1.7 I need some advice..


here is the issue

car starts fine, after swapping plug wire 2 and 4. good power at first take off, after driven for a 5 minutes it starts loosing power , smoking bad and rattling. it feels as if its overheating. I also have oil dripping on both sides... oil trail....

when I open the oil cap there is a lot of smoke I also see sign of oil on the heat-sink like block on top.

I am thinking the head gasket could do that... was thinking of removing the heads tomorrow.... any suggestion will be appreciated....

also would it be easier if I take the engine down to work on the heads..?? of should I attemp to remove them and see whats going on?//

Compression test shows
1-3 100
2-4 150

[Dave at Pelican Parts]

In the 914 and other air-cooled cars, the head gasket is only there to make sure that combustion gases don't come out from between the head and cylinder. HG problems won't cause the sorts of problems you are observing.

It sounds like you have temperature-related problems, but those can be in the basic engine itself, in the valve train, in the fuel injection (or carburetors), and so on.

A 50% difference in compression pressures shows problems with the top end of the motor--either the valves or the rings aren't sealing that well on #1 and #3. Since your problem is with cylinders which share cam lobes, those are also suspect.

Check your valves. If they're in spec, see if you can visually tell if the rocker arms on the front cylinders actually move as much as the ones on the rear cylinders. If not, you have a cam problem which means a complete engine rebuild.

You know you have low compression in two cylinders; a leak-down test can help you tell where the problem is. If pressurizing the cylinder results at hissing at the intake, the intake valve is leaking. If it results in hissing at the tailpipe, the exhaust valve isn't sealing well. If it results in hissing at the oil filler, the rings aren't sealing.

Those compression numbers are the biggest worry to me.

--DD

[ppetion]

Thanks dave. can you tell me the procedure to do a leak down test?

[Dave at Pelican Parts]

Go to a good shop that knows air-cooled motors, preferably VWs or Porsches. Ask them to run a leak-down test for you, and give them money.

You need a supply of compressed air, and a specialized tester. You set the engine to TDC for a cylinder and lock it in place (e.g., with a flywheel lock) and then screw the tester into the spark plug hole. You pressurize the cylinder with air, and the gauges on the tester tell you how much pressure is going in versus how much is leaking out. And you listen for where the air comes out; intake or exhaust or oil filler.

Repeat for each cylinder, and you have a little more info on what is going on in there.

--DD

[ppetion]

lol thanks Dave. I will take advice #2